Granted Patent B2

US 12,654,016 · App. 18/509,170 · Granted Jun 16, 2026

Inventors: Zubin Nanavati (Macquarie Park, AU); Daniel John Parker (Macquarie Park, AU)

Assignee: Saluda Medical Pty Ltd

A61N1/36157A61B5/388A61B5/4836A61N1/08A61N1/36139A61N1/36175A61B5/686

Abstract

Claims (57)

1 . A neural stimulation system comprising:

an implantable device for controllably delivering neural stimuli, the device comprising:

a plurality of electrodes including one or more stimulus electrodes and one or more measurement electrodes;

a stimulus source configured to provide neural stimuli to be delivered via the one or more stimulus electrodes to a neural pathway of a patient in order to evoke neural responses from the neural pathway;

measurement circuitry configured to capture signal windows from signals sensed on the neural pathway via the one or more measurement electrodes subsequent to respective neural stimuli; and

a control unit configured to:

control the stimulus source to provide a neural stimulus according to a stimulus intensity parameter;

measure an intensity of an evoked neural response in a captured signal window subsequent to the neural stimulus;

compute a feedback variable from the measured intensity of the evoked neural response; and

adjust, using a feedback controller, the stimulus intensity parameter so as to maintain the feedback variable at a target response intensity; and

a processor configured to:

estimate an out-of-compliance current limit for each of the one or more stimulus electrodes;

estimate a closed-loop current requirement for the implantable device;

compare the out-of-compliance current limit for each of the one or more stimulus electrodes to the closed-loop current requirement; and

take a mitigating action based on the comparison.

2 . The system of claim 1 , wherein the processor is configured to estimate the out-of-compliance current limit for a stimulus electrode by:

measuring an electrode resistance of the stimulus electrode; and

estimating the out-of-compliance current limit for the stimulus electrode using the measured electrode resistance of the stimulus electrode.

3 . The system of claim 1 , wherein the processor is configured to estimate the closed-loop current requirement for the implantable device by:

estimating a threshold value of the stimulus intensity parameter; and

estimating the closed-loop current requirement by applying a model to the estimated threshold value.

4 . The system of claim 1 , wherein the processor is configured to estimate the closed-loop current requirement for the implantable device from a pulse width of the provided neural stimuli.

5 . The system of claim 1 , wherein the processor is configured to take the mitigation action upon the closed-loop current requirement for the implantable device exceeding the out-of-compliance current limit for at least one stimulus electrode of the one or more stimulus electrodes.

6 . The system of claim 5 , wherein the mitigation action comprises increasing the out-of-compliance current limit for the at least one stimulus electrode of the one or more stimulus electrodes.

7 . The system of claim 6 , wherein the processor is configured to increase the out-of-compliance current limit by increasing a number of return electrodes via which the neural stimulus current is returned from the neural pathway.

8 . The system of claim 6 , wherein the processor is configured to increase the out-of-compliance current limit by selecting an alternative stimulus electrode to the at least one stimulus electrode of the one or more stimulus electrodes.

9 . The system of claim 5 , wherein the mitigation action comprises decreasing the closed-loop current requirement for the implantable device.

10 . The system of claim 9 , wherein the processor is configured to decrease the closed-loop current requirement by increasing a pulse width of the provided neural stimuli.

11 . The system of claim 10 , wherein the processor is configured to use population statistics to increase the pulse width such that the out-of-compliance current limit for a stimulus electrode is likely to exceed the closed-loop current requirement for the implantable device.

12 . An automated method of controllably delivering neural stimuli to a neural pathway of a patient, the method comprising:

delivering a neural stimulus to the neural pathway of the patient in order to evoke a neural response from the neural pathway, the neural stimulus being delivered according to a stimulus intensity parameter via one or more stimulus electrodes;

capturing a signal window from a signal sensed on the neural pathway subsequent to the delivered neural stimulus;

measuring an intensity of a neural response evoked by the delivered neural stimulus in the captured signal window;

computing, from the measured intensity of the evoked neural response, a feedback variable;

adjusting the stimulus intensity parameter so as to maintain the feedback variable at a target response intensity;

estimating an out-of-compliance current limit for each of the one or more stimulus electrodes;

estimating a closed-loop current requirement;

comparing the out-of-compliance current limit for each of the one or more stimulus electrodes to the closed-loop current requirement; and

taking a mitigating action based on the comparison.

13 . The method of claim 12 , wherein estimating the out-of-compliance current limit for a stimulus electrode by:

measuring an electrode resistance of the stimulus electrode; and

estimating the out-of-compliance current limit for the stimulus electrode using the measured electrode resistance of the stimulus electrode.

14 . The method of claim 12 , wherein estimating the closed-loop current comprises:

estimating a threshold value of the stimulus intensity parameter; and

estimating the closed-loop current requirement by applying a model to the estimated threshold value.

15 . The method of claim 12 , wherein taking a mitigating action based on the comparison comprises taking the mitigation action upon the closed-loop current requirement exceeding the out-of-compliance current limit for at least one stimulus electrode of the one or more stimulus electrodes.

16 . The method of claim 15 , wherein the mitigation action comprises increasing the out-of-compliance current limit for the at least one stimulus electrode of the one or more stimulus electrodes.

17 . The method of claim 16 , wherein increasing the out-of-compliance current limit comprises increasing a number of return electrodes via which the neural stimulus current is returned from the neural pathway.

18 . The method of claim 15 , wherein the mitigation action comprises decreasing the closed-loop current requirement.

19 . The method of claim 18 , wherein decreasing the closed-loop current requirement comprises increasing a pulse width of the neural stimuli.

20 . A neural stimulation system comprising:

an implantable closed-loop neural stimulation device for controllably delivering neural stimuli via one or more stimulus electrodes, the device comprising the one or more stimulus electrodes and a feedback controller configured to adjust a stimulus intensity parameter so as to maintain a measured neural response intensity at a target response intensity; and

a processor configured to:

estimate an out-of-compliance current limit for each of the one or more stimulus electrodes;

estimate a closed-loop current requirement for the implantable closed-loop neural stimulation device;

compare the out-of-compliance current limit for each of the one or more stimulus electrodes to the closed-loop current requirement; and

take a mitigating action based on the comparison.

Assignments (2)

Priority Claims (1)

Continuity (1)

References Cited (250)