Phase modulated spectrophotometry
US4972331A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 6, 1989 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | Feb 6, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/06113
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention to provides methods and apparatus for studying photon migration using signal modulation techniques such as time, frequency and phase modulation. The photon migration data may then be converted, using the principles of time-resolved spectroscopy, to determine the concentration of an absorptive constituent in a scattering medium, such as the concentration of hemoglobin in a brain of other tissue. The methods and apparatus of the present invention provide as a specific embodiment, a dual wavelength phase modulation system which allows the clinical application of time resolved spectroscopy in a commerically feasible embodiment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.