Abstract: A method of treating patients suffering from refractory hypertension includes identifying a patient suffering from the disorder and applying a stimulating electrical signal to the patient's vagus nerve predetermined to modulate the electrical activity of the nerve and to alleviate the hypertension. The step of applying the stimulation may be performed manually by the patient, or automatically following detection of the hypertension by sensing the patient's blood pressure, or, preferably by continuous or periodic application without use of a sensor. The stimulating signal is a pulse waveform with programmable signal parameter values including pulse width, output current, frequency, on time and off time.

Abstract: A method of treating a patient in coma is performed by placing an electrode in juxtaposition with a preselected cranial nerve of the patient for electrical stimulation of the nerve, applying an electrical pulse waveform to the electrode to stimulate the cranial nerve, and adjusting electrical parameters of the pulse waveform to modulate electrical activity of the nerve in an effort to rouse the patient from the coma. The patient's response to the treatment is monitored and assessed by the attending physician according to Glasgow coma scale. The preferred cranial nerve is the vagus nerve, and the stimulation is performed either for acute treatment by positioning an esophageal electrode in the patient for stimulating a region of the vagus nerve in the neck, or for longer term treatment by implanting a nerve electrode on the vagus nerve.

Abstract: Apparatus for treating patients with motility disorders applies a modulating signal to the patient's vagus nerve to stimulate or inhibit neural impulses and produce excitatory or inhibitory neurotransmitter release by the vagus nerve according to the specific nature of the motility disorder. The apparatus includes a neurostimulator which can be activated to generate an electrical output signal. The neurostimulator is responsive to the sensing of a selected event having occurred which is indicative of the need for treatment of the motility disorder, and includes an activation element which responds to sensing of that event to activate the neurostimulator, and a lead with an electrode array to apply the electrical output signal as the modulating signal to the patient's vagus nerve. Certain parameters of the output signal are programmable, and the neurostimulator can be calibrated according to the specific patient and the specific motility disorder being treated.

Abstract: Method and apparatus for treating and controlling sleep disorders by detecting the presence of the sleep disorder under treatment, and, in response, selectively applying a predetermined electrical signal to the patient's vagus nerve for stimulation thereof to alleviate the sleep disorder under treatment. The method and apparatus includes several techniques for detecting the presence of the sleep disorder under treatment, such as sensing the patient's EEG activity in the case of insomniac and hypersomniac patients, or detecting a sudden nodding of the head in the case of narcoleptic patients, or sensing the cessation of respiration in the case of sleep apnea patients.

Abstract: Method and apparatus for treating severe chronic, persistent or recurring neuropathic or psychogenic pain, or pain which is nociceptive if the patient is suffering from terminal disease, by selectively applying a pulse waveform to a lead/electrode implanted on the patient's cervical vagus nerve or other site preferably above the location of the pain to stimulate afferent fibers for activating a descending anti-nociceptive pathway and thereby blocking incoming pain signals. The pulse waveform has programmable pulse width, current level and frequency, and pulse sequence on and off time durations. The programmed pulse sequences are applied to the implanted electrode either on a continuous basis, or only during the period the patient is normally awake, or is initiated by the patient or automatically in response to the onset of pain.

Abstract: Improvements are disclosed in apparatus and techniques for activating an implantable medical device, such as a neurostimulator adapted to treat and control a disorder of a patient where the disorder is susceptible to relief in response to predetermined modulation of the electrical activity of a selected nerve or group of nerves of the patient. The neurostimulator includes a stimulus generator responsive, when activated, to generate a programmable electrical waveform, and an electrode array electrically connected to the stimulus generator for delivering the waveform to a selected nerve of the patient, such as the vagus nerve. The neurostimulator is also adapted to be programmed to provide the waveform with parameter values selected to stimulate the selected nerve to produce the predetermined modulation of the nerve's electrical activity.

Abstract: Method and apparatus for treating and controlling neuropsychiatric disorders including schizophrenia, depression, and borderline personality disorder by selectively applying a predetermined electrical signal to the patient's vagus nerve for stimulation thereof to alleviate the symptoms of the disorder being treated. The electrical signal may be applied continuously, periodically, or intermittently to the vagus nerve depending, in part, on the nature of the disorder being treated. In certain instances, the electrical signal is applied upon detection of an event indicative of onset of the disorder. In other instances, the electrical signal is selectively applied at will to the vagus nerve, such as by patient activation of the signal generator. Parameter values of the electrical signal including pulse width, output current, frequency, on time and off time, are selectively programmable.

Abstract: A method of treating symptoms of dementia, including cortical dementia, subcortical dementia, and multi-infarct dementia, includes selecting a patient suffering from dementia, and applying to the patient's vagus nerve an electrical stimulation signal having parameter values selected to modulate the electrical activity of the vagus nerve in a manner to modulate the activity of preselected portions of the reticular activating system of the brain stem.

Abstract: A method of treating patients with compulsive eating disorders includes the steps of detecting a preselected event indicative of an imminent need for treatment of the specific eating disorder of interest, and responding to the detected occurrence of the preselected event by applying a predetermined stimulating signal to the patient's vagus nerve appropriate to alleviate the effect of the eating disorder of interest. For example, the preselected event may be a specified level of food consumption by the patient within a set interval of time, or the commencement of a customary mealtime according to the patient's circadian cycle, or the passage of each of a sequence of preset intervals of time, or the patient's own recognition of the need for treatment by voluntarily initiating the application of the stimulating signal to the vagus nerve. In cases in which the disorder is compulsive eating to excess, the stimulating signal is predetermined to produce a sensation of satiety in the patient.

Abstract: An implantable medical device is provided with a removable dummy load across its connector output terminals to allow the device to be tested without removal from the sterile disposable package in which it is shipped and stored. The dummy load is confined with the device entirely within the sterile package to simulate the electrical impedance across the output terminals when the device is implanted in a patient and connected to an electrical lead for tissue stimulation. Testing is performed using a conventional external programmer normally provided for programming and monitoring output functions and parameters of the device. The programmer communicates by telemetry with the device confined within the package, to test selected functions and parameters. The dummy load has posts adapted to mate with the receptacles of the electrical connector of the device, and to be secured mechanically and electrically in the receptacles by set screws.

Abstract: Method and apparatus are described for treating and controlling diabetes and other systemic pancreatic endocrine disorders attributable to abnormal levels of secretion of endogenous insulin. An electrical stimulator implanted into or worn external to the patient's body is adapted, when activated, to generate a programmable electrical waveform for application to electrodes implanted on the vagus nerve of the patient. The electrical waveform is programmed using parameter values selected to stimulate or inhibit the vagus nerve to modulate the electrical activity thereof to increase or decrease secretion of natural insulin by the patient's pancreas. The stimulator is selectively activated manually by the patient in response to direct measurement of blood glucose or symptoms, or is activated automatically by programming the activation to occur at predetermined times and for predetermined intervals during the circadian cycle of the patient.

Abstract: Method and apparatus for treating and controlling migraine by selectively applying a predetermined electrical signal to the patient's vagus nerve for stimulation thereof to alleviate the migraine attack. The signal is a pulse waveform having parameters programmed to desynchronize the patient's EEG if paroxysmal activity is detected in the EEG, or to synchronize the EEG if low voltage fast wave activity is detected. Alternatively, the application of the stimulating signal to the vagus nerve may be initiated manually by the patient upon recognition of the onset of a migraine attack. The neurostimulator device implanted in the patient to generate the appropriate signal has a power down circuit to conserve battery power between migraine episodes.

Abstract: A method of treating patients with compulsive eating disorders includes the steps of detecting a preselected event indicative of an imminent need for treatment of the specific eating disorder of interest, and responding to the detected occurrence of the preselected event by applying a predetermined stimulating signal to the patient's vagus nerve appropriate to alleviate the effect of the eating disorder of interest. For example, the preselected event may be a specified level of food consumption by the patient within a set interval of time, or the commencement of a customary mealtime according to the patient's circadian cycle, or the passage of each of a sequence of preset intervals of time, or the patient's own recognition of the need for treatment by voluntarily initiating the application of the stimulating signal to the vagus nerve. In cases in which the disorder is compulsive eating to excess, the stimulating signal is predetermined to produce a sensation of satiety in the patient.

Abstract: An implantable, flexible, helical electrode strcuture is disclosed having an improved connector for attaching the lead wires to the nerve bundle, thereby minimizing damage which might otherwise occur to the contact points between the lead wires and helical electrode.

Abstract: An external command device and an internal decoding and verification device are used to non-invasively alter the operating parameters of a programmable device implanted in an animal body. Thus, physiological changes can be easily accommodated by the implanted device. In a preferred embodiment, pulse position modulation is used to externally encode the command information. A resulting string of current pulses generates voltage spikes (in the internal decoding device) through inductively coupled coils. Each incoming data bit is verified and the entire command word is verified. After verification, the decoded command is transferred to a command register for simultaneously altering the selected operating parameters. The internal receiver circuitry may conveniently utilize energy from the induced voltage spike, using passive components for forming an output suitable for processing.

Abstract: Method of and apparatus for automatic defibrillation of the cardiac ventricles of a heart wherein both the mechanical and electrical activities of the ventricles are sensed and used as operating inputs to the controls. Electrical activity is detected and measured with a pair of electrodes, and the waves of an electrocardiogram (ECG) are analyzed. When such electrical analysis indicates that ventricular fibrillation is present and persists, an electrical circuit is actuated for detecting mechanical pumping activity of the heart. Mechanical pumping activity is measured by the change in impedance between the pair of electrodes in one of the ventricles. The change of ventricular impedance is caused by the varying volume of blood contained within the ventricle and depends upon whether the ventricle is in a contracted or a relaxed state. The defibrillator is actuated only when both the mechanical and electrical activity of the ventricle indicates a need for defibrillation.