Automatic activation of a neurostimulator device using a detection algorithm based on cardiac activity
First Claim
1. A medical device for treating an epileptic patient, comprising:
- implantable electronic means housed in a case substantially impervious to body fluids and tissue and operative when activated for generating selected ones of electrical waveforms representing preprogrammed therapy regimens to control epileptic seizures;
implantable lead means adapted for electrical connection to the electronic means via an electrical connector mounted on the case thereof, for delivering selected ones of said therapy regimens to a preselected cranial nerve of the patient to electrically stimulate and thereby modulate electrical activity of the selected nerve in a manner which is predetermined to control seizures;
said electronic means including means for detecting time rate of change of the patient'"'"'s heart rate from cardiac activity, and activation means responsive to detection of a sudden time rate of change of heart rate which is inconsistent with normal physical activity of the patient, as being indicative of an impending seizure, for automatically activating the electronic means to generate a selected one of the therapy regimens for application to said lead means, whereby to deliver a desired stimulus to the selected cranial nerve.
4 Assignments
0 Petitions
Accused Products
Abstract
A device and method of controlling seizures in an epileptic patient, in which the device is implanted in the patient for selective activation to generate an electrical waveform constituting a pre-programmed therapy regimen for application to the patient'"'"'s vagus nerve to modulate the electrical activity thereof in a manner to inhibit, abort, or reduce the severity and duration of the seizure. The device is activated to generate the waveform upon detecting a time rate of change in the patient'"'"'s heart rate relative to a predetermined threshold time rate of change which is sufficiently abrupt and of sufficient magnitude to be inconsistent with normal physical activity, as being indicative of an imminent epileptic seizure. Sustained cardiac activity at the highest heart rate detected in the change in heart rate is used as a confirmation of imminent seizure. The electrical waveform is generated a burst of pulses, with a minimum time interval between consecutive pulse bursts selected to avoid overstimulation of the nerve. Cardiac activity of the patient is detected using electrodes which include the conductive housing for the device and a stimulating electrode to be mounted on the nerve for large signal detection, or which are integral with the device housing itself so that no electrical leads are required to be implanted for such detection and the electrodes are arranged to detect the cardiac activity with a sensitivity that is substantially independent of orientation of the device as implanted in the patient.
-
Citations
27 Claims
-
1. A medical device for treating an epileptic patient, comprising:
-
implantable electronic means housed in a case substantially impervious to body fluids and tissue and operative when activated for generating selected ones of electrical waveforms representing preprogrammed therapy regimens to control epileptic seizures; implantable lead means adapted for electrical connection to the electronic means via an electrical connector mounted on the case thereof, for delivering selected ones of said therapy regimens to a preselected cranial nerve of the patient to electrically stimulate and thereby modulate electrical activity of the selected nerve in a manner which is predetermined to control seizures; said electronic means including means for detecting time rate of change of the patient'"'"'s heart rate from cardiac activity, and activation means responsive to detection of a sudden time rate of change of heart rate which is inconsistent with normal physical activity of the patient, as being indicative of an impending seizure, for automatically activating the electronic means to generate a selected one of the therapy regimens for application to said lead means, whereby to deliver a desired stimulus to the selected cranial nerve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An electrical stimulus generator adapted for implantation in a patient suffering from epilepsy, to provide electrical stimuli for application to a selected cranial nerve as a therapy to alleviate a seizure, the stimulus generator comprising:
-
electronics effective when energized for generating said electrical stimuli; an electrically conductive case housing said electronics; and electrode means electrically connected to said electronics for sensing cardiac activity of the patient, said electronics including means responsive to sudden time rate of change of the patient'"'"'s heart rate in the sensed cardiac activity for distinguishing a change which is a precursor of an imminent epileptic seizure from a change attributable to normal physical exercise, to energize the electronics to generate said electrical stimuli upon the seizure-indicative change. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. A device-implemented method of controlling seizures in an epileptic patient, comprising the steps of:
-
implanting into the patient a medical device adapted to be selectively activated to generate an electrical waveform constituting a pre-programmed therapy regimen to control epileptic seizures by application of the waveform to modulate electrical activity of the patient'"'"'s vagus nerve; detecting time rate of change of cardiac activity of the patient indicative of an imminent epileptic seizure; and responding to the detection of such time rate of change of cardiac activity to automatically activate the device and thereby generate said electrical waveform for application as an electrical stimulus to the vagus nerve. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
Specification