Abstract: A pacing system and method for determining a heart failure condition such as left ventricular dysfunction in a patient are provided, based upon obtaining information from cardiac signals, which information is processed and examined for an indication of the onset or progression of LVD. Since LVD is generally characterized by conduction disorders and other body responses calling for different heart rates during exercise, an examination of sensed cardiac signals is utilized to obtain data reflective of an LVD condition. In one embodiment, a QT rate responsive pacemaker is utilized, wherein variations in QT interval corresponding to heart rate are detected and stored, and then periodically analyzed to detect changes of sufficient magnitude to indicate onset of LVD. In another embodiment, changes in lower natural rate at nighttime or rest are monitored and analyzed for detection for a trend indicating LVD.

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: There is provided a pacemaker system having the feature of delivering a ventricular safety pulse (VSP) following an early ventricular sense (VS), wherein the pacemaker automatically determines whether VSPs are to be delivered following early VSs, and if yes, with what timing. The pacemaker gathers data following delivered VSPs, which data contains information indicative of whether each early VS was indeed the result of a spontaneous R wave, or was due to crosstalk from a prior delivered atrial pace pulse. This data is processed and, when it presents a high statistical confidence, is used to make a determination of whether to respond with the assumption of a true R wave, or of crosstalk. If the data is not statistically significant, the pacemaker delivers VSPs in a normal fashion, e.g., at the end of a programmable VSP interval timed out following delivery of an atrial pace pulse.

Abstract: An ambulatory recorder having a volatile and a non-volatile memory is described. The recorder actively manages the transfer of the data in the volatile to the non-volatile memory. In particular, the sampling frequency and number of channels to be sampled are monitored. These parameters, along with the total buffer size available, are used to determine the final complete data set which can be stored in the buffer. Thereafter, the contents of the buffer are transferred to the non-volatile memory. In such a manner the recorder avoids filling the buffer in the middle of a sampling tick, in which case the remaining data to be sampled would be lost.

Abstract: There is provided an implantable device with two or more output stages for delivering concurrent output pulses to two or more sites within a patient's body. Each output circuit has a common architecture, including a switchable generator which has a plurality of storage capacitors and switches for arranging the capacitors either to be charged by the battery, or to discharge a stimulus pulse. A programmable regulator is provided for further regulation of the output voltage; and a multiplexer connects the output to the desired electrodes placed at the patient site.

Abstract: A compact blood oxygenator has a minimal priming volume and is particularly advantageous for pediatric cardiac surgery. A generally rectangular housing has longitudinally spaced and interspersed heat exchanger conduit groups and oxygenator fiber bundles. The conduits and oxygenator fibers extend transversely across the interior of the housing in criss-cross fashion. Cured potting compound and flanges on the interior surfaces of the housing define hermetically sealed heat transfer fluid, blood and gas mixture flow paths. The inlet and outlet ends of the heat exchanger conduits communicate with first and second chambers formed on opposite sides of the housing. The inlet and outlet ends of the oxygenator fibers communicate with third and fourth chambers on the other opposite sides of the housing.

Abstract: An ambulatory device having a case with an integral splash cover about the area of the catheter input ports is described. Moreover, the ports are angled such that when the device is carried in its intended manner by a patient, the ports are angled downwards. Through the case design, in combination with the angle of the ports, the device is relatively more resistant to splash-related problems as compared to prior devices.

Abstract: Bioprosthetic devices made of collagen-based material having collagen amine groups and collagen carboxyl groups are provided as well as methods for their formation. The methods comprise combining an epoxy functionalized crosslinking agent with the collagen-based material in an aqueous medium at an acidic pH to react a portion of the collagen carboxyl groups with the epoxy functionalized crosslinking agent to form crosslinked collagen-based material comprising residual collagen carboxyl groups.

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: An implantable medical device having a hermetic canister a battery positioned within the hermetic canister; a pulse generator system positioned within the hermetic canister and electrically coupled to the battery; a receiver positioned within the hermetic canister and electrically coupled to the battery and the pulse generator system; a transmitter positioned within the hermetic canister and electrically coupled to the battery and the pulse generator system; and an antenna positioned outside the hermetic canister and coupled to the pulse generator by a feedthrough. The antenna is constructed of a series of planar windings enclosed by an enclosure; each winding is between 1-100 microns wide, wherein each winding is between 1-1000 microns thick and wherein each winding is spaced apart from each of the other windings between 1-100 microns.

Abstract: An ambulatory recorder which features an enhance technique for sampling. The ambulatory recorder has a programmable number of channels, each channel having a programmable sampling frequency rate. The multi channel ambulatory recorder is fashioned so as to sample and records data only from each channel as desired at the frequency as desired. The recorder examines the frequencies on the channels for which data is to be sampled and recorded, and selects a common tick frequency for the microprocessor to awaken, sample and sleep again. Moreover, the microprocessor is directed to only sample at each tick on each channels as needed reducing the amount of required memory and shortening the time it is consuming power.

Abstract: There is provided an implanted system and method for delivering subsonic mechanical waves to one or more selected patient areas, the areas including the patient's heart and/or lungs. The mechanical waves are delivered for the purpose of treating fibrillation or like arrhythmias, for enhancing lung gas exchange, enhancing cardiac muscle fiber relaxation, and enhancing coronary perfusion. Mechanical waves are generated in a frequency range of about 1-100,000 Hz, and preferably 1-50,000 Hz. The waves may be delivered continuously for short or long time periods, or may be controlled in timing either with respect to detected portions of a patient's heartbeat signal or in response to a detected event such as fibrillation. In one preferred embodiment, the implantable system includes a defibrillation shock generator and control for responding to a defibrillation event by first delivering a sequence of mechanical waves and then delivering an electrical defibrillation shock.

Abstract: An ambulatory recording system, for medical and especially diagnostic purposes, is described having a communication watchdog between two processors. The two processors may be of differing types. For example, the first processor may be real time processor ("RTP") which handles the sampling function, while the second processor may be a non real time processor ("NRTP") which handles the operating system function. This dual processor design permits relatively low power consumption for data recording (which is handled by the relatively lower power consuming RTP), while also providing a graphical user interface for user simple user operation (which is handled by the relatively higher power consuming NRTP). A communication watchdog between the two processors is provided to reset the device upon the detection of a processor failure or communication failure between the two processors.

Abstract: A device and method useful in the diagnosis and treatment of congestive heart failure. Specifically the present invention senses the trans-thoracic impedance as well as patient posture. By correlating changes in posture with trans-thoracic impedance changes, the present invention is able to diagnose and assess the degree of congestive heart failure. The present invention is described in the context of an implantable pulse generator system, but it may also be practiced in conjunction with various types of implantable devices.

Abstract: A system and method for providing medical electrical stimulation to a portion of the nervous system. The system includes a rigid hollow needle having a lumen, a flexible lead body disposed within the lumen of the needle, the lead body having a insulated coiled proximal section and an electrode section, the proximal section comprising a conductor which is coiled and insulated, the electrode section comprises a portion of the coiled conductor which is not insulated. In an alternative embodiment the electrode section features a crimp core around which a distal end of the coiled conductor which is not insulated is crimped, the rigid hollow needle is metal but which is partially covered along its outer surface with an insulation. In still further embodiments the flexible lead body has a stylet lumen therein and the lead body also has a connector pin for electrically connecting the electrical conductor to a pulse generator.

Abstract: There is provided a system and method for directly stimulating the LES of a patient in order to normally maintain it in a closed state, thereby preventing reflux and treating the symptoms of GERD. The stimulation is inhibited in response to patient swallowing, by monitoring esophageal motility and timing out an inhibition period following detection of motility representative of swallowing. The system utilizes an implanted stimulator which is programmed to deliver a train of stimulus pulses to one or more electrodes fixed around the gastro-esophageal junction and connected to the stimulator by one or more leads. The motility sensing is done by a sensor for sensing mechancial wave movement or electrical signals representative of high motility following swallowing. The motility sensor and stimulating electrodes are attached laproscopically, and are preferably carried by a common stent carrier which is sutured around the lower esophagus.

Abstract: An electrosurgery medical device is enhanced with unique solution-assistance, and includes, in combination, co-operating device jaws including jaw portions for manipulating tissue, and a plurality of solution infusion openings defined and spaced along each of the jaw portions, for receiving electrolytic solution and infising the solution onto and into tissue to be manipulated, along said jaw portions. As preferred, the device further comprises at least one, and most preferably, many, longitudinal groove(s) along at least one and most preferably, both, of the jaw portions, with the solution infusion openings located in the groove or grooves. The solution is energized with RF energy and contributes to the functions and beneficial effects of the instrument. The solution exits the openings in the grooves at sufficient flow rates to separate substantially all the operative surfaces of the device from tissue, thereby substantially completely preventing adherence between the operative surfaces and tissue.

Abstract: There is provided an implantable system and method for monitoring pancreatic beta cell electrical activity in a patient in order to obtain a measure of a patient's insulin demand and blood glucose level. A stimulus generator is controlled to deliver stimulus pulses so as to synchronize pancreatic beta cell depolarization, thereby producing an enhanced electrical signal which is sensed and processed. In a specific embodiment, the signal is processed to determine the start and end of beta cell depolarization, from which the depolarization duration is obtained. In order to reduce cardiac interference, each stimulus pulse is timed to be offset from the QRS signal which can interfere with the pancreas sensing. Additionally, the beta cell signals are processed by a correction circuit, e.g., an adaptive filter, to remove QRS artifacts, as well as artifacts from other sources, such as respiration.

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 system to provide cardiac assistance to a patient's heart. The system includes a pulse generator adapted to be coupled to patient's heart and adapted to be coupled to a skeletal muscle ventricle (SMV). The system further includes a sewing ring adapted to be coupled to the SMV and adapted to be coupled to the patient's circulatory system, the sewing ring has a flexible cylindrical sleeve having a distal end and a proximal end, the flexible cylindrical sleeve defining a lumen therewithin, the ring further features a means for maintaining the patency of the lumen, the means for maintaining the patency positioned on the proximal end. In the preferred embodiment the means for maintaining the patency of the lumen is a reinforcing ring mounted to the proximal end of the flexible cylindrical sleeve, preferably a silicone ring.