Fetal pulse oximetry sensor
US6285896A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1999 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Jul 7, 2019 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B2503/02
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A sensor provides pulse oximetry measurements from the presenting portion of a fetus. In particular, a spiral probe is designed to attach the sensor to the fetal scalp. In one sensor configuration, a light emitting region of the probe embedded in the scalp in conjunction with a light detector located at the scalp surface measures absorption from a larger volume of the scalp tissue than conventional fetal sensors. In another sensor configuration, light emitting and light collecting regions of the probe embedded in the scalp are angled with respect to the scalp surface to measure absorption from a larger volume and deeper layers of the scalp tissue than conventional fetal sensors. These sensors increase the likelihood of measuring blood volume changes occurring in larger arterioles versus smaller arterioles or capillaries, yielding a representative measurement of central arterial oxygen saturation. These sensors also reduce the calibration errors caused by a low blood fraction. Localized arteriolar flow is stimulated with heat or vasodilating substances to reduce the effects of localized oxygen consumption and to increase blood fraction. A three-wavelength sensor is utilized to detec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.