Non-invasive measuring method and apparatus of blood constituents
US4927264A · kind A · utility
251Cited by
4References
8Claims
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Key dates
| Filing date | Dec 1, 1988 |
| Grant date | May 22, 1990 |
| Priority date | — |
| Expiry date | Dec 1, 2008 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/6838
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
In order to measure the oxygen saturation in venous blood, a venous blood stream is made time-variant by applying pressure with a peak value of the minimum blood pressure to a proximal portion from a measuring part. Light beams with different wavelengths are transmitted from the measuring part and detected by photodiodes. Photodetected signals are logarithm-converted and venous signal components are separated from logarithm-converted signals with a filter circuit. The oxygen saturation of venous blood is calculated on the basis of separated venous signal components.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.