• Y Mendelson and B L Yocum.
• Biomedical Engineering Department, Worcester Polytechnic Institute, Massachusetts 01609.
• Biomed Instrum Technol. 1991 Nov 1;25(6):472-80.

AbstractThe feasibility of measuring arterial oxyhemoglobin saturation (SaO2) noninvasively using a skin reflectance pulse oximeter sensor attached to the scalp, neck, and thigh regions of anesthetized swine was investigated. The optical reflectance sensor used consisted of a pair of red and infrared light-emitting diodes and a concentric array of six identical photodiodes. Two prototype sensor assemblies were evaluated: one assembly housed only the optical sensor, whereas the other also included a miniature heater. Measurements made from the scalp and neck regions were obtained with the non-heated skin reflectance sensor, and measurements from the thigh were made with the heated prototype. Each sensor was interfaced to a commercial transmittance pulse oximeter adapted to perform as a reflectance pulse oximeter. SaO2 values obtained by the reflectance pulse oximeters (SpO2(r) were compared simultaneously with SaO2 values obtained from arterial blood samples and analyzed in vitro with a CO-oximeter. The equations for the best-fitted linear regression lines describing the relationships between SpO2(r) and SaO2 values in the range between 30 and 100% were: SpO2(r) = 10.7 + 0.90 (SaO2), n = 321, r = 0.97; SpO2(r) = 16.72 + 0.82 (SaO2), n = 217, r = 0.95; and SpO2(r) = 20.21 + 0.77 (SaO2), n = 37, r = 0.97 for the neck, thigh, and scalp measurements, respectively. The regression analysis revealed significant correlation and a relatively small standard error of estimate (SEE = 4.05% for the neck, 4.79% for the thigh, and 3.50% for the scalp measurements). This study demonstrated the feasibility of measuring SaO2 noninvasively over a wide range of values utilizing the principle of reflectance pulse oximetry.

7 keywords...

hide…