Research In Reflectance Low Oxygen Saturation Detecting System

Oxygen saturation is one of the important parameters reflecting oxygen delivery ability in human's blood. The measurement of oxygen saturation is applied widely in clinical diagnosis. The non-invasive detecting oxygen saturation provides quickly, directly, efficiently operational reference to doctors. Transmittance oximetry is well developed as a monitoring technique. However, the using scope of the transmittance sensor is limited, reflectance oximetry is necessary in some circumstances, such as cerebral oxygen saturation, muscle oxygen saturation, or fetal oxygen saturation. At first, the current issues of fetal pulse oximetry are analyzed. Because of the important clinical meaning, we hope to develop reflectance low saturation pulse oximetry that applies to intrapartum fetal surveillance. The relationship between transmittance and reflectance oxygen saturation monitoring principle is demonstrated by means of the diffuse transport theory. And oxygen saturation formula applying practice is brought forward. Basing on the theory, reflectance oximetry and reflectance sensor are designed and developed. During development instrument, we found that vernix of fetal body surface would produce effect on instrumental monitoring result. So the effect of vernix on instrument is analyzed as soon as developing reflectance oximeter.Reflectance detecting system is calibrated after system debugging was finished. In calibration experimentation, we obtain calibration curve of oxygen saturation scope from 35 percent to 100 percent. And calibration curves of two kinds ofsensor of two different wavelengths of light(660-940nm or 730-830nm) are found. And by analysis selecting the right sensor do vernix experimentation. The result of the effect of vernix is found. In the paper, clinical test on neonates verify the result of vernix experimentation, because neonate's state accords with our demand At the same time, the clinical experiment results show that oxygen saturation derived from our reflectance monitoring correlates well with the other oximetry...