Testing of body fluid constituents through measuring light reflected from tympanic membrane
US5115133A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1990 |
| Grant date | May 19, 1992 |
| Priority date | — |
| Expiry date | Apr 19, 2010 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B5/1491
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
An apparatus and method are disclosed for determining a level of a constituent such as glucose in a body fluid such as blood. The apparatus and method utilize a light generator for generating a testing light of known intensity with the testing light including a wavelength absorbable by the constituent being measured. The light generator also generates a reference light of known intensity having a wavelength not absorbable by the constituent being measured. The testing light and reference light are directed toward a fluid containing an unknown concentration of a constituent. A light detector is provided for measuring the intensity of the testing light and reference light being spectrally modified by the fluid. A light path distance measurer is provided for measuring a distance of a light path traveled by the testing light and reference light. A circuit is provided for calculating a level of the constituent in the fluid in response to a reduction in intensity of the testing light and reference light and in response to the measured distance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.