Abstract: A cardiac pacemaker of the type responsive to heart activity to affect the operation of the pacemaker. Detecting circuitry is provided having a differential input and an essentially polarity independent degree of response to sensed signals. A single polarity output signal is provided representative of sensed signals of either polarity. In a preferred embodiment, a differential input and differential output preamplifier is responsive to sensed signals to provide output signals of opposite polarity but like absolute value. An absolute value circuit responds to the opposite polarity signals to provide a single polarity output signal, the output signal being the same polarity without regard to the polarity of the sensed signals.
Type:
Grant
Filed:
January 16, 1981
Date of Patent:
November 9, 1982
Assignee:
Medtronic, Inc.
Inventors:
David L. Thompson, Jerome T. Hartlaub, Marc T. Stein
Abstract: Apparatus which detects ventricular depolarizations originating at an ectopic focus. Ventricular depolarization is sensed at a plurality of areas of the heart including one area within the interventricular septum or near the right ventricular apex. Logic circuity responds to the sensed depolarizations to discriminate between normal and abnormal origination of an impulse propagated through the ventricular conduction system. A signal representative of such abnormal impulse origination may be employed in any desired manner.
Abstract: A communications terminal for use with a programmable controller to permit transmission of status and control information between that programmable controller and a plurality of programmable controllers having similar communications terminals associated therewith and connected in a communications loop. The communications terminal permits one programmable controller to utilize signals originating in other programmable controllers and to provide asynchronous time division multiplexed signals to other programmable controllers via a shielded, twisted-pair conductor to control devices connected to those other programmable controllers.
Abstract: A body implantable lead and a stiffening stylet with a flexible tip for imparting rigidity to the lead to facilitate attachment of the lead to an internal body organ and for transmitting torque to the distal end of the lead. A flexible tip stiffening stylet is provided for insertion into a lumen in the lead extending from a pin at its proximal end along the length of the lead conductor to the electrode. A portion of the stylet wire inserted in the lumen has a thinner diameter over a portion of its length near the distal end to permit smooth transmission of torque by rotation of the stylet wire even in applications where the lead and stylet are tightly bent in the vicinity of the thinned portion of the lead.
Abstract: An elongated flexible plastic member having barbs at one end thereof and a plurality of transverse holes therethrough for use with a lure or hook to maintain a bait fish on a fishing line.
Abstract: A body implantable medical infusion system including an infusate reservoir, a system for regulating infusate discharge and a catheter for delivery of discharged infusate to the desired infusion site. An unregulated infusate discharge is prevented, in a preferred embodiment, by a normally open valve positioned intermediate the pump and the catheter, the valve closing in response to the sensing of unregulated infusate. A sensor, to which the valve responds, may be positioned at the output of the pump or at any other location within the system to sense infusate leakage. The valve may be additionally closed in response to an externally generated signal.
Abstract: Apparatus for processing waveform signals of physiological origin. The apparatus includes circuitry for developing a signal representative of the peak-to-peak amplitude between each waveform signal peak and the next successive waveform signal peak as well as circuitry for developing a signal representative of the slew rate of the waveform signal between successive waveform signal peaks. In a preferred embodiment, developed signals are stored in resettable memories, the memories being reset on the occurrence of a sign or polarity change in the slope of the waveform signal. Sampling circuitry is provided for establishing a maximum peak-to-peak amplitude within the waveform signal as well as its associated slew rate. Within the context of an ECG, the maximum peak-to-peak amplitude and associated slew rate represent the QRS complex and the apparatus of the present invention may be employed within a pacemaker as a sense amplifier.
Abstract: A body implantable stimulator for providing stimulation signals having selectable energy levels. The stimulator provides a series of one of a predetermined plurality of independent output initiate signals and responds to those signals to provide stimulation signals having an amplitude, duration and repetition rate established by the series of output initiate signals that is provided.
Type:
Grant
Filed:
August 29, 1980
Date of Patent:
July 20, 1982
Assignee:
Medtronic, Inc.
Inventors:
David L. Thompson, Ray S. McDonald, Yan S. Lee, Marc T. Stein
Abstract: Lithium-iodine cells with cathode having more than about 97% I.sub.2 (by weight) and less than about 2.5% (by weight) poly (2-vinylpyridine) prepared in the conventional manner.
Type:
Grant
Filed:
November 12, 1980
Date of Patent:
July 20, 1982
Assignee:
Medtronic, Inc.
Inventors:
William G. Howard, John C. Strohkirch, Marilyn A. Pehl