Noninvasive fetal oxygen monitor using NMR.

摘要

A non-invasive method for continuously monitoring blood and tissue oxygenation of a human fetus prior to and during labor and delivery. A specialized NMR spectrometer, whose static-field magnet is large enough to admit the abdomen of a pregnant woman at term, obtains resonance signals from a spatial region within the mother that includes the fetus. Resonance signals originating from the oxygen-transport protein hemoglobin are continuously obtained and analyzed. Signals originating from the special form of hemoglobin found in the fetal circulation are distinguished from those from the adult form of hemoglobin found in the maternal circulation. By continuously comparing the amplitudes of specific fetal hemoglobin resonances that are characteristically shifted upon oxygen binding with the amplitudes of other fetal hemoglobin resonances that are not so shifted, the method yields a continuous measurement of fetal blood and tissue oxygenation. Further analysis of the resonance signals yields indications of fetal blood acidity, heartbeat and respiration and corresponding indications of maternal condition. The method is also applicable to newborn infants and to certain mammals other than humans.