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EP-4313260-B1 - MULTI-ELECTRODE SPINAL CORD STIMULATION THERAPY

EP4313260B1EP 4313260 B1EP4313260 B1EP 4313260B1EP-4313260-B1

Inventors

  • Slee, Sean
  • KIBLER, ANDREW B.
  • BARU, MARCELO

Dates

Publication Date
20260506
Application Date
20220310

Claims (8)

  1. A device for neurostimulation (100) of a patient's body, wherein the device comprises a plurality of electrodes (102.a, 102.b, 102.c, 102.d, 200.a, 200.b), wherein the number of the plurality of electrodes is Z, wherein a group of N electrodes (102.a, 102.b, 102.c) of the plurality of electrodes (N less than or equal to Z) is equal to or larger than 3, wherein the device is configured to deliver a number of N+1 electrical phases during one cycle via the plurality of electrodes • such that during N electrical phases of the cycle each electrode of the group delivers alternating a therapeutic electric phase and a number of N-1 charge balancing electric phases, wherein the therapeutic electric phase of one electrode has an amplitude I1, I2, ... IN specific to this electrode, wherein during a time of one phase one electrode of the group delivers its specific therapeutic electric phase and the other electrodes of the group or of the plurality of electrodes deliver a charge balancing phase having a polarity being opposite to the polarity of the specific therapeutic electric phase delivered at the same time, and • such that during an additional electrical phase each electrode of the plurality of electrodes delivers an electrical phase with an amplitude that establishes charge neutrality for residual charge on each respective electrode based on phases of the N other electrical phases.
  2. The device of claim 1, wherein the device is configured such that an amount of the amplitudes of the charge balancing electric phases is the (N-1)th part or the (Z-1)th part of the amount of the specific amplitude of the specific therapeutic electric phase delivered at the same time during one of the N therapeutic electrical phases.
  3. The device of any of the previous claims, wherein the device is configured such that the amplitude of the specific therapeutic phase of each electrode of the group (102.a, 102.b, 102.c) is automatically adjusted using ECAP waveform measurement.
  4. The device of claim 3, wherein the device is configured such that ECAP waveform measurement is provided using at least one auxiliary electrode (200.a, 200.b) of the plurality of electrodes Z (102.a, 102.b, 102.c, 102.d, 200.a, 200.b) different from the group of electrodes N (102.a, 102.b, 102.c).
  5. The device of any of claims 3 to 4, wherein the device is configured such that the ECAP waveform measurement is provided in predefined time intervals and/or if the patient's body position and/or activity change is detected, for example by using an accelerometer contained within the device.
  6. The device of any of the previous claims, wherein the device is configured such that for assessing the amplitude of the specific therapeutic electric phase of each electrode of the group N (102.a, 102.b, 102.c) the specific activation threshold (1) for each electrode is determined, wherein the amplitude of one specific electrode of the group is a pre-defined part of the measured specific activation threshold of this electrode.
  7. The device of any of the previous claims, wherein during any of the N+1 phases, the device casing sources or sinks current to provide balance to the net currents of the active electrodes.
  8. The device of any of the previous claims, wherein the group of N electrodes of the plurality of electrodes is a subset of electrodes of the plurality of electrodes.

Description

The present description is directed to a device for neurostimulation and a respective method. Neurostimulation devices are used to deliver electrical stimulation therapy to a patient's body to various tissue sites to treat a variety of symptoms or conditions such as chronic pain, Parkinson's disease, epilepsy, urinary or fecal incontinence, sexual dysfunction, obesity or gastroparesis. Such devices usually deliver electrical stimulation therapy via one or more leads that comprise electrodes located proximate to target locations associated with the brain, the spinal cord, pelvic nerves, peripheral nerves, or the gastrointestinal tract of the patient. Hence, electrical simulation may be used in different therapeutic applications, such as deep brain stimulation (DBS), spinal cord stimulation (SCS), pelvic stimulation, gastric stimulation, or peripheral nerve stimulation (PNS). Spinal cord stimulation (SCS), as a means of pain relief for patients suffering from neuropathic pain, has traditionally been thought of as requiring paresthesia sensations to overlap a patient's region of pain in order to provide relief. Recent research has shown that an alternate paresthesia-free mechanism of pain relief is available through higher frequency (compared to traditional tens of Hz) stimulation which is effective in patients without requiring intra-operative electrode mapped selection. In the last few years, therapies have demonstrated efficacy of a paresthesia-free method of pain relief whereby the patient does not experience paresthesia and the stimulation electrodes selected may not map directly to a dermatomal alignment with the patient's region of pain. High-frequency SCS therapy utilizes stimulation frequencies between 1.5 kHz and 100 kHz, preferred 10 kHz, to achieve a neuromodulatory effect without recruiting the dorsal column fibers associated with paresthesia. Research indicates that this therapy modality reduces the wind-up hypersensitivity of dorsal horn interneurons responsible for relaying a painful sensation from the peripheral to the central nervous system. Pain relief associated with this stimulation may require several hours to a day to take effect. The mechanism of action of this mode of therapy is still under debate; however; the prevailing theory is as follows. High-frequency SCS stimulation has little influence on the dorsal column axons which facilitate paresthesia therapy, instead directly inducing slight potentiation changes on lamina I neurons in the dorsal horn of the spinal cord. The potentiation changes trigger a cascade of intracellular signalling responses which induce a direct inhibition of sensitization and suppression of activity of neuropathic pain relay neurons in the dorsal horn. This paresthesia-free SCS approach is similar in frequencies to high-frequency transcutaneous spinal electroanalgesia (TSE) which has been available for decades. Whether the underlying mechanisms and site of pain relief action are, the same between high-frequency TSE and high-frequency SCS remains to be determined. Drawbacks of 10,000 Hz stimulation are as follows: it requires very high frequency stimulation control, energy is wasted through parasitic capacitive charge and discharge as a result of frequent polarity transitions of current delivery, and most important neuronal response is not efficient at 10,000 Hz stimulation frequency given the anodic pulse amplitude is constrained by timing to be the same as the cathodic pulse amplitude, which in turn influences cathodic stimulation thresholds. The consequences of a high-energy SCS implantable device include frequent recharging and large device size, both of which can have a significantly negative patient impact. The number of recharge cycles is also limited requiring the patient to have more frequent revision surgeries for device replacement. EP 3 381 507 A1 describes a device for neurostimulation, comprising a number N of electrodes. N is equal or larger than 3, wherein the device is configured to deliver via each electrode therapeutic electric phases of amplitudes I 1 , I2,..I N , with a frequency f and after each therapeutic electric phase a number of N-1 charge balancing electric phases. The charge balancing electric phases of the respective electrode each have a polarity that is opposite the polarity of the preceding therapeutic electric phase of the respective electrode. The device is configured to return for each electrode the current of each therapeutic electric phase in the other N-1 electrodes. EP 3 791 923 A1 relates to a medical device for generating electrical stimulation of a patient, comprising: a pulse generator configured to generate current pulses for electrical stimulation of the patient, and at least one electrode lead configured to be connected to the pulse generator and comprising a plurality of electrode contacts for delivering said current pulses to tissue of the patient, wherein the pulse generator is configured to generate said curren