SYSTEM AND METHOD FOR NON-INVASIVE AUTONOMIC NERVE ACTIVITY MONITORING USING ARTIFICIAL INTELLIGENCE
20240299754 ยท 2024-09-12
Assignee
Inventors
Cpc classification
G16H20/30
PHYSICS
G16H50/20
PHYSICS
G16H20/40
PHYSICS
A61N1/36514
HUMAN NECESSITIES
G16H20/10
PHYSICS
A61N1/3627
HUMAN NECESSITIES
A61B5/4836
HUMAN NECESSITIES
G16H50/70
PHYSICS
International classification
Abstract
A method of therapeutically treating a subject includes the steps of: sensing sympathetic nerve activity; communicating the sensed sympathetic nerve activity to a processor; using machine learning in the processor to identify input data sets correlated to a physiological end point in the subject by processing the input data input sets to experientially optimize an algorithmically defined physiological goal defined in output data sets by the machine learning; and dynamically controlling a therapeutic device in real time with the processor using the output data sets to treat the subject mediated by the therapeutic device by establishing or tending to establish the physiological end point in the subject.
Claims
1-34. (canceled)
35. A method for modifying a therapeutic device setting, the method comprising: receiving a first sympathetic nerve activity signal (SNA) signal, the first SNA signal being generated by an SNA sensor; receiving a physiological endpoint; providing the first SNA signal and the physiological endpoint to a machine learning model trained to output a subset of the first SNA signal based on the physiological endpoint; receiving the subset of the first SNA signal output from the machine learning model; determining a first current physiological state based on the subset of the first SNA signal; determining the therapeutic device setting based on the first current physiological state and the physiological endpoint; and causing a therapeutic device to be modified based on the therapeutic device setting.
36. The method of claim 35, further comprising: receiving a second SNA signal, the second SNA signal being generated by the SNA sensor; providing the second SNA signal and the physiological endpoint to the machine learning model; receiving a subset of the second SNA signal output by the machine learning model based on the second SNA signal and the physiological endpoint; and determining a second current physiological state based on the subset of the second SNA signal.
37. The method of claim 36, further comprising training the machine learning model based on the first current physiological state and the second current physiological state.
38. The method of claim 36, further comprising: determining an updated therapeutic device setting based on the second current physiological state and the physiological endpoint; and causing the therapeutic device to be modified based on the updated therapeutic device setting.
39. The method of claim 35, wherein the subset of the first SNA signal excludes portions of the first SNA signal collected during a blanking period.
40. The method of claim 39, wherein the blanking period corresponds to a duration of time during which the therapeutic device outputs an electrical impulse.
41. The method of claim 35, wherein the physiological endpoint is a target blood pressure.
42. The method of claim 41, wherein the target blood pressure is one of a systolic blood pressure, diastolic blood pressure, or mean arterial pressure.
43. The method of claim 35, wherein the SNA sensor is associated with a wearable device.
44. The method of claim 35, wherein receiving the first SNA signal further comprises: receiving a sensed SNA signal; amplifying the sensed SNA signal to generate an amplified sensed SNA signal; and processing the amplified sensed SNA signal using a band pass filter to generate the first SNA signal.
45. A system comprising: a memory configured to store processor-readable instructions; and a processor operatively connected to the memory, and configured to execute the instructions to perform operations that include: receiving a first sympathetic nerve activity signal (SNA) signal, the first SNA signal being generated by an SNA sensor; receiving a physiological endpoint; providing the first SNA signal and the physiological endpoint to a machine learning model trained to output a subset of the first SNA signal based on the physiological endpoint; receiving the subset of the first SNA signal output from the machine learning model; determining a first current physiological state based on the subset of the first SNA signal; determining a therapeutic device setting based on the first current physiological state and the physiological endpoint; and causing a therapeutic device to be modified based on the therapeutic device setting.
46. The system of claim 45, wherein the operations further include: receiving a second SNA signal, the second SNA signal being generated by the SNA sensor; providing the second SNA signal to the machine learning model; receiving a subset of the second SNA signal output by the machine learning model based on the second SNA signal and the physiological endpoint; and determining a second current physiological state based on the subset of the second SNA signal.
47. The system of claim 46, wherein the operations further include training the machine learning model based on the first current physiological state and the second current physiological state.
48. The system of claim 46, wherein the operations further include: determining an updated therapeutic device setting based on the second current physiological state and the physiological endpoint; and causing the therapeutic device to be modified based on the updated therapeutic device setting.
49. The system of claim 45, wherein receiving the first SNA signal further comprises: receiving a sensed SNA signal; amplifying the sensed SNA signal to generate an amplified sensed SNA signal; and processing the amplified sensed SNA signal using a band pass filter to generate the first SNA signal.
50. A method for modifying a therapeutic device setting, the method comprising: receiving input signals comprising a sympathetic nerve activity signal (SNA) and an electrocardiogram activity (ECG) signal; providing the SNA signal and the ECG signal to a machine learning model trained to output a subset of the SNA signal based on the ECG signal; receiving the subset of the SNA signal output from the machine learning model; receiving a physiological endpoint; determining a first current physiological state based on the subset of the SNA signal; determining the therapeutic device setting based on the first current physiological state and the physiological endpoint; and causing a therapeutic device to be modified based on the therapeutic device setting.
51. The method of claim 50, wherein the subset of the first SNA signal excludes portions of the SNA signal collected during a blanking period.
52. The method of claim 51, wherein the blanking period corresponds to a duration of time during which the therapeutic device outputs an electrical impulse.
53. The method of claim 51, wherein the machine learning model is configured to determine the blanking period based on the ECG signal.
54. The method of claim 51, wherein the SNA signal is generated at a first sensor and the ECG signal is generated at a second sensor.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0037]
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[0040]
[0041]
[0042]
[0043]
[0044] The disclosure and its various embodiments can now be better understood by turning to the following detailed description of the preferred embodiments which are presented as illustrated examples of the embodiments defined in the claims. It is expressly understood that the embodiments as defined by the claims may be broader than the illustrated embodiments described below.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045]
A. Signal Extraction.
[0046] Before turning to the illustrated embodiments of the invention, first consider the prior art approach in more general terms. Chen et al. reasoned that the output of the sympathetic nervous system should be responsible for cardiac rhythm disturbances, and therefore that modulating it in some way could be therapeutic. What was first needed was a means to measure the sympathetic nervous system output and the prior art looked at the well-known galvanic skin response for this output. To do so, one or more conductive pads are placed against the skin to register electrical potentials that are proportional to known higher level stimuli, such as stress or a change in temperature. The signals are amplified and sampled. The question then becomes if a particular wave length of that sympathetic nervous system outflow correlated with stimuli related to various bodily functions. The signal is highly complex with many layers of noise. Chen used conventional band pass technology to sequentially filter out one noise layer at a time until he arrived at a signal waveform that reproducibly correlated with a physiologic endpoint of interest. That particular combination of sequentially applied band pass filters is the basis of U.S. Pat. No. 10,448,852. Electromagnetic signals are characterized not only by amplitude, but by frequency. The band pass filters are gated by frequency and amplitude is the gain.
[0047] An analogy helps to explain how we can significantly improve the prior art technology. The search for extra-terrestrial intelligence (SETI) is in many ways the same process, sifting through layers of electromagnetic waves trying to find something unique or intelligible. The original approach was to use layered band pass filters to dissect out discrete wavelengths as the prior art has done with nerve activity.
[0048] Turning to
[0049] AI or digital filtering/processing techniques are also used to create a blanking period during the pacemaker initiated electric signals, which are orders of magnitude (volts) larger than cardiac signals (mV) and the yet smaller sympathetic nerve signals (0.02-.08 mV) which are about one tenth the amplitude of the cutaneous ECG signal. The relevant analysis that we perform blanks or ignores a window that is about 0.4-1.0 msec in duration, i.e. the typical pulse width of a pacemaker impulse. Also, our hypothesis is that cutaneous recording of nerve activity mirrors stellate ganglion nerve activity, and hence is a reliable measure of sympathetic tone.
[0050] The known method of finding a wavelength of interest can be expressed as:
Wavelength of interest, W.sub.i=W.sub.total (all measurable existing wavelengths)?W.sub.1 (first wavelength not of interest)?W.sub.2?W.sub.3- . . . -W.sub.n (all various wavelengths bearing noise)A.
[0051] A Machine Learning method can be expressed as:
W.sub.total.fwdarw.Machine Learning algorithm.fwdarw.W.sub.iB.
[0052] Machine learning (ML) relates to the use of computer algorithms that improve automatically through experience. It is seen as a subset of artificial intelligence. Machine learning algorithms build a model based on sample data, known as training data, in order to make predictions or decisions without being explicitly programmed to do so. Machine learning algorithms are used in a wide variety of applications, such as email filtering and computer vision, where it is difficult or unfeasible to develop conventional algorithms to perform the needed tasks. The detailed operation of what takes place in the machine learning black box processor may be currently poorly understood in detail, but it is characterized by a relentless experimentation with or training of the data input sets to optimize an algorithmically defined goal defined in output data sets. The analysis process externally is fairly basic. Feed the black box a sample of a desired data output, such as a fall in blood pressure, plus the data input set, W.sub.total. Then give the machine-learning black box or program access to all possible filters or other data processing tools, and allow the machine-learning program to process the input data signals until it learns which combination yields the highest probability of finding the wavelength(s) (W.sub.i) that correlates with a physiological endpoint of interest, such as blood pressure.
[0053] This control method is very different than prior methods which are based on physician derived alarms relative to predefined baselines of nerve activities. The prior method is a physician-defined parametrically controlled method by which an alarm is generated when a previously defined data parameter is exceeded to prompt physician intervention or automatic dispensation by a drug pump. Moreover, it is possible that the nervous system output (W.sub.i) which needed the correct data input sets are not the same as those that the prior art identifies using a combination of filters.
[0054] According to the illustrated embodiments of the current invention, the input data sets, W.sub.i, needed or useful for blood pressure is or are different than the input data sets, W.sub.i, for cardiac arrhythmias. The needed input data sets, W.sub.i, will likely be not one wavelength, but a specific combination of a family of wavelengths that describe an individual effect, such as lowering blood pressure as opposed to a decrease in atrial action potential threshold or other cardiac parameter.
B. Making Use of the Extracted Signal, W.SUB.i
[0055] Once the artificial intelligence identifies the W.sub.i for blood pressure, then the task becomes how to use it. At each discrete point in the therapeutic algorithm, besides the need to make decisions very rapidly, there are too many possible permutations of the data set to make that decision linearly or by conventional medical analysis by a physician.
[0056] Suppose at any moment in time a subject's physiologic state is characterized by the subject's blood pressure, systolic and diastolic, the heart rate, and the sympathetic nerve activity output (W.sub.i). Some combination of that input data will be used to decide whether to increase heart rate, decrease it or leave it the same using a pacemaker. In addition, that decision will be made by comparing the instantaneous data to archived data that is continuously updated in order to determine the unique parameter set that is most likely to result in the desired physiologic response at a moment in time. Added to this is the complexity of exercise which requires a different blood pressure response than the steady state blood pressure. The possible permutations of input data sets would be a long multiplication function of the discrete variables, each with three possible endpoints. Artificial intelligence is the only practical method to sort out the solution from the characterizing input data sets.
[0057] Current pacemakers use two sensor inputs to know when the patient has begun exercise and when rate modulation should be activated, specifically these sensor inputs are provided by a motion sensor and a respiratory rate monitor which senses diaphragmatic movement. Exercise also increases the sympathetic nervous system output and is a further indicator of exercise. Current rate modulation is programmed empirically. The device only self-adjusts for different levels of activity on the basis of the degree of motion reported by the motion sensor, or how fast the subject is breathing, and only then within the empirically pre-determined ranges for several physiologic variables, including but not limited to: heart rate acceleration with exercise, heart rate deceleration after exercise, and maximum and minimum heart rate.
[0058] The industry has failed to consider modifying the rate modulation to include machine learning, whereby the pacemaker contains a machine learning software subroutine that learns the patient's exercise profile and then updates the rate modulation programming on the fly. Current rate modulation is adjusted in the doctor's office and not in the pacemaker. Such a pacemaker method is greatly enhanced if it also includes blood pressure regulation.
[0059] AI as described above is used to sort out the nervous system output from either a skin sensor or from the passive phase of the pacemaker electrodes between heart beats via wavelength filter combination found by the AI that best correlates with exercise intensity. Using AI to identify a unique wavelength or add a frequency filter combination to measure sympathetic nervous system output for rate modulation of a pacemaker is a problem solving approach which materially modifies the prior art approach. The identified wavelength filter combination is then usable to treat DRH and HFpEf using PressurePace.sup.AI as defined in PCT/US19/59703 incorporated herein by reference. Using AI to find the unique or best wavelength filter combination to know when the patient with a pacemaker is exercising, and how intense the exercise is to improve basic pacemaker rate modulation comprises a material advance in the art.
[0060] Further, using the electrically quiet period between heartbeats, when the pacemaker is not pacing, to measure nearby autonomic nervous system activity by the same method used for a skin sensor according to prior art is an improved insight into pacing not previously practiced.
[0061] Using Machine Learning/AI to define the input data sets, W.sub.i, and process them for a complex physiologic endpoint used in a real-time dynamic manner defines a significantly new and important improvement needed to make the prior art Chen system and method useful and to realize its potential capability.
[0062] It can now be appreciated that the above disclosed embodiments are an improvement over the art in that the method of sensing sympathetic nerve activity is performed using machine learning/AI, which has the added advantage of considering all possible combinations of, and all possible sequencing of the filtering process, including using more than one filter combination in short sequences. The method and apparatus of the disclosed embodiments process raw data derived from surface or skin electrodes that sample the electrical signals sensed from central nervous system activity in response to a known stimulus, and determine one or more unique electrical frequencies or wavelengths using AI/machine learning algorithms to monitor the response, calibrate it, and form the basis of feedback inhibition to the nervous system. The disclosed embodiments create a real-time dynamic autonomous feedback loop that continually adjusts nervous system feedback inhibition for an optimal effect.
[0063] The disclosed embodiments can also use and record non-electrical signals, such as sound or heat signatures, to induce or calibrate a nervous system response for the purpose of detecting and/or calibrating a feedback inhibition for a defined therapeutic effect.
[0064] The disclosed embodiments use a cardiac electrode which could be an ECG-like electrode on the skin, or one of the pacemaker leads internally, as the sensing or stimulating element and apply the stimulus during the quiet period of the cardiac cycle, either with predetermined timing, or several stimuli in sequence using the BaroPace? algorithm. Hence, the disclosed embodiments employ the BaroPace? stimulus architecture algorithm to deliver an optimal frequency, amplitude, timing, and sequence of multiple stimuli. For example, an optimal magnitude of an individual stimulus is either a pacing level stimulus, or a sub-threshold stimulus, which is performed in a combination in a predetermined sequence, such as first a supra threshold stimulus followed by a subthreshold stimulus during the quiet period.
[0065] The disclosed embodiments provide for cardiac pacing via a standard pacing electrode or newly design pacing electrode adapted to sympathetic nerve stimulation or near-cardiac ganglia to apply a pacing stimulus at a subthreshold amplitude alone or in combination with other pacing stimuli, or a subthreshold stimulus to produce nervous system inhibition, or a non-nervous system effect such as stimulated release of atrial naturietic peptide or other tissue factor related to a hemodynamic effect. The prior art discussed above assumes that the result of their ganglionic stimulus method is a nervous system feedback. The disclosed embodiments contemplate a feedback that is not related to the nervous system.
[0066] The disclosed embodiments illustrate how to adjust stimulus strength and stimulus architecture or protocols to produce an optimal feedback effect for a specific endpoint that is not cardiac rhythm disturbances, such as a reduction in blood pressure.
[0067] The disclosed embodiments add or layer more than one sensor input or add more than one type of stimulation using artificial intelligence to one or more locations on the body using one or more types of stimuli. The central nervous system is inhibited in response to more than one stimuli or inputs, which include blood pressure and the patient's subjective report of symptoms.
[0068] The disclosed embodiments control cardiac pacemaker rate modulation by adding a new measure of exercise intensity via monitoring of the central nervous system which does not involve stimulation, instead uses a filtered signal that measures the degree of exercise intensity in a quantitative manner without the inhibition of the nervous system.
[0069] Thus, it can be understood that the disclosed embodiment use monitoring nervous system activity to treat DRH and/or HFpEF in combination with BaroPacing or what is defined as PressurePace AI using the disclosed trend analysis, or Stimulus Architecture Algorithm (SAA), as defined and disclosed in An Intelligently, Continuously And Physiologically Controlled Pacemaker And Method Of Operation Of The Same, International Pat. App. PCT/US20/25447; and Method of Treatment of Drug Resistant Hypertension by Electrically Stimulating the Right Atrium to Create Inhibition of the Autonomic Nervous System, International Pat. Appl., PCT/US20/44784, incorporated herein by reference.
[0070] It can also now be appreciated that the treatment of cardiac arrhythmias is improved using the improvements ofthe disclosed embodiments described above.
[0071] A substantial improvement in cardiac treatments is obtained by combining the nervous system sensing of the discussed prior art with BaroPacing to treat a patient including the use of a class of drugs, that without BaroPacing does not produce a therapeutic response. At the same time this improvement includes the elimination of one or more drug classes that currently are in use to further improve treatment benefits. For example, treating a patient with ACEI/ARB provides a therapeutic drug effect not present without BaroPacing, and removes the adverse effects on heart rate modulation experienced with beta blockers, which are eliminated from the treatment protocol.
[0072] The illustrated embodiments also extend to sensing the activity of the parasympathetic or autonomous nervous system (ANS), specifically including the vagal nerve, either from a peripheral (skin or otherwise) sensor, or directly from an electrode in or near the heart, such as a pacemaker lead or other in vivo sensing element connected internally or externally to the pacemaker.
[0073] Turning to
[0074] A Bluetooth data link for the sensor to an app or between a satellite bracelet app and a smartwatch or other repository of the processing software is subject to a 300-millisecond transfer delay in the Bluetooth signal. Thus, instead of a Bluetooth data signal, radio waves of higher frequency with no delay may need to be used, which is conventional with the realtime transmission of ECG signals.
[0075] Before considering the system in greater detail, first turn your attention to the peripheral sensor station 30 to monitor the central nervous system activity as schematically illustrated in
[0076] The added peripheral sensors 30 have processing capabilities as shown in
[0077] Another embodiment could add a third sensor of the same type as the wrist bracelet 30 for use on the ankle to further increase three-dimensional signal acquisition.
[0078] Another embodiment could add an AI module in the system of
[0079] Consider now how the process would be performed as shown in
[0080] Return now and consider the system of
[0081] In the first method of calibration, a calibration signal of known amplitude, frequency, and ECG-timing is sent to a pre-amplifier 36 through signal input receiver 46 shown in
[0082] In the second method of calibration, a subject or patient with a known physiologic marker of interest, such as hypertension or atrial fibrillation is monitored by the functioning system and the system collects full spectral data, which is archived. The archived data is processed by the AI module 40 using machine learning. Machine learning correlates the desired physiologic or electrocardiographic marker with the spectral data, sifting out the signal properties that best correlate with the presence of that signal in a quantifiable manner. The filter combination/sequence of array 38 that best extracts the signal of interest becomes the filter combination/sequence for the subject patient, or can be preselected for other subjects searching for the quantifiable presence of electrocardiographic timing of the same marker omitting the calibration process for the new subject.
[0083] Consider now the methodology in greater detail. The basic system is comprised of a smart watch 28 with a skin electrode similar to an ECG electrode and one or more peripheral sensors 30 wirelessly linked thereto. In the preferred embodiment, the smart watch 28 functions as the primary sensor platform with one peripheral sensor 30, such as a bracelet worn on the opposite wrist as shown in
[0084] For an individual patient, system functioning can commence as disclosed above in the first calibration type based on a standard input calibration signal. The second calibration type is followed in the same individual patient by autonomous function using the previously derived optimal filter combination/sequence of array 38 corresponding to that patient, or using an autonomous function in a separate subject based on a filter sequence that is pre-selected.
[0085] By way of review, the method performed by the system of
[0086] In addition to the foregoing, turn now to consider how the methodology of PressurePace integrates with standard rate pacemaker modulation, or prior art rate modulation protocols used in pacemakers. Rate-modulated pacing is an advancement in pacing technology that has opened the way for the development of a wide variety of pacemaker generators and pacing modes. Rate-modulated pacemakers use a physiologic sensor other than the sinus node, namely the intrinsically occurring or natural heartbeat. The sinus node (SN) is not a sensor. When it is working the SN generates an electrical pulse that begins propagating through the cardiac tissues from top to bottom and right to left causing a sequential heart beat to adjust the pacing rate according to the physiologic needs of the patient. As rate-modulated pacemakers become more widely used, those caring for patients with these devices need to understand pacing physiology as well as rate-modulated pacing technology to provide optimal patient care.
[0087] When using the disclosed system with exercise, the simplest iteration of our PressurePace technology is to have the software off or inactive when the patient is at rest, and active when exercise/exertion is sensed. A later iteration is to have the system active during rest as well, but likely with a different pacemaker right atrial pressure (RAP) control algorithm for long-term blood pressure regulation.
[0088] There are two different subsets of patients to which the disclosed system is advantageously applied. One group has standard rate modulation turned on all the time, and we turn it off and replace it with PressurePace rate modulation or a blend the two, when our system or ANS discrimination becomes active. This results in a pacemaker sensor-driven by RAP with a blood pressure regulation higher in the control hierarchy with PressurePace taking over when exercise begins. We define this as blended hierarchal software with PressurePace in the primary control position.
[0089] There is a second group of patients where the physician has the rate modulation already off. In such patients the disclosed system turns the rate modulation back on, with the RAP controlled by again by a blended system. In this instance, however, because the rate modulation was previously off, we don't know in advance what the correct rate modulation settings will be. One solution is to have the software activate in phases. For instance, start with PressurePace off, and standard rate modulation on, but in the learning mode. The subject exercises by walking and the system learns the range of rate modulation settings available. Then PressurePace is added and it picks the RAP best suiting the blood pressure within the previously defined range of rate modulation settings blending or alternating the application of the two rate modulation algorithms.
[0090] The invention may be exploited in another embodiment wherein a high fidelity mobile monitor, senses the ANS signals and stores them, along with other data parameters, like conventional ECG signals, and/or with patient noted events, like exercising, sleeping, stress or the like. The mobile monitor is similar to a Holter monitor used to record ECG signals for a cardiac study of a patient, but in this embodiment, the mobile monitor must be capable of accurately recording signals with a frequency range of 1 Hz-5000 Hz as taught be Chen U.S. Pat. No. 10,448,852, whereas ECG signals. ANS signals generally are in the range of hundreds of Hz to several kHz. The recorded ANS signals are then communicated to the cardiologist's office or the monitor brought in to be downloaded into a computer, where the recorded ANS signals are then processed with the filtration techniques and AI described above to generate a pacemaker control algorithm, which is then uploaded into the patient's pacemaker. The process can be repeated daily to derive an optimal algorithm for the patient using an AI analysis of the recorded filtered ANS and cardiac data until the cardiac or vascular goal is reached. In this manner, a conventional programmable pacemaker not having the filtration circuitry or AI capabilities of the BaroPace AI algorithm can be programmed to become functionally equivalent in operation to the BaroPace AI algorithmic pacemakers described above.
[0091] Many alterations and modifications may be made by those having ordinary skill in the art without departing from the spirit and scope of the embodiments. Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the embodiments as defined by the following embodiments and its various embodiments.
[0092] For example, there are a number of different storage media possible for the sensed and recorded data sets, such as a chip worn under a bandage. The potential uses are far more than that expressly disclosed above. The above technology can be adapted for use in law enforcement in relation to lie-detector methodology, which currently employs the more simple galvanic skin response. ANS sensing could be adapted to the same kind of application.
[0093] Further, the technology disclosed above could be used as part of a pharmaceutical screening tool to test drugs thought to influence the sympathetic nervous system. Examples include beta adrenergic blocking drugs of various flavors, some anti-depressants, and/or cardiac anti-arrhythmic drugs to monitor the potential negative influence of all manner of drugs on the GI track where excess sympathetic or parasympathetic stimulation can adversely affect gut motility, acid secretion, etc.
[0094] The technology disclosed above is usable as an adjunct to EEG for seizure diagnosis and therapeutic monitoring.
[0095] Therefore, it must be understood that the illustrated embodiment has been set forth only for the purposes of example and that it should not be taken as limiting the embodiments as defined by the following claims. For example, notwithstanding the fact that the elements of a claim are set forth below in a certain combination, it must be expressly understood that the embodiments includes other combinations of fewer, more or different elements, which are disclosed in above even when not initially claimed in such combinations. A teaching that two elements are combined in a claimed combination is further to be understood as also allowing for a claimed combination in which the two elements are not combined with each other, but may be used alone or combined in other combinations. The excision of any disclosed element of the embodiments is explicitly contemplated as within the scope of the embodiments.
[0096] The words used in this specification to describe the various embodiments are to be understood not only in the sense of their commonly defined meanings, but to include by special definition in this specification structure, material or acts beyond the scope of the commonly defined meanings. Thus if an element can be understood in the context of this specification as including more than one meaning, then its use in a claim must be understood as being generic to all possible meanings supported by the specification and by the word itself.
[0097] The definitions of the words or elements of the following claims are, therefore, defined in this specification to include not only the combination of elements which are literally set forth, but all equivalent structure, material or acts for performing substantially the same function in substantially the same way to obtain substantially the same result. In this sense it is therefore contemplated that an equivalent substitution of two or more elements may be made for any one of the elements in the claims below or that a single element may be substituted for two or more elements in a claim. Although elements may be described above as acting in certain combinations and even initially claimed as such, it is to be expressly understood that one or more elements from a claimed combination can in some cases be excised from the combination and that the claimed combination may be directed to a subcombination or variation of a subcombination.
[0098] Insubstantial changes from the claimed subject matter as viewed by a person with ordinary skill in the art, now known or later devised, are expressly contemplated as being equivalently within the scope of the claims. Therefore, obvious substitutions now or later known to one with ordinary skill in the art are defined to be within the scope of the defined elements.
[0099] The claims are thus to be understood to include what is specifically illustrated and described above, what is conceptionally equivalent, what can be obviously substituted and also what essentially incorporates the essential idea of the embodiments.