title: Near-infrared spiroximetry: noninvasive measurements of venous saturation in piglets and human subjects.
abstract: We present a noninvasive method to measure the venous oxygen saturation (Sv(O(2))) in tissues using near-infrared spectroscopy (NIRS). This method is based on the respiration-induced oscillations of the near-infrared absorption in tissues, and we call it spiroximetry (the prefix spiro means respiration). We have tested this method in three piglets (hind leg) and in eight human subjects (vastus medialis and vastus lateralis muscles). In the piglet study, we compared our NIRS measurements of the Sv(O(2)) (Sv(O(2))-NIRS(resp)) with the Sv(O(2)) of blood samples. Sv(O(2))-NIRS(resp) and Sv(O(2)) of blood samples agreed well over the whole range of Sv(O(2)) considered (20-95%). The two measurements showed an average difference of 1.0% and a standard deviation of the difference of 5.8%. In the human study, we found a good agreement between Sv(O(2))-NIRS(resp) and the Sv(O(2)) values measured with the NIRS venous occlusion method. Finally, in a preliminary test involving muscle exercise, Sv(O(2))-NIRS(resp) showed an expected postexercise decrease from the initial baseline value and a subsequent recovery to baseline.
authors.affiliation: Bioengineering Center, Department of Electrical Engineering and Computer Science Tufts University, Medford, Massachusetts 02155-6013, USA. mari@eecs.tufts.edu
authors.forename: Maria Angela
authors.initials: MA
authors.lastname: Franceschini
authors.forename: David A
authors.initials: DA
authors.lastname: Boas
authors.forename: Anna
authors.initials: A
authors.lastname: Zourabian
authors.forename: Solomon G
authors.initials: SG
authors.lastname: Diamond
authors.forename: Shalini
authors.initials: S
authors.lastname: Nadgir
authors.forename: David W
authors.initials: DW
authors.lastname: Lin
authors.forename: John B
authors.initials: JB
authors.lastname: Moore
authors.forename: Sergio
authors.initials: S
authors.lastname: Fantini
mesh_terms: D000328:Adult; D000465:Algorithms; D000818:Animals; D015444:Exercise / Q000502:physiology; D005260:Female; D006614:Hindlimb / Q000098:blood supply; D006801:Humans; D008297:Male; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D012039:Regional Blood Flow / Q000502:physiology; D019265:Spectroscopy, Near-Infrared; D013147:Spirometry / Q000379:methods*; D013552:Swine
chemical_list: D010100:Oxygen