Apparatus for transmitting patient physiological signals
US4987902A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 30, 1988 |
| Grant date | Jan 29, 1991 |
| Priority date | — |
| Expiry date | Dec 30, 2008 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/308
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An apparatus (10) for transmitting a patient physiological signal is provided. A converter (12) includes a front end circuit (28) that receives and conditions a patient physiological signal, V.sub.P, and produces conditioned signal, V.sub.C. A magnitude of V.sub.C is proportional to an amplitude of V.sub.P offset by a negative DC voltage. A track and ramp circuit (30) receives V.sub.C and produces a tracking voltage, V.sub.T. A magnitude of V.sub.T is inversely proportional to the magnitude of V.sub.C when the track and ramp circuit is in a tracking mode. A controller (16) includes a clock that produces clock pulses, V.sub.CK and a divider (38) that divides the clock pulse frequency and produces a trigger pulse, V.sub.TRIG. A leading edge of the V.sub.TRIG pulse starts a counter (40) counting V.sub.CK pulses. The leading edge of an optically transmitted V.sub.TRIG pulse is applied to the latch circuit (32), which produces a ramp command voltage, V.sub.R. A high V.sub. R voltage places the track and ramp circuit (30) in a ramping mode and causes the magnitude of V.sub.T to decay at a constant rate. The latch circuit produces an echo pulse, V.sub.E, when V.sub.T decays to zero volts.…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.