Patent 4938218 Issued on July 3, 1990. Estimated Expiration Date: October 28, 2008. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
An apparatus for use in measuring fetal blood flow characteristics. The apparatus includes a non-invasive pulse oximetry probe that is inserted into the uterus between the fetus and the uterine wall. The probe is deformable and is positively attached to the fetal tissue surface using a vacuum pump which causes the probe to deform from a pre-set curvature to the curvature of the fetal tissue surface and to form a gasket-type seal with the fetal tissue surface. The probe is manually inserted into the uterus using a curved insertion tool, and is shaped to fit through a slightly dilated cervix. In a preferred embodiment, the probe includes fetal and maternal ECG sensors and additional sensing devices, and is provided with apparatus for improving the efficiency of the pulse oximetry optics.
Holscher, Uvo, "A Novel Approach for an ECG Electrode Integrated Into a Transcutaneous Sensor", Continuous Transcutaneous Monitoring, Plenum Press, 1987; pp. 291-293
Rudelstorfer, Rudolf, et al., "Scalp Heat Flux and its Relationship to Scalp Blood pH of the Fetus", Am. J. Obstset, Gynocol., Aug. 1977; 157:372-377
Geddes, et al., Med. & Bio. Eng. & Comput., May 1977; 15:228-231
Takatani, et al., ACEMB, LA, Calif., Nov. 1977; 30:171
Viniker, D. A., The Fetal EEG (Detection of Oxygen Deprivation), British Journal of Hospital Medicien, Nov. 1979; 504-510
Weller, C., et al., Fetal Electroencephalography Using a New, Flexible Electrode, British Journal of Obstetrics and Gynecology, Oct. 1981; 88:983-986
Silicon Detector Corporation ("SDC"), Data Sheet, General Purpose Detectors, undated