USE OF AN IMPLANTABLE CARDIAC PACING, DEFIBRILATION AND/OR RESYNCHRONIZATION GENERATOR AS A VNS GENERATOR FOR VAGUS NERVE STIMULATION

摘要

On a channel of an implantable cardiac generator, a cardiac lead is replaced by a vagus nerve stimulation VNS lead. The control circuit controlling the stimulation circuit of this channel of the generator is configured to generate sequences of VNS neurostimulation bursts according to a specific profile, synchronized or not with the heart rate. The control circuit dynamically controls the initial load voltage of the reservoir capacitor so as to adjust to a constant target value the electrical charge delivered to the nerve by each stimulating pulse, from a pulse to the next one and from a burst to the next one. This improves the consistency of the physiological effects of neurostimulation despite significant variations that may occur in impedance at the electrode/vagus nerve interface.

主权项

1. An active medical device, comprising:
an implantable cardiac generator for myocardium stimulation, defibrillation and/or resynchronization, comprising:
at least two detection/stimulation terminals, with a first and a second terminal;a stimulation circuit capable of generating electrical stimulation pulses;a control circuit capable of controlling delivery on at least the first terminal pulses generated by the stimulation circuit and the timing of these pulses; anda circuit for collection of an endocardial electrogram EGM signal and of detection of a spontaneous or stimulated cardiac depolarization wave in each cardiac cycle;wherein:
the device further includes at least one lead for vagus nerve stimulation, VNS, able to be implanted on the vagus nerve or near it;the VNS lead is provided with a connection mechanism suitable for a cardiac generator;the VNS lead is connected to the first terminal of the cardiac generator so as to receive the pulses produced on this terminal by the cardiac generator to apply these pulses to the vagus nerve;the control circuit of the cardiac generator is adapted to control the stimulation circuit so as to produce burst of pulses, these bursts being VNS bursts generated continuously in succession for periods of activity separated by intermediate periods of inactivity, and/or generated synchronously on detection of a cardiac depolarization wave, characterized in that:
the control circuit is further adapted to measure the impedance of the VNS lead during each stimulation pulse and, in response, to dynamically control the pulse voltage generated by the stimulation circuit so as to adjust to a constant value, from a pulse to the next and from one burst to the next, the charge delivered by each stimulation pulse.