Cardiac pacer circuit
US4300566A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1979 |
| Grant date | Nov 17, 1981 |
| Priority date | — |
| Expiry date | Oct 31, 1999 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61N1/365
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An electronic switching circuit for use in a demand-type cardiac pacer for (1) allowing the amplitude of the stimulating pulses to be selected, (2) ensuring a high input impedance for the heartbeat sensing amplifier, and (3) ensuring a low recovery time following the generation of a pacer pulse. Disposed between the heart contacting electrodes and the sensing amplifier is an electronic switch which is closed during a predetermined period (the sensing interval), but which is opened when the pulse generator is producing a pacer pulse. Thus, the sensing amplifier is shielded from receiving the high voltage surge occasioned by the application of a pacer pulse to the heart. Similarly, an electronic switching device is interposed between the pulse generator and the heart contacting electrodes, which device is closed during a pacing interval, but open during the aforesaid sensing interval, thus isolating the sensing amplifier from the pacer circuitry. Included in the system is a voltage doubler and associated switches which can selectively double or not double the amplitude of the stimulating pacer pulse. In either event, the charge on the voltage doubling capacitor is recovered through t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.