US 12,138,457 B2
Feedback control of neuromodulation
James Hamilton Wah, Artarmon (AU)
Assigned to Saluda Medical Pty Ltd, Macquarie Park (AU)
Filed by Saluda Medical Pty Ltd, Artarmon (AU)
Filed on Nov. 9, 2021, as Appl. No. 17/454,237.
Application 17/454,237 is a continuation of application No. 16/091,428, granted, now 11,191,966, previously published as PCT/AU2017/050296, filed on Apr. 5, 2017.
Claims priority of application No. 2016901264 (AU), filed on Apr. 5, 2016.
Prior Publication US 2022/0168574 A1, Jun. 2, 2022
Int. Cl. A61N 1/36 (2006.01); A61B 5/00 (2006.01); A61B 5/388 (2021.01); A61N 1/05 (2006.01); A61N 1/18 (2006.01); A61N 1/372 (2006.01); A61N 1/378 (2006.01)
CPC A61N 1/36132 (2013.01) [A61B 5/0031 (2013.01); A61B 5/388 (2021.01); A61B 5/4836 (2013.01); A61N 1/0551 (2013.01); A61N 1/18 (2013.01); A61N 1/36067 (2013.01); A61N 1/36071 (2013.01); A61N 1/36075 (2013.01); A61N 1/36139 (2013.01); A61N 1/37264 (2013.01); A61N 1/3787 (2013.01)] 30 Claims
OG exemplary drawing
 
1. An automated method of controlling a neural stimulus, the method comprising:
applying, via one or more stimulus electrodes of a plurality of implanted electrodes, the neural stimulus to a neural pathway in order evoke a neural compound action potential response on the neural pathway, the neural stimulus being defined by at least one stimulus parameter;
measuring, via one or more sense electrodes of the plurality of implanted electrodes, a neural compound action potential response evoked by the neural stimulus,
deriving from the measured evoked response and the stimulus parameter a feedback variable that is a proxy for a level of recruitment of neurons on the neural pathway by the neural stimulus, independent of the distance between the implanted electrodes and the neural pathway; and
completing a feedback loop by using the feedback variable to control the at least one stimulus parameter value;
wherein deriving the feedback variable is configured to compensate for both (i) a distance-dependent transfer function from stimulus parameter to level of recruitment, and (ii) a distance dependent transfer function from level of recruitment to measured evoked response which is distinct from (i).
 
16. An implantable device for controllably applying a neural stimulus, the device comprising:
a plurality of electrodes including one or more stimulus electrodes and one or more sense electrodes;
a stimulus source for providing a stimulus to be delivered from the one or more stimulus electrodes to a neural pathway in order to evoke a neural compound action potential response on the neural pathway;
measurement circuitry for processing a neural compound action potential response signal sensed at the one or more sense electrodes; and
a control unit configured to:
control application of a neural stimulus as defined by at least one stimulus parameter;
measure via the measurement circuitry the neural compound action potential response evoked by the neural stimulus;
derive from the measured evoked response and the stimulus parameter a feedback variable that is a proxy for a level of recruitment of neurons on the neural pathway by the neural stimulus, independent of the distance between the plurality of electrodes and the neural pathway; and
complete a feedback loop by using the feedback variable to control the at least one stimulus parameter value;
wherein deriving the feedback variable is configured to compensate for both (i) a distance-dependent transfer function from stimulus parameter to level of recruitment, and (ii) a distance-dependent transfer function from level of recruitment to measured evoked response which is distinct from (i).