Abstract: A multi-mode, adaptable, implantable pacemaker is described including a microprocessor and memory programmed or capable of being programmed with a variety of processes for stimulating the patient's heart and/or for sensing and transmitting to a device external of the patient's body, various conditions of or activities of the patient's heart, or conditions of the pacemaker itself. The pacemaker includes a multiplexer by which a variety of analog and digital inputs are accessed under the control of the microprocessor and operated upon by the processes stored in the memory and executed by the microprocessor. The output of the pacemaker comprises a plurality of latch drivers and switches, which are selectively operable to apply stimulation to the patient's heart, as well as to sense signals indicative of the patient's heart activity as well as other internal conditions. The pacemaker is capable of transmitting these signals via a link such as an RF or acoustical link to an external monitoring apparatus.

Abstract: A multi-mode, adaptable, implantable pacemaker is described including a microprocessor and memory programmed or capable of being programmed with a variety of processes for stimulating the patient's heart and/or for sensing and transmitting to a device external of the patient's body, various conditions of or activities of the patient's heart, or conditions of the pacemaker itself. The pacemaker includes a multiplexer by which a variety of analog and digital inputs are accessed under the control of the microprocessor and operated upon by the processes stored in the memory and executed by the microprocessor. The output of the pacemaker comprises a plurality of latch drivers and switches, which are selectively operable to apply stimulation to the patient's heart, as well as to sense signals indicative of the patient's heart activity as well as other internal conditions. The pacemaker is capable of transmitting these signals via a link such as an RF or acoustical link to an external monitoring apparatus.

Abstract: A multi-mode, adaptable, implantable pacemaker is described including a microprocessor and memory programmed or capable of being programmed with a variety of processes for stimulating the patient's heart and/or for sensing and transmitting to a device external of the patient's body, various conditions of or activities of the patient's heart, or conditions of the pacemaker itself. The pacemaker includes a multiplexer by which a variety of analog and digital inputs are accessed under the control of the microprocessor and operated upon by the processes stored in the memory and executed by the microprocessor. The output of the pacemaker comprises a plurality of latch drivers and switches, which are selectively operable to apply stimulation to the patient's heart, as well as to sense signals indicative of the patient's heart activity as well as other internal conditions. The pacemaker is capable of transmitting these signals via a link such as an RF or acoustical link to an external monitoring apparatus.

Abstract: An implantable drug administration device can be non-invasively programmed to change both the dosage amount and the dosage interval. Verification of received dosage and interval commands is being achieved by means of an audio transducer which is attached to the device case. Application of a magnet or a programmer to the device inhibits drug delivery.

Abstract: Acoustic signalling apparatus is provided for use with implantable devices for therapeutic, diagnostic or other medical or scientific purposes, for implantation in living animal bodies, including human bodies. A piezoelectric element positioned adjacent the inside wall of the implantable device is selectively energized by an oscillator circuit operating from an energy storage capacitor. Switching devices are provided for activating the acoustic signal according to sensed medical conditions within the body, or according to operating conditions of the device itself, such as indicating approaching end of battery life.

Abstract: Pacer output circuitry for providing biphasic stimulation pulses to heart tissue at a voltage twice the supply voltage. Additionally, the circuit may be configured to sense the intracardiac electrogram in a unipolar or bipolar configuration.

Abstract: A tunable electrocardiogram sensing filter for a pacemaker includes a tapped analog delay (40) having a plurality of tap load resistors (44) selected according to a tap weight function to give a bandpass characteristic. The electrical ECG from the heart pacemaker lead (11) is applied to an input (41) of the tapped analog delay, and is successively sampled and transferred from stage to stage through the delay under control of a clock (34). The filtered output (33) is obtained by summing the tap load resistors, and may be applied for resetting pacemaker timing and output circuits in a demand type pacemaker. In an implantable implementation of the invention, the clock is programmable to different frequencies, which allows scaling the bandpass characteristic of the filter upwards or downwards in frequency to accommodate different frequency component characteristics of the ECG's of individual patients.

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: An improved telemetry transmission system for transmitting electrocardiographic information, indications of the occurrence of the pacing pulse and for transmitting digitally encoded information from an implanted pacemaker, an implanted drug dispensing device, or other implanted device, to a remote receiver. Digital data transmitted by the implanted system may include all programmed parameters as well as power source status and self test indications, or other programmed digital data such as the device serial number and lot number.

Abstract: An improved telemetry transmission system for transmitting electrocardiographic information, indications of the occurrence of the pacing pulse and for transmitting digitially encoded information from an implanted pacemaker, an implanted drug dispensing device, or other implanted device, to a remote receiver. Digital data transmitted by the implanted system may include all programmed parameters as well as power source status and self test indications, or other programmed digital data such as the device serial number and lot number.