Photoplethysmographics using energy-reducing waveform shaping
US5343818A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 1991 |
| Grant date | Sep 6, 1994 |
| Priority date | — |
| Expiry date | Mar 5, 2011 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/1455
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A method of energy-reducing waveform shaping of carrier signals in a photoplethysmographic system, in which a carrier signal may comprise a time-varying periodic waveform comprising a sum of carrier components. The carrier signal has its energy reduced by adding additional carrier components, which reduce the energy envelope for a period of the carrier signal, while preserving the signal information. The method of energy-reducing waveform shaping may be coupled with frequency-division, phase-division and component-amplitude-division multiplexing, and more generally with any method of multiplexing which employs a time-varying periodic carrier signal. Redundant information may be used for error detection and correction. A plurality of carrier components may be chosen which reduces the energy envelope for a period of the carrier signal, and which employs more carrier components than needed to perform the preferred form of multiplexing and demultiplexing of the modulation effects introduced by a tissue section of the patient. Majority voting of carrier components may then provide for error detection and correction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.