A multi-electrode static sequence control system for DRG electrical stimulation

Abstract

This application discloses a multi-electrode static sequence control system for DRG electrical stimulation, comprising: M electrodes, each used to electrically stimulate M different DRGs, where M is an integer greater than 1; and an implantable pulse generator electrically connected to each of the M electrodes. The implantable pulse generator is configured to: determine the electrical stimulation sequence of the M electrodes based on the electrical stimulation sequence; and sequentially control the corresponding electrodes to perform electrical stimulation according to the electrical stimulation sequence. In the electrical stimulation sequence, the (i+1)th electrode is the electrode with the largest spatial distance from the i-th electrode among the (i+1)th to the M-th electrodes, where 1 ≤ i < M. In this application embodiment, spatial isolation is introduced to reduce the risk of electric field overlap and crosstalk. Simultaneously, due to the use of a static preset sequence, complex optimization calculations are not required during actual electrical stimulation, which helps support high-frequency electrical stimulation therapy and can reduce power consumption.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a multi-electrode static sequence control system for DRG electrical stimulation. Background Technology

[0002] Dorsal root ganglion (DRG) electrical stimulation is a neuromodulation technique that has been increasingly applied in the treatment of chronic pain and other diseases in recent years. By placing electrodes (also called "stimulation electrodes") near the dorsal root ganglion and applying stimulation signals, the transmission of pain signals can be modulated, thereby achieving a therapeutic effect of pain relief. Due to the relatively fixed anatomical position and sensitive response to stimulation of the dorsal root ganglion, DRG electrical stimulation shows promising clinical application prospects for specific indications.

[0003] However, in actual clinical practice, many patients with chronic pain (such as those with complex regional pain syndrome, polyneuropathy, or failed back surgery syndrome) often exhibit multi-segmental and widespread pain distribution. To achieve comprehensive and effective pain coverage, physicians typically need to implant multiple electrodes in different spinal cord segments to simultaneously perform multi-point neuromodulation targeting multiple different DRGs (i.e., multiple targets).

[0004] When an implantable pulse generator drives the electrodes to output stimulation signals, a specific spatial electric field distribution is formed in the conductive tissues surrounding the electrode contacts (such as cerebrospinal fluid, epidural fat, and tissues surrounding nerve roots). Traditional control strategies for driving multiple electrodes typically employ a fixed anatomical sequence (e.g., discharging sequentially from top to bottom along the spine) or a random polling sequence. However, because human tissue is an excellent conductive medium, there is a time delay in the dissipation of stimulation signals within the tissue. When two electrodes that are spatially close discharge consecutively within a very short time interval, the residual electric field generated by the first electrode has not yet completely dissipated before the new electric field generated by the second electrode is superimposed.

[0005] This overlap and coupling of spatial electric fields can cause serious interference problems between multiple electrodes. Specifically: on the one hand, the abnormal superposition and amplification of local spatial electric fields may lead to overactivation of target nerves and even non-target nerves (such as ventral motor nerve roots), causing patients to experience tingling sensations, unexpected paresthesia, or severe muscle spasms, posing a great safety hazard; on the other hand, the disordered interweaving of electric fields may also lead to distortion of charge distribution or mutual cancellation, destroying the original analgesic mechanism and causing a significant reduction in the overall therapeutic effect.

[0006] In summary, in multi-DRG electrical stimulation therapy, how to plan the working sequence of multiple electrodes to effectively avoid or reduce the mutual interference caused by the superposition of spatial electric fields between multiple electrodes, thereby ensuring the accuracy of analgesic effect and patient safety, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] This application provides a multi-electrode static sequence control system for DRG electrical stimulation, which helps to solve the problem of mutual interference between multiple electrodes due to the superposition of spatial electric fields in the prior art.

[0008] In a first aspect, embodiments of this application provide a multi-electrode static sequence control system for DRG electrical stimulation, comprising: M electrodes, wherein the M electrodes are respectively used to electrically stimulate M different DRGs, wherein M is an integer greater than 1; and an implantable pulse generator, wherein the implantable pulse generator is electrically connected to the M electrodes respectively. The implantable pulse generator is configured to: determine the electrical stimulation sequence of the M electrodes based on the electrical stimulation sequence; and control the corresponding electrodes to perform electrical stimulation sequentially according to the electrical stimulation sequence of the M electrodes; wherein the (i+1)th electrode in the electrical stimulation sequence is the electrode with the largest spatial distance from the i-th electrode among the (i+1)th to the M-th electrodes, 1≤i<M.

[0009] In this embodiment, by pre-planning the electrode with the farthest spatial distance as the next stimulation target, spatial isolation is actively introduced, reducing the risk of electric field overlap and crosstalk. Simultaneously, due to the use of a statically preset sequence, the system does not need to perform complex optimization calculations during actual electrical stimulation, resulting in extremely low computational latency and almost no additional occupation of the stimulation time interval. This helps support high-frequency electrical stimulation therapy and can reduce the operating power consumption of the system processor.

[0010] In one possible implementation, before determining the electrical stimulation order of the M electrodes based on the electrical stimulation sequence, the method further includes: obtaining spatial distance information between each pair of the M electrodes; and generating the electrical stimulation sequence containing the M electrodes based on the spatial distance information between each pair of the M electrodes.

[0011] In this embodiment, by obtaining the spatial distance between all pairs of electrodes at once before arranging the sequence, the preset sequence arrangement can objectively reflect the true global spatial topology of the electrodes, which helps to ensure the effectiveness of the sequence anti-crosstalk logic.

[0012] In one possible implementation, obtaining the spatial distance information between each pair of the M electrodes includes: obtaining the position information of the M electrodes in an electrode distribution map; determining the spatial distance information between each pair of the M electrodes based on the position information of the M electrodes; wherein the electrode distribution map includes the position information of each of the electrodes.

[0013] In this embodiment, spatial distance is directly calculated by reading a pre-stored electrode distribution map, avoiding tedious physical detection tests during sequence generation. This approach further reduces the overall power consumption of the system to some extent, helping to extend the battery life of the implanted pulse generator.

[0014] In one possible implementation, the position information is coordinate information. Before obtaining the position information of the M electrodes in the electrode distribution map, the method further includes: applying a first test signal between any two electrodes among the M electrodes; measuring the impedance between the arbitrary two electrodes; converting the measured impedance between the arbitrary two electrodes into spatial distance information between the arbitrary two electrodes based on a preset impedance-distance mapping relationship; using any one of the M electrodes as a spatial reference, performing three-dimensional spatial coordinate calculation based on all the spatial distance information to obtain the coordinate information of each electrode in three-dimensional space; generating an electrode distribution map based on the coordinate information of each electrode in three-dimensional space; wherein the amplitude of the first test signal is less than the amplitude of the stimulation signal when the DRG is electrically stimulated; and / or, the pulse width of the first test signal is less than the pulse width of the stimulation signal when the DRG is electrically stimulated.

[0015] In this embodiment, the system is able to independently and autonomously complete spatial coordinate self-calibration within the body, reducing reliance on external surveying equipment; at the same time, the use of subthreshold test signals avoids accidental nerve excitation during the ranging phase, improving patient comfort and treatment safety.

[0016] In one possible implementation, the location information is coordinate information. Before obtaining the location information of the M electrodes in the electrode distribution map, the method further includes: controlling a target electrode among the M electrodes to output a second test signal, wherein the target electrode is any one of the M electrodes; controlling the remaining electrodes other than the target electrode as listening electrodes to collect neurally evoked compound action potentials triggered by the second test signal; obtaining the time delay between the second test signal output by the target electrode and the neurally evoked compound action potentials collected by each of the listening electrodes; converting the measured time delay into spatial distance information between the target electrode and each of the listening electrodes based on a preset delay-distance mapping relationship; using the target electrode as a spatial reference, performing three-dimensional spatial coordinate calculation based on all the spatial distance information to obtain the coordinate information of each electrode in three-dimensional space; and generating an electrode distribution map based on the coordinate information of each electrode in three-dimensional space.

[0017] In this embodiment, the distance is estimated by relying on the physiological time delay of nerve signal transmission, which can more realistically reflect the "physiological effective distance" along the spinal cord anatomical pathway. This makes the generated anti-crosstalk preset sequence more consistent with the actual electrophysiological coupling characteristics of nerve tissue and improves the accuracy of regulation.

[0018] In one possible implementation, the location information is coordinate information. Before obtaining the location information of the M electrodes in the electrode distribution map, the method further includes: receiving coordinate calibration data sent by an external programmable device through the implantable pulse generator, wherein the coordinate calibration data includes the coordinate information of the M electrodes in three-dimensional space extracted based on human medical images; and generating an electrode distribution map based on the coordinate information of each electrode in three-dimensional space.

[0019] In this embodiment, coordinates are transmitted using external high-precision medical images, resulting in high physical location accuracy and resistance to interference from internal physiological fluctuations. At the same time, the massive image recognition and coordinate calculation work is offloaded to external devices, saving the implant's power and computing power to a certain extent.

[0020] In one possible implementation, the implantable pulse generator is further configured to update the electrode distribution map when a first preset update condition is met; wherein the first preset update condition includes at least one of the following: system initialization; reaching a preset first update cycle; or detecting that the impedance change between any two electrodes exceeds a preset offset threshold.

[0021] In the embodiments of this application, when a chronic drift or acute displacement of the electrode occurs, the system can recalibrate the electrode distribution map to avoid generating an incorrect static sequence due to the failure of the underlying electrode distribution map, thus maintaining long-term anti-crosstalk security.

[0022] In one possible implementation, obtaining the spatial distance information between any two of the M electrodes includes: applying a third test signal between any two of the M electrodes; measuring the impedance between any two electrodes; and converting the measured impedance between any two electrodes into spatial distance information between any two of the M electrodes based on a preset impedance-distance mapping relationship; wherein the amplitude of the third test signal is less than the amplitude of the stimulation signal when the DRG is electrically stimulated; and / or the pulse width of the third test signal is less than the pulse width of the stimulation signal when the DRG is electrically stimulated.

[0023] In this embodiment, the distance is mapped directly through impedance measurement without relying on the electrode distribution map, making the processing logic simpler and enabling the rapid acquisition of spatial distance information between electrodes.

[0024] In one possible implementation, the implantable pulse generator is further configured to: after the current electrode completes electrical stimulation, if the spatial distance between the current electrode and the electrode for the next electrical stimulation is less than or equal to a preset spatial distance threshold, then reduce the amplitude and / or pulse width of the next electrical stimulation; wherein the current electrode is any electrode in the electrical stimulation sequence except for the last electrode.

[0025] In this embodiment of the application, when the distance between adjacent electrodes inevitably becomes too close in the preset sequence, the system reduces the volume of the spatial electric field by actively reducing the amplitude or pulse width of the stimulation signal, effectively preventing the safety hazards caused by local charge superposition overload.

[0026] In one possible implementation, the implantable pulse generator is further configured to: randomly select one electrode from the M electrodes as the first electrode in the electrical stimulation sequence when a second preset update condition is met, and update the electrical stimulation sequence; wherein the second preset update condition includes at least one of the following: completing a stimulation cycle, in which each electrode performs an electrical stimulation action once; reaching a preset second update cycle; and detecting that the impedance change between any two electrodes exceeds a preset offset threshold.

[0027] In the embodiments of this application, by periodically or under specific conditions resetting the random starting point of the initial electrode, the regenerated electrical stimulation sequence exhibits macroscopic diversity, which may help reduce synaptic habituation of the nervous system to fixed stimulation pathways, thereby maintaining a stable analgesic effect in long-term treatment. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a structural block diagram of a multi-electrode static sequence control system for DRG electrical stimulation provided in an embodiment of this application. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0031] Dorsal root ganglion (DRG) electrical stimulation is a neuromodulation technique that has been increasingly applied in the treatment of chronic pain and other diseases in recent years. By placing electrodes (also called "stimulation electrodes") near the dorsal root ganglion and applying stimulation signals, the transmission of pain signals can be modulated, thereby achieving a therapeutic effect of pain relief. Due to the relatively fixed anatomical position and sensitive response to stimulation of the dorsal root ganglion, DRG electrical stimulation shows promising clinical application prospects for specific indications.

[0032] However, in actual clinical practice, many patients with chronic pain (such as those with complex regional pain syndrome, polyneuropathy, or failed back surgery syndrome) often exhibit multi-segmental and widespread pain distribution. To achieve comprehensive and effective pain coverage, physicians typically need to implant multiple electrodes in different spinal cord segments to simultaneously perform multi-point neuromodulation targeting multiple different DRGs (i.e., multiple targets).

[0033] When an implantable pulse generator drives the electrodes to output stimulation signals, a specific spatial electric field distribution is formed in the conductive tissues surrounding the electrode contacts (such as cerebrospinal fluid, epidural fat, and tissues surrounding nerve roots). Traditional control strategies for driving multiple electrodes typically employ a fixed anatomical sequence (e.g., discharging sequentially from top to bottom along the spine) or a random polling sequence. However, because human tissue is an excellent conductive medium, there is a time delay in the dissipation of stimulation signals within the tissue. When two electrodes that are spatially close discharge consecutively within a very short time interval, the residual electric field generated by the first electrode has not yet completely dissipated before the new electric field generated by the second electrode is superimposed.

[0034] This overlap and coupling of spatial electric fields can cause serious interference problems between multiple electrodes. Specifically: on the one hand, the abnormal superposition and amplification of local spatial electric fields may lead to overactivation of target nerves and even non-target nerves (such as ventral motor nerve roots), causing patients to experience tingling sensations, unexpected paresthesia, or severe muscle spasms, posing a great safety hazard; on the other hand, the disordered interweaving of electric fields may also lead to distortion of charge distribution or mutual cancellation, destroying the original analgesic mechanism and causing a significant reduction in the overall therapeutic effect.

[0035] In summary, in multi-DRG electrical stimulation therapy, how to plan the working sequence of multiple electrodes to effectively avoid or reduce the mutual interference caused by the superposition of spatial electric fields between multiple electrodes, thereby ensuring the accuracy of analgesic effect and patient safety, is a technical problem that urgently needs to be solved by those skilled in the art.

[0036] To address the aforementioned issues, this application provides a multi-electrode static sequence control system for DRG electrical stimulation. By pre-planning the electrode with the greatest spatial distance as the next stimulation target, spatial isolation is actively introduced, reducing the risk of electric field overlap and crosstalk. Furthermore, due to the use of a statically preset sequence, the system does not require complex optimization calculations between two electrical stimulation sessions, resulting in extremely low latency. It almost does not occupy the time interval between two conventional stimulation signals, which helps support high-frequency electrical stimulation therapy and significantly reduces the system processor's power consumption. The specific implementation method is described in detail below.

[0037] See Figure 1 This is a structural block diagram of a multi-electrode static sequence control system for DRG electrical stimulation provided in an embodiment of this application. Figure 1 As shown, the control system includes M electrodes, each used to electrically stimulate M different DRGs, where M is an integer greater than 1; and an implantable pulse generator, which is electrically connected to each of the M electrodes.

[0038] In this embodiment, to more clearly describe the operating logic of the control system, the electrodes and spatial distance information are first explained. Typically, an electrode physically includes an electrode wire and electrode contacts located at the ends (distal ends) of the electrode wire. The spatial distance information processed by the implantable pulse generator usually refers to the spatial distance between the electrode contacts of each electrode. Since the electrode contacts are the physical interfaces through which the electrical stimulation signal is actually released and comes into contact with human tissue, using them as the basis for distance calculation can more accurately reflect the distribution of the spatial electric field.

[0039] Specifically, the implantable pulse generator determines the electrical stimulation sequence of M electrodes based on a pre-set electrical stimulation sequence. Then, according to this sequence, it sequentially controls the corresponding electrodes to perform electrical stimulation. The electrical stimulation sequence is arranged according to a specific anti-crosstalk spatial logic: the (i+1)th electrode in the sequence is the electrode with the largest spatial distance from the ith electrode among the (i+1)th to the Mth electrodes, where 1 ≤ i < M. In other words, in the pre-planned sequence, the next electrode to discharge immediately following the current electrode must be the one furthest from the current electrode among the remaining unstimulated electrodes.

[0040] It is understandable that, due to the conductivity of human tissue and internal fluid environment, electrode contacts generate a specific spatial electric field around them when outputting stimulation signals. If two electrodes with relatively close physical locations discharge consecutively on the time axis, the dissipation of the preceding electric field requires a certain amount of time, and the appearance of the subsequent electric field may cause local spatial electric fields to overlap and couple. In the embodiments of this application, by pre-planning the electrode with the farthest spatial distance as the next stimulation target, maximum physical spatial isolation is actively introduced between two consecutive electrical stimulations. This spatial isolation mechanism allows the residual electric field generated by the preceding electrode to be attenuated to a large extent when it diffuses to the next working electrode, thereby reducing the cross-coupling of local electric fields and reducing the risk of non-target nerves being mistakenly activated (such as causing muscle spasms) or the analgesic effect being reduced.

[0041] Meanwhile, due to the use of a statically preset sequence, the underlying hardware is directly triggered sequentially during actual electrical stimulation, eliminating the need to wake the processor for complex optimization calculations between stimulation sessions. This mechanism results in low computational latency, barely occupying the time interval between two regular stimulation signals, which helps support seamless transitions in high-frequency electrical stimulation therapy and significantly reduces the system processor's power consumption.

[0042] In one possible implementation, before determining the electrical stimulation sequence of the M electrodes based on the electrical stimulation sequence, the implantable pulse generator needs to first acquire the spatial distance information between each pair of the M electrodes; then, based on the spatial distance information between each pair of the M electrodes, an electrical stimulation sequence containing the M electrodes is generated.

[0043] In specific implementations, this application provides different implementation schemes for obtaining the spatial distance information between each pair of M electrodes.

[0044] In one possible implementation, the implantable pulse generator can acquire the position information of M electrodes from an electrode distribution map; then, based on the position information of the M electrodes, it can determine the spatial distance information between each pair of the M electrodes. Specifically, the electrode distribution map includes the position information of each electrode. At the physical level, the position information typically refers to the coordinate data of the electrode contacts of each electrode within the human anatomical structure or the device's three-dimensional coordinate system. The electrode distribution map can be understood as a spatial topology mapping table stored in the memory of the implantable pulse generator, recording the relative positional relationships of all electrode contacts in three-dimensional space.

[0045] In this embodiment, spatial distance is calculated directly using spatial geometry algorithms by reading a pre-stored electrode distribution map, avoiding the cumbersome physical signal transmission and reception and detection performed temporarily during sequence generation. This approach further reduces the overall power consumption of the system to some extent, helping to extend the battery life of the implanted pulse generator.

[0046] Based on this, the positional information of the electrodes can be specifically represented as coordinate information in three-dimensional space. To construct the aforementioned electrode distribution map, this application provides the following three possible implementation schemes: The first approach is based on the impedance characteristics of human tissue. Specifically, the implanted pulse generator applies a first test signal between any two of the M electrodes and measures the impedance between them. Since the tissues of the epidural space (such as fat and cerebrospinal fluid) have specific resistivity, the equivalent impedance of an electrical signal propagating through the tissue is usually strongly correlated with the physical conduction distance. Therefore, the system can convert the measured impedance into spatial distance information between any two electrodes based on a preset impedance-distance mapping relationship. Subsequently, using any one of the M electrodes as a spatial reference, three-dimensional spatial coordinates are calculated based on all the spatial distance information to obtain the coordinate information of each electrode in three-dimensional space, and an electrode distribution map is generated accordingly.

[0047] Furthermore, to ensure a better patient experience, the amplitude of the first test signal is smaller than the amplitude of the stimulation signal when the DRG is electrically stimulated; and / or, the pulse width of the first test signal is smaller than the pulse width of the stimulation signal when the DRG is electrically stimulated. This parameter setting ensures that the first test signal is typically in a subthreshold state of neural activation.

[0048] In this embodiment, the implantable pulse generator can independently perform spatial coordinate self-calibration within the body, reducing reliance on external mapping equipment. Simultaneously, using a subthreshold first test signal with smaller amplitude or pulse width avoids accidental neural depolarization during the detection and ranging phase, reducing the likelihood of unexpected paresthesia or muscle twitching in patients and improving system safety.

[0049] The second approach is based on the neurophysiological conduction characteristics. Specifically, an implantable pulse generator controls the target electrode (any one of the M electrodes) to output a second test signal; simultaneously, the remaining electrodes (excluding the target electrode) are controlled as listening electrodes to collect the evoked compound action potential (ECAP) triggered by the second test signal. The ECAP refers to the macroscopic electrophysiological response signal synchronously generated by a group of nerve fibers after effective electrical stimulation. Next, the time delay between the second test signal output by the target electrode and the ECAP collected by each listening electrode is obtained. Since nerve conduction velocity is relatively stable under specific physiological conditions, the system can convert the measured time delay into spatial distance information based on a preset delay-distance mapping relationship, and then perform three-dimensional spatial coordinate calculations using a spatial reference benchmark to generate an electrode distribution map.

[0050] In this embodiment, the distance is calculated by the time delay of action potential conduction. The system actually obtains the "physiological conduction distance" between electrodes along the neuroanatomical pathway. Compared to a purely physical straight-line distance, this physiological distance can more realistically reflect the topological coupling relationship of the various nodes of the nervous system in response to electrical stimulation. The electrode distribution map generated using this data can more realistically reflect the "effective physiological distance" along the neuroanatomical pathway, making the generated anti-crosstalk preset sequence more closely match the actual electrophysiological coupling characteristics of neural tissue and improving the accuracy of modulation.

[0051] The third approach is based on external medical imaging. The implantable pulse generator directly receives coordinate calibration data from an external programmable device. This coordinate calibration data includes the coordinate information of M electrodes in three-dimensional space extracted from human medical images (such as intraoperative X-ray fluoroscopy, CT scan, or MRI images), and generates an electrode distribution map accordingly.

[0052] In this embodiment, coordinate information is extracted directly from high-resolution medical images, which typically has high anatomical and physical accuracy and is less susceptible to interference from local tissue inflammation, fluctuations in body fluid impedance, or individual differences in nerve conduction velocity. Furthermore, the massive computational work involved in image recognition and coordinate calculation is primarily performed by external medical devices or the cloud, with the implant only needing to perform receiving and storage actions. This conserves the computational resources of the implantable pulse generator and conserves valuable battery power.

[0053] Considering the dynamic changes in the human body's internal environment, the implantable pulse generator is also configured to update the electrode distribution map when a first preset update condition is met. Specifically, the first preset update condition includes at least one of the following: system initialization; reaching a preset first update cycle; or detecting an impedance change between any two electrodes exceeding a preset offset threshold.

[0054] In practice, the "system initialization" condition typically occurs after the implantable pulse generator is first powered on, after a system reset, or after a firmware upgrade. Triggering an update to the electrode distribution map at this stage provides the latest and most reliable spatial reference topology data for the static sequence control of the electrodes throughout the entire operational lifecycle.

[0055] To meet the condition of "reaching the preset first update cycle," the implantable pulse generator can be configured with a long-term timer. When the system's continuous operation or standby time reaches the set time interval (e.g., several days or weeks), a reassessment and update of the electrode distribution map is automatically triggered. This periodic maintenance mechanism is mainly used to correct chronic electrode displacement caused by factors such as slow growth and encapsulation of human tissue and minute muscle traction.

[0056] Regarding the update condition of "detecting an impedance change between any two electrodes exceeding a preset offset threshold," in practice, the implantable pulse generator can monitor the loop impedance between the two electrodes in the background using a weak detection signal during breaks in routine electrical stimulation therapy. Because the impedance between two electrodes is highly correlated with their physical distance in a relatively stable bodily fluid environment, when a patient experiences a drastic change in position, an accidental fall, or strenuous exercise, causing sudden slippage or significant displacement of the electrodes, the corresponding loop impedance value will exhibit a significant jump. Once the calculated impedance change exceeds the preset offset threshold, the system can determine that the current electrode map is invalid, thereby immediately triggering an update of the electrode map. In practice, to reduce system data processing load and shorten update time, only the position information of the electrodes that have shifted in the electrode map (i.e., the electrodes whose impedance change exceeds the preset offset threshold) can be updated, rather than a global update of the electrode map.

[0057] In the embodiments of this application, when a chronic drift or acute displacement of the electrode occurs, the system can recalibrate the electrode distribution map to avoid generating an incorrect static sequence due to the failure of the underlying spatial data, thus maintaining long-term anti-crosstalk security.

[0058] Besides the electrode distribution map-based approach described above, another possible implementation is to obtain the spatial distance information between each pair of M electrodes without relying on memory data, but instead using direct physical detection. Specifically, the implanted pulse generator applies a third test signal between any two of the M electrodes; measures the impedance between any two electrodes; and converts the measured impedance into spatial distance information between each pair of the M electrodes based on a preset impedance-distance mapping relationship. Similarly, the amplitude and / or pulse width of the third test signal are smaller than the normal stimulation signal, remaining in a subthreshold state. This method of directly mapping distance through impedance measurement has a flatter and more direct processing logic, enabling rapid capture of the current actual physical distance before generating the electrical stimulation sequence.

[0059] In the actual execution of the electrical stimulation sequence, considering the limitations of the actual anatomical space, the implantable pulse generator is also configured to: after the current electrode completes electrical stimulation, if the spatial distance between the current electrode and the electrode for the next electrical stimulation (the current electrode is any electrode in the electrical stimulation sequence other than the last electrode) is less than or equal to a preset spatial distance threshold, then reduce the amplitude and / or pulse width of the next electrical stimulation.

[0060] In practice, the preset spatial distance threshold typically represents a physical isolation safety boundary benchmark. When the distance between two electrodes activated sequentially is lower than this benchmark, the probability of severe superposition and crosstalk between their respective spatial electric fields increases significantly. Amplitude and pulse width are the core stimulation parameters that determine the total energy output of a single pulse of the electrical stimulation signal. Reducing the amplitude and / or pulse width of the next electrical stimulation can be achieved by individually lowering the voltage or current amplitude of the stimulation signal, individually shortening the pulse duration, or simultaneously reducing both amplitude and duration.

[0061] Specifically, during the pre-planning and generation of the electrical stimulation sequence, although the algorithm follows the constraint of finding the farthest spatial distance, the number of remaining electrodes to be sorted gradually decreases when arranging the sequence in the latter part of a stimulation cycle. In some scenarios, the remaining few electrodes may be physically adjacent to each other; or in scenarios where the anatomical structure of a specific nerve segment of the patient is limited and the density of multiple electrode implantations is high, this will inevitably lead to a situation in the final generated electrical stimulation sequence where the absolute physical spatial distance between two adjacent electrodes is less than the preset spatial distance threshold. In this case, when the system executes the static sequence in sequence, it will trigger the corresponding parameter reduction logic once it encounters the aforementioned short-distance continuous stimulation steps.

[0062] In this embodiment, when the system has to select a physically close electrode for continuous stimulation due to a reduction in the number of unstimulated electrodes or anatomical layout limitations, maintaining the usual stimulation parameters can easily lead to overload of charge accumulation in local nerve tissue by superimposing the residual electric field from the previous stimulation with the newly generated high-intensity spatial electric field. This can result in misactivation of motor nerves or cause intense tingling in the patient. This application proactively reduces the amplitude and / or pulse width of the next electrical stimulation by monitoring if the execution distance is less than or equal to a preset spatial distance threshold. In effect, this dynamically compensates for insufficient physical spatial isolation by actively reducing the volume range of the subsequent spatial electric field. This compensation mechanism can weaken the superposition peak of the local electric field to a certain extent, ensuring that the overall electric field strength after coupling remains within a safe physiological tolerance range. This helps to further prevent the safety risks of multi-electrode electric field crosstalk in dense electrode array control and timing scheduling at the end of the stimulation cycle, improving the system's robustness in complex and extreme topological environments.

[0063] Finally, to break the long-term rigidity of static sequences, the implantable pulse generator is configured to: randomly select one electrode from M electrodes as the first electrode in the electrical stimulation sequence when a second preset update condition is met, thus regenerating and updating the electrical stimulation sequence. The second preset update condition includes at least one of the following: completing one stimulation cycle (i.e., each electrode performs one electrical stimulation action); reaching a preset second update cycle; or detecting an impedance change between any two electrodes exceeding a preset offset threshold. By periodically or under specific conditions resetting the random starting point of the first electrode, the regenerated electrical stimulation sequence exhibits dynamic diversity on a macroscopic scale. In long-term neuromodulation therapy, this macroscopically constantly changing spatial stimulation sequence can, to some extent, break the synaptic habituation of the nervous system to fixed electrical stimulation pathways. This helps to delay or reduce the nervous system's tolerance to stimulation signals, thereby maintaining a more stable and long-lasting analgesic effect in long-term chronic pain intervention. Simultaneously, the constantly changing timing also helps to avoid long-term, regular accumulation interference of residual spatial electric fields in a single local area.

[0064] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0065] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0066] The embodiments described above do not constitute a limitation on the scope of protection of this application.

Claims

1. A multi-electrode static sequence control system for DRG electrical stimulation, characterized in that, include: M electrodes, each used to electrically stimulate M different DRGs, where M is an integer greater than 1; An implantable pulse generator, wherein the implantable pulse generator is electrically connected to the M electrodes respectively; The implantable pulse generator is configured as follows: Based on the electrical stimulation sequence, the order of electrical stimulation of the M electrodes is determined; According to the electrical stimulation sequence of the M electrodes, the corresponding electrodes are controlled to perform electrical stimulation in sequence; In the electrical stimulation sequence, the (i+1)th electrode is the electrode with the largest spatial distance from the i-th electrode among the (i+1)th to the Mth electrodes, where 1 ≤ i < M.

2. The control system according to claim 1, characterized in that, Before determining the electrical stimulation sequence of the M electrodes based on the electrical stimulation sequence, the method further includes: Obtain the spatial distance information between each pair of the M electrodes; Based on the spatial distance information between each pair of the M electrodes, the electrical stimulation sequence containing the M electrodes is generated.

3. The control system according to claim 2, characterized in that, The step of obtaining the spatial distance information between each pair of the M electrodes includes: Obtain the position information of the M electrodes from the electrode distribution map; Based on the position information of the M electrodes, determine the spatial distance information between each pair of the M electrodes; The electrode distribution map includes the location information of each electrode.

4. The control system according to claim 3, characterized in that, The location information is coordinate information. Before obtaining the location information of the M electrodes in the electrode distribution map, the method further includes: A first test signal is applied between any two electrodes among the M electrodes; Measure the impedance between any two electrodes; Based on a preset impedance-distance mapping relationship, the measured impedance between any two electrodes is converted into spatial distance information between the two electrodes. Using any one of the M electrodes as a spatial reference, three-dimensional spatial coordinates are calculated based on all the spatial distance information to obtain the coordinate information of each electrode in three-dimensional space; An electrode distribution map is generated based on the coordinate information of each electrode in three-dimensional space; Wherein, the amplitude of the first test signal is less than the amplitude of the stimulation signal when the DRG is electrically stimulated; and / or, the pulse width of the first test signal is less than the pulse width of the stimulation signal when the DRG is electrically stimulated.

5. The control system according to claim 3, characterized in that, The location information is coordinate information. Before obtaining the location information of the M electrodes in the electrode distribution map, the method further includes: The target electrode among the M electrodes is controlled to output a second test signal, wherein the target electrode is any one of the M electrodes; The electrodes other than the target electrode are controlled as listening electrodes to collect neural evoked compound action potentials triggered by the second test signal; The time delay between the second test signal output by the target electrode and the neural evoked compound action potential acquired by each of the listening electrodes is obtained; Based on a preset delay-distance mapping relationship, the measured time delay is converted into spatial distance information between the target electrode and each of the listening electrodes; Using the target electrode as a spatial reference, three-dimensional spatial coordinates are calculated based on all the spatial distance information to obtain the coordinate information of each electrode in three-dimensional space; An electrode distribution map is generated based on the coordinate information of each electrode in three-dimensional space.

6. The control system according to claim 3, characterized in that, The location information is coordinate information. Before obtaining the location information of the M electrodes in the electrode distribution map, the method further includes: The implantable pulse generator receives coordinate calibration data from an external programmable device. The coordinate calibration data includes the coordinate information of the M electrodes in three-dimensional space extracted from human medical images. An electrode distribution map is generated based on the coordinate information of each electrode in three-dimensional space.

7. The control system according to claim 3, characterized in that, The implantable pulse generator is also configured to: The electrode distribution map is updated when the first preset update condition is met; The first preset update condition includes at least one of the following: system initialization; reaching a preset first update cycle; or detecting that the impedance change between any two electrodes exceeds a preset offset threshold.

8. The control system according to claim 2, characterized in that, The step of obtaining the spatial distance information between each pair of the M electrodes includes: A third test signal is applied between any two of the M electrodes; Measure the impedance between any two electrodes; Based on a preset impedance-distance mapping relationship, the measured impedance between any two electrodes is converted into spatial distance information between each pair of the M electrodes; Wherein, the amplitude of the third test signal is less than the amplitude of the stimulation signal when the DRG is electrically stimulated; and / or, the pulse width of the third test signal is less than the pulse width of the stimulation signal when the DRG is electrically stimulated.

9. The control system according to claim 1, characterized in that, The implantable pulse generator is also configured to: After the current electrode completes electrical stimulation, if the spatial distance between the current electrode and the electrode for the next electrical stimulation is less than or equal to a preset spatial distance threshold, then the amplitude and / or pulse width of the next electrical stimulation are reduced. The current electrode is any electrode in the electrical stimulation sequence except for the last electrode.

10. The control system according to claim 2, characterized in that, The implantable pulse generator is also configured to: When the second preset update condition is met, an electrode is randomly selected from the M electrodes as the first electrode in the electrical stimulation sequence, and the electrical stimulation sequence is updated. The second preset update condition includes at least one of the following: completing a stimulation cycle, in which each electrode performs an electrical stimulation action once; reaching a preset second update cycle; and detecting that the impedance change between any two electrodes exceeds a preset offset threshold.

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