CATHETER POSITIONING SYSTEM WITH SENSORY FEEDBACK
20250135181 ยท 2025-05-01
Assignee
Inventors
Cpc classification
A61M60/531
HUMAN NECESSITIES
A61M2205/3592
HUMAN NECESSITIES
A61M60/90
HUMAN NECESSITIES
A61M2230/04
HUMAN NECESSITIES
A61M2230/005
HUMAN NECESSITIES
International classification
A61M60/531
HUMAN NECESSITIES
Abstract
Methods and apparatus for providing sensory feedback to an operator of a mechanical circulatory support (MCS) device are provided. The method comprises monitoring, using a controller of the MCS device, one or more physiological signals associated with a heart of a patient within which the MCS device is placed, generating an alert signal based, at least in part, on the monitored one or more physiological signals, and transmitting in response to generating the alert signal, a control signal from the controller of the MCS to a feedback device, wherein the feedback device is configured to provide sensory feedback to an operator of the MCS device based on the control signal.
Claims
1. A method of providing sensory feedback to an operator of a mechanical circulatory support (MCS) device, the method comprising: monitoring, using a controller of the MCS device, one or more physiological signals associated with a heart of a patient within which the MCS device is placed; generating an alert signal based, at least in part, on the monitored one or more physiological signals; and transmitting in response to generating the alert signal, a control signal from the controller of the MCS to a feedback device, wherein the feedback device is configured to provide sensory feedback to an operator of the MCS device based on the control signal.
2. The method of claim 1, wherein the one or more physiological signals include an electrocardiogram signal and/or a pressure signal sensed by at least one pressure sensor associated with the MCS device.
3. (canceled)
4. (canceled)
5. The method of claim 1, wherein generating the alert signal comprises generating the alert signal when it is determined based, at least in part, on the one or more physiological signals that the heart of the patient is in a systolic phase.
6. The method of claim 1, wherein the sensory feedback includes tactile feedback.
7. (canceled)
8. (canceled)
9. The method of claim 1, wherein the feedback device is a wearable device configured to be worn by the operator of the MCS device.
10-12. (canceled)
13. The method of claim 1, wherein the feedback device is coupled to a catheter associated with the MCS device.
14. The method of claim 1, wherein transmitting the control signal comprises wirelessly transmitting the control signal from the controller of the MCS device to the feedback device.
15. The method of claim 1, wherein generating the alert signal comprises generating the alert signal when it is determined based, at least in part, on the one or more physiological signals, that the MCS device is not in a desired position within the heart of the patient.
16. (canceled)
17. The method of claim 1, wherein generating the alert signal comprises generating the alert signal when it is determined based, at least in part, on the one or more physiological signals, that the MCS device is in a desired position within the heart of the patient.
18. (canceled)
19. The method of claim 1, wherein monitoring one or more physiological signals associated with a heart of a patient within which the MCS device is placed is performed during insertion of the MCS device into the heart of the patient.
20. The method of claim 1, further comprising: determining that the MCS device is being repositioned in the heart of the patient without reducing a pump speed of the MCS device, wherein generating an alert signal is further based, at least in part, on the determination that the MCS device is being repositioned in the heart of the patient without reducing the pump speed.
21. The method of claim 20, where determining that the MCS device is being repositioned in the heart of the patient without reducing a pump speed of the MCS device comprises detecting a femoral arterial pulse while the MCS device is operating.
22. The method of claim 1, further comprising: receiving information associated with manipulation of the MCS device by the operator of the MCS device, wherein generating the alert signal is further based, at least in part, on the information associated with manipulation of the MCS device.
23. The method of claim 22, further comprising: training a machine learning (ML) model based on the information associated with manipulation of the MCS device to generate a trained ML model, wherein generating the alert signal is further based, at least in part, on an output of the trained ML model.
24. A mechanical circulatory support (MCS) device, comprising: a pump configured to be placed in a heart of a patient; a feedback device configured to provide sensory feedback to an operator of the MCS device; and a controller configured to: monitor one or more physiological signals associated with the heart of the patient during operation of the pump; generate an alert signal based, at least in part, on the monitored one or more physiological signals; and transmit in response to generating the alert signal, a control signal from the controller of the MCS to the feedback device, wherein the feedback device is configured to provide the sensory feedback based on the control signal.
25-27. (canceled)
28. The MCS device of claim 24, wherein generating the alert signal comprises generating the alert signal when it is determined based, at least in part, on the one or more physiological signals that the heart of the patient is in a systolic phase.
29-35. (canceled)
36. The MCS device of claim 24, further comprising: a catheter, wherein the feedback device is coupled to the catheter.
37-41. (canceled)
42. The MCS device of claim 24, wherein the controller is further configured to: determine that the pump is being repositioned in the heart of the patient without reducing a pump speed of the pump, wherein generating an alert signal is further based, at least in part, on the determination that the pump is being repositioned in the heart of the patient without reducing the pump speed.
43. (canceled)
44. The MCS device of claim 24, wherein the controller is further configured to: receive information associated with manipulation of the pump by the operator, wherein generating the alert signal is further based, at least in part, on the information associated with manipulation of the pump.
45. (canceled)
46. A controller for a mechanical circulatory support (MCS) device, the controller comprising: at least one hardware computer processor programmed to: generate an alert signal based, at least in part, on one or more physiological signals associated with a heart of a patient within which the MCS device is placed; and transmit, in response to generating the alert signal, a control signal to a feedback device, wherein the feedback device is configured to provide sensory feedback to an operator of the MCS device based on the control signal.
47-48. (canceled)
Description
BRIEF DESCRIPTION OF DRAWINGS
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
DETAILED DESCRIPTION
[0029] Transcatheter transvalvular pumps are increasingly adopted to provide hemodynamic support to patients with manifest or at the risk of reduced cardiac function. The transcatheter pump is typically inserted either through the femoral or axillary artery and introduced into the left ventricle through a transaortic retrograde route. Other heart pump types have been described to provide support to patients with right ventricle (RV) failure; in this scenario, the RV pump catheter is introduced either through the internal jugular or the femoral veins, through the central vasculature of the patient, and is finally positioned across heart valves spanning 2-3 heart chambers.
[0030] Pump insertion into the desired intra-cardiac position is typically achieved through a standard catheterization technique (e.g., access site might be either percutaneous or surgical), utilizing fluoroscopic imaging, and ultrasound imaging for position optimization.
[0031] Under certain disease conditions, patients may require prolonged support time with a mechanical cardiac support (MCS) device, such as a heart pump, beyond the time of the imaging guided procedure (e.g., percutaneous coronary intervention (PCI), surgery). In such instances, the patient is typically transferred, on-support, to the intensive care unit (ICU) or other units in the hospital facility where imaging support is not readily available. Under certain conditions of illness and/or prolonged support, the intra-cardiac pump may depart, unintentionally, from its originally-intended anatomical position in the patient's heart, thereby requiring repositioning to guarantee optimal support conditions. Such circumstances may arise from, for example, unintentional manipulation (push/pulls) of the extra-corporeal portion of the pump catheter causing the pump to exit its original position. Another situation could arise from development of acute decompensation of the left/right heart causing significant dilation of the affected chamber and loss of the catheter back-up support originally provided by cardiac structure prior to decompensation.
[0032] An operator who practices catheterization, including pump insertion is typically trained to receive information visually (from monitors, etc.) and to execute manipulation of the catheter manually based on visually received information. Despite being standard in cardiac catheterization, the above image-guidance is limited by the operator's (sensory followed by cortico-motoric) reaction time spanning the chain of receiving visual/auditory information, cortical processing and manual execution (typically in the form of holding, pushing or releasing the catheter). In certain clinical scenarios, this constitutes a critical delay especially when the operator is expected to execute manipulations of the catheter within milli-seconds time windows (e.g. Systolic phase of the cardiac cycle), during which the operator must notice the beginning of the systolic phase (e.g., from an EKG monitor), process and react in the form of catheter manipulation, prior to the end of the systolic phase.
[0033] The above scenario is one of several examples where an operator's reaction during catheterization must occur at ganglionic level and must bypass slower cortical processes. The following additional clinical scenarios can be presented, in which a swift imaging-free execution of the cascade of receiving physiological information, processing, and catheter execution would be desired: [0034] Transcatheter crossing of the aortic valve, into the left ventricle (LV): Especially in the case of wireless introduction an intra-cardiac catheter; the crossing of the aortic valve (AV) is only possible during systolic phase (when the AV is physiologically open). [0035] Repositioning of a transvalvular pump, originally located in intra-cardiac position, with the objective of optimizing pump position (e.g., into a transvalvular position). [0036] Catheter manipulation in clinical situations where no imaging is available (e.g., bedside pump optimization). [0037] Transcatheter intracoronary recanalization utilizing mechanical or laser means. [0038] Cardiac electrophysiologic ablation. [0039] Clinical scenario in which repositioning of an intra-cardiac pump is required, and pump operation must be reduced/minimized during the repositioning maneuver.
[0040] Some embodiments of the present disclosure relate to methods and apparatus for communicating physiological (e.g., hemodynamic) information to an extra-corporeal portion of a catheter by providing the operator with sensory feedback (e.g., tactile feedback) that can be detected by the operator while manipulating the extra-corporeal portion of catheter. As described in further detail below, in some embodiments, the sensory feedback may be provided on the catheter itself or via a device coupled to the catheter. In other embodiments, the sensory feedback may be provide on a wearable device (e.g., a bracelet, a watch, a ring, an in-ear insert) in wireless communication with a controller of the MCS device.
[0041] A pump system 100 for use with some embodiments of the present technology is shown in
[0042] Control unit 200 includes one or more memory 202, one or more processors 204, user interface 206, and one or more current sensors 208. Processor(s) 204 may comprise one or more microcontrollers, one or more microprocessors, one or more application specific integrated circuits (ASICs), one or more digital signal processors, program memory, or other computing components. Processor(s) 204 is communicatively coupled to the other components (e.g., memory 202, user interface 206, current sensor(s) 208) of control unit 200 and is configured to control one or more operations of pump 100. As a non-limiting example, control unit 200 may be implemented as an Automated Impella Controller from ABIOMED, Inc., Danvers, MA. In some aspects, memory 202 is included as a portion of processor(s) 204 rather than being provided as a separate component.
[0043] During operation, processor(s) 204 is configured to control the electrical power delivered to motor 150 (e.g., by controlling a power supply (not shown)) by a power supply line (not shown) in cable 140, thereby controlling the speed of the motor 150. Current sensor(s) 208 may be configured to sense motor current associated with an operating state of the motor 150, and processor(s) 204 may be configured to receive the output of current sensor(s) 208 as a motor current signal. Processor(s) 204 may further be configured to determine a flow through the pump 100 based, at least in part, on the motor current signal and the motor speed, as described in more detail below. Current sensor(s) 208 may be included in control unit 200 or may be located along any portion of the power supply line in cable 140. Additionally or alternatively, current sensor(s) 208 may be included in motor 150 and processor(s) 204 may be configured to receive the motor current signal via a data line (not shown) in cable 140 coupled to processor(s) 204 and motor 150.
[0044] Memory 202 may be configured to store computer-readable instructions and other information for various functions of the components of control unit 200. In one aspect, memory 202 includes volatile and/or non-volatile memory, such as, an electrically erasable programmable read-only memory (EEPROM).
[0045] User interface 206 may be configured to receive user input via one or more buttons, switches, knobs, etc. Additionally, user interface 206 may include a display configured to display information and one or more indicators, such as light indicators, audio indicators, etc., for conveying information and/or providing alerts regarding the operation of pump 100.
[0046] Pump 100 is designed to be insertable into a patient's body, e.g., into a left ventricle of the heart, with an introducer system. In one aspect, housing 104, rotor 108, and outflow tube 106 are radially compressible to enable pump 100 to achieve a relatively small outer diameter of, for example, 9 Fr (3 mm) during insertion. When pump 100 is inserted into the patient, e.g., into a left ventricle, handle 130 and motor 150 remain disposed outside the patient. It should be appreciated that in other embodiments, motor 150 may be inserted into the patient (e.g., by being located onboard the pump 100). During operation, motor 150 is controlled by processor(s) 204 to drive rotation of drive shaft 114 and rotor 108 to convey blood from inlet 116 to outlet 118. It is to be appreciated that rotor 108 may be rotated by motor 150 in reverse to convey blood in the opposite direction (in this case, the openings of 118 form the inlet and the openings of 116 form the outlet). In one aspect, pump 100 is intended to be used during high-risk procedures for a duration of up to six hours, up to one day, up to one week, up to two weeks, up to one month, etc., though it should be understood that the technology described herein is not limited to any particular types of procedures and/or use durations.
[0047] As described above, some embodiments of the present disclosure relate to a system and methods for providing sensory feedback to an operator tasked with positioning a mechanical circulatory support (MCS) device (e.g., pump 100) within a heart of a patient by manipulating a catheter (e.g., catheter 120) associated with the pump. Such sensory feedback may facilitate initial placement or repositioning of the pump within the heart of the patient into a desired position (e.g., across the aortic valve for a left-side device). In some embodiments, sensory feedback may be provided to an operator of an MCS device to alert the operator to take certain actions, such as reducing the speed of the pump prior to repositioning and/or removing the pump from the heart of the patient. Sensory feedback may be provided for any other suitable reason, examples of which are discussed in further detail herein.
[0048]
[0049]
[0050]
[0051] A feedback device for providing sensory feedback to an operator of an MCS device in accordance with the techniques described herein may be configured to receive control signals from another device (e.g., a controller of the MCS device, a processor in communication with the controller of the MCS device). For instance, when implemented as a wearable device, the feedback device may include a wireless communication interface configured to wirelessly receive control signals from the controller of the MCS device and to provide sensory feedback to the operator in response to receiving the control signals. In some embodiments, the feedback device may be configured to provide sensory feedback to the operator based on a configuration of the feedback device and/or operator preferences stored in an operator profile.
[0052]
[0053] In some embodiments, an alert event may represent that the blood pump is not in a desired position within the heart of the patient. For example, a desired position of a left-side MCS device may be such that the inlet of the pump resides in the left ventricle and the outlet of the pump resides in the aorta such that blood is pumped through the aortic valve. Some MCS devices may include one or more pressure sensors configured to sense the pressure at the inlet, the outlet, or both the inlet and the outlet of the MCS device. Pressure signals sensed by the pressure sensor(s) may be used to determine the position of the MCS within the patient's heart.
[0054] For instance, when the pump is located entirely within the left ventricle, the differential pressure between the inlet and outlet may be zero (or close to zero) indicating that the pump is not properly positioned across the aortic valve. When such a situation occurs, an alert event may be detected in act 312, and a control signal may be transmitted to the feedback device in act 314 to provide sensory feedback to the operator. In some embodiments, the control signal transmitted to the feedback device may be the same regardless of the type of alert event detected. In other embodiments, information about the type of alert event may be coded in the control signal transmitted to the feedback device. By coding alert event type information into the control signal, the feedback device may provide different types of sensory feedback for different types of detected alert events. For instance, the different types of sensory feedback may include different vibratory stimulus sequences and/or intensities, different modalities of sensory feedback or combinations thereof.
[0055] In some embodiments, detecting that the MCS device is not in a desired position may include one or more of the following scenariosthe catheter is fully in the ventricle, the catheter is in close proximity to ventricular structure, including mitral valve leaflets, cordae, or papillary muscles, the catheter is in close proximity to aortic valve structure, including aortic valve leaflets, the catheter is fully in the aorta, or the catheter is fully in arterial tree
[0056] It should be appreciated that detecting that the pump is not in a desired position is merely one example of an alert event that can be detected using one or more of the techniques described herein. For instance, an alert event may be detected when, during manipulation of the catheter, the pump is detected to be in a desired position to inform the operator to cease manipulation of the catheter. In other instances, an alert event may be detected when it is determined that the catheter is being withdrawn from the heart of the patient, but that the pump speed has not been reduced. As such, it should be appreciated that in addition to physiological signals associated with the patient, one or more signals (e.g., pump speed, motor current, etc.) associated with operation of the MCS device may in some embodiments, be taken into consideration when determining in act 312 whether an alert event is detected.
[0057] In some embodiments, the inventors have recognized that it may be useful to identify to the operator during manipulation of the catheter, a timing of the systolic phase of the patient's cardiac cycle. To properly position a left side MCS device across the aortic valve, the pump must traverse the aortic valve when it is open (during systole). Using conventional techniques, the operator may rely on trial and error to advance the pump past the aortic valve. Alternatively, the operator may view the EKG waveform and/or one or more pressure signals displayed on a display in an attempt to identify the start of the systolic phase of the patient's cardiac cycle. However, due to the time needed for the operator's brain to process the displayed signals (e.g., using cortical processing), it is often challenging for the operator to react in sufficient time to advance the pump during the relatively short systolic phase. Some embodiments of the present disclosure process one or more physiological signals for a patient to detect the beginning of the systolic phase of the patient's cardiac cycle as an alert event. In such instances, sensory feedback may be provided to the operator with considerably shorter lag time compared to the conventional visual processing techniques described above.
[0058] Returning to process 300 shown in
[0059] The inventors have recognized and appreciated that there is variability between operators in how they perform catheter manipulation, and that it may be helpful to train a model (e.g., a machine learning (ML) model) such that the model is tuned to the behavior of an individual operator to provide personalized predictions regarding alert events. The output of the trained model may then be used to adjust the timing of providing the sensory feedback to a particular operator, which may further facilitate the operator's understanding of how to manipulate the catheter. For instance, continuing with the example of analyzing one or more physiological signals to detect the onset of the systolic phase of a patient's cardiac cycle, a timing of transmitting a control signal to the feedback device may be adjusted based, at least in part, on an operator's behavior (e.g., reaction time) when receiving the sensory feedback. In this way, the system may learn how different operators perform catheter manipulation, which may in turn be used to facilitate catheter manipulation operations to achieve proper placement of an MCS device in a patient.
[0060] In some embodiments the timing of providing the sensory feedback may adjusted based on other factors. For instance, the timing of providing the sensory feedback may be adjusted based on data acquisition delays introduced by a patient device or monitor, which provides the physiological signals for processing. As another example, the timing of providing the sensory feedback may be adjusted based on data communication delays introduced by wired or wireless communications in various components of the data communication system and/or data processing delays introduced by one or more data processing components. As yet further examples, the timing of providing the sensory feedback may be adjusted based on one or more of a Visual Reaction Time (VRT) of the operator when visual sense is used to perform the task (e.g., catheter manipulation), Audible Reaction Time (ART) of the operator when audio sense is used to perform the task, Tactile Reaction Time (TRT) of the operator when tactile sense is used to perform the task, or a combination VRT, ART, and TRT when a combination of Visual, Audible and Tactile senses are used to perform the task.
[0061] In some embodiments of the present disclosure, sensory feedback may cease to be provided when the sensory feedback system enters a particular mode. For example, the system may stop providing the operator with systolic pulse stimulation when one or more of the following takes place: the pump is detected to be in the correct position, arrythmia is detected, a suction condition is detected, or a clot ingestion signature is detected. In some embodiments, sensory feedback associated with systolic phase detection may be initiated in response to an operator-initiated request and/or the pump is detected to be in the aorta.
[0062]
[0063]
[0064]
[0065] Sensory feedback system 700 includes controller 720 configured to control a heart pump 702 coupled thereto. An operator 710 may insert the heart pump 702 into the heart of a patient using a catheter 712 and a catheter introducer 704. An example of inserting a heart pump into the heart of a patient is described herein in connection with
[0066] As shown in
[0067] The above-described embodiments can be implemented in any of numerous ways. One or more aspects and embodiments of the present disclosure involving the performance of processes or methods may utilize program instructions executable by a device (e.g., a computer, a processor, or other device) to perform, or control performance of, the processes or methods. In this respect, various inventive concepts may be embodied as a computer readable storage medium (or multiple computer readable storage media) (e.g., a computer memory, one or more floppy discs, compact discs, optical discs, magnetic tapes, flash memories, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement one or more of the various embodiments described above. The computer readable medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computers or other processors to implement various ones of the aspects described above. In some embodiments, computer readable media may be non-transitory media.
[0068] The above-described embodiments of the present technology can be implemented in any of numerous ways. For example, the embodiments may be implemented using hardware, software or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. It should be appreciated that any component or collection of components that perform the functions described above can be generically considered as a controller that controls the above-described function. A controller can be implemented in numerous ways, such as with dedicated hardware, or with general purpose hardware (e.g., one or more processor) that is programmed using microcode or software to perform the functions recited above, and may be implemented in a combination of ways when the controller corresponds to multiple components of a system.
[0069] Further, it should be appreciated that a computer may be embodied in any of a number of forms, such as a rack-mounted computer, a desktop computer, a laptop computer, or a tablet computer, as non-limiting examples. Additionally, a computer may be embedded in a device not generally regarded as a computer but with suitable processing capabilities, including a Personal Digital Assistant (PDA), a smartphone or any other suitable portable or fixed electronic device.
[0070] Also, a computer may have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible formats.
[0071] Such computers may be interconnected by one or more networks in any suitable form, including a local area network or a wide area network, such as an enterprise network, and intelligent network (IN) or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks, wired networks or fiber optic networks.
[0072] Also, as described, some aspects may be embodied as one or more methods. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments.
[0073] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms.
[0074] The indefinite articles a and an, as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean at least one.
[0075] The phrase and/or, as used herein in the specification and in the claims, should be understood to mean either or both of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with and/or should be construed in the same fashion, i.e., one or more of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the and/or clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to A and/or B, when used in conjunction with open-ended language such as comprising can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.
[0076] As used herein in the specification and in the claims, the phrase at least one, in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase at least one refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, at least one of A and B (or, equivalently, at least one of A or B, or, equivalently at least one of A and/or B) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.
[0077] Also, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of including, comprising, or having, containing, involving, and variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
[0078] In the claims, as well as in the specification above, all transitional phrases such as comprising, including, carrying, having, containing, involving, holding, composed of, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases consisting of and consisting essentially of shall be closed or semi-closed transitional phrases, respectively.
[0079] Use of ordinal terms such as first, second, third, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.