Demand pacemaker using an artificial baroreceptor reflex
Laryngeal pacemaker Patent #: 5111814
AbstractIn conjunction with a medical device for stimulating the vagus nerve of a patient to modulate the electrical activity thereof as part of a prescribed therapy, apparatus is provided to selectively suppress the stimulation while the patient is speaking, to avoid undesirable modulation of the voice. The suppression apparatus includes a speech sensor and discriminator, to detect speech by the patient while avoiding false detection attributable to sounds other than speech. The suppression of nerve stimulation is ceased after a preset time interval regardless of continued detection of speech, to assure that beneficial therapy is not unduly inhibited in favor of mere cosmetic considerations or in the presence of prolonged false detections. In the preferred embodiment, the discriminator selectively varies the sensitivity of the suppression apparatus to speech by the patient to enhance its selectivity over sounds attributable to other sources, such as by changing the value of a threshold level which must be crossed before the suppression of nerve stimulation can occur or continue, and by filtering out disturbances.