Systems and methods for reducing artifacts in neural response signals using customized recharge configurations.

Abstract

A system or method according to an embodiment of the present disclosure includes: generating a first electrical impulse at a first time; measuring a first neural response to the first electrical impulse; generating a second electrical impulse at a second time having at least one characteristic different from the first electrical impulse; measuring a second neural response to the second electrical impulse; and removing at least one artifact from at least one of the first neural response and the second neural response.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 545,903, filed on October 26, 2023, the entire contents of which are incorporated herein by reference. Background Technology

[0003] This disclosure relates generally to medical devices, and more specifically to neural responses to stimuli.

[0004] Neuromodulation therapy can be performed by transmitting electrical signals generated by a pulse generator to a stimulation target, which can then generate a response. The response can be recorded and used during the neuromodulation therapy process. Summary of the Invention

[0005] The embodiments of this disclosure advantageously achieve artifact elimination while preserving the timing of neural signals by optimizing the recharge parameters of the stimulation signal delivered by the implanted device. While alternating polarity of the stimulation signal can eliminate artifacts, this alternation can interfere with the timing of neural responses. To preserve the timing of neural signals while also ensuring alternating polarity relative to the artifact, the recharge parameters of the second stimulation signal can be adjusted to differ from those of the first initial stimulation signal. This difference in recharge parameters allows for better destructive interference of artifacts during signal superposition, while maintaining the timing of neural signals.

[0006] Examples of aspects of this disclosure include: A method according to at least one embodiment of the present disclosure includes: generating a first electrical pulse at a first time; measuring a first neural response to the first electrical pulse; generating a second electrical pulse at a second time having at least one characteristic different from the first electrical pulse; measuring a second neural response to the second electrical pulse; and removing at least one artifact from at least one of the first neural response and the second neural response.

[0007] Any aspect of this article, wherein at least one of the first and second neural responses includes an evoked compound action potential (ECAP) response or a compound muscle action potential (CMAP) response.

[0008] In any aspect of this article, the at least one feature includes a passive recharge phase that occurs after the second electrical pulse being paused to allow for measurement of the amount of time prior to the second neural response.

[0009] Any aspect of this article, wherein the at least one feature includes a recharging mechanism.

[0010] In any aspect of this document, the first electrical pulse includes an active recharging mechanism, and the second electrical pulse includes a passive recharging mechanism.

[0011] In any aspect of this article, the first electrical pulse includes a passive recharging mechanism, and the second electrical pulse includes an active recharging mechanism.

[0012] In any aspect of this document, the at least one characteristic includes at least one of the amplitude of the recharge phase of the second electrical pulse and the pulse width.

[0013] In any aspect of this document, the at least one characteristic includes the amplitude of the recharge phase, and wherein the amplitude of the recharge phase of the first electrical pulse is greater than the amplitude of the recharge phase of the second electrical pulse.

[0014] In any aspect of this document, the at least one characteristic includes the pulse width of the recharge phase, and wherein the pulse width of the recharge phase of the first electrical pulse is less than the pulse width of the recharge phase of the second electrical pulse.

[0015] In any aspect of this article, removing the at least one artifact further includes combining the first neural response and the second neural response into a composite response.

[0016] In any aspect of this article, combining the first neural response and the second neural response includes weighting at least one of the first neural response and the second neural response.

[0017] Any aspect of this paper, wherein the composite response has reduced noise compared to the first and second neural responses.

[0018] In any aspect of this paper, the first neural response and the second neural response are generated by anatomical elements, and the method further includes selecting at least one recharge parameter that increases the signal-to-noise ratio of the composite response.

[0019] An apparatus according to at least one embodiment of the present disclosure includes: a pulse generator configured to generate electrical pulses delivered to an anatomical element via stimulating electrodes; a processor; and a memory coupled to the processor and storing data that, when processed by the processor, enables the processor to: cause the pulse generator to generate a first electrical pulse; receive a first neural response from the anatomical element to the first electrical pulse; cause the pulse generator to generate a second electrical pulse having at least one characteristic different from the first electrical pulse; receive a second neural response from the anatomical element to the second electrical pulse; and combine the first neural response and the second neural response into a composite response signal, wherein the composite response signal has less noise than the first neural response and the second neural response.

[0020] In any aspect of this article, at least one of the first and second neural responses includes an evoked compound action potential (ECAP) response or a compound muscle action potential (CMAP) response of an anatomical element.

[0021] In any aspect of this article, the at least one feature includes a passive recharge phase that occurs after the second electrical pulse being paused to allow for measurement of the amount of time prior to the second neural response.

[0022] Any aspect of this article, wherein the at least one feature includes a recharging mechanism.

[0023] In any aspect of this document, the first electrical pulse includes an active recharging mechanism, and the second electrical pulse includes a passive recharging mechanism.

[0024] In any aspect of this article, the first electrical pulse includes a passive recharging mechanism, and the second electrical pulse includes an active recharging mechanism.

[0025] In any aspect of this document, the at least one characteristic includes at least one of the amplitude of the recharge phase of the second electrical pulse and the pulse width.

[0026] In any aspect of this document, the at least one characteristic includes the amplitude of the recharge phase, and wherein the amplitude of the recharge phase of the first electrical pulse is greater than the amplitude of the recharge phase of the second electrical pulse.

[0027] In any aspect of this document, the at least one characteristic includes the pulse width of the recharge phase, and wherein the pulse width of the recharge phase of the first electrical pulse is less than the pulse width of the recharge phase of the second electrical pulse.

[0028] In any aspect of this article, combining the first neural response and the second neural response includes weighting at least one of the first neural response and the second neural response.

[0029] In any aspect of this paper, the data, when processed by the processor, further enables the processor to: select at least one recharge parameter that increases the signal-to-noise ratio of the composite response signal; cause a pulse generator to generate a third electrical pulse according to the at least one recharge parameter; receive a third neural response from the anatomical element to the third electrical pulse; and combine at least one of the first and second neural responses with the third neural response.

[0030] An apparatus according to at least one embodiment of the present disclosure includes: a pulse generator that generates electrical pulses; a stimulation electrode electrically coupled to the pulse generator that delivers the electrical pulses generated by the pulse generator to an anatomical element; a processor; and a memory coupled to the processor and storing data that, when processed by the processor, enables the processor to: receive a first neural signal from the anatomical element in response to a first electrical pulse generated by the pulse generator and delivered by the stimulation electrode; receive a second neural signal from the anatomical element in response to a second electrical pulse generated by the pulse generator and delivered by the stimulation electrode, wherein at least one characteristic of the second electrical pulse differs from that of the first electrical pulse; and combine the first neural signal and the second neural signal into a composite signal, wherein the composite signal has less noise than the first neural signal and the second neural signal.

[0031] In any aspect of this article, at least one of the first and second neural signals includes an evoked compound action potential (ECAP) response or a compound muscle action potential (CMAP).

[0032] In any aspect of this article, the at least one feature includes the amount of time prior to the passive recharging phase that occurs after the second electrical pulse, which is then paused to allow measurement of the second neural signal.

[0033] Any aspect of this article, wherein the at least one feature includes a recharging mechanism.

[0034] In any aspect of this document, the first electrical pulse includes an active recharging mechanism, and the second electrical pulse includes a passive recharging mechanism.

[0035] In any aspect of this article, the first electrical pulse includes a passive recharging mechanism, and the second electrical pulse includes an active recharging mechanism.

[0036] In any aspect of this document, the at least one characteristic includes at least one of the amplitude of the recharge phase of the second electrical pulse and the pulse width.

[0037] In any aspect of this article, combining the first neural signal and the second neural signal includes weighting at least one of the first neural signal and the second neural signal.

[0038] Any one aspect can be combined with any one or more other aspects.

[0039] Any one or more of the features disclosed in this article.

[0040] This article generally discloses one or more of the features.

[0041] Any one or more of the features generally disclosed in this article are combined with any one or more other features generally disclosed in this article.

[0042] Any aspect / feature / implementation may be combined with any one or more other aspects / features / implementations.

[0043] Use any one or more of the aspects or features disclosed herein.

[0044] It should be understood that any feature described herein may be combined with any other feature as described herein to claim protection, regardless of whether the feature comes from an implementation of the same description.

[0045] Details of one or more aspects of this disclosure are set forth in the following drawings and description. Other features, objects, and advantages of the technology described in this disclosure will be apparent from the description, drawings, and claims.

[0046] The phrases “at least one,” “one or more,” and “and / or” are open-ended expressions that possess both connective and disjoint qualities in operation. For example, each of the expressions “at least one of A, B, and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C,” and “A, B, and / or C” means only A, only B, only C, A and B together, A and C together, B and C together, or A, B, and C together. When each of A, B, and C in the above expressions refers to elements such as X, Y, and Z or element classes such as X1-Xn, Y1-Ym, and Z1-Zo, the phrase is intended to refer to a single element selected from X, Y, and Z, a combination of elements selected from the same class (e.g., X1 and X2), and a combination of elements selected from two or more classes (e.g., Y1 and Zo).

[0047] The term "a" refers to one or more of the same entity. Therefore, the terms "a," "one or more," and "at least one" are used interchangeably herein. It should also be noted that the terms "comprising," "including," and "having" are used interchangeably.

[0048] The foregoing is a simplified overview of this disclosure to provide an understanding of some aspects thereof. This summary is neither a broad nor an exhaustive overview of this disclosure and its various aspects, embodiments, and configurations. It is not intended to identify key or essential elements of this disclosure, nor to define its scope, but rather to present the concepts of this disclosure in a simplified form as an introduction to the more detailed description presented below. It should be understood that other aspects, embodiments, and configurations of this disclosure may utilize one or more of the features set forth above or described in detail below, individually or in combination.

[0049] Many additional features and advantages of this disclosure will become apparent to those skilled in the art upon consideration of the embodiments described below. Attached Figure Description

[0050] The accompanying drawings are incorporated in and form a part of this specification to illustrate several examples of this disclosure. These drawings, together with the description, explain the principles of this disclosure. The drawings illustrate only preferred and alternative examples of how to implement and use this disclosure, and these examples should not be construed as limiting this disclosure solely to the illustrated and described examples. Further features and advantages will become apparent from the following more detailed description of various aspects, embodiments, and configurations of this disclosure, as illustrated by the accompanying drawings referenced below.

[0051] Figure 1A It is a diagram of a system aspect according to at least one embodiment of this disclosure; Figure 1B This is a block diagram of an additional aspect of a system according to at least one embodiment of the present disclosure; Figure 2 This is a diagram of leads and electrodes according to at least one embodiment of this disclosure; Figure 3A Aspects of delivering a first stimulus signal according to at least one embodiment of the present disclosure are described; Figure 3B Aspects of delivering a second stimulus signal according to at least one embodiment of the present disclosure are described; Figure 3C A composite signal according to at least one embodiment of the present disclosure is described; Figure 4 Aspects of delivering stimulation signals with different recharge parameters according to at least one embodiment of the present disclosure are described; Figure 5 Example data from a recording electrode according to at least one embodiment of this disclosure is depicted; Figure 6 Example data from a recording electrode according to at least one embodiment of this disclosure is depicted; Figure 7 Example data from a recording electrode according to at least one embodiment of this disclosure is depicted; Figure 8 This is a flowchart of at least one embodiment of the present disclosure; and Figure 9 It is a flowchart of at least one embodiment according to this disclosure. Detailed Implementation

[0052] It should be understood that the various aspects disclosed herein can be combined with combinations different from those specifically presented in the specification and drawings. It should also be understood that, depending on the example or embodiment, certain actions or events of any process or method described herein may be performed in a different order, and / or may be added, combined, or omitted entirely (e.g., implementing the disclosed technology may not require all described actions or events depending on the different embodiments of this disclosure). Furthermore, although some aspects of this disclosure are described as being performed by a single module or unit for clarity, it should be understood that the technology of this disclosure can be performed by a combination of units or modules associated with, for example, a processor and / or a medical device.

[0053] In one or more examples, the described methods, processes, and techniques may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the function may be stored as one or more instructions or code on a computer-readable medium and executed by a hardware-based processing unit. Alternatively or additionally, the function may be implemented using machine learning models, neural networks, artificial neural networks, or combinations thereof (instructions alone or in combination). The computer-readable medium may include a non-transitory computer-readable medium that corresponds to a tangible medium, such as a data storage medium (e.g., RAM, ROM, EEPROM, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible by a computer).

[0054] Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general-purpose microprocessors (e.g., Intel Core i3, i5, i7, or i9 processors; Intel Celeron processors; Intel Xeon processors; Intel Pentium processors; AMD Ryzen processors; AMD Athlon processors; AMD Phenom processors; Apple A10 or 10X Fusion processors; Apple A11, A12, A12X, A12Z, or A13 Bionic processors; or any other general-purpose microprocessor), graphics processing units (e.g., Nvidia GeForce RTX 2000 series processors, Nvidia GeForce RTX 3000 series processors, AMD Radeon RX 5000 series processors, AMD Radeon RX 6000 series processors, or any other graphics processing units), application-specific integrated circuits (ASICs), field-programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuits. Therefore, the term "processor" as used herein may refer to any of the foregoing structures or any other physical structures suitable for implementing the described techniques. Furthermore, these techniques may be fully implemented in one or more circuit or logic elements.

[0055] Before explaining any embodiment of this disclosure in detail, it should be understood that this disclosure is not limited in its application to the construction details and component arrangements set forth in the following description or illustrated in the accompanying drawings. This disclosure can have other embodiments and can be practiced or implemented in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting. The use of “comprising,” “including,” or “having,” and variations thereof, is intended to cover items listed thereafter and their equivalents, as well as additional items. In addition, this disclosure may use examples to illustrate one or more aspects thereof. Unless expressly stated otherwise, the use or listing of one or more examples (which may be indicated by “for example,” “by way of example,” “such as,” or similar language) is not intended to, and does not limit, the scope of this disclosure.

[0056] Systems and methods for reducing sensing artifacts are of great significance for spinal cord stimulation (SCS), deep brain stimulation (DBS), and pelvic health (PH) products, aiming to achieve tighter and more flexible sensing / stimulation configurations. Alternating polarity stimulation can be used to effectively eliminate stimulation artifacts in SCS, PH, and CI implants. However, while the alternating polarity approach is effective in eliminating artifacts, it can negatively impact the amplitude and signal-to-noise ratio (SNR) of evoked compound action potentials (ECAPs). Since ECAPs can be recorded after each alternating polarity stimulation, the recorded signals can be averaged after two polarization stimulations. Due to the opposite polarity of the stimulation signals, artifacts in the first signal have the opposite sign to those in the second signal, making them eliminated when the signals are averaged. However, some biological signals, such as ECAPs, are primarily initiated by the first cathodic phase of the first stimulation signal. Because the alternation of polarity changes the location on the anatomical element experiencing the cathodic phase, the ECAP timing varies with each alternating pulse. This can lead to a reduction or even elimination of the neural signal, depending on how the two recordings are superimposed or combined. In other words, while alternating polarity effectively reduces artifact presence, it can also lead to a decrease in SNR. Although active recharging of implanted devices can be adjusted to optimize artifact cancellation, hardware limitations may make it difficult to deliver optimized recharge values. The systems and methods according to this disclosure deliver electrical signals that optimize artifact cancellation while maintaining ECAP timing.

[0057] It should be understood that while this article discusses examples of ECAP, any other type of sensing stimulus, such as compound muscle action potential (CMAP) response, can be generated and recorded. Furthermore, sensing of ECAP responses, CMAP responses, etc., can occur in or under various medical or therapeutic applications, such as during SCS applications, DBS applications, PH applications, and combinations thereof.

[0058] According to an example embodiment of this disclosure, the recharge parameters of the stimulation device can be adjusted to achieve an optimized recharge ratio that eliminates artifacts while maintaining the ECAP timing between multiple alternating polarity stimuli. By manipulating the recharge parameters (e.g., amplitude, pulse width, etc.) of the stimulation signal during active recharge (which may include features of passive recharge), passive recharge, or a hybrid recharge that achieves both active and passive recharge, artifacts can alternate in sign while the ECAP timing remains the same. For example, during passive recharge, the duration of passive recharge can be manipulated before sensing neural signals (e.g., ECAP, CMAP, etc.). In other words, after a certain period of time, passive recharge can be truncated, paused, or otherwise stopped to allow the recording electrodes to measure neural signals. As another example, a first stimulus can be operated using passive recharge, and a second, slightly later stimulus can be operated using passive recharge (or vice versa). The stimuli can then be combined to perform artifact elimination.

[0059] According to example embodiments of this disclosure, various recharge configurations can be achieved by delivering a series of stimuli to a target anatomical element, each with a different recharge configuration. The differences in recharge configurations result in alternating artifact amplitudes, while the timing used to sense the ECAP response remains the same. Averaging the recharge configurations can then minimize artifacts while producing better ECAP measurements, thereby increasing the signal's SNR. In some examples, a weighted average of the signal can be used to minimize artifacts. In some examples, mathematical characteristics of the artifacts (e.g., the ratio of slopes, the area under the curve, etc.) can be used to adjust the recharge parameters. Where the optimal recharge configuration can be delivered by hardware, the optimal recharge configuration can be selected and used to generate the ECAP response. If the hardware cannot deliver the optimal recharge configuration, the hardware can be configured to deliver a stimulus with a recharge configuration that is closest to the optimal ratio achievable by the hardware.

[0060] The embodiments disclosed herein provide technical solutions to one or more of the following problems: (1) shifted ECAP timing in alternating polarity stimulation; (2) high noise signals; and (3) hardware limitations in generating stimulation signals.

[0061] First turn Figures 1A to 1BThis illustration shows aspects of a system 100 according to at least one embodiment of the present disclosure. System 100 can be used to provide electrical signals to a patient and / or perform one or more other aspects of one or more of the methods disclosed herein. For example, system 100 may include an implantable medical device (IMD) 112 that can be configured to generate current or electrical signals, such as signals capable of stimulating or responding to a target anatomical element. System 100 also includes an external device 136 that can be used to program, command, or otherwise control the IMD 112. The IMD 112 may generate, for example, current or electrical signals capable of stimulating an ECAP response or stimulating a LFP from one or more nerves. In other examples, the IMD 112 may generate stimulation near the sacral nerve, within the brain, and / or near peripheral nerves to perform SCS, sacral nerve modulation (SNM), DBS, peripheral nerve stimulation (PNS), combinations thereof, etc. Figure 1A The IMD 112 depicted includes a first lead 116A and a second lead 116B implanted near or on the spinal cord 104 of the patient 102. In some cases, the IMD 112 may have additional or alternative numbers of leads 116. Leads 116A and 116B may be implanted on or near any target anatomical element (e.g., on or near any organ, anatomical tissue, anatomical element, nerve, combination thereof, etc.). In some cases, leads 116A and 116B may be implanted in the epidural space between the spinal cord and the vertebrae. Once implanted, leads 116A and 116B can provide electrical signals from the IMD 112 to the target anatomical element. The IMD 112 may be implantable inside the patient or outside the patient, such as during testing of leads 116A and 116B.

[0062] In some examples, leads 116A, 116B can provide electrical signals to the respective nerves via electrodes 124 connected to the nerves (e.g., sutured in place, wrapped around the nerves, etc.). In some examples, leads 116A, 116B can be referred to as cuff electrodes, or can otherwise include cuff electrodes (e.g., at the unconnected or inserted ends of leads 116A, 116B into IMD 112). Additionally or alternatively, although physical wires are shown for providing a connection between IMD 112 and one or more nerves, the electrodes can wirelessly (e.g., with or without IMD 112) provide electrical signals to one or more nerves.

[0063] Electrode 124 may include a stimulating electrode (e.g., an electrode configured to stimulate a target anatomical element) or a recording electrode (e.g., an electrode configured to record a physiological response to stimulation). Figure 2Example electrode 124 is described in further detail below. In some cases, both the first lead 116A and the second lead 116B comprise both a stimulating electrode and a recording electrode. In other cases, the first lead 116A comprises a stimulating electrode, while the second lead 116B comprises a recording electrode (or vice versa). In some examples, the recording electrode may record or measure the ECAP based on the stimulation delivered by the stimulating electrode, which can be used to modulate or adjust the electrical signal generated by the IMD 112. Such adjustment of the delivered electrical signal can beneficially enhance the therapy delivered by the IMD 112.

[0064] refer to Figure 1B The IMD 112 includes a memory 106, a communication interface 108, a processor 120, leads 116A and 116B, one or more sensors 128, and one or more pulse generators 132. Other examples of the IMD according to this disclosure may include additional or alternative components besides the IMD 112.

[0065] The processor 120 of IMD 112 may be any processor described herein or any similar processor. The processor 120 may be configured to execute instructions stored in memory 106, which may enable the processor 120 to perform one or more computational steps using or based on data received from leads 116A, 116B, database 130, cloud 134 and / or external device 136. Processor 120 may be or include one or more digital signal processors (DSPs), general-purpose microprocessors (e.g., Intel Core i3, i5, i7, or i9 processors; Intel Celeron processors; Intel Xeon processors; Intel Pentium processors; AMD Ryzen processors; AMD Athlon processors; AMD Phenom processors; Apple A10 or 10X Fusion processors; Apple A11, A12, A12X, A12Z, or A13 Bionic processors; or any other general-purpose microprocessors), graphics processing units (e.g., Nvidia GeForce RTX 2000 series processors, Nvidia GeForce RTX 3000 series processors, AMD Radeon RX 5000 series processors, AMD Radeon RX 6000 series processors, or any other graphics processing units), application-specific integrated circuits (ASICs), field-programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuits.

[0066] Memory 106 may be or include RAM, DRAM, SDRAM, other solid-state memory, any memory described herein, or any other tangible non-transitory memory used to store computer-readable data and / or instructions. Memory 106 may store information or data that can be used to perform any steps of, for example, methods 800 and / or 900 described herein or any other method. Memory 106 may store, for example, instructions and / or machine learning models supporting one or more functions of IMD 112. For example, memory 106 may store content (e.g., instructions and / or machine learning models) that, when executed by processor 120, cause leads 116A, 116B to apply electrical signals to corresponding target anatomical elements, cause leads 116A, 116B to record response signals from corresponding target anatomical elements, and / or cause processor 120 to process the response signals.

[0067] If provided as instructions, the contents of memory 106 can be organized into one or more applications, modules, packages, layers, or engines. Alternatively or additionally, memory 106 may store other types of content or data (e.g., machine learning models, artificial neural networks, deep neural networks, etc.) that can be processed by processor 120 to implement the various methods and features described herein. Therefore, although the various contents of memory 106 can be described as instructions, it should be understood that the functions described herein can be implemented using instructions, algorithms, and / or machine learning models. Data, algorithms, and / or instructions can enable processor 120 to manipulate data stored in memory 106 and / or data received from or via leads 116A, 116B, database 130, cloud 134, and / or external device 136.

[0068] Communication interface 108 can be used to receive data or other information from external sources (such as database 130, cloud 134, external device 136, and / or any other system or component not part of system 100), and / or to send instructions, data, or other information to external systems or devices (e.g., database 130, cloud 134, external device 136, and / or any other system or component not part of system 100). Communication interface 108 may include one or more wired interfaces (e.g., USB port, Ethernet port, FireWire port) and / or one or more wireless transceivers or interfaces (configured to send and / or receive information, for example, via one or more wireless communication protocols such as 802.11a / b / g / n, Bluetooth, NFC, ZigBee, etc.). In some embodiments, communication interface 108 can be used to enable IMD 112 to communicate with one or more other processors 120 or external devices 136, whether to send information related to ECAP signals or for any other reason.

[0069] Sensor 128 may be or include sensing elements that detect values ​​of corresponding patient parameters, such as the posture of patient 102. Sensor 128 may be or include one or more gyroscopes, accelerometers, chemical sensors, temperature sensors, pressure sensors, combinations thereof, etc. Sensor 128 may generate information and transmit such information to one or more components of system 100, such as to memory 106, database 130, and / or external device 136. In some cases, processor 120 may process such information and adjust the parameters of the electrical stimulation generated by IMD 112 accordingly. For example, sensor 128 may detect increased patient activity (e.g., patient 102 has stood up), and processor 120 may cause IMD 112 to increase the frequency at which electrical stimulation is delivered to patient 102.

[0070] Pulse generator 132 can be configured to generate an electrical stimulation signal (e.g., current) to be delivered to a target anatomical element. Pulse generator 132 can generate current according to one or more electrical stimulation parameters. The electrical stimulation signal can be a continuous-time signal. Pulse generator 132 can be controlled by a signal transmitted from processor 120. The electrical stimulation signal generated by pulse generator 132 can be propagated via leads 116A, 116B and applied to the target surgical site or anatomical element via electrodes 124. It should be understood that although a single pulse generator 132 has been discussed herein, pulse generator 132 may include multiple different pulse generators or other pulse generation circuits capable of generating electrical pulses.

[0071] As described above, external device 136 may be a device external to IMD 112 capable of being programmed, commanded, or otherwise controlled. External device 136 includes user interface 110, communication interface 140, processor 144, and memory 148. External devices according to other examples of this disclosure may include additional or alternative components of those components shown in external device 136.

[0072] User interface 110 may be or include a keyboard, mouse, trackball, monitor, television, screen, touchscreen, and / or any other device for receiving information from and / or providing information to the user. User interface 110 may be used, for example, to receive user selections or other user input regarding any step of any of the methods described herein. In some cases, user interface 110 may be used to select one or more parameters of the electrode (or other components of IMD 112), including but not limited to selecting whether the electrode is active or inactive, recharge parameters after stimulation has been applied, etc. Nevertheless, any required input for any step of any of the methods described herein may be automatically generated by system 100 (e.g., by processor 120 or another component of system 100) or received by system 100 from a source external to system 100. In some embodiments, user interface 110 may be used to allow a user to modify instructions to be executed by processor 120 according to one or more embodiments of this disclosure, and / or modify or adjust settings displayed on user interface 110 or corresponding to other information on user interface 110.

[0073] Although the user interface 110 is shown as part of the external device 136, in some examples, the external device 136 may utilize a user interface 110 housed separately from one or more other components of the external device 136. In some examples, the user interface 110 may be located proximal to one or more other components of the external device 136, while in other embodiments, the user interface 110 may be located remotely from one or more other components of the external device 136.

[0074] Communication interface 140 may be similar to or the same as any communication interface discussed herein (e.g., communication interface 108). Communication interface 140 may be configured to receive data or other information from external sources (such as IMD 112, database 130, cloud 134, and / or any other system or component not part of system 100), and / or to send instructions, data, or other information to external systems or devices (e.g., IMD 112, database 130, cloud 134, and / or any other system or component not part of system 100).

[0075] Processor 144 may be similar to or the same as any processor discussed herein (e.g., processor 120). Processor 144 may be configured to execute instructions stored in memory 148 that enable processor 144 to perform one or more computational steps using or based on data received from IMD 112, database 130, cloud 134 and / or any other component of system 100 or a component external to system 100.

[0076] Memory 148 may be similar to or the same as any memory discussed herein (e.g., memory 106). Memory 148 may be or include RAM, DRAM, SDRAM, other solid-state memory, any memory described herein, or any other tangible non-transitory memory used to store computer-readable data and / or instructions. Memory 106 may store information or data for performing one or more steps of, for example, methods 800 and / or 900 described herein or any other method.

[0077] Database 130 may store information such as patient data; the results of stimulation procedures; stimulation parameters (including recharge parameters, electrical signal parameters, electrode parameters, etc.); thresholds that can be used to optimize recharge parameters associated with IMD 112, to weight measured neural signals, combinations thereof, etc. Database 130 may be configured to provide any such information to IMD 112, external device 136 and / or any other device of system 100, or any other device outside system 100, whether directly or via cloud 134. In some examples, database 130 may be or include part of a hospital image storage system, such as a Picture Archiving and Communication System (PACS), a Health Information System (HIS), and / or another system for collecting, storing, managing, and / or transmitting electronic medical records.

[0078] Cloud 134 can be or represents the Internet or any other wide area network. IMD 112 and / or external device 136 can be connected to cloud 134 via wired connection, wireless connection, or both via communication interface 108 and communication interface 140 respectively. In some embodiments, IMD 112 and / or external device 136 can communicate with database 130, each other, and / or external devices via cloud 134.

[0079] System 100 or a similar system may be used, for example, to implement one or more aspects of any of the methods 800 and / or 900 described herein. System 100 or a similar system may also be used for other purposes.

[0080] refer to Figure 2 The diagram illustrates leads 116A, 116B and electrode 124 according to an embodiment of this disclosure. Electrode 124 can be arranged in different patterns on leads 116A, 116B depending on the type of IMD 112, the type of treatment applied to patient 102, the characteristics of the stimulation signal to be delivered to the target anatomical element, their combination, etc. Although Figure 2The illustrated leads 116A and 116B each include eight electrodes, but additional or alternative numbers of electrodes may be present. Electrode 124 may be connected to one or more components of system 100, such as to memory 106, processor 120, database 130, cloud 134, and / or external device 136 or components of such external device. This connection allows signals captured by electrode 124 to be relayed to one or more other components of system 100.

[0081] Electrode 124 includes a first electrode 204, a second electrode 208, a third electrode 212, and a fourth electrode 216. As previously described, the electrodes can be used as stimulating electrodes (e.g., electrodes configured to stimulate a target anatomical element) or recording electrodes (e.g., electrodes configured to record a physiological response to a stimulus). For example, the first electrode 204 and the second electrode 208 can be used as stimulating electrodes to deliver a stimulus signal to the target anatomical element, while the third electrode 212 and the fourth electrode 216 can be recording electrodes to sense a response from the target anatomical element (e.g., an ECAP response, a CMAP response, etc.). In some examples, such as when the IMD 112 delivers alternating polarity stimuli, the electrodes can alternately act as a cathode / anode pair. For example, in the cathodic leading phase, the first electrode 204 can operate as a cathode, and the second electrode 208 can operate as an anode. During the recharge phase following the cathodic leading phase, the first electrode 204 can switch to operate as an anode, while the second electrode 208 operates as a cathode.

[0082] refer to Figures 3A to 3B This illustrates an aspect of using the IMD 112 to stimulate the target anatomical element 304 according to an embodiment of the present disclosure. The stimulation signal applied by the electrodes 124 of the IMD 112 can be a signal capable of generating a neural response (e.g., an ECAP response) in the target anatomical element 304, which can be recorded and used, for example, to validate or adjust the treatment delivered by the IMD 112.

[0083] Figure 3AA first lead 116A is shown, positioned near or on the first electrode 204 such that the first electrode 204 and the second electrode 208 can deliver a stimulation signal to the target anatomical element 304. The first electrode 204 can operate as a cathode, while the second electrode 208 can operate as an anode (or vice versa). The first electrode 204 and the second electrode 208 can deliver a cathode leader stimulation 308 to the target anatomical element 304. The cathode leader stimulation 308 includes a leader phase 312 and a recharge phase 316. The leader phase 312 occurs when the first electrode 204 and the second electrode 208 pass a current generated by the pulse generator 132 through the target anatomical element 304. After stimulation, the recharge phase 316 begins. During the recharge phase 316, one or more capacitors in the IMD 112 are connected to a current source whose polarity is opposite to that of the stimulation current generated by the pulse generator 132 in the leader phase 312. The recharge phase 316 serves as a charge balancing phase for the IMD 112. Therefore, IMD 112 discharges current into target dissecting element 304 in the opposite direction to the leader phase 312. Additionally or alternatively, IMD 112 may undergo passive recharging, where one or more capacitors are connected to ground or a common reference to perform charge balancing. In some cases, IMD 112 may exclusively undergo passive recharging (e.g., IMD 112 does not undergo active recharging), or IMD 112 may undergo a combination of active and passive recharging.

[0084] Once the recharge phase 316 occurs, the target anatomical element 304 can generate a neural response 324 to the stimulus. In some examples, the neural response 324 may be an ECAP response, a CMAP response, etc. The neural response 324 may occur at time t1 within the sensing window 320. The sensing window 320 may be or includes the time during which one or more recording electrodes 124 of leads 116A, 116B are turned on or enabled, such that the neural response 324 can be recorded by the recording electrodes 124 and transmitted to the memory 106, processor 120, external device 136, etc. During the sensing window 320, the recording electrodes 124 may also sense non-neural signals, such as sensing artifacts 328. In some cases, the sensing window 320 may occur during the recharge phase 316 (e.g., when the target anatomical element generates a neural response, the IMD 112 is still recharged). In this case, the recharge phase 316 may be truncated, paused, or otherwise stopped to allow the recording electrodes 124 to record the neural response 324. Once the sensing window 320 has passed, the recharge phase 316 can resume or continue. In some examples, the cutoff or pause of the recharge phase 316 (which may be passive) may include keeping the capacitor in IMD 112 loosely connected to ground or a common reference via a high-impedance connection (e.g., a connection with an impedance greater than 1 megohm (MΩ)). In other words, in some examples, the cutoff or pause may not cause the capacitor in IMD 112 to be disconnected from ground or a common reference, but may instead be loosely connected to a high impedance.

[0085] To account for sensing artifact 328, IMD 112 can generate another stimulus of opposite polarity at a later time. This opposite polarity can be an anode leader stimulus 332. In the anode leader stimulus 332, the first electrode 204 and the second electrode 208 can switch polarities from those used to deliver the cathode leader stimulus 308. In other words, if the first electrode 204 is used as the cathode and the second electrode 208 is used as the anode when delivering the cathode leader stimulus 332, then the first electrode 204 is now used as the anode and the second electrode 208 is now used as the cathode to deliver the anode leader stimulus 308. Similar to the cathode leader stimulus 308, the anode leader stimulus 332 includes a leader phase 336 and a recharge phase 340. The leader phase 336 can be similar to or the same as the leader phase 312, except that the polarity of the current can be switched, thereby causing a potential in the leader phase 336 that is opposite to that in the leader phase 312. Recharge phase 340 can be similar to or the same as recharge phase 316, except that the polarity of the current can be reversed, thereby causing a potential in recharge phase 340 that is opposite to that in recharge phase 316.

[0086] Similar to cathode leader stimulation 308, delivery of anode leader stimulation 332 enables target anatomical element 304 to generate a neural response 348 at time t2 within sensing window 344. In some examples, neural response 348 may be an ECAP response. Sensing window 344 may be or include the time during which one or more recording electrodes 124 of leads 116A, 116B are turned on or enabled, such that neural response 348 can be recorded by recording electrodes 124 and transmitted to memory 106, processor 120, external device 136, etc. During sensing window 344, recording electrodes 124 may also sense non-neural signals, such as sensing artifact 352.

[0087] refer to Figure 3C The data recorded by electrode 124 during sensing window 320 and sensing window 344 can be superimposed or otherwise combined into a composite signal. For example... Figure 3C As shown, the composite signal can be superimposed relative to time axis 356, which can correspond to the same time unit as sensing windows 320 and 344. The combination of data can result in sensing artifacts 328 and 352 having equal and opposite magnitudes (e.g., due to the alternating polarities of cathode leader 308 and anode leader 332). These equal and opposite magnitudes can cancel each other out, thus removing, reducing, or minimizing the total noise generated by sensing artifacts 328 and 352. However, due to the difference in cathode position on the target anatomical element 304 during cathode leader 308 and anode leader 332, the timing of neural responses 324 and 348 may differ. For example, neural response 324 may have started at time t1, while neural response 348 may have started at time t2. When neural responses 324 and 348 are combined, this timing difference can lead to destructive interference, thereby reducing the SNR of the composite signal.

[0088] refer to Figure 4 The diagram illustrates multiple stimulation signals with various recharge parameters according to embodiments of the present disclosure. To address temporal discrepancies while preserving alternating polarity artifacts (to minimize artifacts when combining neural signals), the IMD 112 can deliver stimulation signals with various recharge parameters. Variations in the recharge parameters can make artifacts in the signal equal in magnitude and opposite in magnitude, while maintaining the overall temporal order of the sensed neural response, thereby reducing the likelihood of destructive interference of neural signals when multiple neural signals are combined.

[0089] As an example, the IMD 112 may deliver a first stimulation signal 404 to the target anatomical element 304, which may be similar to or identical to the cathode leader stimulation 308. The first stimulation signal 404 includes a leader phase 408 and a recharge phase 412, which may be similar to or identical to the leader phase 312 and the recharge phase 316, respectively. The stimulation may cause the target anatomical element to generate a neural response, such as a neural response 420, which is captured by one or more electrodes of the IMD 112 in a sensing window 416. The recording of the neural response 420 by the electrodes may also include a sensing artifact 424, which may be non-neural noise or include non-neural noise. In some embodiments, the sensing window 416, the neural response 420, and the sensing artifact 424 may be similar to or identical to the sensing window 320, the neural response 324, and the sensing artifact 328, respectively.

[0090] The IMD 112 can then deliver a second stimulation signal 428 to the target anatomical element 304. The second stimulation signal 428 can be similar to the first stimulation signal 404, since the first stimulation signal 404 includes a lead phase 432 and a recharge phase 436. However, unlike the stimulation discussed relative to the anode lead stimulus 332, the second stimulation signal 428 can be another cathode lead stimulus (opposite to the anode lead stimulus). For example, the first electrode 204 and the second electrode 208 can be used by the IMD 112 to deliver both the first stimulation signal 404 and the second stimulation signal 428. Therefore, instead of switching the cathode / anode pair between stimulation signals, the cathode / anode pair remains the same. In other words, for both the first stimulation signal 404 and the second stimulation signal 428, the first electrode 204 acts as the cathode, and the second electrode 208 acts as the anode (or vice versa). Because the cathode / anode pair remains the same, the timing of the neural responses generated from the target anatomical tissue remains the same.

[0091] The recharge phase 436 of the second stimulus signal 428 may be similar to or the same as the recharge phase 316. In other words, the recharge phase 436 may occur when one or more capacitors in the IMD 112 are connected to a current source whose polarity is opposite to that of the stimulus current generated and delivered to the target anatomical tissue by the pulse generator 132 during the lead phase 432. The recharge phase 436 may have one or more parameters, characteristics, or aspects that are different from the recharge phase 412 of the first stimulus signal 404. For example, the recharge phase 436 may have a different amplitude (e.g., a larger or smaller amplitude), a different pulse width (e.g., a larger or smaller pulse width), a different time period before the recharge phase (e.g., a passive recharge phase) is truncated or paused to measure the neural response, a different recharge mechanism (e.g., the recharge phase 436 undergoes passive recharge while the recharge phase 412 undergoes active recharge), a combination of these, etc. The recharge parameters of the recharge phase 436 can be manipulated by: prematurely disconnecting one or more capacitors in the IMD 112 from a current source whose polarity is opposite to that of the stimulation current generated by the pulse generator 132 during the lead phase 432; adjusting the amplitude of the opposite polarity current source; or combinations thereof.

[0092] Following recharge phase 436, target anatomical element 304 can generate a neural response 444 to the second stimulus signal 428, which can be measured and recorded by electrodes of IMD 112 within sensing window 440. The electrodes can also record sensing artifact 448. Due to adjustments in the recharge parameters of recharge phase 436, sensing artifact 448 can be equal in magnitude and opposite in magnitude to sensing artifact 424. Therefore, when neural responses 420 and 444 are combined, sensing artifacts 424 and 448 may experience destructive interference (e.g., artifacts are canceled out). Furthermore, because the cathode leader stimulation used in both the first stimulus signal 404 and the second stimulus signal 428 can result in similar or identical timing of neural responses 420 and 444 (e.g., ECAP response), the likelihood of destructive interference between neural responses 420 and 444 during combination is reduced.

[0093] Figures 5 to 7 Example data from the recording electrodes is illustrated when stimulation is applied to a target anatomical element by the IMD 112. It should be understood that such examples are by no means limiting, and additional or alternative stimuli at various currents, amplitudes, pulse widths, etc., can be applied to the target anatomical element. In some cases, such as Figure 5 The example data shown indicates that recharging (e.g., passive recharging) can be paused or paused during the sensing window (e.g., ...). Figure 5(As indicated by the "PR Blk" language in the illustration), enabling the recording electrodes to record neural response signals. Recharging can resume after the neural response signals have been recorded.

[0094] refer to Figure 5 The diagram illustrates a graph of artifacts generated with various recharge parameters according to at least one embodiment of the present disclosure. The data depicted in the graph can be, or includes, sampled values ​​(e.g., in microvolts (μV)) of data captured within a sensing window (e.g., sensing window 320, sensing window 344, etc.) after the target anatomical element has been stimulated with both a first stimulation signal and a second stimulation signal, where each stimulation signal has different recharge parameters. Various examples of different recharge parameters include both stimulation signals having different recharge parameters (e.g., different amplitudes, different pulse widths, etc.), the first stimulation signal using active recharge and the second stimulation signal using passive recharge (or vice versa), both stimulation signals using passive recharge with different cutoff timings (e.g., the passive recharge of the first stimulation signal is cut off earlier than the passive recharge of the second stimulation signal), combinations thereof, etc. Sampling can occur for a known or predetermined number of samples within the sensing window. For example, a recording electrode can capture 50 samples within the sensing window.

[0095] The first curve 504 depicts sample values ​​(e.g., voltage measured across the recording electrode) when the first stimulation signal 404 (e.g., a 1.2 mA current with a pulse width of 200 μs) is applied to the target anatomical element in a blank passive recharge manner. The second curve 508 depicts sample values ​​when the second stimulation signal 428 is applied to the target anatomical element. As previously discussed, the recharge parameters of the second stimulation signal 428 may have at least one parameter / characteristic / aspect, etc., different from the recharge parameters of the first stimulation signal 404. As an example, the second curve 508 may depict data when the current of recharge phase 436 is half (1 / 2) of the amplitude of the current of recharge phase 412. The average curve 512 may represent the average of the first curve 504 and the second curve 508. As can be seen in the graph, the value of the average curve 512 is close to zero, indicating that the first curve 504 and the second curve 508 (which correspond to cathode leader stimuli with different recharge parameters) have equal and opposite magnitudes. In some cases, sample values ​​can be correlated with artifacts of recorded neural responses, enabling system 100 to eliminate artifacts (e.g., using data processing performed by processor 120, processor 144, etc.).

[0096] refer to Figure 6The diagram illustrates a graph of artifacts generated with various recharge parameters according to at least one embodiment of the present disclosure. The data depicted in the graph may be, or include, sampled values ​​(e.g., in μV) of data captured within a sensing window (e.g., sensing window 320, sensing window 344, etc.) after the target anatomical element has been stimulated with both a first stimulation signal and a second stimulation signal, where each stimulation signal has a different recharge parameter. For example, the recording electrode may capture 50 samples within the sensing window.

[0097] The first curve 604 depicts sample values ​​when the first stimulus signal 404 (e.g., a 5.5 mA, 200 μs signal) is applied to the target anatomical element. The second curve 608 depicts the application of the second stimulus signal 428 in a passive recharging process, rather than an active recharging process, of the IMD 112 during recharging phase 436. Passive recharging may include connecting one or more capacitors of the IMD 112 to ground or a common reference to perform charge balancing, which is the opposite of active recharging balancing where capacitors are connected to current sources of opposite polarity. The third curve 612 depicts the average of the first curve 604 and the second curve 608. In other words, the third curve 612 depicts sample values ​​when the first stimulus signal 404 achieves active recharging and when the second stimulus signal 428 achieves passive recharging. The fourth curve 616 depicts sample values ​​when the second stimulus signal 428 is applied to the target anatomical element. As previously discussed, the recharging parameters of the second stimulus signal 428 may have at least one parameter / characteristic / aspect, etc., different from the recharging parameters of the first stimulus signal 404. As an example, the second curve 608 can depict data when the amplitude of the current in recharge phase 436 is half (1 / 2) of the amplitude of the current in recharge phase 412.

[0098] As in Figure 6 As can be seen from the curves, the use of passive recharging with the second stimulus signal 428 causes the third curve 612 to reach zero after approximately 15 samples, but in the first 15 samples, active recharging with adjusted recharging parameters produces sample values ​​closer to zero.

[0099] refer to Figure 7 The diagram illustrates a graph of artifacts generated with various recharge parameters according to at least one embodiment of the present disclosure. The data depicted in the graph may be, or include, sampled values ​​(e.g., in μV) of data captured within a sensing window (e.g., sensing window 320, sensing window 344, etc.) after the target anatomical element has been stimulated with both a first stimulation signal and a second stimulation signal, where each stimulation signal has a different recharge parameter. For example, the recording electrode may capture 50 samples within the sensing window.

[0100] The first curve 704 depicts sample values ​​when a first stimulus signal 404 (e.g., a 9.9 mA, 200 μs signal) is applied to the target anatomical element. The second curve 708 depicts sample values ​​when a second stimulus signal 428 is applied to the target anatomical element. As previously discussed, the recharge parameters of the second stimulus signal 428 may have at least one parameter / characteristic / aspect, etc., different from the recharge parameters of the first stimulus signal 404. In one example, the second curve 708 may depict data when the amplitude of the recharge phase 436 current is one-eighth (1 / 8) of the amplitude of the recharge phase 412 current. The third curve 712 depicts the average of the first curve 704 and the second curve 708. The fourth curve 716 depicts sample values ​​when the second stimulus signal 428 is applied to the target anatomical element with a recharge phase 412 current that is half the amplitude of the recharge phase 436 current. Figure 7 As can be seen from the curves, both the third curve 712 and the fourth curve 716 oscillate around the zero mark.

[0101] Figure 8 A method 800 is described that can be used, for example, to remove one or more artifacts from a stimulus response signal.

[0102] Method 800 (and / or one or more of its steps) may be implemented by, for example, at least one processor or otherwise performed. This at least one processor may be the same as or similar to processor 120 of the IMD 112 or processor 144 of the external device 136 described above. This at least one processor may be part of the IMD 112, part of the external device 136, or part of a control unit communicating with the IMD 112 and / or the external device 136. Method 800 may also be performed using processors other than any processor described herein. This at least one processor may perform method 800 by executing elements stored in memory (such as memory 106 or memory 148). Elements stored in memory and executed by the processor may cause the processor to perform one or more steps of the function shown in method 800. One or more portions of method 800 may be performed by the processor executing any contents of memory: such as applying electrical signals to target anatomical elements, causing leads (e.g., leads 116A, 116B) to record response signals from the corresponding target anatomical elements, processing the response signals, and / or any associated operations as described herein.

[0103] Method 800 includes generating a first electrical pulse at a first moment (step 804). The first electrical pulse may be generated by IMD 112 (e.g., using pulse generator 132). In some examples, the first electrical pulse may be similar to or the same as the first stimulation signal 404. In some embodiments, the first electrical pulse may be generated by IMD 112 based on instructions received from external device 136. In some embodiments, the first electrical pulse may be generated based on one or more parameters (e.g., stimulation parameters, such as recharge parameters, electrical signal parameters, electrode parameters, etc.). The first electrical pulse may be delivered to the target anatomical element 304 by one or more stimulation electrodes 124 of IMD 112.

[0104] Method 800 further includes measuring a first neural response to a first electrical impulse (step 808). After the first electrical impulse has stimulated the target anatomical element 304, the target anatomical element 304 may generate a first neural response. The first neural response may be similar to or the same as neural response 420 and may be or include any type of neural response to stimulation generated by delivering the first electrical impulse. The first neural response may be measured by one or more sensing electrodes 124 of the IMD 112.

[0105] Method 800 further includes generating a second electrical pulse at a second time having at least one characteristic different from the first electrical pulse (step 812). In some examples, the second electrical pulse may be similar to or the same as the second stimulation signal 428. In some embodiments, the second electrical pulse may be generated by the IMD 112 based on instructions received from an external device 136. In some embodiments, the second electrical pulse may be generated according to one or more parameters, such as stimulation parameters, such as recharge parameters, electrical signal parameters, electrode parameters, etc. The second electrical pulse may be delivered to the target anatomical element 304 by one or more stimulation electrodes 124 of the IMD 112.

[0106] The second electrical pulse has at least one characteristic different from the first pulse (e.g., amplitude, pulse width, etc.). For example, the recharge parameters associated with the recharge phase of the second electrical pulse may differ from those associated with the recharge phase of the first electrical pulse. The amplitude of the recharge phase current of the second electrical pulse may differ from the amplitude of the recharge phase current of the first electrical pulse (e.g., a larger current or a smaller current). Additionally or alternatively, the pulse width of the recharge phase current of the second electrical pulse may differ from the pulse width of the recharge phase current of the first electrical pulse (e.g., a larger pulse width or a smaller pulse width). As another example, the recharge phase of the second electrical pulse may be paused or truncated at a time interval different from the corresponding time interval of the first electrical pulse (e.g., faster, slower). In another example, the first and second electrical pulses may use different recharge mechanisms, such as when the first electrical pulse uses an active recharge phase and the second electrical pulse uses a passive recharge phase (or vice versa). It should be understood that while amplitude, pulse width, recharge phase cutoff and / or recharge mechanism are provided as examples, any other features, characteristics and / or parameters of the second electrical pulse may be modified to be different from the corresponding features, characteristics and / or parameters of the first electrical pulse (e.g., based on information from external device 136).

[0107] Method 800 further includes measuring a second neural response to a second electrical impulse (step 816). After the second electrical impulse has stimulated the target anatomical element 304, the target anatomical element 304 may generate a second neural response. The second neural response may be similar to or the same as neural response 444 and may be or include any type of neural response to stimulation generated by the delivery of the second electrical impulse. The second neural response may be measured by one or more sensing electrodes 124 of the IMD 112.

[0108] Method 800 further includes removing at least one artifact from at least one of the first and second neural responses (step 820). The first and second neural responses may be combined into a composite signal to reduce, eliminate (e.g., via destructive interference), or otherwise minimize artifacts recorded in the first and second neural responses. In some embodiments, the first and second neural responses may be ECAP responses with similar timing due to the cathode leader phases of the first and second electrical pulses. Therefore, the combination of the first and second neural responses can use destructive interference to remove one or more artifacts from the composite signal while preserving the ECAP response.

[0109] This disclosure covers embodiments of method 800 that include more or fewer steps than those described above and / or one or more steps that are different from those described above.

[0110] Figure 9 A method 900 is described that can be used, for example, to select optimized recharge parameters for IMD 112.

[0111] Method 900 (and / or one or more of its steps) may be performed by, for example, at least one processor or otherwise. This at least one processor may be the same as or similar to processor 120 of the IMD 112 or processor 144 of the external device 136 described above. This at least one processor may be part of the IMD 112, part of the external device 136, or part of a control unit communicating with the IMD 112 and / or the external device 136. Method 900 may also be performed using a processor other than any of the processors described herein. This at least one processor may perform method 900 by executing elements stored in memory (such as memory 106 or memory 148). Elements stored in memory and executed by the processor may cause the processor to perform one or more steps of the function shown in method 900. One or more portions of method 900 may be performed by the processor executing any contents of memory: such as applying an electrical signal to a target anatomical element, causing leads (e.g., leads 116A, 116B) to record a response signal from the corresponding target anatomical element, processing the response signal, and / or any associated operations as described herein.

[0112] Method 900 includes setting recharge parameters for the pulse generator (step 904). The set recharge parameters may be based on user input via user interface 110 of external device 136. In some embodiments, the recharge parameters may be based on predetermined values ​​or stored values ​​from database 130. The recharge parameters can then be transmitted from external device 136 to IMD 112 to program IMD 112 to deliver electrical pulses according to the recharge parameters.

[0113] Method 900 further includes generating a set of electrical pulses based on recharge parameters (step 908). This set of electrical pulses may be similar to or identical to the first stimulation signal 404 and / or the second stimulation signal 428. The number of electrical pulses is not limited, and the pulse generator 132 may generate two, three, four, five, six, or more electrical stimulation signals. The electrical stimulation signals may conform to the set recharge parameters. In some embodiments, the recharge parameters of one or more electrical pulses may differ from the recharge parameters of one or more other electrical pulses. In some embodiments, the set of electrical pulses may be simultaneously delivered to the target anatomical element 304 using the stimulation electrode 124 of the IMD 112, wherein a sensing window between each electrical pulse is used to detect neural responses from the anatomical element, as discussed in step 912 below.

[0114] Method 900 further includes measuring a set of neural responses in response to the set of electrical impulses (step 912). After each electrical impulse in the set of neural impulses is delivered, the target anatomical element 304 may generate a neural response. Each neural response may be measured and recorded by one or more sensing electrodes 124 of the IMD 112.

[0115] Method 900 further includes weighting one or more neural responses in the set of neural responses (step 916). Optionally, one or more neural responses in the set of neural responses may be weighted. Such weighting may affect the amplitude of the neural responses as well as the amplitude of non-neural data (e.g., artifacts). When neural responses are combined into composite signals, the responses may be weighted to improve destructive interference of non-neural data.

[0116] Method 900 further includes combining one or more neural responses to generate a composite signal (step 920). Starting from step 916 (or from step 912 if the neural responses are unweighted), one or more neural responses may be combined into a composite signal. In some examples, the combination of neural responses may reduce, minimize, or eliminate artifacts present in the neural responses. In some embodiments, the composite signal may be similar to or identical to the mean curve 512, the third curve 612, or the third curve 712. In embodiments where weighting is applied to one or more neural responses, the composite signal may be mathematically adjusted to compensate for the weighting (e.g., if the neural signal is amplified during weighting, the composite signal may be correspondingly reduced so that the magnitude of the composite signal is consistent with the magnitude of the pre-weighted neural response).

[0117] Method 900 further includes determining whether artifacts have been minimized (step 924). Based on the composite signal (or, in some cases, various combinations of neural responses in the set of neural responses), external device 136 can determine whether artifacts have been minimized. External device 136 may use the contents of memory 148, which may include data enabling processor 144 to perform data analysis on the composite signal. For example, processor 144 may determine a ratio of the slope of a curve representing artifacts and compare that ratio to a threshold. The threshold may be a predetermined threshold (e.g., a value stored in database 130). The threshold may reflect a tolerance for the presence of artifacts in the composite signal, such that when the ratio of the slope meets or exceeds the threshold, external device 136 determines that the recharge parameters are insufficient to minimize noise in the recorded neural signal. In some cases, processor 144 may examine additional or alternative features of the artifact curve (e.g., area under the curve, inflection points, ratios, and combinations thereof) and compare these features with other thresholds. Additionally or alternatively, processor 144 may determine the SNR ratio of the composite signal and compare the SNR ratio with a threshold, which may be a predetermined threshold (e.g., a value stored in database 130). When the SNR ratio is below the threshold, external device 136 may determine that the recharge parameters are insufficient.

[0118] When the artifacts have been sufficiently minimized, method 900 may optionally proceed to step 804 of method 800. In this case, the recharge parameters used in method 900 can be used in method 800 to generate a neural response with sufficiently minimized artifacts. In some embodiments, external device 136 may determine whether the hardware of IMD 112 (e.g., pulse generator 132, leads 116A, 116B, electrodes 124, etc.) is capable of generating pulses with optimized recharge parameters. When the hardware of IMD 112 is capable of generating pulses with optimized recharge parameters, external device 136 may set the recharge parameters to the default settings of IMD 112. If the hardware of IMD 112 cannot generate pulses with optimized recharge parameters, external device 136 may configure IMD 112 to generate electrical pulses with recharge parameters as close to the optimized recharge parameters as allowed by the hardware of IMD 112.

[0119] Method 900 further includes adjusting recharge parameters (step 928). When the artifacts have not been sufficiently minimized, external device 136 may adjust one or more recharge parameters of the electrical pulse. External device 136 may use one or more numerical optimization methods (e.g., gradient descent, stochastic gradient descent, Newton's method, etc.) to adjust the recharge parameters such that the artifacts travel in directions with similar amplitudes and opposite signs (e.g., in the direction that maximizes destructive interference between artifact signals, in the direction that increases SNR, etc.).

[0120] In some cases, method 900 can be repeated until the recharge parameters are optimized. The recharge parameters can be considered optimized if: after a predetermined or selected number of iterations (e.g., after 6 iterations, the recharge parameters used in the 6th iteration are selected as optimized); based on parameters that cause the least amount of noise / optimal artifact elimination (e.g., the recharge parameters are optimized 6 times, and the 4th iteration produces the least amount of noise / highest SNR, therefore the recharge parameters associated with the 4th iteration are used), etc. Any one or more other criteria can be used to determine if the recharge parameters are optimized.

[0121] This disclosure covers embodiments of method 900 that include more or fewer steps than those described above and / or one or more steps that are different from those described above.

[0122] As stated above, this disclosure covers those having more than Figure 8 and Figure 9 (and the corresponding descriptions of methods 800 and 900) methods with fewer steps than those identified in the descriptions, and methods including those exceeding... Figure 8 and Figure 9 (and the corresponding descriptions of methods 800 and 900) include additional steps to those steps identified herein. This disclosure also covers methods that include one or more steps from one method described herein and one or more steps from another method described herein. Any correlation described herein may be or includes registration or any other correlation.

[0123] The foregoing is not intended to limit this disclosure to the one or more forms disclosed herein. In the foregoing detailed description, for example, for the purpose of simplification, various features of this disclosure are grouped together in one or more aspects, embodiments, and / or configurations. Features of aspects, embodiments, and / or configurations of this disclosure may be combined in alternative aspects, embodiments, and / or configurations other than those discussed above. The approach of this disclosure should not be construed as reflecting an intention that the claims require more features than expressly recited in each claim. Rather, as reflected in the following claims, aspects of the invention lie in fewer than all the features of a single foregoing aspect, embodiment, and / or configuration. Therefore, the following claims are hereby incorporated into this detailed description, wherein each claim exists independently as a separate preferred embodiment of this disclosure.

[0124] Furthermore, while the foregoing has already included descriptions of one or more aspects, embodiments, and / or configurations, as well as certain variations and modifications, other variations, combinations, and modifications may be made within the scope of this disclosure, for example, within the skill and knowledge of those skilled in the art, upon understanding of this disclosure. It is intended to obtain, to the permissible extent, rights including alternative aspects, embodiments, and / or configurations, including alternative, interchangeable, and / or equivalent structures, functions, scopes, or steps of those claimed, regardless of whether such alternative, interchangeable, and / or equivalent structures, functions, scopes, or steps are disclosed herein, and not to disclose for use in any patentable subject matter.

[0125] The following is a set of example statements: Statement 1: A method, the method comprising: generating a first electrical pulse at a first time; Measure a first neural response to the first electrical pulse; generate a second electrical pulse having at least one characteristic different from the first electrical pulse at a second time; Measure a second neural response to the second electrical impulse; and remove at least one artifact from at least one of the first neural response and the second neural response.

[0126] Statement 2: According to the method of Statement 1, at least one of the first neural response and the second neural response includes an evoked compound action potential (ECAP) response or a compound muscle action potential (CMAP) response.

[0127] Statement 3: The method according to any one of Statements 1 to 2, wherein the at least one characteristic includes a passive recharge phase occurring after the second electrical pulse being paused to allow measurement of the amount of time prior to the second neural response.

[0128] Statement 4: The method according to any one of Statements 1 to 3, wherein the at least one feature includes a recharging mechanism.

[0129] Statement 5: The method according to any one of Statements 1 to 4, wherein the first electrical pulse includes an active recharging mechanism, and wherein the second electrical pulse includes a passive recharging mechanism.

[0130] Statement 6: In the method according to any one of Statements 1 to 5, the first electrical pulse includes a passive recharging mechanism, and the second electrical pulse includes an active recharging mechanism.

[0131] Statement 7: The method according to any one of Statements 1 to 6, wherein the at least one characteristic includes at least one of the amplitude of the recharge phase of the second electrical pulse and the pulse width.

[0132] Statement 8: The method according to any one of Statements 1 to 7, wherein the at least one characteristic includes the amplitude of the recharge phase, and wherein the amplitude of the recharge phase of the first electrical pulse is greater than the amplitude of the recharge phase of the second electrical pulse.

[0133] Statement 9: The method according to any one of Statements 1 to 8, wherein the at least one characteristic includes the pulse width of the recharge phase, and wherein the pulse width of the recharge phase of the first electrical pulse is less than the pulse width of the recharge phase of the second electrical pulse.

[0134] Statement 10: The method according to any one of Statements 1 to 9, wherein removing the at least one artifact further comprises: combining the first neural response and the second neural response into a composite response.

[0135] Statement 11: The method according to any one of Statements 1 to 10, wherein combining the first neural response and the second neural response comprises: weighting at least one of the first neural response and the second neural response.

[0136] Statement 12: The method according to any one of Statements 1 to 11, wherein the composite response has reduced noise compared to the first neural response and the second neural response.

[0137] Statement 13: The method according to any one of Statements 1 to 12, wherein the first neural response and the second neural response are generated by anatomical elements, and wherein the method further comprises: selecting at least one recharge parameter that increases the signal-to-noise ratio of the composite response.

[0138] Statement 14: An apparatus comprising: a pulse generator configured to generate electrical pulses delivered to an anatomical element via stimulating electrodes; a processor; and a memory coupled to the processor and storing data thereon, the data, when processed by the processor, enabling the processor to: cause the pulse generator to generate a first electrical pulse; receive a first neural response of the anatomical element to the first electrical pulse; cause the pulse generator to generate a second electrical pulse having at least one characteristic different from the first electrical pulse; receive a second neural response from the anatomical element to the second electrical pulse; and combine the first neural response and the second neural response into a composite response signal, wherein the composite response signal has less noise than the first neural response and the second neural response.

[0139] Statement 15: In the device according to Statement 14, at least one of the first neural response and the second neural response includes an evoked compound action potential (ECAP) response or a compound muscle action potential (CMAP) response of the anatomical element.

[0140] Statement 16: The device according to any one of Statements 14 to 15, wherein the at least one feature includes a passive recharge phase that occurs after the second electrical pulse being paused to allow measurement of the amount of time prior to the second neural response.

[0141] Statement 17: The device according to any one of Statements 14 to 16, wherein the at least one feature includes a recharging mechanism.

[0142] Statement 18: The device according to any one of Statements 14 to 17, wherein the first electrical pulse includes an active recharging mechanism, and wherein the second electrical pulse includes a passive recharging mechanism.

[0143] Statement 19: The device according to any one of Statements 14 to 18, wherein the first electrical pulse includes a passive recharging mechanism, and wherein the second electrical pulse includes an active recharging mechanism.

[0144] Statement 20: The device according to any one of statements 14 to 19, wherein the at least one characteristic includes at least one of the amplitude and pulse width of the recharge phase of the second electrical pulse.

[0145] Statement 21: The device according to any one of Statements 14 to 20, wherein the at least one characteristic includes the amplitude of a recharge phase, and wherein the amplitude of the recharge phase of the first electrical pulse is greater than the amplitude of the recharge phase of the second electrical pulse.

[0146] Statement 22: The device according to any one of Statements 14 to 21, wherein the at least one characteristic includes the pulse width of the recharge phase, and wherein the pulse width of the recharge phase of the first electrical pulse is less than the pulse width of the recharge phase of the second electrical pulse.

[0147] Statement 23: The device according to any one of statements 14 to 22, wherein combining the first neural response and the second neural response comprises: weighting at least one of the first neural response and the second neural response.

[0148] Statement 24: The device according to any one of Statements 14 to 23, wherein the data, when processed by the processor, further enables the processor to: select at least one recharge parameter that increases the signal-to-noise ratio of the composite response signal; cause the pulse generator to generate a third electrical pulse according to the at least one recharge parameter; receive a third neural response of the anatomical element to the third electrical pulse; and combine at least one of the first neural response and the second neural response with the third neural response.

[0149] Statement 25: An apparatus comprising: a pulse generator that generates electrical pulses; a stimulating electrode electrically coupled to the pulse generator, the stimulating electrode delivering the electrical pulses generated by the pulse generator to an anatomical element; a processor; and a memory coupled to the processor and storing data thereon, the data enabling the processor, when processed by the processor, to: receive a first neural signal from the anatomical element in response to a first electrical pulse generated by the pulse generator and delivered by the stimulating electrode; receive a second neural signal from the anatomical element in response to a second electrical pulse generated by the pulse generator and delivered by the stimulating electrode, wherein at least one characteristic of the second electrical pulse is different from that of the first electrical pulse; and combine the first neural signal and the second neural signal into a composite signal, wherein the composite signal has less noise than the first neural signal and the second neural signal.

[0150] Statement 26: In the device according to Statement 25, at least one of the first neural signal and the second neural signal includes an evoked compound action potential (ECAP) response or a compound muscle action potential (CMAP).

[0151] Statement 27: The device according to any one of Statements 25 to 26, wherein the at least one feature includes a time amount prior to the passive recharge phase occurring after the second electrical pulse being paused to allow measurement of the second neural signal.

[0152] Statement 28: The device according to any one of Statements 25 to 27, wherein the at least one feature includes a recharging mechanism.

[0153] Statement 29: The device according to any one of Statements 25 to 28, wherein the first electrical pulse includes an active recharging mechanism, and wherein the second electrical pulse includes a passive recharging mechanism.

[0154] Statement 30: The device according to any one of Statements 25 to 29, wherein the first electrical pulse includes a passive recharging mechanism, and wherein the second electrical pulse includes an active recharging mechanism.

[0155] Statement 31: The device according to any one of statements 25 to 30, wherein the at least one characteristic includes at least one of the amplitude of the recharge phase of the second electrical pulse and the pulse width.

[0156] Statement 32: The device according to any one of statements 25 to 31, wherein combining the first neural signal and the second neural signal includes weighting at least one of the first neural signal and the second neural signal.

Claims

1. A method, the method comprising: The first electrical pulse is generated immediately. Measure the first neural response to the first electrical impulse; A second electrical pulse with at least one characteristic different from the first electrical pulse is generated at a second time. Measure the second neural response to the second electrical impulse; as well as Remove at least one artifact from at least one of the first neural response and the second neural response.

2. The method of claim 1, wherein at least one of the first neural response and the second neural response comprises an evoked compound action potential (ECAP) response or a compound muscle action potential (CMAP) response.

3. The method of claim 1, wherein the at least one characteristic includes a passive recharge phase occurring after the second electrical pulse being paused to allow measurement of the amount of time prior to the second neural response.

4. The method of claim 1, wherein the at least one feature includes a recharge mechanism.

5. The method of claim 4, wherein the first electrical pulse includes an active recharging mechanism, and wherein the second electrical pulse includes a passive recharging mechanism.

6. The method of claim 4, wherein the first electrical pulse includes a passive recharging mechanism, and wherein the second electrical pulse includes an active recharging mechanism.

7. The method of claim 1, wherein the at least one characteristic includes at least one of the amplitude of the recharge phase of the second electrical pulse and the pulse width.

8. The method of claim 1, wherein the at least one characteristic includes the amplitude of the recharge phase, and wherein the amplitude of the recharge phase of the first electrical pulse is greater than the amplitude of the recharge phase of the second electrical pulse.

9. The method of claim 1, wherein the at least one characteristic includes the pulse width of the recharge phase, and wherein the pulse width of the recharge phase of the first electrical pulse is less than the pulse width of the recharge phase of the second electrical pulse.

10. The method of claim 1, wherein removing the at least one artifact further comprises: The first neural response and the second neural response are combined into a composite response.

11. The method of claim 10, wherein combining the first neural response and the second neural response comprises: At least one of the first neural response and the second neural response is weighted.

12. The method of claim 10, wherein the composite response has reduced noise compared to the first neural response and the second neural response.

13. The method of claim 10, wherein the first neural response and the second neural response are generated by anatomical elements, and wherein the method further comprises: Select at least one recharge parameter that increases the signal-to-noise ratio of the composite response.

14. An apparatus, the apparatus comprising: A pulse generator configured to generate electrical pulses delivered to an anatomical element via a stimulating electrode; processor; and A memory, connected to the processor and storing data, which, when processed by the processor, enables the processor to: The pulse generator generates a first electrical pulse; Receive the first neural response of the anatomical element to the first electrical pulse; The pulse generator is used to generate a second electrical pulse having at least one characteristic different from the first electrical pulse. Receive a second neural response to the second electrical impulse from the anatomical element; as well as The first neural response and the second neural response are combined into a composite response signal, wherein the composite response signal has less noise than the first neural response and the second neural response.

15. An apparatus, the apparatus comprising: A pulse generator that generates electrical pulses; A stimulation electrode electrically coupled to the pulse generator, the stimulation electrode delivering the electrical pulses generated by the pulse generator to the anatomical element; processor; and A memory, connected to the processor and storing data, which, when processed by the processor, enables the processor to: In response to a first electrical pulse generated by the pulse generator and delivered by the stimulating electrode, a first neural signal is received from the anatomical element; In response to a second electrical pulse generated by the pulse generator and delivered by the stimulating electrode, a second neural signal is received from the anatomical element, wherein at least one characteristic of the second electrical pulse is different from that of the first electrical pulse; as well as The first neural signal and the second neural signal are combined into a composite signal, wherein the composite signal has less noise than the first neural signal and the second neural signal.

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