Abstract: A sensor patch for attachment to a patient's body for obtaining physiological data from the patient and transmitting the physiological data to monitoring equipment. The sensor patch includes a structural support for supporting the sensor patch on the patient's body, a sensor for sensing physiological data from the patient's body, an adhesive for attaching the sensor patch to the patient's body, an electronics package including a power supply and circuitry for processing the sensed data to produce a conditioned signal, communications equipment for passing the sensed data from the sensor to the electronics package, and a transmitter for transmitting the conditioned signal from the sensor patch to the monitoring equipment. In a preferred embodiment, the electronics package and transmitter form part or parts of the sensor patch itself, and the sensor comprises one or more thermistors to sense the temperature of the patient's body. In another embodiment, the transmitter is an infra-red transmitter.

Abstract: A portable combined pacemaker parameter and vital sign monitor acquires data relating to a patient's ECG waveform and an in vivo pacemaker waveform by means of electrodes which contact the patients's skin near the location of the patient's pacemaker. The monitor detects signals from the pacemaker and displays derived waveforms on a self-contained display screen. The monitor also includes a storage device to store data derived from the detected signals for subsequent recall and analysis. The waveform information is displayed on the monitor so as to show the relationship in time between the ECG waveform and the pacemaker waveform. The monitor is particularly useful for the portable measurement of ECG and/or pacemaker waveforms and for the ongoing analysis of the condition of a working pacemaker in vivo.

Abstract: A dual-chamber heart pacer whose ventricular pacing rate is closely matched to the physiological requirements of the patient. A "true" atrial rate is determined by counting over a 3-second interval the number of sensed atrial beats, including those which occur during atrial refractory periods. When the atrial rate rises to a threshold level, the ventricular pacing rate decreases gradually from the Wenckebach rate to a fall-back rate independent of atrial sensing. During this decline, atrial pacing pulses may be generated simultaneously with ventricular pacing pulses in an effort to terminate tachycardia. The controlled decline in ventricular pacing rate begins after a 3:2 block has resulted, but before a 2:1 block would otherwise result. The fall-back rate is higher than the standby rate to compensate for the lack of atrial pacing when the system operates at the fall-back rate.

Abstract: There is disclosed a dual chamber pacer which offers several advantages over prior art devices. Although the pacer requires for its operation AV delay and VA delay parameter values, most physicians characterize dual chamber pacers in terms of AV delay and ventricular pacing rate. The pacer of the invention can be programmed under external control by the physician setting values for the parameters with which he is most familiar. A subtractor in the pacer forms the difference between the reciprocal of the ventricular pacing rate and the AV delay to derive the value of the VA delay. The pacer is also characterized by active recharge of the atrial output capacitor so that a very short ventricular refractory period following atrial pacing may be provided. A single maximum rate timer prevents the generation of excessively fast ventricular stimuli, whether due to the ventricular or atrial sub-systems, or even if atrial contractions are being sensed at too rapid a rate.