Methods, apparatuses, and systems for the treatment of pulmonary disorders
11369433 · 2022-06-28
Assignee
Inventors
- Jonathan Reuben Waldstreicher (West Orange, NJ, US)
- William Sanford Krimsky (Forest Hill, MD, US)
- Denise Marie Zarins (Saratoga, CA, US)
- Robert J. Beetel, III (Sunnyvale, CA, US)
- Paul Brian Friedrichs (Belmont, CA, US)
- Kevin James Taylor (San Mateo, CA, US)
- Roman Turovskiy (San Francisco, CA, US)
- Gary L. Long (Cincinnati, OH, US)
Cpc classification
A61B2018/1467
HUMAN NECESSITIES
A61B18/1492
HUMAN NECESSITIES
A61B2018/0016
HUMAN NECESSITIES
A61N1/327
HUMAN NECESSITIES
International classification
A61B18/12
HUMAN NECESSITIES
Abstract
Apparatuses, systems and methods are provided for treating pulmonary tissues via delivery of energy, generally characterized by high voltage pulses, to target tissue using a pulmonary tissue modification system (e.g., an energy delivery catheter system). Example pulmonary tissues include, without cells), lamina propria, submucosa, submucosal glands, basement membrane, smooth muscle, cartilage, nerves, pathogens resident near or within the tissue, or a combination of any of these. The system may be used to treat a variety of pulmonary diseases or disorders such as or associated with COPD (e.g., chronic bronchitis, emphysema), asthma, interstitial pulmonary fibrosis, cystic fibrosis, bronchiectasis, primary ciliary dyskinesia (PCD), acute bronchitis and/or other pulmonary diseases or disorders.
Claims
1. A system for treating a wall of a lung passageway of a patient comprising: a catheter comprising at least one electrode disposed near its distal end, wherein the at least one electrode is configured to be positioned within a lumen of the lung passageway so that the at least one electrode is able to transmit energy toward the wall of the lung passageway; and a generator in electrical communication with the at least one electrode, wherein the generator includes at least one energy delivery algorithm configured to provide an electric signal to the at least one electrode causing the energy to be transmitted to a targeted cell depth not extending beyond a basement membrane of the wall from the at least one electrode for a treatment duration so as to provide a treatment of a condition of the lung passageway, wherein the electric signal comprises distinct energy packets wherein each energy packet comprises a series of biphasic pulses.
2. A system as in claim 1, wherein the energy is below a threshold for thermal ablation of the wall of the lung passageway throughout the duration of treatment.
3. A system as in claim 1, wherein each distinct packet has a cycle count of up to 60 biphasic pulses.
4. A system as in claim 1, wherein each distinct energy packet has a duration of up to 100 microseconds.
5. A system as in claim 4, wherein the electric signal comprises five distinct energy packets and wherein each energy packet has a duration of 100 microseconds.
6. A system as in claim 1, wherein the treatment comprises selectively removing or killing cells of the wall of the lung passageway associated with the condition.
7. A system as in claim 1, wherein the treatment comprises selectively modifying cells of the wall of the lung passageway associated with the condition.
8. A system as in claim 1, wherein the treatment selectively targets endothelial cells, pseudostratified columnar epithelial cells, goblet cells, and/or basal cells.
9. A system as in claim 1, wherein the at least one energy delivery algorithm is configured to provide an electric signal to the at least one electrode causing the energy to be transmitted from the at least one electrode toward and not beyond an epithelial layer.
10. A system as in claim 1, further comprising a return electrode wherein the system is configured to provide the electric signal of the energy to the patient in a monopolar fashion with the use of the return electrode.
11. A system as in claim 10, wherein each pulse of the series of biphasic pulses is between approximately 1000-2500 volts.
12. A system as in claim 1, wherein the at least one electrode comprises at least one bipolar electrode pair and wherein the generator is in electrical communication with the at least one bipolar electrode pair so as to provide the electric signal to the at least one bipolar electrode pair causing the energy to be transmitted to the wall of the lung passageway in a bipolar fashion.
13. A system as in claim 12, wherein each pulse of the series of biphasic pulses is between approximately 100-1900 volts.
14. A system as in claim 1, wherein at least one of the at least one electrode comprises a plurality of wires forming an expandable basket configured to expand within the lung passageway.
15. A system as in claim 1, wherein at least one of the at least one electrode comprises an energy delivery body having a plurality of separate active areas which are each insulated from each other.
16. A system as in claim 1, wherein the at least one of the at least one electrode comprises an energy delivery body having an active area isolated from a remainder of the energy delivery body.
17. A system as in claim 1, wherein the generator comprises a processor in communication with at least one sensor, wherein the processor modifies at least one of the at least one energy delivery algorithm based on data from the at least one sensor.
18. A system as in claim 2, wherein the threshold for thermal ablation is 65 degrees Celsius.
19. A system as in claim 1, wherein the at least one energy delivery algorithm is configured to provide an electric signal to the at least one electrode causing the energy to be transmitted from the at least one electrode to a mucus layer.
20. A system as in claim 1, wherein the treatment comprises selectively removing or killing one or more pathogens.
21. A system as in claim 1, wherein each distinct energy packet has a frequency of 500-800 kHz.
22. A system as in claim 17, wherein the at least one sensor comprises a temperature sensor and wherein the generator modifies at least one of the at least one energy delivery algorithm based on temperature data from the temperature sensor so as to maintain temperature at or below 65 degrees Celsius.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
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DETAILED DESCRIPTION OF THE INVENTION
(60) Specific embodiments of the disclosed device, delivery system, and methods will now be described with reference to the drawings. Nothing in this detailed description is intended to imply that any particular component, feature, or step is essential to the invention.
I. Overview
(61) The secretion of mucus in the bronchial airways is an inherent part of the defense of the lungs, protecting the interior membranes and assisting in fighting off infections. The amount of mucus secretion varies with a range of stimuli, including bacteria, particles and chemical irritants. Normal secretion levels rise and fall depending on the transient conditions of the environment. Mucus on the epithelial layer of the bronchial airways traps particles and the ciliated cells permits moving of the mucus out of the lower airways so that it can ultimately be cleared by coughing or swallowing. Mucus also contains antibacterial agents to aid in its defense function. Pathogens and harmless inhaled proteins are thus removed from the respiratory tract and have a limited encounter with other immune components. In the bronchial airways, mucus is produced by goblet cells. Goblet cells produce mucins that are complexed with water in secretory granules and are released into the airway lumen. In the large airways, mucus is also produced by mucus glands. After infection or toxic exposure, the airway epithelium upregulates its mucus secretory ability to cause coughing and release of sputum. Subsequently, the airway epithelium recovers and returns to its normal state, goblet cells disappear, and coughing abates.
(62) However, in some instances, such as in the development of many pulmonary disorders and diseases, the body does not recover, chronically producing too much mucus and causing it to accumulate in the lungs. This creates symptoms such as chronic coughing, difficulty breathing, fatigue and chest pain or discomfort. Such hypersecretion of mucus occurs in many disease states and is a major clinical and pathological feature in cystic fibrosis (CF) related bronchiectasis, non-CF bronchiectasis, chronic obstructive pulmonary disease and asthma, to name a few.
(63) These disorders are all associated with an impaired innate lung defense and considerable activation of the host inflammatory response. Abnormal levels of antimicrobial peptides, surfactant, salivary lysozyme, sputum secretory leukocyte protease inhibitor, and macrophages in addition to signaling of toll-like receptors (TLRs), trigger pathways for mucin transcription and NF-KB (nuclear factor kappa-light-chain-enhancer of activated B cells). The increased mucus production and decreased clearance causes increased exacerbations and airway epithelial injury. Ciliary activity is disrupted and mucin production is upregulated. There is expansion of the goblet cell population. Epithelial cell proliferation with differentiation into goblet cells increases. Likewise, inflammation is elevated during exacerbations which activates proteases, destroying the elastic fibers that allow air and CO.sub.2 to flow in and out of alveoli. IN response to injury, the airway epithelium produces even more mucus, which cannot be cleared. This primes the airways for another exacerbation cycle. As exacerbation cycles continue, the excessive mucus production leads to a pathological state with increased risk of infection, hospitalization and morbidity.
(64) To interrupt or prevent the cycle of disease progression, the airways are treated with a pulmonary tissue modification system useful for impacting one or more cellular structures in the airway wall such that the airway wall structures are restored from a diseased/remodeled state to a relatively normal state of architecture, function and/or activity. The pulmonary tissue modification system treats pulmonary tissues via delivery of energy, generally characterized by high voltage pulses. In some embodiments, the energy delivery allows for modification or removal of target tissue without a clinically significant inflammatory response, while in other embodiments, some inflammatory response is permissible. This allows for regeneration of healthy new tissue within days of the procedure.
(65) In one method, the energy output from the pulmonary tissue modification system induces a separation in the epithelial layer E in which abnormal and dysfunctional ciliated pseudostratified columnar epithelial cells PCEC and hyperplastic and abnormal goblet cells GC are separated from the basal cells BC and pulled into the airway lumen, where they are expelled from the lumen of the airway. As a result, the basal cells BC are left on the basement membrane BM to regenerate normal goblet cells GC and normal ciliated pseudostratified columnar epithelial cells PCEC, thereby inducing reverse remodeling of the disease to reduce the mucus hypersecretion. The newly regenerated goblet cells GC are significantly less productive of mucus and the newly regenerated ciliated pseudostratified columnar epithelial cells PCEC regrown normally functioning cilia C, which more easily expel mucus M. The reduction in mucus volume is felt directly by the patient, whose cough and airway obstruction are reduced. Over the ensuing weeks, this translates into a reduction in exacerbations and an improved quality of life.
(66) In some embodiments, the energy induces epithelial separation between the basal cells BC and more superficial goblet GC and ciliated pseudostratified columnar epithelial cells PCEC because of the relative strength of the cell-cell connections. The basal cells BC are connected to the basement membrane BM by hemidesmosomes H (illustrated in
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(69) The catheter 102 includes a handle 110 at its proximal end. In some embodiments, the handle 110 is removable, such as by pressing a handle removal button 130. In this embodiment, the handle 110 includes an energy delivery body manipulation knob 132 wherein movement of the knob 132 causes expansion or retraction/collapse of the basket-shaped electrode. In this example, the handle 110 also includes a bronchoscope working port snap 134 for connection with the bronchoscope 112 and a cable plug-in port 136 for connection with the generator 104.
(70) Referring back to
(71) It may be appreciated that in some embodiments, the generator 104 is comprised of three sub-systems: 1) a high energy storage system, 2) a high voltage, medium frequency switching amplifier, and 3) the system control, firmware, and user interface. The system controller includes a cardiac synchronization trigger monitor that allows for synchronizing the pulsed energy output to the patient's cardiac rhythm. The generator takes in AC (alternating current) mains to power multiple DC (direct current) power supplies. The generator's controller instructs the DC power supplies to charge a high-energy capacitor storage bank before energy delivery is initiated. At the initiation of therapeutic energy delivery, the generator's controller, high-energy storage banks and a bi-phasic pulse amplifier operate simultaneously to create a high-voltage, medium frequency output.
(72) The processor 154 can be, for example, a general-purpose processor, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a digital signal processor (DSP), and/or the like. The processor 154 can be configured to run and/or execute application processes and/or other modules, processes and/or functions associated with the system 100, and/or a network associated with the system 100.
(73) As used herein the term “module” refers to any assembly and/or set of operatively-coupled electrical components that can include, for example, a memory, a processor, electrical trances, optical connectors, software (executing in hardware), and/or the like. For example, a module executed in the processor can be any combination of hardware-based module (e.g., a FPGA, and ASIC, a DSP) and/or software-based module (e.g., a module of computer code stored in memory and/or executed at the processor) capable of performing one or more specific functions associated with that module.
(74) The data storage/retrieval unit 156 can be, for example, a random access memory (RAM), a memory buffer, a hard drive, a database, an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), a read-only memory (ROM), flash memory, and/or so forth. The data storage/retrieval unit 156 can store instructions to cause the processor 154 to execute modules, processes and/or functions associated with the system 100.
(75) Some embodiments the data storage/retrieval unit 156 comprises a computer storage product with a non-transitory computer-readable medium (also can be referred to as a non-transitory processor-readable medium) having instructions or computer code thereon for performing various computer-implemented operations. The computer-readable medium (or processor-readable medium) is non-transitory in the sense that it does not include transitory propagating signals per se (e.g., a propagating electromagnetic wave carrying information on a transmission medium such as space or a cable). The media and computer code (also can be referred to as code) can be those designed and constructed for the specific purpose or purposes. Examples of non-transitory computer-readable media include, but are not limited to: magnetic storage media such as hard disks, floppy disks, and magnetic tape; optical storage media such as Compact Disc/Digital Video Discs (CD/DVDs, Compact Disc-Read Only Memories (CD-ROMs), and holographic devices; magneto-optical storage media such as optical disks; carrier wave signal processing modules; and hardware devices that are specially configured to store and execute program code, such as ASICs, Programmable Logic Devices (PLDs), Read-Only Memory (ROM) and Random-Access Memory (RAM) devices. Other embodiments described herein relate to a computer program product, which can include, for example, the instructions and/or computer code discussed herein.
(76) Examples of computer code include, but are not limited to, micro code or micro-instructions, machine instructions, such as produced by a compiler, code used to produce a web service, and files containing higher-level instructions that are executed by a computer using an interpreter. For example, embodiments can be implemented using imperative programming languages (e.g., C, Fortran, etc.) functional programming languages (Haskell, Erlang, etc.), logical programming languages (e.g., Prolog), object-oriented programming languages (e.g., Java, C++, etc.) or other suitable programming languages and/or development tools. Additional examples of computer code include, but are not limited to, control signals, encrypted code, and compressed code.
(77) In some embodiments, the system 100 can be communicably coupled to a network, which can be any type of network such as, for example, a local area network (LAN), a wide area network (WAN), a virtual network, a telecommunications network, a data network, and/or the internet, implemented as a wired network and/or a wireless network. In some embodiments, any or all communications can be secured using any suitable type and/or method of secure communication (e.g., secure sockets layer (SSL)) and/or encryption. In other embodiments, any or all communications can be unsecured.
(78) The user interface 150 can include a touch screen and/or more traditional buttons to allow for the operator to enter patient data, select a treatment algorithm (i.e. energy delivery algorithm 152), initiate energy delivery, view records stored on the storage/retrieval unit 156, or otherwise communicate with the generator 104.
(79) Any of the systems disclosed herein can include a user interface 150 configured to allow operator-defined inputs. The operator-defined inputs can include duration of energy delivery or other timing aspects of the energy delivery pulse, power, target temperature, mode of operation, or a combination thereof. For example, various modes of operation can include system initiation and self-test, operator input, algorithm selection, pre-treatment system status and feedback, energy delivery, post energy delivery display or feedback, treatment data review and/or download, software update, or a combination thereof.
(80) In some embodiments, the system 100 also includes a mechanism for acquiring an electrocardiogram (ECG), such as an external cardiac monitor 170. Example cardiac monitors are available from AccuSync Medical Research Corporation. In some embodiments, the external cardiac monitor 170 is operatively connected to the generator 104. Here, the cardiac monitor 170 is used to continuously acquire the ECG. External electrodes 172 may be applied to the patient P and to acquire the ECG. The generator 104 analyzes one or more cardiac cycles and identifies the beginning of a time period where it is safe to apply energy to the patient P, thus providing the ability to synchronize energy delivery with the cardiac cycle. In some embodiments, this time period is within milliseconds of the R wave to avoid induction of an arrhythmia which may occur if the energy pulse is delivered on a T wave. It may be appreciated that such cardiac synchronization is typically utilized when using monopolar energy delivery, however it may be utilized in other instances.
(81) In some embodiments, the processor 154, among other activities, modifies and/or switches between the energy-delivery algorithms, monitors the energy delivery and any sensor data, and reacts to monitored data via a feedback loop. It may be appreciated that in some embodiments the processor 154 is configured to execute one or more algorithms for running a feedback control loop based on one or more measured system parameters (e.g., current), one or more measured tissue parameters (e.g., impedance), and/or a combination thereof.
(82) The data storage/retrieval unit 156 stores data related to the treatments delivered and can optionally be downloaded by connecting a device (e.g., a laptop or thump drive) to a communication port. In some embodiments, the device has local software used to direct the download of information, such as, for example, instructions stored on the data storage/retrieval unit 156 and executable by the processor 154. In some embodiments, the user interface 150 allows for the operator to select to download data to a device and/or system such as, but not limited to, a computer device, a tablet, a mobile device, a server, a workstation, a cloud computing apparatus/system, and/or the like. The communication ports, which can permit wired and/or wireless connectivity, can allow for data download, as just described but also for data upload such as uploading a custom algorithm or providing a software update.
(83) As described herein, a variety of energy delivery algorithms 152 are programmable, or can be pre-programmed, into the generator 104, such as stored in memory or data storage/retrieval unit 156. Alternatively, energy delivery algorithms can be added into the data storage/retrieval unit to be executed by processor 154. Each of these algorithms 152 may be executed by the processor 154. Examples algorithms will be described in detail herein below. In some embodiments, the catheter 102 includes one or more sensors 160 that can be used to determine temperature, impedance, resistance, capacitance, conductivity, permittivity, and/or conductance, to name a few. Sensor data can be used to plan the therapy, monitor the therapy and/or provide direct feedback via the processor 154, which can then alter the energy-delivery algorithm 152. For example, impedance measurements can be used to determine not only the initial dose to be applied but can also be used to determine the need for further treatment, or not.
(84) It may be appreciated that any of the systems disclosed herein can include an automated treatment delivery algorithm that could dynamically respond and adjust and/or terminate treatment in response to inputs such as temperature, impedance, treatment duration or other timing aspects of the energy delivery pulse, treatment power and/or system status.
(85) In some embodiments, imaging is achieved with the use of a commercially-available system, such as a bronchoscope 112 connected with a separate imaging screen 180, as illustrated in
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(87) As mentioned previously, the user interface 150 can include a touch screen and/or more traditional buttons to allow for the operator to enter patient data, select a treatment algorithm 152, initiate energy delivery, view records stored on the storage/retrieval unit 156, or otherwise communicate with the generator 104. The processor 154 manages and executes the energy-delivery algorithm, monitors the energy delivery and any sensor data, and reacts to monitored via a feedback loop. The data storage/retrieval unit 156 stores data related to the treatments delivered and can be downloaded by connecting a device (e.g., a laptop or thumb drive) to a communication port 167.
(88) The catheter 102 is operatively connected to the generator 104 and/or a separate imaging screen 180. Imaging modalities 162 can be incorporated into the catheter 102 or used alongside or in conjunction with the catheter 102. Alternatively or in addition, a separate imaging modality or apparatus 169 can be used, such as a commercially-available system (e.g., a bronchoscope). The separate imaging apparatus 169 can be mechanically, operatively, and/or communicatively coupled to the catheter 102 using any suitable mechanism.
(89) Referring to
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(91) Once the energy delivery body 108 is desirably positioned, treatment energy is provided to the airway wall W by the energy delivery body 108. The treatment energy is applied according to at least one energy delivery algorithm.
(92) In some embodiments, the user interface 150 on the generator 104 is used to select the desired treatment algorithm 152. In other embodiments, the algorithm 152 is automatically selected by the generator 104 based upon information obtained by one or more sensors on the catheter 102, which will be described in more detail in later sections. A variety of energy delivery algorithms may be used. In some embodiments, the algorithm 152 generates a signal having a waveform comprising a series of energy packets with rest periods between each packet, wherein each energy packet comprises a series of high voltage pulses. In some embodiments, each high voltage pulse is between about 500 V to 10 kV, or about 500 V to about 5,000 V, including all values and subranges in between. In some embodiments, the energy provided is within the frequency range of about 10 kHz to about 10 MHz, or about 100 kHz to about 1 MHz, including all values and subranges in between. The algorithm 152 delivers energy to the walls of the airway so as to provide the desired treatment with minimal or not tissue heating. In some embodiments, a temperature sensor is used to measure electrode and/or tissue temperature during treatment to ensure that energy deposited in the tissue does not result in any clinically significant tissue heating. For example, a temperature sensor can monitor the temperature of the tissue and/or electrode, and if a pre-defined threshold temperature is exceeded (e.g., 65° C.), the generator can alter the algorithm to automatically cease energy delivery or modify the algorithm to reduce temperature to below the pre-set threshold. For example, if the temperature exceeds 65° C., the generator can reduce the pulse width or increase the time between pulses and/or packets in an effort to reduce the temperature. This can occur in a pre-defined step-wise approach, as a percentage of the parameter, or by other methods.
(93) Conventional radiofrequency ablation (RFA) kills cells by application of high frequency alternating current in the 350-550 kHz range, generating heat in the tissue to product thermal necrosis of the cells. Many RFA devices have been developed to treat cardiac arrhythmias, solid tumors, renal nerves, and others. Microwave ablation is another thermal ablation modality in which 300 MHz to 300 GHz alternating current is used, also leading to thermal necrosis. This energy source is employed to target solid tumors because of the large ablation zones and uniform heating. In general, heat-related thermal ablation denatures the proteins within the tissue, causes a significant inflammatory response and can be difficult to control, often leading to injury to a non-target tissues. For certain types of treatments (e.g., tumor treatments), inflammation is acceptable, but when focused within the pulmonary airways, substantive inflammation can lead to serious complications (e.g., exacerbation). While the denaturation of proteins along may or may not produce clinical morbidity, more intact, less denatured proteins allow for the opportunity to enhance the host response to various challenges to the immune system, whether that is to affect pathogens, tumor, etc. These limitations especially make heat-related thermal ablation in the airways less desirable.
(94) In contrast, the algorithm 152 prescribes energy delivery to the airway walls W which is non-thermal, thereby reducing or avoiding inflammation. In some embodiments, the algorithm 152 is tailored to affect tissue to a pre-determined depth and/or to target specific types of cells within the airway wall. In some embodiments, the generator has several fixed algorithm settings whereby the targeted cell depth is reflected in each setting. For instance, one setting/algorithm may primarily affect the pathogens resident in the mucus layer, another setting/algorithm may target the epithelium, another setting/algorithm may primarily target the epithelium, basement membrane, submucosa and/or smooth muscle, while yet another setting/algorithm may primarily target the epithelium, basement membrane, submucosa, smooth muscle, submucosal glands and/or nerves. In some embodiments, treatment is performed at the same location, but in others, the operator may choose to affect certain cell types at different locations. The setting utilized by the operator may be dependent on the physiologic nature of the patient's condition.
(95) The biological mechanisms and cellular processes by which the energy removes the cells will be described in more detail in later sections. The energy treats the airway wall W at the target location in a manner which allows the regeneration of healthy tissue. For example, normal goblet cells GC and normal ciliated pseudostratified columnar epithelial cells PCEC are able to regenerate, thereby inducing reverse remodeling of the disease to reduce the mucus hypersecretion. The newly regenerated goblet cells GC are significantly less productive of mucus and the newly regenerated ciliated pseudostratified columnar epithelial cells PCEC regrow normally functioning cilia C, which more easily expel mucus M. Thus, healthy new target tissue can be regenerated within days of the procedure. This dramatically reduces symptoms of cough and mucus hypersecretion in patients which results in fewer and less severe exacerbations and improvement in quality of life.
(96)
(97) In some embodiments, the treatment can be performed immediately after the pre-procedure assessment. In this embodiment, it may not be necessary to gain access again. In this embodiment, the next step 305 of the procedure is to deliver the catheter. As described above, the catheter can be delivered by various methods, however for the of providing an example, the catheter is delivered via a working channel of a bronchoscope. In the next step 306, the catheter is positioned at a target site. Again, as an example, the bronchoscope can be used to provide real-time direct visual guidance to the target site and be used to observe accurate positioning of the catheter. This can include placement of one or more energy delivery bodies into contact with the airway wall. Additional imaging 307 can then be used to verify positioning and/or make additional measurements (e.g., depth). At the next step 308, the operator can optionally select the desired energy delivery algorithm 152. As described in detail above, this can include for example, selecting an algorithm based on target depth of treatment. Alternatively, the generator is configured to apply a pre-defined algorithm suitable for most patients. In this embodiment, the next step 309 is to execute or apply the energy delivery algorithm. This can be accomplished via a foot pedal or other mechanism described herein. After the energy is applied, the operator can assess the energy application 310. This can include performing additional imaging with or without measurements and/or reacting to messages communicated by the generator (e.g., an error with the energy delivery that can have led to incomplete treatment). If the treatment is not acceptable 311, then operator would go back to the Position at Target Site step 306. If the treatment is acceptable 312, then operator would proceed. The next step in the procedure can be to determine if more treatment sites are to be treated. If ‘No’ 313, the operator would then move on to Final Imaging 315 and the remaining steps until END 322. If ‘Yes’ 314, the operator would then re-position at the next target site 316 and repeat the steps for applying a treatment. Once all treatments are complete, the operator then moves on to optional Final Imaging 315, where the operator can perform additional confirmatory imaging to ensure all targeting areas were treated to his/her satisfaction. If ‘No’ 317, the operator would proceed back to ‘Re-position at next target site’ and perform additional treatments. If ‘Yes’ 318, the operator can then decide to perform one or more acute biopsies and/or sputum samples 319 to compare to any pre-procedure biopsies and/or sputum samples 301 that can have been taken. At a later date, follow-up imaging and/or, biopsies, and/or sputum samples 320 can be taken and compared to any other images or, biopsies, and/or sputum samples to help assess and/or document the outcome of the therapy. The operator can then decide to deliver materials, active agents, etc. 321 to assist in the normative healing process and as such further reduce the potential for peri-procedural issues or complications. Moreover, this might further reduce the degree or frequency of exacerbations, especially in the short term. Some examples of these agents include isotonic saline gel, medicated films, antibacterials antivirals, antifungals, anti-inflammatories, etc. As a result of exposing the tissue(s) to high-energy fields, the treated tissue(s) can be conditioned for improved agent uptake. The procedure then ends 322. The patient can then continue to be followed by a physician and can undergo this entire procedure again, should the disease or disorder recur and/or continue.
(98) Thus, it is contemplated that in certain embodiments where the desired clinical effect was not achieved or where it was achieved but then subsequently the condition re-occurred, repeat procedures may be desired. In these embodiments, it might be desired not only to re-treat certain areas but also to target a different portion of the pulmonary anatomy. Thus, the system 100 may be used to specifically re-treat the same portion of tissue as the original treatment or a distinctly different portion of tissue from the first intervention.
(99) While various embodiments have been described above, it should be understood that they have been presented by way of example, and not limitation. Where methods described above indicate certain events occurring in certain older, the ordering of certain events can be modified. Additionally, certain of the events can be performed concurrently in a parallel process when possible, as well as performed sequentially as described above.
II. Energy Delivery Algorithms
(100) As mentioned previously, one or more energy delivery algorithms 152 are programmable, or can be pre-programmed, into the generator 104 for delivery to the patient P. The one or more energy delivery algorithms 152 specify electric signals which provide energy delivered to the airway walls W which are non-thermal, reducing or avoiding inflammation. In general, the algorithm 152 is tailored to affect tissue to it pre-determined depth and/or to target specific types of cellular responses to the energy delivered. It may be appreciated that depth and/or targeting may be affected by parameters of the energy signal prescribed by the one or more energy delivery algorithms 152, the design of the catheter 102 (particularly the one or more energy delivery bodies 108), and/or the choice of monopolar or bipolar energy delivery. In some instances, bipolar energy delivery allows for the use of a lower voltage to achieve the treatment effect, as compared to monopolar energy delivery. In a bipolar configuration, the positive and negative poles are close enough together to provide a treatment effect both at the electrode poles and in-between the electrode poles. This can spread the treatment effect over a larger surface area thus requiring a lower voltage to achieve the treatment effect, compare to monopolar. Likewise, this lower voltage may be used to reduce the depth of penetration, such as to affect the epithelial cells rather than the submucosal cells. In addition, lower voltage requirements may obviate the use of cardiac synchronization if the delivered voltage is low enough to avoid stimulation of the cardiac muscle cells.
(101) It may be appreciated that a variety of energy delivery algorithms 152 may be used. In some embodiments, the algorithm 152 prescribes a signal having a waveform comprising a series of energy packets wherein each energy packet comprises a series of high voltage pulses. In such embodiments, the algorithm 152 specifies parameters of the signal such as energy amplitude (e.g., voltage) and duration of applied energy, which is comprised of the number of packets, number of pulses within a packet, and the frequency of each pulse, to name a few. There may be a fixed rest period between packets, or packets may be gated to the cardiac cycle and are thus variable with the patient's heart rate. A feedback loop based on sensor information and an auto-shutoff specification, and/or the like, may be included.
(102)
(103) In some embodiments, each high voltage pulse or the set voltage 416 is between about 500 V to 10 kV, particularly about 500 V to 4000 V, including all values and subranges in between. In some embodiments, each high voltage pulse is in range of approximately 1000 V to 2500 V which typically penetrates the airway wall W so as to treat or affect particular cells somewhat shallowly, such as epithelial cells. In some embodiments, each high voltage pulse is in the range of approximately 2600 V to 4000 V which typically penetrates the airway W so as to treat or affect particular cells somewhat deeply positioned, such as submucosal cells or smooth muscle cells. It may be appreciated that the set voltage 416 may vary depending on whether the energy is delivered in a monopolar or bipolar fashion. In some embodiments, the energy is delivered in monopolar fashion and each high voltage pulse is in the range of approximately 2000 V to 3500 V, more particularly 2500 V. In bipolar delivery, a lower voltage may be used due to the smaller, more directed electric field. In some embodiments, the energy is delivered in a bipolar fashion and each pulse is in the range of approximately 100 V to 1900 V, particularly 100 V to 999 V, more particularly approximately 500 V to 800 V, such as 500 V, 550 V, 600 V, 650 V, 700 V, 750 V, 800 V.
(104) It may be appreciated that in some embodiments the set voltage 416 is between about 50 V and about 4 kV or about 500 V and about 4 kV, including all values and subranges in between. And in other embodiments, the set voltage 416 is in a range of about 500 V to about 5 kV, including all values and subranges in between.
(105) The number of pulses per unit of time is the frequency. In some embodiments, the has a frequency in the range 100 kHz-1 MHz. In some embodiments, the signal has a frequency in the range of approximately 100-500 kHz which typically penetrates the airway W so as to treat or affect particular cells somewhat deeply positioned, such as submucosal cells or smooth muscle cells. In some embodiments, the signal has a frequency in range of approximately 600 kHz-1 MHz which typically penetrates the airway wall W so as to treat or affect particular cells somewhat shallowly, such as epithelial cells. It may be appreciated that at frequencies at or 300 kHz, undesired muscle stimulation may occur. Therefore, in some embodiments, the signal has a frequency in the range of 500-800 kHz, such as 500 kHz, 550 kHz, 600 kHz, 650 kHz, 700 kHz, 750 kHz, 800 kHz. In particular, in some embodiments, the signal has a frequency of 606 kHz. In addition, cardiac synchronization is typically utilized to reduce or avoid undesired cardiac muscle stimulation. In some embodiments, biphasic pulses are utilized to reduce undesired muscle stimulation, particularly cardiac muscle stimulation. It may be appreciated that even higher frequencies may be used with components which minimize signal artifacts.
(106) In some embodiments, the time between packets, referred to as the rest period 406, is set between about 0.1 seconds and about 5 seconds, including all values and subranges in between. In other embodiments, the rest period 406 ranges from about 0.001 seconds to about 10 seconds, including all values and subranges in between. In some embodiments, the rest period 406 is approximately 1 second. In particular, in some embodiments the signal is synced with the cardiac rhythm so that each packet is delivered between heartbeats, thus the rest periods coincides with the heartbeats. In other embodiments wherein cardiac synchronization is utilized, the rest period 406 may vary, as the rest period between the packets can be influenced by cardiac synchronization, as will be described in later sections.
(107) The cycle count 420 is the number of pulses within each packet. Referring to
(108) The packet duration is determined by the cycle count. The higher the cycle count, the longer the packet duration and the larger the quantity of energy delivered. In some embodiments, packet durations are in the range of approximately 50 to 100 microseconds, such as 50 μs, 60 μs, 70 μs, 80 μs, 90 μs of 100 μs.
(109) The number of packets delivered during treatment, or packet count, may include 1 packet, 2 packets, 3 packets, 4 packets, 5 packets, 10 packets, 15 packets, 20 packets, up to 5 packets, up to 10 packets, up to 15 packets, up to 20 packets, up to 100 packets, or up to 1,000 packets, including all values and subranges in between. In some embodiments, 5 packets are delivered, wherein each packet has a packet duration of 100 microseconds and set voltage of 2500 V. In some embodiments, 5 to 10 packets are delivered, wherein each packet has a packet duration of 100 microseconds and a set voltage of 2500 V, which results in a treatment effect that has increased uniformity. In some embodiments, less than 20 packets, wherein each packet has a packet duration of 100 microseconds and a set voltage of 2500 V, are delivered to avoid affecting the cartilage layer CL. In some embodiments, a total energy-delivery duration between 0.5 to 100 milliseconds at a set voltage of 2500 V can be optimal for the treatment effect.
(110) In some embodiments, the dead time 412 is set between about 0 and about 500 nanoseconds, including all values and subranges in between. In some embodiments, the dead time 412 is in a range of approximately 0 to 10 microseconds, or about 0 to about 100 microseconds, or about 0 to about 100 milliseconds, including all values and subranges in between. In some embodiments, the dead time 412 is in the range of 0.2 to 0.3 microseconds.
(111) It may be appreciated that the specific settings to desirably alter target tissue are dependent on one another and the electrode design. Therefore, the embodiments provided herein depict specific waveform example, and it is within the scope of this invention to use multiple waveforms and/or characteristics in any combination to achieve the desired tissue effects. A first example combination of parameters for an energy signal comprises a frequency of 600 kHz, a voltage of 3000 V and a packet count of 10. A second example combination of parameters for an energy signal comprises a frequency of 600 kHz, a voltage of 2500 V and packet count of 5. A third example combination of parameters for an energy signal comprises a frequency of 600 kHz, a voltage of 2300 V and a packet count of 20. The first example led to greater epithelial and submucosal gland treatment due to the higher voltage. The second example led to less epithelial and submucosal gland treatment due to the lower voltage and lower packet count. The third example, yielded stronger epithelial treatment effect and a lower voltages do not penetrate deep enough to have the same treatment effect on submucosal glands than higher voltages.
(112)
(113)
(114)
(115) Energy delivery may be actuated by a variety of mechanisms, such as with the use of a button 163 on the catheter 102 or a foot switch 168 operatively connected to the generator 104. Such actuation typically provides a single energy dose. The energy dose is defined by the number of packets delivered and the voltage of the packets. Each energy dose delivered to the airway wall W maintains the temperature at or in the wall W below a threshold for thermal ablation, particularly thermal ablation of the basement membrane BM. In addition, the doses may be titrated tor moderated over time so as to further reduce or eliminate thermal build up during the treatment procedure. Instead of inducing thermal effects, the energy does provides energy at a level which induces biological mechanisms and cellular effects ultimately leading to the regeneration of healthy tissue.
III. Biological Mechanisms & Cellular Effects
(116) As mentioned previously, the algorithm provides energy to the airway walls W at a level which induces biological mechanisms and cellular effects while reducing or avoiding inflammation. Example biological mechanisms and cellular process are described herein, but are not so limited.
(117) The energy provided to the airway walls W may cause a variety of cellular effects which ultimately lead to the regeneration of healthy lung airway tissue. Example cellular effects include removal of particular cell types, such as by detachment of the cells from the airway wall W (so that the detached cells can be carried away by natural or induced methods) or by cell death (e.g. lysis and apoptosis). Other cellular effects include modification of particular cell types without removal, such as reprogramming the cells or conditioning the cells for improved agent uptake.
(118) In some embodiments, particular cells are removed by detachment of the cells from the airway wall W.
(119) In other embodiments, particular cells are removed by cell death, wherein the affected cells die by lysis or apoptosis, ultimately removing the cells from the airway wall W.
(120) After cell death, the inflammatory cascade ensues. Cell fragments and intracellular contents signal leukocytes and macrophages to enter the affected area of the airway wall W. Over the course of hours to days, the dead cells are cleared from the area via phagocytosis. Unlike thermal ablation which damages the extracellular matrix, phagocytosis is limited to the cellular remains and not the collagen or matrix components of the extracellular matrix.
(121) In some embodiments, particular cells are not removed, rather the targeted cells are modified or affected, such as reprogrammed. For example, in some embodiments, the ability of the goblet cells GC to secrete stored mucus or produce mucus at all is altered. Or, modification causes the cilia C on ciliated pseudostratified columnar epithelial cells PCEC to regain their function and better expel mucus up the airway. In other embodiments, ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC are unchanged but deeper structures are primarily affected such as a reduction in smooth muscle hypertrophy or neutralization of chronic inflammatory cells and cosinophils.
(122) Whether the cells are removed or modified, the airway wall W regenerates and restores normal function. It may be appreciated that in some instances the epithelial cells may regenerate to their pre-treated stale but the deeper cells, including the smooth muscle SM, eosinophils, submucosal glands SG, and chronic inflammatory cells, may be permanently reduced.
(123) As mentioned previously, the algorithms may be tailored to affect tissue to a pre-determined depth and/or to target specific types of cells within the airway wall. For instance, various algorithms may specifically target the mucus layer M, the epithelial layer E, the basement membrane BM, the lamina propria LP, the smooth muscle cells SM, the submucosa, submucosal glands SG, nerves N, or various combinations of these. In one embodiment, the algorithm is configured to generate energy that penetrates the epithelial layer E of the airway wall W up to the basement membrane BM. Within this embodiment, a variety of different cell types may be targeted. For example, the energy may be configured to target the ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC causing their removal while leaving the basal cells BC behind. In such embodiments, the airway wall W may have abnormal and non-functioning ciliated pseudostratified columnar epithelial cells PCEC and hyperplastic, abnormal goblet cells GC causing mucus hypersecretion. The delivered energy causes the abnormal ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC to be removed, such as by cell death or detachment, leaving the basal cells BC intact along the basement membrane BM. Recall, the ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC are connected to each other by tight junctions TJ and adherens junctions AJ. In addition, the ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC are connected to the basal cells BC by desmosomes D. In some embodiments, the energy is configured so as to overcome the tight junctions TJ and adherens junctions AJ, and additionally the desmosomes D, allowing removal of ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC. Likewise, the energy may be configured to allow preservation of the hemidesmosomes H which connect the basal cells BC to the basement membrane 126. Thus, the basal cells BC remain intact.
(124) Removal of ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC can reduce mucus production and mucus secretion by a variety of mechanisms. For example, such removal can mute the signaling mechanisms that lead to the expression of proteins found in mucin, thereby reducing mucus production. In particular, Muc5ac is a protein found in the mucin in the airway goblet cells GC that is encoded by the MUC5AC gene. There are several ligands and transcription factors that are involved in Muc5ac expression. Interleukin-13 binds to a receptor that includes the interleukin-4Rα subunit, activating Janus kinase 1 (Jak1), leading to the phosphorylation of Stat6. There is no consensus Stat6 binding site in the MUC5AC and Muc5ac promoter, but Stat6 activation leads to increased expression of SPDEF (SAM pointed domain-containing Ets transcription factor), which up-regulates multiple genes involved in mucous metaplasia, and inhibits expression Foxa2, which negatively regulates Muc5ac. Several ligands bind ErbB receptors, including epidermal growth factor, transforming growth factor α, amphiregulin, and neuregulin, activating mitogen-activated protein kinases (MAPK). Hypoxia-inducible factor 1 (HIF-1) also can be activated downstream of ErbB receptors, and there is a conserved HIF-1 binding site in the proximal MUC5AC and Muc5ac promoter. Complement C3 and β2-adrenergic-receptor signaling, also amplify Muc5ac production, whereas transcription factors such as Sox2, Notch, E2f4, and Math primarily regulate development.
(125) In the case of removal of ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC, by cell death or detachment, the signaling mechanisms that lead to Muc5ac expression are muted. Therefore, mucus is not produced, resulting in a decrease in mucus in the airway. This leads to benefits in patients with COPD (chronic bronchitis, emphysema), asthma, interstitial pulmonary fibrosis, cystic fibrosis, bronchiectasis, acute bronchitis and other pulmonary diseases or disorders.
(126) Removal of such epithelial cells can also reduce mucus secretion by a variety of mechanisms. In particular, removal of the mucus producing goblet cells GC leaves no cells to secrete mucus into the airway. Secretion of mucus is induced by the molecular mechanism of mucin exocytosis. A mucin-containing secretory granule is docked to the plasma membrane by the interaction of a granule-bound Rab protein with an effector protein that acts as a tether to Munc18, which binds the closed conformation of Syntaxin anchored to the plasma membrane. Secretion is triggered when ATP binds to P2Y2 purinergic receptors (P2Y2R) coupled to Gq, activating phospholipase C (PLC, which generates the second messengers diacylglycerol (DAG) and inositol triphosphate (IP3). DAG activates Munc1314 to open Syntaxin so it can form a four-helix SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex with SNAP-23 (synaptosomal-associated protein 23) and VAMP (vesicle-associated membrane protein), drawing together the granule and plasma membranes. IP3 induces the release of calcium from IP3 receptors (IP3R) in the endoplasmic reticulum (ER), activating Synaptotagmin to induce final coiling of the SNARE complex, which results in fusion of the membranes and release of the mucins.
(127) With the removal of these epithelial cells, the signaling mechanisms that lead to mucin exocytosis are muted. Therefore, less mucus is secreted, resulting in a decrease in mucus in the airway. This leads to benefits in patients with COPD (chronic bronchitis, emphysema), asthma, interstitial pulmonary fibrosis, cystic fibrosis, bronchiectasis, acute bronchitis and other pulmonary diseases or disorders.
(128) In some embodiments, the basal cells BC left on the basement membrane BM are able to regenerate normal goblet cells GC and normal ciliated pseudostratified columnar epithelial cells PCEC, thereby inducing reverse remodeling of the disease to reduce the mucus hypersecretion. In some embodiments, ciliated pseudostratified columnar epithelial cells PCEC additionally repopulate by migration from surrounding areas of the airway wall W to assist in regeneration of healthy tissue in the target area. The goblet cells GC typically regenerate at a lower level as compared to mild, moderate, or severe goblet cell hyperplasia that is present before the application of energy. The newly regenerated goblet cells GC are significantly less productive of mucus and the newly regenerated ciliated pseudostratified columnar epithelial cells PCEC regrow normally functioning cilia C, which more easily expel mucus M. Thus, healthy new target tissue can be regenerated within days of the procedure. This dramatically reduces symptoms of cough and mucus hypersecretion in patients which results in fewer and less severe exacerbations and improvement in qualify of life.
(129) It may be appreciated that in other embodiments, the energy may be configured to target the abnormal goblet cells CG causing their removal, such as by cell death or detachment, leaving behind the ciliated pseudostratified columnar epithelial cells PCEC and the basal cells BC. Removal of the abnormal goblet cells CG can reduce mucus production and/or mucus secretion by many of the mechanisms described above. Likewise, the energy may be configured to target the abnormal ciliated pseudostratified columnar epithelial cells PCEC causing their removal, such as by cell death or detachment, leaving behind the goblet cells CG and the basal cells BC. Likewise, the energy may be configured to target the abnormal basal cells BC causing their removal, such as by cell death or detachment, leaving behind the ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC. In any of these combinations of cell removal, it may be appreciated that the remaining cells may be additionally modified or affected by the delivered energy or by energy delivered subsequently. For example, abnormal goblet cells CG left behind may be modified so as to reduce mucus production and/or mucus secretion while remaining intact. It may also be appreciated that cell populations may be partially removed wherein some cells of a particular cell type are removed by the delivered energy while some remain, optionally modified.
(130) In other embodiments, the algorithm is configured to generate energy that penetrates the epithelial layer E of the airway wall W up to and including the basement membrane BM. In such embodiments, changes to the epithelial layer E may occur as described above. Additionally, the basement membrane BM may be affected by the delivered energy so as to assist in remodeling the airway wall W to a healthy state. In some embodiments, the basement membrane BM is altered so as to stabilize or reduce the thickness of the basement membrane BM. Basement membrane BM thickening is a feature of many pulmonary diseases, including chronic bronchitis and asthma. Thus, the delivered energy may target the basement membrane BM so as halt or reverse such thickening. In some embodiments, such altering of the basement membrane BM affects the ability of cells, such as neutrophils, and inflammatory molecules, such as cytokines, to cross the basement membrane BM, thus assisting in regeneration of a healthy airway wall W.
(131) In some embodiments, the algorithms configured to generate energy that penetrates the epithelial layer E of the airway wall W and beyond the basement membrane BM. The position of various layers of the airway wall W beyond the basement membrane BM may vary due to variations in the anatomy along the lung passageways. For example, the position of the smooth muscle layer SM may vary along the length of the lung passageway, ranging from adjacent to the basement membrane BM to below the lamina propria LP. Thus, energy delivery may be titrated to target select layers of the airway wall W for a particular lung passageway segment. For example, the algorithm may be chosen or adjusted to affect the smooth muscle layer SM at its particular location. Smooth muscle hypertrophy is a feature of many pulmonary diseases, including chrome bronchitis, asthma and several other airway diseases resulting in airway hyperactivity. In some embodiments, the delivered energy induces cell death of smooth muscle cells. This may reduce airway hyperactivity and cause desired bronchodilation.
(132) In some embodiments, the algorithm is chosen or adjusted to affect the submucosal glands SG. Submucosal glands overproduce and hypersecrete mucus in diseased airways. In some embodiments, the delivered energy induces cell death of submucosal glands SG. A reduction in submucosal glands SG may lead to less mucus in the airways and improvement in patient outcomes.
(133) In some embodiments, the algorithm is chosen or adjusted so that the delivered energy affects the lamina propria LP. The lamina propria LP is comprised of loose connective tissue. The connective tissue and matrix architecture of the lamina propria LP is vary compressible and elastic which allows expansion of the lung passageways. In addition, the loose structure allows for the presence of many cell types. The cell population of the lamina propria LP is variable and can include, for example, fibroblasts, lymphocytes, plasma cells, macrophages, eosinophilic leukocytes, and mas cells. Patients with airway disease often have chronic inflammation, specifically increased populations of lymphocytes and macrophages. In some embodiments, the delivered energy reduces the quantity of inflammatory cells, particularly lymphocytes, macrophages and/or eosinophils, thus reducing inflammation. Such energy removes, such as by cell death, cells from the lamina propria LP while maintaining the extracellular matrix. By maintaining the matrix architecture, stem cells and/or other cells are able to repopulate the matrix forming a healthy tissue. This is in contrast to fibrosis or other scar forming mechanisms wherein the layers of the airway wall W, including the extracellular matrix, are permanently changed, such as by melting or collapsing the layers together. In addition, the cartilage layer CL is not injured so as to maintain the structural integrity of the airway and prevent collapse.
(134) Thus, it may be appreciated that one or more algorithms may be used to provide energy to affect one or more layers of the airway wall W. The energy may penetrate to a particular depth within the airway wall W, affecting numerous layers extending from the surface of the wall W to the particular depth. Or, the energy may be configured to affect cells at a particular depth without affecting surrounding layers. The affects may include cell removal, such as by cell death or detachment, or modification of the cell, such as to change particular functioning of the cell. In some instances, only a portion of cells of the same type or in the same layer may be affected by the delivered energy. Optionally, additional energy, either utilizing the same or different algorithm, may be delivered to affect a larger portion or all of the cells of the same type or in the same layer. Or, additional energy, either utilizing the same or different algorithm may be delivered to increase the affect. For example, additional energy may result in cell removal of previously modified cells. Still further, additional energy, either utilizing the same or different algorithm, may hebe delivered to affect a different portion or depth of the airway wall.
(135) The actual mechanisms by which the cells are removed or modified may vary depending on the algorithm 152 energy delivery bodies 108, and patient anatomy, to name a few. In some embodiments, cells are removed (e.g. detached) by dielectrophoresis.
(136) Dielectrophoresis describes the movement of particles under the influence of applied electric fields which are non-uniform. The dielectrophoretic motion is determined by the magnitude and polarity of the charges induced in a particle by the applied field. The dipole moment induced in a particle can be represented by the generation of equal and opposite charges at the particle boundary. Since this induced charge is not uniformly distributed over the particle surface, it creates a macroscopic dipole. Since the applied field is non-uniform, the local electric field and resulting force on each side of the particle will be different. Thus, depending on the relative polarizability of the particle with respect to the surrounding medium, it will be induced to move either towards the inner electrode and the high-electric-field region (positive dielectrophoresis) or towards the outer electrode, where the field is weaker (negative dielectrophoresis). The dielectrophoretic force is a function of cell volume and polarization, the conductivity and permittivity of the surrounding media, and the frequency and spatial gradients of the magnitude of the generated electric field.
(137) In some embodiments, removal of the abnormal epithelial cells, is such as ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC, is the result of dielectrophoresis induced by one or more energy pulses delivered by the energy delivery body 108. In particular, in some embodiments, the epithelial layer E is separated by the action of dielectrophoresis, wherein the abnormal ciliated pseudostratified columnar epithelial cells PCEC and goblet cells GC are pulled away from the anchored basal cells BC and removed from the airway wall W. Recall, the basal cells BC are connected to the basement membrane BM by hemidesmosomes H whereas the basal cells BC connect to the goblet cells GC and ciliated epithelial cells EC via desmosomes D. The energy parameters and electrode configuration can be designed such that the desmosomes connections D separate but the hemidesmosomes H remain intact thereby removing the surface cells, leaving the basal cells BC substantially intact, and ready to regenerate epithelium.
(138)
(139) It may be appreciated that in some embodiments, the cells are removed or modified by other mechanisms, such as electroporation. Reversible electroporation in a non-thermal technique in which short, high voltage pulses generate intense electric fields that increase cell membrane voltage, leading to the creation of pores in cell membranes (e.g., plasma membrane). These pores allow chemicals DNA, and/or other agents to be introduced into the cell. Thus, in some embodiments, reversible electroporation may be used, such as to modify cells in the airway wall W, such as to increase uptake of drugs or agents. Irreversible electroporation (IRE) is a non-thermal ablation technique in which short, high voltage pulses generate intense electric fields that increase cell membrane voltage, leading to the creation of pores in cell membranes (e.g., plasma membrane), inducing necrosis of cells, without substantial protein denaturation. Thus, in some embodiments, irreversible electroporation may be used, such to remove cells by cell death. It may also be appreciated that in some embodiments, cells are removed or modified by combination of mechanism, such as a combination of dielectrophoresis and electroporation.
(140) Alternatively or in addition to affecting tissue cells within the airway wall W, the delivered energy may affect pathogens resident in or near the airway wall W. Example pathogen types include without limitation bacteria (e.g., Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia, opportunistic gram-negatives, Mycoplasma pneumoniae, and Chlamydia pneumoniae), viruses (rhinoviruses, influenze/parainfluenza viruses, respiratory syncytial virus, coronaviruses, herpes simplex virus, adenoviruses), and other organisms (e.g., fungi).
(141) In some embodiments, the pulmonary tissue modification system 100 may additionally or alternatively be useful for impacting pathogens found within a lumen of an airway (e.g. within the mucus layer M) or within tissue layers of the airway wall W of a patient such that infection is controlled, reduced, and/or eliminated. In some embodiments, the energy output from system 100 affects the mucus layer M and any pathogens that may be resident in or near the airway. The mucus layer M may become less viscous, thus making if easier for the patient to expel via coughing. The pathogens may be killed or programmed to die (e.g., apoptosis), thereby reducing or eliminating infection.
(142) In some embodiments, the system 100 may assist the patient in developing antibodies or other commensal and supportive immune responses to targeted pathogens, improving future immunity and resistance to that pathogen in the future. Since the system 100 affects pathogens in a substantially non-thermal manner, leading to cell death, the cellular fragments still contain proteins. As these more intact proteins are released into the local environment and the circulation, the immune system develops new methods of surveillance, recognition and threat responses to these challenges, which can enhance host defense from those challenges or pathogens in the future.
(143) As mentioned previously, it may be appreciated that the energy signal parameters may be manipulated to cause differing effects, such as differing depths of penetration. In some instances, the system 100 can be configured such that only the mucus layer M and any resident pathogens are affected. In some instances, the separation of the epithelial layer E occurs. In some instances, the system 100 can be configured such that the epithelial layer E separation occurs, pathogens are affected, and/or deeper structures are affected via a single energy delivery algorithm. In some instances, the generator can have a variety of energy delivery algorithms stored within it, and the user can apply two or more of these algorithms to tailor therapy to an individual patient. This may be done in a single therapy session or multiple therapy sessions in order to address the needs of individual patients.
(144) In some instances, IT can be desirable to affect deeper cells including smooth muscle cells SM submucosal glands SG, and/or nerves N. A patient's pathology can be more complex than mucus hypersecretion caused by the epithelium E and therefore the procedural intent is to affect deeper structures Airway smooth muscle cells SM are known to contribute to bronchial hyper-responsiveness, submucosal glands SG can contribute to severe mucus hypersecretion, and nerves N innervate both submucosal glands SG and airway smooth muscle SM. Alternatively, patients with mixed pathologies such as asthma and chronic obstructive pulmonary disease (COPD) (e.g., Asthma-COPD Overlap Syndrome) can benefit from a procedure that targets several mechanisms (e.g., mucus hypersecretion, smooth muscle hypertrophy, cilia dysfunction, and/or the like) and/or target tissues. The energy dose can be titrated (e.g., iteratively modified based on sensor and/or other feedback) to affect structures deep to the epithelium E. In some instances, as the energy dose is increased, the submucosal glands SG undergo a mild partial membrane lysis or a significant loss of structural integrity. Uniquely and unlike thermal energy, the lamina propria LP, which is a cell layer that sits between the epithelium E and submucosal glands SG, remains unchanged. A thermal energy source would cause significant changes in the structure of the extracellular matrix and cause fibrosis.
(145) In addition to the submucosal glands SG, the smooth muscle SM can be affected depending on the dosing, ranging from focal changes to obliteration which causes removal of the epithelium E over days to weeks. The cartilage layer CL, the deepest structure in the airway wall, is unaffected by the energy and shows no signs of inflammation or necrosis, acting as an insulative barrier.
IV. Sensors
(146) In some embodiments, one or more sensors 160 are included in the system 100 to measure one or more system or tissue parameters. Example sensors 160 include temperature sensors, impedance sensors, resistance sensor, surface conductance sensors, membrane potential sensors, capacitance sensors, and/or force/pressure sensors, or combinations thereof. Thus, parameter measured by sensors 160 can include impedance, membrane potential or capacitance, and/or temperature, to name a few. Sensors 160 can be used for (a) obtaining a baseline measure, (b) measuring a parameter during the delivery of energy, and/or (c) measuring parameter following energy delivery, among others.
(147) Sensors 160 can be positioned on energy delivery bodies 108, adjacent to energy delivery bodies 108, or in any suitable location along the distal portion of the catheter 102. Temperature sensors can monitor the temperature of an electrode and/or the electrode/tissue interface. Impedance sensors can monitor the impedance of the tissue across any two electrodes. Conductance sensors can monitor the transmission of electrical energy across any two electrodes. Force/pressure sensors can monitor the amount of force or pressure that the electrodes are placing on the tissue.
(148) This sensor information can be used as feedback to the system in order to, as non-limiting examples, determine proper deployment of energy delivery bodies 108, drive a therapeutic algorithm 152, and/or stop energy delivery for safety reasons. Sensors 160 can also be used to sense when an adequate treatment is achieved. An algorithm 152 within the generator 104 can also use the sensed data to automatically titrate the therapeutic algorithm 152 such that the target tissue treatment is achieved. Said another way, one or more parameters and/or aspects of the therapeutic algorithm can be modified based on the sensor data in an iterative manner. For example, in some embodiments, the power and/or energy duration can be increased or decreased based on the sensor data.
(149) A. Impedance Sensors
(150) 1. Ensuring Proper Placement of Energy Delivery Bodies
(151) In some embodiments, one or more impedance sensors are used to determine if the energy delivery bodies 108 are properly inserted and deployed in the airway of the lung. In some embodiments, a short duration, low voltage signal is delivered to the energy delivery bodies 108 during their placement and deployment/expansion within the targeted area of the airway. Based on measured electrical current feedback received by the generator 104 from the one or more impedance sensors, the generator's processor 154 performs a calculation using the set voltage and actual current to calculate the impedance. Calculated impedance is then compared to impedance values that are considered acceptable for the properly inserted and deployed energy delivery bodies 108. If the calculated impedance is outside of the range of acceptable impedances, the generator 104 displays a specific message and/or emits a specific sound alerting the operator. For example, if the energy delivery bodies 108 are still within the bronchoscope 112, the generator 104 may measure a very high impedance outside of the acceptable range. In such instances, the generator may then display a message (e.g., Check Electrode Position) until the operator repositions the energy delivery bodies 108 into the airway where the impedance is significantly lower and within the acceptable range. At this point, the message may change (e.g., Ready).
(152) It may be appreciated that other types of sensors, such as temperature, force or pressure sensors may additionally or alternatively be used to verify electrode to tissue contact prior to initiation of treatment. It may also be appreciated that sufficient contact between electrodes and the walls of the airway is an important factor for effective treatment. Solid and consistent contact is desired satisfactorily couple the energy from the electrode to the tissue and to achieve desired tissue effects.
(153) 2. Ensuring Proper Functioning of Catheter
(154) In some embodiments, one or more impedance sensors are utilized to determine if the catheter 102 is functional or potentially defective. In such embodiments, a short duration, low voltage signal (e.g., a signal having a duration from 1-5 packets, and a voltage of about 500 V) is delivered to the energy delivery bodies during their placement and deployment/expansion within the targeted area. Based on the measured electrical current feedback received by the generator 104, the generator's processor 154 performs a calculation using the set voltage and actual current to calculate the impedance. Calculated impedance is compared to the impedance values that are considered acceptable for a catheter that is functioning properly. If the calculated impedance is outside of the range of acceptable impedances, the generator 104 optionally displays a specific message and/or emits a specific sound alerting the operator. For example, if the catheter is defective, the impedance may be very high. In this embodiment, the generator 14 displays a message (e.g., ‘Replace Catheter’). Once replaced, the generator 104 may then defect a much lower impedance within the acceptable range and display another message (e.g., ‘Position Catheter’). Thus, impedance measurements can be used to avert a safety concern by detecting a malfunctioning catheter.
(155) 3. Modifying the Energy Algorithm
(156) In some embodiments, impedance measurements can be made prior to or after applying energy in order to define which energy delivery algorithm 152 to apply and/or the need to apply additional energy to the target location. In some embodiments, pre-treatment impedance measurements can be used to determine the settings of various signal parameters. In other embodiments, sensors can be used to determine if the energy-delivery algorithm should be adjusted.
(157) In some embodiments, the impedance measurement is performed as follows. A short duration, low voltage signal is delivered to the energy delivery body 108 via a generator (e.g., the generator 104) once positioned as a targeted area within a lung passageway. Based on the measured electrical current feedback received by the generator 104, the generator 104 performs a calculation using the set voltage and actual current to calculate the impedance. The calculated impedance is compared to impedance values that are considered acceptable for the measured impedance. Then, the energy deliver algorithm 152 is modified or tailored based upon the measured impedance. Parameters that can be adjusted include, but are not limited to, voltage, frequency, rest period, cycle count, dead time, packet count or number of packets, or a continuation thereof. Thus, a feedback control loop can be configured to modify a parameter of energy delivery based on the measured one or more system or tissue parameters.
(158) In some embodiments, one or more impedance sensors are used to monitor the electrical properties of the tissue. Impedance values can be regarded as an indicator of tissue state. In some embodiments, impedance is measured at different frequencies to provide an impedance spectrum. This spectrum characterizes the frequency dependent, or reactive, component of impedance. Tissue has both resistive and reactive components; these are components of complex impedance. Reactance is the frequency dependent component of impedance that includes tissue capacitance and inductance. Changes in the state of the tissue can result in changes to overall impedance as well as to changes in the resistive or reactive components of complex impedance. Measurement of complex impedance involves the conduction of a low voltage sensing signal between two electrodes. The signal can include but not be limited to a sine wave. Changes in complex impedance, including changes in resistance or reactance, can reflect the state of treated tissue and therefore be used as indicators that treatment is affecting tissue, not affecting tissue, and/or that treatment can be complete. Impedance values can also change depending on the contact conditions between the sensors and airway tissue. In this way, sensors can also be used to determine the state of contact between electrodes and the tissue.
(159) In some instances, the generator 104 instructs the user that additional energy delivery at the target location is not seeded. Optionally, the generator 104 displays a specific message and/or emits a specific sound alerting the operator as to which energy delivery algorithm 154 has been selected, or that treatment is complete at that target location. Thus, the generator 104 can be configured to automatically select the appropriate algorithm for a particular measured impedance or shut off the delivery of energy signals if the treatment is determined to be completed. Further, impedance or other sensors can be used to determine that a treatment should be automatically stopped due to a safety concern.
(160) B. Temperature Sensors
(161) In some embodiments, one or more temperature sensors are used to measure electrode and/or tissue temperature during treatment to ensure that energy deposited in the tissue does not result in clinically significant tissue heating. In some embodiments, the temperature measured at or near the electrodes is also used to determine the state of contact between the electrode and tissue prior to treatment. This can be achieved by applying energy at a level sufficient to generate heat but insufficient to cause substantial thermal injury. The temperature may differ in its steady state value or in its variability depending upon whether the electrode is pressed against the airway wall, moving, or suspended in the airway lumen.
(162) In some embodiments, one or more temperature sensors are disposed along the surface of one or more energy delivery bodies 108 so as to contact the tissue and ensure that the tissue is not being heated above a pre-defined safety threshold. Thus, the one or more temperature sensors can be used to monitor the temperature of the tissue during treatment. In one embodiment, temperature changes that meet pre-specified criterion, such as temperature increases above a threshold (e.g., 40° C., 45° C., 50° C., 60° C., 65° C.) value, can result in changes to energy delivery parameters (e.g., modifying the algorithm) in an effort to lower the measured temperature or reduce the temperature to below the pre-set threshold. Adjustments can include but not be limited to increasing the rest period or dead time, or decreasing the packet count. Such adjustments occur in a pre-defined step-wise approach, as a percentage of the parameter, or by other methods.
(163) In other embodiments, one or more temperature sensors monitor the temperature of the tissue and/or electrode, and if a pre-defined threshold temperature is exceeded (e.g., 65° C.), the generator 104 alters the algorithm to automatically cease energy deliver. For example, if the safety threshold is set at 65° C. and the generator 104 receives the feedback from the one or more temperature sensors that the temperature safety threshold is being exceeded, the treatment can be stopped automatically.
(164) C. Sensors to Monitor Electrode Contact
(165) In some embodiments, multiple sensors (e.g., temperature, impedance, force, pressure etc.) are placed in various locations, such as circumferentially, on the surface of the one or more energy delivery bodies 108. In such configurations, the sensors may be used to indicate if the contact between the surface of the one or more energy delivery bodies 108 and the bronchial airway wall surface is sufficient, such as suitably circumferential and/or stable. If sensors indicate that the contact is not sufficient, such as not circumferential (e.g., non-uniform temperature, impedance, force etc.) and/or stable (e.g., continuously changing temperature, impedance, force, etc.), the operator may adjust the level of the expansion for the one or more energy delivery bodies or choose a catheter 102 with different sized energy delivery bodies 108 that better match the internal diameter of the bronchus/bronchi that are being treated. In some embodiments, the generator 104 is configured to interpret the degree, quality, and/or stability of contact and provide the operator feedback to aid in the proper positioning of energy delivery bodies. For example, as the operator is in the process of positioning the one or more energy delivery bodies which is not in circumferential contact, the user interface 150 on the generator 104 may display a message such as “Poor Contact”.
(166) In some embodiments, force or pressure sensors can be used to detect and measure the contact force between the energy delivery bodies and the walls of the airway and thereby determine the contact conditions between energy delivery bodies and tissue.
(167) It may be appreciated that any of the system 100 embodiments disclosed herein can incorporate one or more sensors to monitor the application of the therapy.
V. Cardiac Synchronization
(168) In some embodiments, the energy signal is synchronized with the patient's cardiac cycle to prevent induction of cardiac arrhythmias. Thus, the patient's cardiac cycle is typically monitored with the use of an electrocardiogram (ECG). Referring to
(169) The remaining parts of a cardiac cycle are the P wave 602 and the QRS complex 604, which both include periods when atrial or ventricular muscle is refractory to high voltage energy stimuli. If high voltage energy pulses are delivered during the muscle's refractory period, arrhythmogenic potential can be minimized. The ST segment 608 (interval between ventricular depolarization and repolarization) of the first cardiac cycle and the TQ interval 610 (interval including the end of the first cardiac cycle and the mid-point of the second cardiac cycle) are the periods where high voltage energy can be delivered without induction of cardiac arrhythmia due to the cardiac muscle depolarized state (refractory period).
(170)
(171) Because the external cardiac monitor 170 can send false TTL pulses and because the generator should not allow treatment to continue if the patient's heart rate is outside of the normal expected limits, is erratic, and/or has a widened QRS complex not associated with/different from the patient's baseline rhythm, the next step can involve checking the heart rate to establish confidence in the TTL pulse (i.e., cardiac sync pulse) (at step 662). In one embodiment, the processor 154 of the generator 104 is used to monitor the TTL pulses and calculate the time between each beat, referred to as Δt1, Δt2, Δt3, Δt4, Δt5. These values can be stored within the data storage module 156 of the generator 104 as a rolling buffer having the last five Δt calculations. Next, the average of those five values can be calculated, referred to as Δt-ave. The next one or more TTL pulses detected can be used to calculate the next Δt(s) (e.g., Δt6, Δt7, etc.), which can also be stored in the data storage module 156. For example, two TTL pulses can be utilized.
(172) Next, the algorithms module 152 of the generator 104 is used to compare these values to a set of criteria that, if met, provide confidence that the patient's heart rhythm is normal/consistent and that the TTL pulse is reliable. For example, the heart rate can be calculated and checked to ensure it is between 40-150 beats per minute (bpm). In this example, Δt6 and Δt7 can also be compared to Δt-ave to verify that the heart rate is not erratic. In one embodiment, Δt6 and/or Δt7 can be within ±15% of Δt-ave in order to continue. In this example, both criteria must be met in order to confirm confidence (at step 664); however, in other embodiments, both criteria may not be required. Once confidence is confirmed, the user interface 150 can be used to inform the user that it is safe to continue (at step 666). For example, the yellow flashing heart on the user interface 150 can change to a green flashing heart. Next, the user 150 is used to direct the user to charge the high energy storage unit (e.g., one or more capacitors) of the generator 104. In one example, the user interface 150 displays a soft-key labeled ‘Charge’, which the user may press to charge the high energy storage unit. If the charge button has not been pressed (at step 668), the processor 154 continues to check heart rate and confidence in the TTL signals.
(173) Once the processor 154 recognizes that the charge button has been pressed (at step 670), the processor 151 continues to check heart rate and confidence in the TTL signals (at step 672). During that time, if a predefined/predetermined amount of time has passed (e.g., about 30, 40, 50, 60, or up to 120 seconds, including all values and sub ranges in between) without verification that the heart rate and TTL confidence is established (at step 674, the system aborts the charging mode and reverts to the system status wherein it is checking heart rate and establishing confidence in the cardiac sync pulse (at step 662). If the timeout is not reached (step 676), the user interface 150 informs the user (at step 678) until confidence is established (at step 680). The user interface 150 can change such that the soft-key is how labeled ‘Ready’. The system 100 is now waiting for the footswitch 168 to be pressed.
(174) While the system 100 waits for the footswitch 168 to be pressed (at step 348), it continues to monitor heart rate and check for confidence (672). Another timeout can be predefined (e.g., about 30, 40, 50, 60, or up to 120 seconds, including all values and sub ranges in between), such that if the user does not press the footswitch 168 within that time (e.g., timeout is reached, as illustrated, at step 674), the system aborts being ready so deliver energy and returns to the system status wherein it is checking heart rate and establishing confidence in the TTL pulses (at step 662). Once the user presses the footswitch (at step 684), energy delivery can commence (at step 686). However, the generator 104 can be configured to wait until the next cardiac pulse is detected to further ensure that energy delivery occurs after the R-wave is detected. In one embodiment, the energy is not delivered until about 50 milliseconds after the leading edge of the TTL pulse is detected, however this value could range from about 0-300 milliseconds. The first energy packet can then be delivered (at step 686). The processor 104 then checks to determine if all packets have been delivered (at step 688). If not, the processor 154 continues to monitor heart rate and check confidence in the TTL pulses (at step 690) and energy delivery can continue once confidence in the cardiac sync pulse (at step 662) is re-established.
(175) In some instances, it may be beneficial to ignore TTL pulses immediately following energy delivery, as they may be false triggers caused by the high voltage energy being delivered. For example, the processor 154 can ignore TTL pulses for about 400 ms after energy is delivered or about 450 ms after the leading edge of the last TTL pulse. In other situations, the TTL pulses can be ignored for about 50 ms- to about 1 second, including all values and sub ranges in between. Once the processor detects the next TTL pulse, the next Δt can be calculated and compared against the criteria (at step 690) previously defined (i.e., based on a rolling average). Due to the potential for transient delays in the heart beat following energy delivery, if the next Δt falls outside of the criteria, it is simply ignored. Then, the next Δt can then be calculated and compared against the criteria previously defined. If the criteria are met (at step 700), the next packet is delivered (at step 686). If all packets have not been delivered, the system continues to monitor the heart rate and check for confidence in the cardiac sync pulse (at step 690) as previously described. If confidence is established (at step 700), the cycle continues. If confidence is not established (at step 702), the user is informed (at step 704, for example, by the heart turning yellow and flashing or turning solid red.
(176) If the system 100 cannot determine acceptable confidence or no longer detects a TTL pulse within a certain amount of time (e.g., about 10, 20, 30, 40, 50, or 60 seconds), a timeout will be reached (at step 706), and the user interface 150 can be used to notify the user (at step 708). At this time, the cycle can end, and any remaining packets would not be delivered. The process then returns to start (at step 650). If the system can determine acceptable confidence (at step 700) within the set time limit, a timeout will not be reached (at step 688), and the cycle continues with continued monitoring of heart rate and checks for confidence (at step 690), as previously described. If confidence is gained (at step 700), the next energy packet is delivered (at step 686). Once all packets are delivered, the treatment is deemed complete (at step 710) and the user is informed of completion of treatment (at step 708). If the current associated with delivery of any of the high energy packets (at step 686) exceeds a set value (e.g., about 45 amps), the cycle can also end (at step 708).
(177) It may be appreciated that in some embodiments, components for acquiring the electrocardiogram 170 are integrally formed with the generator 104. If the cardiac monitor is limited to acquiring up to a 5-lead ECG, and it may be beneficial to incorporate additional leads into the system. This would further eliminate the need to use the communications port 167 to receive cardiac sync pulses. Rather, the processor 154 can be configured to defect the R-waves directly and to assess the integrity of the entire QRS complex.
(178) In some embodiments, the processor 154 may be configured to use either fewer or more than five Δt's to calculate Δt-ave. In some embodiments, the processor 154 may be configured to use between three and ten Δt's to calculate Δt-ave. Further, the processor 154 may be configured to use a Δt other than Δt6 and Δt7 to confirm confidence. For example, the processor 154 may be configured to use any subsequent Δt. The processor 154 may also be configured to allow heart rates beyond the 40-150 bpm described above. For example, the processor 154 may be configured to allow heart rates in the range of 30-160 bpm, including all values and sub ranges in between. The processor 154 may also be configured to allow Δt6 or other Δt7 to be more or less than ±10%. For example, the processor 154 may be configured to allow Δt6 or other data point, including rolling averages, to be within ±3% to ±50%. User interface 150 examples provided herein are merely examples, and should not be considered limiting.
(179) Thus, it may be appreciated that generator can be configured to continuously monitor the patient's heart rate, and in case cardiac arrhythmias are induced, the treatment will be automatically stopped and an alarm can sound.
VI. Imaging
(180) Methods associated with imaging that can be useful include: (a) detecting diseased target tissue, (b) identifying areas to be treated, (c) assessing areas treated to determine how effective the energy delivery was, (d) assessing target areas to determine if areas were missed or insufficiently treated, (e) using pre- or intra-procedural imaging to measure a target treatment depth and using that depth to choose a specific energy delivery algorithm to achieve tissue effects to that depth, (f) using pre or intra-procedural imaging to identify a target cell type or cellular interface and using that location or depth to choose a specific energy delivery algorithm to achieve tissue effects to that target cell type or cellular interface, and/or (g) using pre-, intra-, or post-procedural imaging to identity the presence or absence of a pathogen with or without the presence of inflamed tissue.
(181) In some embodiments, confocal laser endomicroscopy (CLE), optical coherence tomography (OCT), ultrasound, static or dynamic CT imaging, X-ray, magnetic resonance imaging (MRI), and/or other imaging modalities can be used, either as a separate apparatus/system, or incorporated/integrated (functionally and/or structurally) into the pulmonary tissue modification system 100 by either incorporating into the energy delivery catheter 102 or a separate device. The imaging modality (or modalities) can be used to locate and/or access various sections of tissue as demonstrated by a thick area of epithelium, goblet cell hyperplasia, submucosal glands, smooth muscle, and/or other aberrancies relative to where the system is deployed in the chest. In some embodiments, the targeted depth of treatment can be measured and used to select a treatment algorithm 152 sufficient to treat to the targeted depth. At least one energy delivery body can then be deployed at the site of abnormal airway wall tissue and energy delivered to affect the target tissue. The imaging modality (or modalities) can be used before, during, between, and/or after treatments to determine where treatments have or have not been delivered or whether the energy adequately affected the airway wall. If it is determined that an area was missed or that an area was not adequately affected, the energy delivery can be repeated followed by imaging modality (or modalities) until adequate treatment is achieved. Further, the imaging information can be utilized to determine if specific cell types and or a desired depth of therapy was applied. This can allow for customization of the energy delivery algorithm for treating a wide variety of patient anatomies.
(182) In some embodiments, imaging combined with the use of a fluorescent agent (e.g., fluorescein) can be performed to enhance recognition of pathogens that may be in the airway. The fluorescent agent can be chosen to directly tag certain pathogens (e.g., bacteria) or indirectly tag cells associated with various infections states (e.g., neutrophils), which will then be visible. In some embodiments, such an imaging method/approach can include the steps of gaining access to the airway, delivering the fluorescent agent to within the airway, exciting the fluorescent agent by delivering an excitation signal into the airway, and assessing the presence or absence of fluorescence in response to the excitation signal.
(183) A. Imaging for Access
(184) In general, the methods, apparatuses, and systems disclosed herein can access pulmonary tissue or a target region (e.g., trachea, mainstem bronchi, lobar bronchi, segmental bronchi, sub-segmental bronchi, parenchyma) via a natural orifice route (e.g., from the mouth or nose), an artificially created orifice (e.g., via a tracheotomy, via a surgically created stoma, and/or any suitable intra-operative and/or surgical orifice), and/or via an artificially created orifice through the airway into other areas of the lung and/or tissue (e.g., parenchyma). The type of approach utilized can depend on factors such as a patient's age, comorbidities, need for other concomitant procedures, and/or prior surgical history.
(185) Methods for accessing the airway and/or other lung tissue (e.g., parenchyma) can include using the working channel of a bronchoscope delivered via the nose or month, into the trachea and/or more distal bronchi. As illustrated previously in
(186) It may be appreciated that in some instances, direct visualization may not be necessary and/or desired, and the treatment catheter can be delivered directly into the airway via the nose or mouth.
(187) In other embodiments, accessing the airway and/or lung tissue (e.g., parenchyma) is achieved via other appliances inserted into the chest. Likewise, in some embodiments one or more of a variety of imagine modalities (e.g., CLE, OCT) are used either along with direct visualization, or instead of direct visualization. As an example, a bronchoscope 112 can be delivered via the mouth to allow for direct visualization and delivery of the catheter 102, while an alternate imaging modality can be delivered via another working channel of the bronchoscope 112, via the nose, or adjacent to the bronchoscope via the mouth. In some embodiments, the imaging modality (e.g., direct visualization CLE, and/or OCT) is incorporated into the catheter 102 with appropriate mechanisms to connect the imaging modality to either the system generator 104 or commercially available consoles.
(188) B. Imaging for Treatment Planning
(189) Methods associated with imaging can include using imagine pre-treatment to plan the procedure. Imaging can be used for detecting diseased target tissue, identifying areas to be treated, and/or for determining the appropriate energy delivery algorithm to achieve a desired depth of treatment. For example, a CT scan can be obtained preoperatively or intraoperatively, from which an AWT or Pil0 (theoretical airway wall thickness for an airway with an internal perimeter of 10 mm) measurement is obtained. Target zones can be identified using these metrics. Referring again to
(190) In some embodiments, the use of the bronchoscope 112 may allow for pre-procedural planning, wherein a sputum sample is acquired for analysis. If one or more pathogens are found, this information may be for determining the appropriate energy delivery algorithm 152 to achieve a desired depth of treatment as a consequence of the initial data. In some cases, such as the combination of pathogen identification in conjunction with improved tissue imaging, it may be desirable to limit the treatment depth to merely the mucus layer M, where pathogens thrive; whereas, in other cases, it may be desirable to affect deeper airway structures. For planning the treatment, a sputum sample may be obtained and assessed to determine if an infection of the tracheobronchial tree may be present. If an infection is deemed to be present, the generator can be programmed to affect the mucus layer of the airway without substantially impacting other layers, which contains the pathogens causing the infection, or other pulmonary tissues. The method of performing sputum testing can also be used to assess the effect of the treatment. For assessing the effect of the treatment, additional sputum samples, as well as biopsies, can be taken following the energy-delivery procedure or at a later time. By comparing these samples and biopsies to the planning samples and each other, the effectiveness of the procedure can be determined. These data, combined with a clinical examination of the patient, can be used to further optimize therapy.
(191) The method of performing on or more tissue biopsies can be used to plan treatment and/or assess the effect of the treatment. For planning the treatment, a biopsy can be performed and assessed microscopically to determine patient suitability (e.g., excessive mucus production, goblet cell density, goblet cell hypertrophy, epithelial thickness, inflammation, basement membrane thickening, submucosal inflammation, submucosal eosinophilia, submucosal gland thickening, smooth muscle hypertrophy, or other parameters) and/or degree of airway obstruction (e.g., thickness of epithelial and/or other layers). By measuring one or more of these parameters, the generator can be programmed to affect a certain depth of tissue, allowing for customization of the energy-delivery algorithm for each patient. For example, voltage can be increased for patients with thicker epithelial layers. For assessing the effect of the treatment, additional biopsies can be performed immediately following the energy-delivery procedure or at a later time. By comparing these biopsies to the planning biopsy and each other, the effectiveness of the procedure can be determined. For example, if the post treatment biopsy showed no change from the planning biopsy, either that location was not treated or insufficient energy was applied to affect the tissue. But, if the post treatment biopsy showed a reduction in epithelial thickness and/or structure (i.e., regeneration of healthy epithelium), the effectiveness of the energy delivery can be verified. By performing multiple biopsies along the airway, one could further assess whether or not a sufficient percentage of the total surface area was treated. These data, combined with a clinical examination of the patient can be used to further optimize therapy.
(192) C. Imaging During Treatment
(193) Use of a bronchoscope 112 allows for direct visualization of the target tissues and visual confirmation of catheter 102 placement and deployment. In some embodiments, direct visualization may not be necessary and the catheter 102 is delivered directly into the airway. Alternatively, a variety of imaging modalities (e.g., CLE, OCT) can be used either along with direct visualization or instead of direct visualization. As an example, a bronchoscope 112 can be delivered via the mouth to allow for direct visualization and delivery of the catheter 102, while an alternate imaging modality can be delivered via another working channel of the bronchoscope 112, via the nose, or adjacent to the bronchoscope via the mouth. In some embodiments, the imaging technology (e.g., direct visualization, CLE, and/or OCT) can be incorporated into the catheter with appropriate mechanisms to connect the imaging technology to either the system generator or commercially available consoles.
(194) D. Imaging Post Treatment
(195) In some embodiments, methods associated with imaging can include using imaging (e.g., using the imaging modality 169) to assess the effectiveness of the procedure intra-operatively and/or post procedure. In some embodiments, during the procedure, the operator can use imaging to assess target treatment areas to determine if areas were missed or insufficiently treated. For example, if an area was insufficiently treated, the operator can observe that the target depth was not achieved. The operator can then re-measure the depth, select an appropriate treatment algorithm 152, and treat again in the same location. In some embodiments, if the generator 104 does not have a variety of pre-set algorithms based on desired depth, the same energy delivery algorithm can be used. Imaging can be also used post procedure to monitor the healing process and correlate tissue changes to clinical outcomes. The healing process can make it easier to visualize tissue changes and assess the effectiveness of the procedure. These data can further lead to the physician deciding to perform additional procedures to affect additional tissue.
VII. Catheter Embodiments
(196) A variety of energy delivery catheter 102 embodiments are envisioned. Characteristics and features described herein can be used in any combination to achieve the desired tissue effects. Typically, such catheters 102 are sized and configured to treat lung passageways having a lumen diameter of approximately 3-20 mm. Typically, energy delivery bodies 108 expand within the lung passageway lumen so as to reside near, against, in contact, or exerting pressure or force against the wall W of the lumen. In some embodiments, the energy delivery body 108 expands to a diameter of up to 22 mm, particularity 3-20 mm or 3-22 mm.
(197)
(198) In some embodiments, the energy delivery body 108 comprises a plurality of electrodes 107, wherein each wire 120 acts as a separate electrode 107 and is able fire separately using the wire next to it as a return electrode or using a dispersive electrode attached to the patient as a return electrode. In some instances, each wire 120 of the energy delivery body 108 can be electrically isolated from each other wire 120, and separate conductor wires can transmit the energy from the generator 104 to the wires 120 of the energy delivery body 108. In other instances, two or more wires 120 can be electrically connected to one another to form one or more sets of wires. The algorithm 152 of the generator 104 can perform the appropriate switching from one wire (or set of wires) to another as well as the alternation of the wire's function between active and return (ground) states.
(199)
(200) In the embodiment illustrated in
(201)
(202) In some embodiments, the collapsed configuration of the energy delivery body 108 can be achieved by mechanisms which restrict its expansion without the use of a sheath 126. For example, in some embodiments, a pull wire is attached to the proximal end constraint 122 of the energy delivery body 108 and extends down a lumen along the shaft 126 where it is operatively connected to a lever, slider, or plunger of the catheter's handle 110. In this embodiment, the distal end constraint 124 is fixedly attached to the shaft 106 and the proximal end constraint 122 is configured to slide freely on the shaft 106. While the pull wire is under pull force, the proximal end constraint 122 is positioned so that the energy delivery body 108 is collapsed. The pull wire can be maintained in this position by restraint within the handle 110. Release of the pull force, such as by reduction or removal of the restraint within the handle 110, allows the pull wire to move, thus freeing the proximal end constraint 122 and allowing it to travel closer to its distal end constraint 124 as self-expanding properties of the energy delivery body 108 cause expansion.
(203) In other embodiments, the proximal end constraint 122 is affixed to the shaft 106 and the distal end constraint 124 is free to slide on the shaft 106. Further, a push rod (or tubing to achieve higher column strength) is attached to the distal end constraint 124 and extends down a lumen along the inner shaft 106 where it is operatively connected to mechanism such as a lever, slider, or plunger of the catheter's handle 110. When the push rod is pushed and subsequently restrained within the handle 110 of the catheter 102, the distal constraint 124 is moved away from the proximal end constraint 122 which causes the energy delivery body 108 to collapse. When the energy delivery body 108 is self-expanding, release of the push rod allows the energy delivery body 108 to expand. Alternatively, the push rod may be retracted, pulling the distal end constraint 124 toward the proximal end constraint 122 which causes the energy delivery body 108 to expand.
(204) In the embodiment shown in
(205)
(206) In some embodiments, the collapsed configuration of the energy delivery bodies 108, 108′ can be achieved by restricting their expansion without the use of a sheath 126. For example, in one embodiment the distal end of a pull wire (not shown) is attached to the second distal end constraint 124′ and the proximal end of the pull wire is attached to a mechanism of the handle 110 (for example plunger, slider or lever). The first proximal end constraint 122 is fixedly attached to the catheter shaft 106 and the other end constraints 124, 122′, 124′ slide freely over the catheter shaft 106. Such a configuration assumes that energy delivery bodies 108, 108′ are in a collapsed configuration prior to initiating placement via a bronchoscope and require the operator to deploy/expand them. This deployment/expansion is achieved by the operator activating the mechanism of the handle 110 (e.g., lever, plunger or slider) which pulls the second distal end constraint 124′ toward the first proximal end constraint 122, thus effectively deploying/expanding both energy delivery bodies 108, 108′. In another configuration, expansion can be achieved by employing two pull wires, one attached separately to each energy delivery body 108, 108′. In such embodiments, the operator can control the level of expansion of the energy delivery bodies 108, 108′ separately.
(207) In some embodiments, the one or more energy delivery bodies 108, 108′ are not constrained at both ends, rather one end is unconstrained creating a half-basket shape.
(208) The configuration depicted in
(209)
(210) In some embodiments, the entire surface of the one or more energy delivery bodies 108 is energized by the energy signal for delivery to the target tissue. However, in other embodiments, an active surface area of the energy delivery body 108 is provided wherein the remaining portions are not active. In some embodiments, this is achieved by partially insulating one or more portions of the energy delivery body 108 leaving one or more active region(s). For example,
(211)
(212)
(213)
(214)
(215)
(216)
(217) The energy delivery body 108 can be optimized for situations in which force exerted onto the bronchial wall is desired to be more highly controlled. In this embodiment, the energy delivery body 108 is delivered into the bronchial lumen via a three-step process. First, as illustrated in
(218)
(219) In some embodiments, the insulating substrate 904 with electrodes 107 is configured as a strip (
(220) In some embodiments, a push-pull mechanism as described previously in relation to other embodiments can be employed to deploy the strip or ribbon. In case of the helix, the rotational mechanism can also be used. Electrodes 107 can be electrically connected to each other, can be insulated from each other or different patterns of electrical interconnection between electrodes depending on the energy application algorithm controlled by the generator.
(221) Once the one or more prongs 900 are exposed, the second step of the three-step process involves introducing an expandable member 910, such as a balloon, by advancing the expandable member 910 from the lumen 902 while in an unexpanded state. The third step involves expanding the expandable member 901, such as inflating the balloon, as illustrated in
(222)
(223)
(224) It may be appreciated that many of the figures herein depict energy delivery bodies 108 of essentially the same size (e.g., length, diameter) and shape for illustrative purposes, and should not be considered limiting. In some embodiments, the energy delivery bodies can vary in size in order to account for tapering of the airway lumen, better localize the energy field, and/or enhance treatment of the tissue. For example, if the desired catheter placement resumes a distal energy delivery body to be in the lobar bronchi (about 9 mm-12 mm in diameter) and a proximal energy delivery body to be in the mainstem bronchi (about 12 mm-16 mm in diameter), the distal energy delivery body can be designed to expand to about 12 mm and the proximal energy delivery body to expand to about 16 mm. The energy delivery bodies can also be of different sizes to better localize the energy field. For example, if monopolar energy delivery is desired, it can be beneficial to have the dispersive (neutral) electrode incorporated into the catheter or another device (instead of placed on the outside of the patient, as shown in
(225)
(226) In some embodiments, the length between a distal end 954 of the catheter handle 110 and the proximal end 956 of the most proximal energy delivery body 108 is tailored to be substantially equal to the length of the working channel of the bronchoscope 112, based on the distance between the proximal end of the working channel and the distal end of the working channel. When the catheter handle 110 is connected (e.g. snapped) to the external port 952 of the working channel of the bronchoscope 112, the energy delivery body or bodies 108 is/are introduced into the lung passageway. The step of positioning the one or more energy delivery bodies 108 within the target area of the lung passageway can be accomplished by moving the bronchoscope 112, and thereby moving the catheter 102 there attached. When the one or more energy delivery bodies 108 are successfully positioned within the target area and this position is visually assessed and confirmed by the operator (e.g. using visual bronchoscopy) the one or more energy delivery bodies can be expanded, deployed or otherwise positioned into tissue contact via a mechanism in the catheter handle 110 which is operatively connected to the one of more energy delivery bodies 108 (e.g. lever, slider, plunger, button operatively connected to the one or more energy delivery bodies 108 (via a pull wire or by other mechanisms) and ready for energy delivery.
(227) In some embodiments, the length between the distal end 954 of the catheter handle 110 and the distal most distal end 958 of the one or more energy delivery bodies 108 is tailored to be substantially equal to the length of the working channel of the bronchoscope 112, based on the distance between the proximal end of the working channel 954 and the distal end of the working channel 960. When the catheter handle 110 is connected (e.g., snapped) to the external port 952 of the bronchoscope working channel, the one or more energy delivery bodies 108 are not yet introduced (
(228) In some embodiments, the length between the distal end of the catheter handle and the proximal end of the one or more energy delivery bodies 108 tailored to be substantially longer that the length of the working channel. When one or more energy delivery bodies 108 are introduced into the lung passageway, the handle is not in contact with the external port of the bronchoscope working channel. The step of positioning one or more energy delivery bodies 108 within the target area can be accomplished by moving the bronchoscope or alternatively moving the catheter itself. In this case, the catheter is long enough that the catheter handle can be held by the operator or set down on or near the patient to allow the operator to hold the bronchoscope. When one or more energy delivery bodies 108 are successfully positioned within the target area and this position is visually assessed and confirmed by the operator (e.g. using visual bronchoscopy) the one or more energy delivery bodies 108 can be deployed or otherwise positioned into tissue contact via a mechanism in the catheter handle which is operatively connected to the one or more energy delivery bodies 108 (e.g. lever, slider, plunger, button) and ready for energy delivery.
(229) According to embodiments described herein, which can partially or as a whole combine with other embodiments, the handle of the catheter can include a docking mechanism that can be removably connected (e.g., snapped) onto the external port of the bronchoscope working channel. In another embodiment, the handle can be connected to the various attachments and/or accessories (e.g., valve) that are installed onto the external port of the bronchoscope working channel. In yet another embodiment, the handle may not have any mechanisms that snap onto the external port of the bronchoscope working channel and the stability of the device is achieved by means of friction between the shaft of the catheter and accessories (e.g., valve) that are installed onto the external port of the bronchoscope working channel.
VIII. Treatment Patterns
(230) It may be appreciated that a patient P may possess a single target zone for treatment or multiple target zones. A target zone is a contiguous area of a lung passageway that is targeted for treatment. A single lung passageway may include multiple target zones. Likewise, target zones may be located along separate lung passageways. Each target zone may include one or more target segments. A target segment is a portion of the lung passageway that is treatable by a single placement of the catheter 102 (i.e. single treatment). Thus, the target segment is defined by the outer area borders along the long airway wall W within which the wall tissue has been treated by the one or more electrodes 108 of the catheter 102. It may be appreciated that different embodiments of the catheter 102 may cover differing sized areas of a lung passageway. Thus, the size of a target segment may vary based on catheter 102/system 100 design. In addition, the catheter 102 may be sequentially moved along a lung passageway to create multiple adjacent target segments, wherein adjacent target segments cover the target zone.
(231) Thus, methods for treating the airway of a patient can include: (a) performing a single treatment at a target segment, (b) performing two or more treatments at adjacent target segments such that the overall treatment zone is generally continuous, and/or (c) performing two or more treatments spaced apart from one another.
(232) It may also be appreciated that within a target segment, the lung passageway tissue may receive a variety of treatment patterns at any given cross-section. For example, some embodiments include treating the full circumference of the airway over a given length of the target segment and other embodiments include treating one or multiple discrete portions of the circumference of the airway over a given length of the target segment.
(233)
(234) In some embodiments, in order to achieve substantially continuous, full circumference treatment over a given length, at least the applied electric field (V/cm) and the electrode design are taken into consideration. In one example, the electric field is applied in a monopolar fashion, wherein the field is applied to substantially the energy delivery body 108, and a dispersive (neutral) electrode is positioned either on the exterior of the patient or elsewhere within the body. The change and/or distribution of the magnitude of the field will depend on the applied voltage and the geometric relationship of the wires 120. In the example provided in
(235) It may be appreciated that some embodiments have energy delivery bodies which include treating portions of the circumference ranging from about 25 to about 50%, from about 50% to about 75%, or from about 75% to about 100%, including all values and subranges in between. Some embodiments include treating lengths ranging from about 5 mm to about 20 mm, including all values and subranges in between, allowing for sufficient flexibility to treat a wide range of patient anatomies while minimizing the number of individual treatments to be performed.
IX. General Embodiments
(236) In some embodiments described herein, which can partially or as a whole be combined with other embodiments, a pulmonary tissue modification system for performing a pulmonary procedure can include an energy producing generator, an energy deliver catheter, accessories, and one or more imaging modalities.
(237) In some embodiments, a bipolar catheter with two energy delivery bodies mounted near the distal end is connected to an energy producing generator outside of the body. The distal end of the catheter is passed through the mouth or nose and into the bronchial tree using a bronchoscope or other direct visualization system. The energy delivery bodies are deployed, expanded and/or otherwise positioned such that they contact the airway wall. The operator can then activate the generator via any suitable interface such as, for example, a foot switch, a button on the generator, a button on the catheter, or remote control, to deliver energy to airway tissue adjacent to and/or between the electrodes. In some embodiments, the operator can move the energy delivery bodies to another section of the diseased airway to deliver another treatment, or elect to treat the entire surface of a section of the airway, or multiple sections of the airways. In some embodiments, more than one treatment can be applied to the same portion of the airway, depending on the desired depth of penetration. In some embodiments, two or more different energy delivery algorithms can be employed to affect the depth of penetration.
(238) In some embodiments, a monopolar catheter, with a single energy delivery body mounted near the distal end, is connected to an energy producing generator outside of the body. The distal end of the catheter is passed through the mouth or nose and into the bronchial tree using a bronchoscope or other direct visualization system. The electrode is deployed, expanded and/or otherwise positioned such that it contacts the airway wall. A dispersive (neutral) or return electrode is affixed to another surface of the patient (e.g., an external location, such as the patient's skin), and is also connected to the electrical generator. The operator can then activate the generator via, for example, a foot switch, a button on the generator, a button on the catheter, or remote control to deliver energy to airway tissue via the electrode. The operator can move the energy delivery body to another section of the diseased airway to deliver a treatment, or elect to treat the entire surface of a section of the airway, or multiple sections of the airways. In some embodiments, two or more monopolar energy delivery bodies can be incorporated into one or more catheters to enable treatment of multiple locations without repositioning the catheter(s). More than one treatment can be applied to the same portion of the airway, depending on the desired depth of penetration. In some, embodiments, two or more different energy delivery algorithms can be employed to affect the depth of penetration. In some embodiments, a user interface on the generator can be used to select the desired treatment algorithm, while in other embodiments, the algorithm can be automatically selected by the generator based upon information obtained by one or more sensors.
(239) In some embodiments, a catheter with a plurality of energy delivery bodies mounted near the distal end is connected to an energy producing generator outside of the body. The distal end of the catheter is passed through the mouth or nose and into the bronchial tree using a bronchoscope or other direct visualization system. The energy delivery bodies are deployed, expanded, or otherwise positioned such that they contact the airway wall. The operator can then activate the generator via, for example, a foot switch, a button on the generator, a button on the catheter, or remote control to deliver energy to airway tissue via the energy delivery bodies. In some embodiments, the energy delivery can be multiplexed across any one or more of the energy delivery bodies in any suitable pattern to affect the desired target tissue. In some embodiments, a dispersive (neutral) electrode can be affixed to another surface of the patient, such as the patient's skin, and also connected to the electrical generator to allow for monopolar energy delivery to any of the energy delivery bodies. More than one treatment can be applied to the same portion of the airway, depending on the desired depth of penetration. In some embodiments, two or more different energy delivery algorithms can be employed to affect the depth of penetration. The user interface on the generator can be used to select the desired treatment algorithm, or the algorithm can be automatically selected by the generator based upon information
(240) In some embodiments, the targeted treatment area can be identified and used to select a treatment algorithm sufficient to affect the pathogenic cells and/or deeper tissues. The electrode system can then be deployed at the site of pathogenic cells and/or abnormal airway wall tissue and energy delivered to affect the target tissue. The imaging modality (or modalities) can be used before, during, between, and/or after treatment(s) to determine where treatment(s) have or have not been delivered and/or whether the energy adequately affected the airway wall. If it is determined that a target treatment area was missed or that a target treatment area was not adequately affected, the energy delivery can be repeated followed by imaging as described herein until adequate treatment is achieved. Further, the imaging information can be utilized to determine if specific cell types and or a desired depth of therapy was applied. This can allow for customization of the energy delivery algorithm for treating a wide variety of patient anatomies.
(241) In some embodiments, any of the apparatuses and/or systems described herein can be used in methods for treating diseased airways, and/or other lung tissue (e.g., parenchyma), which can generally include accessing the airway, and optionally performing pre-, intra-, and/or post-procedural imaging to plan, guide and/or verify treatment. In some embodiments, the methods can further include one or more of treating a sufficient treatment zone with each energy application, treating a sufficient overall treatment area, treating to a sufficient depth, treating a pre-defined cell type or types, customizing therapy based on imaging and/or sensor information, and combinations thereof.
X. EXAMPLES
(242) The following examples further illustrate embodiments of the systems and methods disclosed herein, and should not be construed in any way as limiting their scope.
Example 1: Circumferential Treatment and Tissue Effect With a Bipolar System
(243) A non-thermal energy delivery apparatus having bipolar expandable energy delivery bodies was developed. The apparatus included two energy delivery bodies, each comprised of nitinol, braided, expanding electrodes mounted concentrically on a catheter shaft with a mechanism to expanded and contract both energy delivery bodies (e.g., see
(244) Following the procedure, the animals were recovered, then subsequently euthanized after approximately twenty-four hours. The airways were then dissected out and fixed in formalin for about forty-eight hours. The airways were then sectioned at approximately 5 mm increments and processed for histology in typical fashion. Sections of both treated and untreated areas were processed for comparison purposes. Slides were prepared using a hematoxylin and eosin (H&E) stain.
(245)
Example 2: Circumferential Treatment and Tissue Effect With a Monopolar System
(246) A non-thermal energy delivery apparatus having a monopolar expandable energy delivery body was developed. The apparatus included a single energy delivery body comprised of nitinol, braided, expanding electrode mounted concentrically on a catheter shaft with a mechanism to expanded and contract the energy delivery body (e.g., see
(247) Following the procedure, the animals were recovered, then subsequently euthanized after approximately twenty-four hours. The airways then dissected out and fixed in formalin for about forty-eight hours. The airways were then sectioned at approximately 5 mm increments and processed for histology in typical fashion. Sections of both treated and untreated areas were processed for comparison purposes. Slides were prepared using a hematoxylin and cosin (H&E) stain.
(248)
(249) As used herein, the terms “about” and/or “approximately” when used in conjunction with numerical values and/or ranges generally refer to those numerical values and/or ranges near to a recited numerical value and/or range. In some instances, the terms “about” and “approximately” can mean within ±10% of the recited value. For example, in some instances, “about 100 [units]” can mean within ±10% of 100 (e.g., from 90 to 110). The terms “about” and “approximately” can be used interchangeably.
(250) While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.