Phase modulation spectrophotometric apparatus
US6708048B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 13, 1999 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | Jan 13, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/0696
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pathlength corrected spectrophotometer for tissue examination includes an oscillator for generating a carrier waveform of a selected frequency, an LED light source for generating light of a selected wavelength that is intensity modulated at the selected frequency introduced to a subject, and a photodiode detector for detecting light that has migrated in the tissue of the subject. The spectrophotometer also includes a phase detector for measuring a phase shift between the introduced and detected light, a magnitude detector for determination of light attenuation in the examined tissue, and a processor adapted to calculate the photon migration pathlength and determine a physiological property of the examined tissue based on the pathlength and on the attenuation data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.