Abstract: A method and device for detecting arrhythmias in a patient that includes electrodes positioned subcutaneously within the patient, a microprocessor, coupled to the electrodes, determining one of a sequence of the sensing of cardiac signals by the electrodes and a duration between the sensing of cardiac signals by the electrodes, and control circuitry delivering a therapy in response to one of the determined sequence and the determined duration.

Abstract: A method and device for detecting arrhythmias in a patient that includes electrodes positioned subcutaneously within the patient, a microprocessor, coupled to the electrodes, determining one of a sequence of the sensing of cardiac signals by the electrodes and a duration between the sensing of cardiac signals by the electrodes, and control circuitry delivering a therapy in response to one of the determined sequence and the determined duration.

Abstract: The method of presenting concurrent information about the electrical and mechanical activity of the heart using non-invasively obtained electrical and mechanical cardiac activity data from the chest or thorax of a patient comprises the steps of: placing at least three active Laplacian ECG sensors at locations on the chest or thorax of the patient; where each sensor has at least one outer ring element and an inner solid circle element, placing at least one ultrasonic sensor on the thorax where there is no underlying bone structure, only tissue, and utilizing available ultrasound technology to produce two or three-dimensional displays of the moving surface of the heart and making direct measurements of the exact sites of the sensors on the chest surface to determine the position and distance from the center of each sensor to the heart along a line orthogonal to the plane of the sensor and create a virtual heart surface; updating the measurements at a rate to show the movement of the heart's surface; monitoring

Abstract: The method for collecting cardiac activity data non-invasively from the chest or thorax of a patient comprises the steps of:

Abstract: A plurality of locally sensitive, far-field immune sensors are mounted in mutually spaced relation on the exterior of the body of a subject to detect electrical signals associated with voluntary skeletal muscle activity in the immediate physical vicinity of the sensors. The detected signals are used to determine which, if any, of a predetermined series of voluntary skeletal muscle maneuvers is performed by the subject. A signal bearing a predetermined relationship to the maneuver is then transmitted to a device to be controlled based on which maneuver the subject has performed. Also disclosed are a novel sensor and a method of making same.

Abstract: A plurality of locally sensitive, far-field immune sensors are mounted in mutually spaced relation on the exterior of the body of a subject to detect electrical signals associated with voluntary skeletal muscle activity in the immediate physical vicinity of the sensors. The detected signals are used to determine which, if any, of a predetermined series of voluntary skeletal muscle maneuvers is performed by the subject. A signal bearing a predetermined relationship to the maneuver is then transmitted to a device to be controlled based on which maneuver the subject has performed. Also disclosed are a novel sensor and a method of making same.

Abstract: A neural stimulator electrode element and lead includes an elongate sheath having a passage therein and which contains an electrical conductor and electrode, the latter of which communicates through the exterior wall of the sheath. Two pairs of flexible elongate wing members are positioned on the exterior wall of the sheath to stabilize the tip when it is installed in the patient's epidural space. The flexible wing members flex during installation, but extend laterally from the sheath following installation of the element to prevent the element and lead from rotating and maintain the element in position.

Abstract: A cardiac stimulation apparatus is provided which includes an implantable cardiac pacer 10 having an antitachycardia circuit 12 and an implantable defibrillator circuit 58. The patient's electrical heart rate is sensed and if the heart rate exceeds a predetermined threshold, the antitachycardia circuit 12 is activated. If the antitachycardia circuit 12 fails to lower the heart rate to below a selected rate, the defibrillator circuit 58 is activated. A coded pulse train is transmitted between the pacer 10 and the defibrillator circuit 58 for isolating the pacer 10 from the defibrillator circuit 58 during operation of the defibrillator circuit 58.

Abstract: The sense margin evaluation system and method for use of same is based upon (1) the interposition of a variable broad-band attenuator between an implanted cardiac pacer lead set and a pacer which is about to be implanted and (2) the inclusion of a pacer pulse detector at the pacer port. In use, the pacer is first programmed to a standby mode and a condition of 100% inhibition with the attenuator set to 0 dB. This affirms that the pacer's sense amplifier can sense the cardiac signal. Then, attenuation is incrementally added until the pacer just begins to output. The attenuation ratio (input/output) at this point is a direct measure of the ratio effective between the patient's cardiac signal and the pacer's sensing threshold, i.e., the sense margin.

Abstract: A set of electrodes are provided, preferably in a symmetrical array, which electrodes are mounted within a pliable mounting cup that is capable of conforming to the shape and size of various surfaces of body organs, such as the heart. The pliable cup is capable of both epicardial and endocardial types of mapping procedures, each electrode being connected to a thin insulated wire that joins similar wires in a generally centrally located trunk portion of the cup, and a cable containing the thus bundled wires depends from the trunk portion for connection to a suitable data display and/or recording system.

Abstract: A fully implantable programmable cardiac pacer includes two main pacing channels driven by a crystal oscillator circuit. For each channel, amplitude and pulse width are programmed in paired combinations corresponding to monotonically increasing charge density. Selectively combinable constant current sources are shared by each channel. A low battery indicator system samples battery voltage relative to two threshold levels. In magnet rate, if the main battery voltage is above the first threshold, the fixed pacer output will be 70 beats per minute. If the battery voltage is between the first and second threshold levels, the fixed pacer output will be 62.5 beats per minute. An emergency RC oscillator continuously produces an output at 52.5 beats per minute and one millisecond pulse width.

Abstract: An implantable neural stimulator lead for introduction to and fixation in the epidural space of a patient includes an electrical conductor coated with a non-conductive coating and having a contact region thereon including an electrode for stimulating the patient's spinal cord through the dura. The contact region is located substantially intermediate the distal ends of the lead, whereby the lead may be installed and fixed in the epidural space by manipulation of both ends of the lead. A second surrogate lead is also provided for coupling to an end of the stimulator lead to enable the stimulator lead to be pulled into a position in the patient's body where stimulation is to be effected. One end of the surrogate lead includes a groove to facilitate snaring with a looped snare.

Abstract: A method for the introduction and fixation of a neural stimulator lead in the epidural space of a patient's spinal cord includes the percutaneous placement of a pair of spaced Tuohy needles such that their open tips are in the patient's epidural space and the open tips of the needles are spaced from and face each other. A surrogate lead is inserted through the caudad needle and its leading distal end is moved through the epidural space until it is adjacent the opening in the cephalad needle. A snare is inserted through the cephalad needle to snare the distal end of the surrogate lead and the surrogate lead is drawn through the cephalad needle with the snare. The conductive neural stimulator lead is coupled to the trailing end of the surrogate lead and the surrogate lead is withdrawn through the caudad needle drawing the neural stimulator lead through the epidural space until its electrode is positioned at the location on the dura to be stimulated.

Abstract: An internally carbon coated graft or catheter and method of coating said grafts and catheters through the use of a carbon rod or a metal rod having a carbon pellet at its end coaxially positioned within the substrate's lumen. The graft may be concentrically supported by a metal tube. The rod and metal tube are placed into a vacuum chamber and the rod is subjected to a laser beam to cause the carbon end portion of the rod to transform into gaseous carbon and be deposited on the lumen of the substrate. The process is continued by moving the rod axially along the catheter or graft while being subjected to the effects of the laser beam.

Abstract: An endocardial lead which includes an elongated, flexible, insulative tubing, a central flexible conductor positioned within the tubing and having one end adapted to be electrically connected to a pulse generator. A ribbon-shaped bonding member is connected to the other end of the central conductor. The ribbon-shaped bonding member extends through an aperture in the wall of the insulative tubing and is positioned along the outer surface of the tubing. A ribbon-shaped electrode is helically wound around the outer surface of the insulative tubing and positioned over the ribbon-shaped bonding member. With this configuration, a low impedance electrical connection is provided between the ribbon-shaped electrode and the central conductor, and between adjacent turns of the electrode.

Abstract: The temporary pacing lead assembly (10) includes an electrically conductive flexible wire (14), a terminal member (16) electrically connected to one end of the conductive wire (14), an insulative coating or sheath (24) extending over substantially the entire length of the wire (14) and an electrode (12) electrically connected to the other end of the conductive wire (14). An arrow-shaped anchoring device (34) is carried by the electrode (12) for attaching the electrode (12) to the endocavitary wall of an organ to be stimulated. An anchor release mechanism (62, 60, 90) is coupled to the arrow-shaped anchoring device (34) for subsequent removal of the anchoring device (34) from the endocavitary wall.

Abstract: Interchannel crosstalk in an existing dual channel pacer designed for bipolar leads is reduced by inserting a switching circuit between the pacing leads and the pacer terminals. In one embodiment, in each channel an isolation resistance and buffer amplifier in series with the lead electrodes, respectively, are shunted during stimulation. In another embodiment, the lead electrodes are connected to a pair of differential amplifiers which are bypassed during stimulation on a given channel.

Abstract: To prevent crosstalk between atrial and ventricular bipolar cardiac pacer leads, separate input/output circuits for the two channels are powered by respective isolated capacitors. In one embodiment, the capacitors are resistively coupled to the pacer battery for continuous charging. In another embodiment, one side of each capacitor is normally disconnected from the pacer battery. Charging switches momentarily connect one or the other capacitor directly to the battery in response to the output of the corresponding sense amplifier.

Abstract: A fully implantable programmable cardiac pacer includes two main pacing channels driven by a crystal oscillator circuit. For each channel, amplitude and pulse width are programmed in paired combinations corresponding to monotonically increasing charge density. Selectively combinable constant current sources are shared by each channel. A low battery indicator system samples battery voltage relative to two threshold levels. In magnet rate, if the main battery voltage is above the first threshold, the fixed pacer output will be 70 beats per minute. If the battery voltage is between the first and second threshold levels, the first pacer output will be 62.5 beats per minute. An emergency RC oscillator continuously produces an output at 52.5 beats per minute and one millisecond pulse width.

Abstract: A sterile packaging system for an implantable cardiac pacer or tissue stimulator has a ribbon-like electrical connector strip that permits testing and use of the pacer while it remains sealed in a sterile container. The strip is a thin film of a flexible, non-conductive material with a set of longitudinally oriented conductive paths formed on one surface. A nested set of vacuum formed, plastic blister packs surround and secure the pacer. Each blister pack has a removable closure secured to its periphery. The pack and sealant are impervious to biological contaminants. The closure is preferably a film material that is pervious to a sterilizing agent. The connector strip is preferably two strips, each extending through the peripheral seal of one of the packs. The conductive paths of each strip are in series electrical connection when the packs are assembled.