Active electrical nerve stimulation medical device, with automatic charge compensation control

An active medical device, comprising:

• a generator configured to generate functional electrical neurostimulation and produce at least one multi-phase neurostimulation pulse train as output;
• a stimulation lead designed to be disposed on or in the vicinity of a structure of the nervous system of a patient wearing the device and for applying neurostimulation pulse trains to said structure;
• at least one sensor configured to deliver a monitoring signal representative of a physiological and/or physical parameter that can be influenced by the delivery of the at least one neurostimulation pulse train;
• and
• an automatic control circuit configured to automatically control charge compensation, wherein the circuit receives the monitoring signal delivered by the at least one sensor;
• wherein the at least one pulse train comprises:
• at least one stimulation pulse;
• and
• at least one compensatory pulse comprising:
• a pre-charge pulse preceding the stimulation pulse and/or a post-charge pulse following the stimulation pulse;
• and
• a passive discharge pulse terminating the pulse train,
• wherein the stimulation and compensatory pulses are current pulses in which the direction, the duration, and the amplitude are controlled, and wherein the at least one compensatory pulse procures a cumulative electric charge that compensates for the electric charge of the at least one stimulation pulse;
• wherein the automatic control circuit is configured to:
• determine an amplitude and/or a duration for the at least one compensatory pulse as a function of at least one predetermined criterion;
• and
• deliver, to the generator, a control signal for controlling the at least one compensatory pulse to be produced as output by said generator.