Abstract: A method and apparatus for treating gastric arrhythmia. The apparatus features an implantabler pulse generator which may be coupled to the gastric system through one or more medical electrical leads. In the preferred embodiment the leads couple to the circular muscle layer of the stomach. The apparatus further features a sensor to sense slow waves and determines whether the slow waves are occurring in an irregular or unstable manner. The apparatus further permits such slow waves to be diagnosed as either occurring in a bradygastria or a tachygastria and provides the appropriate electrical stimulation in response. Thus the present invention diagnoses and treats irregular gastric rhythm such as bradygastria and tachygastria.

Abstract: A device for treating sleep apnea comprising means for detecting an apnea event and means responsive to detection of an apnea event for stimulating the heart at a higher rate than the heart's natural rate.

Abstract: A method and apparatus for providing electrical stimulation of the gastrointestinal tract. The apparatus features an implantable pulse generator which may be coupled to the gastric system through one or more medical electrical leads. In the preferred embodiment the leads couple to the circular layer of the stomach. The pulse generator preferably features sensors for sensing gastric electrical activity, and in particular, whether peristaltic contractions as occurring. One embodiment particularly solves the problem of accurately detecting gastric arrhythmias by periodically reverting into a sensed intrinsic gastric rhythm mode. In this mode the output of electrical stimulation is adjusted to only occur at an exceedingly slow rate. This slow rate of stimulation thus permits the gastro-intestinal tissues to undergo an intrinsic depolarization so that the underlying intrinsic slow wave rate may be detected.

Abstract: A method and apparatus for providing electrical stimulation of the gastrointestinal tract. The apparatus features an implantable pulse generator which may be coupled to the gastric system through one or more medical electrical leads. In the preferred embodiment the leads couple to the circular layer of the stomach. The pulse generator preferably features sensors for sensing gastric electrical activity, and in particular, whether peristaltic contractions as occurring. One embodiment particularly solves the problem of accurately detecting gastric arrhythmias by periodically reverting into a sensed intrinsic gastric rhythm mode. In this mode the output of electrical stimulation is adjusted to only occur at an exceedingly slow rate. This slow rate of stimulation thus permits the gastrointestinal tissues to undergo an intrinsic depolarization so that the underlying intrinsic slow wave rate may be detected.

Abstract: A method and apparatus for providing electrical stimulation of the gastrointestinal tract. The apparatus features an implantable pulse generator which may be coupled to the gastric system through one or more medical electrical leads. In the preferred embodiment the leads couple to the circular layer of the stomach.

Abstract: A method and apparatus for providing electrical stimulation of the gastrointestinal tract. The apparatus features an implantable pulse generator which may be coupled to the gastric system through one or more medical electrical leads. In the preferred embodiment the leads couple to the circular layer of the stomach. The pulse generator preferably features sensors for sensing gastric electrical activity, and in particular, whether peristaltic contractions as occurring. In particular two sensors are featured. The first sensor senses low frequency gastrointestinal electrical activity between the frequency of 0.017-0.25 Hz and the second sensor senses intrinsic gastrointestinal electrical activity between the frequency of 100-300 Hz, which occurs upon normal peristaltic contractions. The second sensor only senses for a preset period after low frequency gastrointestinal electrical activity has been sensed by the first sensor.

Abstract: A method and apparatus for providing electrical stimulation of the gastrointestinal tract. The apparatus features an implantable pulse generator which may be coupled to the gastric system through one or more medical electrical leads. In the preferred embodiment the leads couple to the circular layer of the stomach. The pulse generator preferably features sensors for sensing gastric electrical activity, and in particular, whether peristaltic contractions are occurring. In particular two sensors are featured. The first sensor senses low frequency gastrointestinal electrical activity between the frequency of 0.017-0.25 Hz and the second sensor senses intrinsic gastrointestinal electrical activity between the frequency of 100-300 Hz, which occurs upon normal peristaltic contractions. The second sensor only senses for a preset period after low frequency gastrointestinal electrical activity has been sensed by the first sensor.

Abstract: A medical electrical lead which may be introduced using a thorascope and is used to electrically stimulate tissue, such as a heart. The lead of the present invention has a "ski-shaped" needle, a strand of between 1-5 cm. attached to the needle, an electrode attached to the strand, and an insulated lead body attached to the electrode. In addition, a test wire is also attached to the needle to permit the electrical characteristics of tissue to be ascertained before the lead is fully inserted. In an alternate embodiment the strand may feature a fixation helix. Due to the shape of the needle and the relatively short strand, the lead is particularly suitable for implantation to a heart using minimally invasive techniques, such as through a trocar.

Abstract: A cardiac assist device having muscle augmentation during confirmed arrhythmia. In particular the present invention operates, in a first embodiment, to sense a cardiac event, next it determines whether the cardiac event is a cardiac arrhythmia, if the event is not a cardiac arrhythmia the devices delivers stimulation to a skeletal muscle grafted about a heart, but if the event is a cardiac arrhythmia the device inhibits delivery of skeletal muscle stimulation and once the arrhythmia is confirmed, then delivers therapeutic stimulation to the heart. In a second embodiment the present invention operates to re-initiate skeletal muscle stimulation once the arrhythmia is confirmed but prior to the delivery of the therapeutic stimulation to the heart.

Abstract: An end-of-life (EOL) indicator for an implantable pulse generator (IPG)--especially of the neuromuscular stimulation variety--indicates an approaching battery EOL condition via an electrocardiogram (ECG) by changing the nature of the muscle stimulation burst signals. IPG internal circuitry detects an approaching EOL condition and modifies the burst signals by, for example, decreasing the number of pulses in a burst, increasing the heart contraction-to-powering-muscle contraction ratio, or alternating between two numbers of pulses in successive burst cycles. The approaching battery EOL condition can be easily ascertained via trans-telephonic monitoring by analyzing a transmitted ECG alone, for the above-mentioned burst signal changes. By observing the patterns in the ECG caused by the burst signal changes, a clinician could be aware of an approaching EOL without having known the original muscle stimulation burst signal parameters.

Abstract: A method and apparatus for providing assistance to a patient's heart using a surgically prepared skeletal muscle. A skeletal muscle, such as the latissimus dorsi, is carefully separated from the skeletal structure leaving enervation and vascularization in tact. The muscle tissue is then separated into two independent contractile masses. Alternatively, two separate skeletal muscles may be used. The first of these is wrapped about the atria. The second is wrapped about the ventricles. Each muscle mass is individually stimulated using an implantable pulse generator. Stimulation to the muscle mass is synchronized to the naturally or artificially paced contractions of the heart to provide the maximum in assistance. During each complete heart cycle, the muscle mass assisting the ventricles is stimulated at the same time as contraction of the ventricular myocardium. The muscle mass assisting the atria is then stimulated at the same time as contraction of the atrial myocardium.

Abstract: A pacemaker having a hysteresis feature which permits intrinsic heart activity, controlled by the sinus node to resume optimally after pacing. The pacemaker has a programmable lower rate and upper rate, a programmable lower hysteresis rate (LRH) corresponding to a lower rate hysteresis interval (LRHI), and a programmable rate (IR) intermediate an upper pacing rate (UR) and a lower pacing rate (LR). A microprocessor measures the average rate of change M.sub.AVG in the intervals between consecutive ventricular depolarizations, and compares the last intrinsic escape interval RR.sub.N to the lower rate hysteresis interval (LRHI).If the last intrinsic escape interval RR.sub.N is longer than the lower rate hysteresis interval (LRHI), and if the value of M.sub.AVG is greater than a first preselected value SL.sub.1 but less than a second preselected value SL.sub.2, the pacemaker stimulates at the lower rate hysteresis (LRH) and thereafter gradually increases the pacing rate up to the intermediate rate (IR).

Abstract: A cardiac pacemaker and related pacing method. The cardiac pacemaker includes atrial and ventricular sense amplifiers for generating atrial and ventricular sense signals. An activity control circuit measures the activity level and initiates an activity interval. A control circuit responds to the atrial sense signals, the ventricular sense signals, and the activity control circuit, for controlling the atrial and ventricular stimuli generation, by matching the activity interval with the depolarization of the atrial tissue, in order to differentiate true exercise induced sinus tachycardia from atrial arrhythmias and retrograde atrial events, and to permit a selective ventricular rate control. The control circuit initiates a 2 to 1 ventricular to atrial response when the activity interval is greater than a VV interval, which is the sum of the interval between the last sensed or paced ventricular event and the atrial intrinsic depolarization (VA.sub.

Abstract: A method and apparatus for providing assistance to a patient's heart using a surgically prepared skeletal muscle. A skeletal muscle, such as the latissimus dorsi, is carefully separated from the skeletal structure leaving enervation and vascularization in tact. The muscle tissue is then separated into two independent contractile masses. Alternatively, two separate skeletal muscles may be used. The first of these is wrapped about the atria. The second is wrapped about the ventricles. Each muscle mass is individually stimulated using an implantable pulse generator. Stimulation to the muscle mass is synchronized to the naturally or artificially paced contractions of the heart to provide the maximum in assistance. During each complete heart cycle, the muscle mass assisting the ventricles is stimulated at the same time as contraction of the ventricular myocardium. The muscle mass assisting the atria is then stimulated at the same time as contraction of the atrial myocardium.

Abstract: A method and apparatus for stimulating the right and/or left carotid sinus nerves or the right stellate ganglion or the epidural space at about T.sub.2 with continuous and/or phasic electrical pulses in response to detected myocardial ischemia to decrease cardiac workload as a method to protect the myocardium. The automatic detection of the need for such stimulation is responsive to a change in ST segment variation different from a predetermined or programmed threshold suggesting acute myocardial ischemia and/or other criteria or indicators of myocardial ischemia, including changes if pH and/or oxygen saturation (SO.sub.2) detected from a sensor located in the heart, preferably the coronary sinus.

Abstract: An intramuscular lead for electrically stimulating muscle tissue particularly configured for a cardiac assist system powered by surgically modified skeletal muscle tissue. Electrical stimulation is supplied via the intramuscular lead to cause contraction of the skeletal muscle in synchrony with the natural or artificially paced heart rate and timed to obtain the desired hemodynamic effect. The improved lead has an electrode which is embedded in the skeletal muscle. The stimulation threshold of the skeletal muscle is held relatively low by the action of a glucocorticosteroid imbedded within the strand of suture material. A spacer coil of biocompatible material is coiled around the strand of suture material, such that the turns of both coils are substantially interleaved. The spacer coil is saturated with a specific agent such as steroid or antibiotic. The compression movement of the muscle tissue and the electrode coil against the spacer coil will cause the drug to be dispensed therefrom.

Abstract: Method of and apparatus for the treatment of angina pectoris using electrical stimulation within the epidural space of the spinal cord. A sensor is used to trigger stimulation only during periods of activity assumed to be symptomatic. The sensor may measure any of a number of parameters including blood oxygen saturation level or mechanical activity. In the preferred embodiment, a piezoelectric activity sensor is programmed to determine when the level of activity is reached at which angina is expected to occur in a particular patient. This determination is used to trigger an implantable pulse generator. Bursts of high frequency stimulation energy are applied by an insulated lead to electrodes implanted in the epidural space at an upper thoracic or lower cervical location. The increased neural activity caused by the stimulation bursts eliminates the pain sensation and allows an equal or higher exercise level of the patient without pain or at a similar pain level.

Abstract: A pacemaker having a hysteresis feature which permits intrinsic heart activity, controlled by the sinus node to resume optimally after pacing. The pacemaker has a programmable lower rate and upper rate, a programmable lower hysteresis rate (LRH) corresponding to a lower rate hysteresis interval (LRHI), and a programmable rate (IR) intermediate an upper pacing rate (UR) and a lower pacing rate (LR). A microprocessor measures the average rate of change MAVG in the intervals between consecutive ventricular depolarizations, and compares the last intrinsic escape interval RRN to the lower rate hysteresis interval (LRHI). If the last intrinsic escape interval RRN is longer than the lower rate hysteresis interval (LRHI), and if the value of MAVG is greater than a first preselected value SL1 but less than a second preselected value SL2, the pacemaker stimulates at the lower rate hysteresis (LRH) and thereafter gradually increases the pacing rate up to the intermediate rate (IR).