Computer assisted admittance plethysmograph
US4548211A · kind A · utility
Inventor
Key dates
| Filing date | Jan 12, 1984 |
| Grant date | Oct 22, 1985 |
| Priority date | — |
| Expiry date | Jan 12, 2004 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/7239
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An improved method and apparatus for measuring the pulsatile volume and net inflow in a body segment (e.g. a limb) is disclosed. An amplitude stabilized oscillator of high quality is utilized, together with normalization of the output signal measured at the body segment relative to the input signal delivered to the body segment such that an improved signal-to-noise ratio is achieved. In addition, utilizing a digital computer and an EKG signal as a time reference, the individual plethysmograph volume pulse and its first derivative are selectively averaged over many beats, thus further improving the signal-to-noise ratio and allowing a more critical examination of the wave profile. The outputs from the computer include the plethysmogram, the first and second derivatives thereof, the averaged EKG waveform, and the absolute physiologic values of peak-to-peak pulsatile volume, and peak net inflow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.