Abstract: Myocardial sutureless unipolar lead including an insulated conductor coil adjacent to a base pad, and a barbed electrode spaced adjacent to the base pad and connected to the conductor coil. The sutureless myocardial unipolar lead requires no stab wound or sutures for electrode placement and support. The barbed electrode is secured to the heart by gently pushing the tip into the myocardial tissue and the electrode is thereby secured to the myocardial tissue. The lead accepts a stiffening stylet for controlling the stiffness to aid in placement of the electrode within the myocardial tissue, and without the need for further insertion tool. The angle of the barbed electrode determines the specific application of the lead for ventricular or atrial pacing applications.

Abstract: A CMOS inverter is used to compare pacemaker battery voltage to a referenced voltage. When the reference voltage exceeds the measured battery voltage, the inverter changes state to indicate battery depletion.

Abstract: A body implantable cardiac pacemaker having a Hall effect switch which may be activated by a magnetic field in order to alter one or more pacemaker characteristics. A circuit in the pacemaker produces a strobe signal which is used to turn on a current flow through the Hall effect element once each pacemaker pulse cycle for a period of 25.mu. sec. The Hall effect element is part of an integrated circuit and is oriented in a plane parallel to the broad plane of the pacemaker.

Abstract: A wrist watch size heart rate monitor coupled with a flexible metal expansion band detects a electrocardiac signal on one arm and applies that detected signal to electronic circuitry within the monitor. Means are also included for receiving a second electrocardiac signal from the other arm to obtain an electrocardiac lead I signal. The receiving means may be a contact member adapted to being placed in physical contact with a second flexible metal expansion band around the wrist of the other arm and having a like contact member associated therewith or the receiving means may be metal members adapted to having the thumb and a finger of the hand of the other arm squeezed thereagainst.

Abstract: Atrial-ventricular coaxial transvenous pacing lead including an inner ventricular lead having an electrode and an outer atrial lead having an atrial sidearm lead, the atrial sidearm lead including a sigmoidal shape and an electrode at the distal end of the sidearm lead. Outwardly extending tines can surround either or both of the electrodes. The atrial sidearm lead maintains geometrical memory of the sigmoidal shape. The atrial sidearm head can be used absent the ventricular lead.

Abstract: An atrial pacemaker having an atrial pacing rate adjusted to correspond to a detected ventricular heart rate to maintain A-V synchrony in a range between a minimum and maximum pacing rate. Sensed ventricular depolarizations not associated with a preceding atrial pacing stimulus cause the atrial pacing rate to be increased. When A-V synchrony is restored at a higher rate, the rate is decreased. Underdrive stimulation to treat pathologic tachycardia is achieved as the atrial pacing rate is increased in steps to the maximum pacing rate, normally lower than typical tachycardia rates.

Abstract: Adhesive bonded positive fixation epicardial lead including an electrode support member for supporting an electrode and an adhesive which adheres the electrode support member and the accompanying electrode to an exterior wall of the heart. Surgical mesh can also be affixed to the electrode support member so that after decay of the adhesive, tissue ingrowth provides for adherence of the electrode support member to the tissue of the heart wall.

Abstract: A gamma ray scintillation camera generating (X,Y) spatial coordinate and Z energy signals relative to detected radiation events. The system provides for calibration of the camera Z signal response as a function of camera face location. In addition, the camera signals are converted to their digital equivalents subsequent to which the apparent coordinate locations of detected events as determined by the camera are corrected to their true spatial coordinates based upon correction information stored in the system.

Abstract: Ring electrode for a pacing lead where the ring electrode is secured to a conductor coil by soft metal disposed in a slit in insulation over the conductor coil. A slit or hole is punched into the insulation before or after the insulation is pulled over the coiled conductor, silver ball or wire or other like soft metal is placed in the slit or hole, a ring is slid over the insulation and centered over the soft metal, and the ring is swaged to the same diameter as the insulation utilizing an internal mandrel in the conductor coil so that the soft metal is pressed between the ring electrode and the coiled conductor resulting in a mechanically crimped joint. The ring electrode provides flexibility within the lead and the insulation extending through the ring electrode. Tensile strength at the ring electrode is substantially equal to that of the insulation. The ring electrode is swaged to the same diameter as the lead body resulting in a smooth surface and providing for easy lead passage.

Abstract: A programmable cardiac pacemaker pulse generator utilizing digital circuitry for controlling the provision of cardiac stimulating pulses. The pulse generator is capable of having the rate, the pulse width, the pulse amplitude, the refractory period, the sensitivity and the mode of operation programmed. In addition, the pulse generator can have the output inhibited and can respond to programming signals causing a threshold margin test to be performed, effects of closure of the reed switch overridden, a hysteresis function added and a high rate exceeding the normal upper rate limit programmed. Many of the programmable functions of the pulse generator can either be programmed on a permanent or a temporary basis. The pulse generator further includes means for signaling the acceptance of a programming signal, and means to reset the program acceptance circuit if extraneous signals are detected as programming signals.

Abstract: There is disclosed herein a programmable cardiac pacemaker pulse generator utilizing digital circuitry for controlling the provision of cardiac stimulating pulses. The pulse generator is capable of having the rate, the pulse width, the pulse amplitude, the refractory period, the sensitivity and the mode of operation programmed. In addition, the pulse generator can have the output inhibited and can respond to programming signals causing a threshold margin test to be performed, accomplished by threshold safety margin means responsive to a programmed test signal for causing a series of stimulating pulses to be provided a rate different than the previously programmed rate with at least one of the stimulating signals having its energy reduced a predetermined amount. Capture at the reduced energy can be monitored by external equipment.

Abstract: A programmable cardiac pacemaker pulse generator utilizing digital circuitry for controlling the provision of cardiac stimulating pulses. The pulse generator is capable of having the rate, the pulse width, the pulse amplitude, the refractory period, the sensitivity and the mode of operation programmed. In addition, the pulse generator can have the output inhibited and can respond to programming signals causing a threshold margin test to be performed, effects of closure of the reed switch overridden, a hysteresis function added and a high rate exceeding the normal upper rate limit programmed. Many of the programmable functions of the pulse generator can either be programmed on a permanent or a temporary basis. The pulse generator further includes means for signaling the acceptance of a programming signal, and means to reset the program acceptance circuit if extraneous signals are detected as programming signals.

Abstract: Temporary adjustable bipolar lead including an inner lead and an outer coaxial lead. A self-sealing lead introducer head at a junction of the inner lead and outer lead provides for takeoff of the end of the outer coaxial lead. The inner lead is in slidable engagement with the outer lead through a hole in a diaphragm of the lead introducer head.

Abstract: A programmable cardiac pacemaker pulse generator utilizing digital circuitry for controlling the provision of cardiac stimulating pulses. The pulse generator is capable of having the rate, the pulse width, the pulse amplitude, the refractory period, the sensitivity and the mode of operation programmed. In addition, the pulse generator can have the output inhibited and can respond to programming signals causing a threshold margin test to be performed, effects of closure of the reed switch overridden, a hysteresis function added and a high rate exceeding the normal upper rate limit programmed. Many of the programmable functions of the pulse generator can either be programmed on a permanent or a temporary basis. The pulse generator further includes means for signaling the acceptance of a programming signal, and means to reset the program acceptance circuit if extraneous signals are detected as programming signals.

Abstract: The lead anchoring bobbin for containing a transvenous pacing lead at an entry site in human tissue and including a grooved bobbin and buttons which frictionally engage and detain the lead on either side of the bobbin. The lead anchoring bobbin is made of medical silicone rubber or like material.

Abstract: A programmable cardiac pacemaker pulse generator utilizing digital circuitry for controlling the provision of cardiac stimulating pulses. The pulse generator is capable of having the rate, the pulse width, the pulse amplitude, the refractory period, the sensitivity and the mode of operation programmed. In addition, the pulse generator can have the output inhibited and can respond to programming signals causing a threshold margin test to be performed, effects of closure of the reed switch overridden, a hysteresis function added and a high rate exceeding the normal upper rate limit programmed. Many of the programmable functions of the pulse generator can either be programmed on a permanent or a temporary basis. The pulse generator further includes means for signalling the acceptance of a programming signal, and means to reset the program acceptance circuit if extraneous signals are detected as programming signals.

Abstract: Tine protector which protects a plurality of outwardly angular extending tines from an electrode of a pacing lead. The tine protector includes four sides and a bottom where two of the opposing sides include a first round hole in one side, and a second round hole joined to a longitudinal vertical slit in the other side. The electrode frictionally engages into the first hole, and the other electrode or lead of the pacing lead frictionally engages down through the slit and into the second hole. The tines are protected by their close proximity to these two opposing sides.

Abstract: Terminal pin which engages into a wire coil of a transvenous pacing lead and mechanically attaches to the wire coil with a metal crimping sleeve which engages over the wire coil. The terminal pin includes a tapered distal end portion from an outward radial shoulder in a midportion of the terminal pin to the distal end of the terminal pin. A stylet easily passes through a longitudinal hole extending through the terminal pin and into the wire coil of the transvenous pacing lead.

Abstract: A programmable cardiac pacemaker pulse generator utilizing digital circuitry for controlling the provision of cardiac stimulating pulses. The pulse generator is capable of having the rate, the pulse width, the pulse amplitude, the refractory period, the sensitivity and the mode of operation programmed. In addition, the pulse generator can have the output inhibited and can respond to programming signals causing a threshold margin test to be performed, effects of closure of the reed switch overridden, a hysteresis function added and a high rate exceeding the normal upper rate limit programmed. Many of the programmable functions of the pulse generator can either be programmed on a permanent or a temporary basis. The pulse generator further includes means for signaling the acceptance of a programming signal, and means to reset the program acceptance circuit if extraneous signals are detected as programming signals.