Measurement of neural responses to neurostimulation

Abstract

Disclosed is a neurostimulation system comprising an implantable device for controllably delivering a neural stimulus, and a processor. Signals evoked by a stimulus are sensed at each pair of sense electrodes, each sensed signal including a differential evoked compound action potential (ECAP) evoked by the delivered neural stimulus. The differential ECAP is decomposed in each sensed signal into a first single-ended ECAP corresponding to one sense electrode of the pair of sense electrodes and a second single-ended ECAP corresponding to the other sense electrode of the pair of sense electrodes. ECAP propagation model parameters are determined from the first single-ended ECAP model and the second single-ended ECAP model and from distances of the respective sense electrodes from the stimulus electrode configuration. An indication may be given to a user if one of the one or more ECAP propagation model parameters departs from a predetermined range. Or, originating ECAP model parameters may be determined from the first single-ended ECAP model and from the distance of the corresponding sense electrode from the stimulus electrode configuration. Parameters of a model of a differential ECAP at a second pair of sense electrodes may be computed; and an optimal combination of parameters for a parametric ECAP detector at the second pair of sense electrodes may be computed from the parameters of the model of the differential ECAP.