Drive circuit for light-emitting diode in pulse oximeter
US5590652A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1996 |
| Grant date | Jan 7, 1997 |
| Priority date | — |
| Expiry date | Feb 22, 2016 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/02416
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Disclosed is a drive circuit for driving a light emitting diode in a pulse oximeter comprising at least two light emitting elements different in wavelength for irradiating a living tissue containing an arterial blood; a light receiving element for receiving light containing one of a reflected light and a transmitted light irradiated from the light emitting elements; a power supply for applying intermittently an inverse bias voltage toward the light emitting elements; and an inductor for applying an inverse electromotive voltage to the light emitting elements, the inductor being connected to the light emitting elements in parallel, wherein a ratio between light absorption change with respect to two wavelengths obtained from optical outputs of the light receiving element so as to obtain a degree of oxygen saturation of arterial blood.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.