Methods of enhancing optical signals by mechanical manipulation in non-invasive testing
US6222189A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 1998 |
| Grant date | Apr 24, 2001 |
| Priority date | — |
| Expiry date | May 6, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/3137
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention relates to the enhancement of the signal-to-background ratio of a non-invasive measurement of the concentration of a blood constituent at a measurement site by applying an external pressure at a location near the measurement site. In one embodiment, sufficient pressure is applied proximate to a measurement site to stop blood flow. The pressure is then suddenly relased, thereby generating a blood bolus passing through the site. By illuminating the measurement site before and during the passage of the blood bolus and observing the interaction of the input radiation with the measurement site, the concentration of a blood constituent can be measured. In another embodiment, the venous pulse is occluded by applying a pressure midway between systolic and diastolic pressure. By illuminating the measurement site in the absence of a venous pulse, the signal-to-background ration can be enhanced and the concentration of a blood constituent can be measured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.