Examiner’s finger-mounted fetal tissue oximetry

Abstract

Abstract. The best way to assess fetal condition is to observe the oxygen status of the fetus (as well as to assess the condition of infants, children, and adults). Previously, several fetal oximeters have been developed; however, no instrument has been utilized in clinical practice because of the low-capturing rate of the fetal oxygen saturation. To overcome the problem, we developed a doctor's finger-mounted fetal tissue oximeter, whose sensor volume is one hundredth of the conventional one. Additionally, we prepared transparent gloves. The calculation algorithm of the hemoglobin concentration was derived from the light propagation analysis based on the transport theory. We measured neonatal and fetal oxygen saturation (StO 2 ) with the new tissue oximeter. Neonatal StO 2 was measured at any position of the head regardless of amount of hair. Neonatal StO 2 was found to be around 77%. Fetal StO 2 was detected in every position of the fetal head during labor regardless of the presence of labor pain. Fetal StO 2 without labor pain was around 70% in the first stage of labor and around 60% in the second stage of labor. We concluded that our new concept of fetal tissue oximetry would be useful for detecting fetal StO 2 in any condition of the fetus.

Examiner’s finger-mounted fetal tissue oximetry: a preliminary report on 30 cases

“…We have developed a fetal tissue oximetry technique involving a probe mounted on the examiner ' s finger [14] . During the present study, we succeeded in obtaining FtO 2 measurements in all cases.…”

“…Recently, we developed a new approach to fetal tissue oximetry [14] , which changes the placement of the sensor to overcome these issues. We attached an NIRS probe to the doctor ' s finger, rather than the fetal head or cheek.…”

Examiner’s finger-mounted near-infrared spectroscopy is feasible to analyze cerebral and skeletal muscle oxygenation in conscious Chihuahuas

“…In the Toccare probe, the distance between the emitter and detectors was 8 mm and the width of the detectors was 3.5 mm. 13 Thus, to perform brain NIRS in Chihuahua, we needed at least an 8 × 3.5 mm square as a measurement window. The Toccare LED beams reached a sub-tissue space of 5-mm depth (Fig.…”

“…The measurement method of this device depends on spatially resolved NIRS with two LED light sources (770 and 830 nm). 13 Toccare enabled us to measure rSO 2 (0% to 99%) and total HbI (0 to 1.0) of each organ at 5-mm depth with a sampling interval of 0.5 s. Values of rSO 2 and total HbI were directly displayed on the monitor of the Toccare and also recorded on a secure digital memory card. To perform NIRS, we did not need to prepare a dark room and shading component due to the high power of the Toccare LED.…”

Craniofacial tissue oxygen saturation is associated with blood pH using an examiner’s finger-mounted tissue oximetry in mice

“…[6][7][8][9] According to a recent case report, one serious complication, cerebrospinal fluid leakage from the incision site, occurred during FSBS. 9 Kanayama and Niwayama 10 have developed a smaller oximetry with the sensor attached to the examiner's finger (KN-15, ASTEM, Kwasaki, Japan). This medical instrument consists of a probe with near-infrared spectroscopy (NIRS) and a numeral display device [Figs.…”