Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Ortner J, Gallea B, Myers D, Seifert R (HTI Internal Study 1996)
Study Summary: The objective of this study was to determine the correlation between measurements of tissue oxygen saturation in a forearm muscle taken with HTI’s NIR Tissue Spectrometer and oxygen saturation measurements of venous blood, determined by a CO-Oximeter analyzer.
Study Design: Nine individuals participated, four female and five male. Venous blood samples were drawn from an arm vein that was as close to the measured muscle as possible. Pulse oximeter readings of arterial oxygen saturation and heart rate were obtained from the opposite arm.
Measurements were taken at five times: baseline, after light and rigorous exercise, after a period of rest to allow a return to baseline, and finally after 5 minutes of ischemia (a blood pressure cuff on the upper arm was inflated to 200 mmHg for 5 minutes to halt arterial blood flow to the forearm).
Key Results: An analysis of variance was completed to determine differences between Hutchinson Technology NIR StO2 (tissue saturation) values and CO-Oximeter peripheral venous SO2 values. There was no statistical difference between StO2 and venous SO2 at baseline, light exercise, rigorous exercise, and the return to baseline.
A comparison of gender differences was also analyzed. Venous SO2 values were not significantly different between genders. StO2 was significantly higher in males as compared to females during both baseline conditions. No other conditions showed gender differences.
Conclusions: The study was successful in demonstrating correlation between the HTI NIR Tissue Spectrometer and an established clinical measure of saturation although the model had limitations (the vein sampled drained blood from more tissue than was monitored by the NIR probe). It is significant that the HTI NIR Tissue Spectrometer correlated to the CO-Oximeter during conditions where blood low was not interrupted—baseline, light exercise, rigorous exercise, and return to baseline.