Optical Measurement of Tissue Oxygen Saturation

Abstract

Advances in opto-electronic systems have meant that optical spectroscopy can now be used for noninvasive measurements in tissue in patients. A number of techniques have evolved over the last 15 years that make use of the characteristic differences in the absorption spectrum of deoxygenated and oxygenated hemoglobin to measure oxygen saturation. This article summarizes, in particular, those techniques that may prove to be applicable to measurements relating to lower extremity wounds. A short introduction is given about existing electrode methods before describing applications of near infrared and visible wavelength spectroscopy to measurements in tissue. The advantages and limitations of these methods are discussed. An example of an area where tissue spectroscopy is now in routine clinical use for tissue healing viability assessment is presented.

Hematopoietic Stem Cells: NormalVersusMalignant

“…The BM niche, or extracellular components surrounding HSPCs, and peripheral tissues have oxygen tensions ranging from 1% to 7%. In vitro study of primary normal and malignant HSPCs, as well as various culture lines, has demonstrated the beneficial effects of a hypoxic environment (18,26,27,60,61,131,133). Both normal and malignant HSCs benefit from growth conditions that have oxygen concentrations ranging from 1% to 3%, compared with cultures at normoxic (5%) and atmospheric (21%) O 2 concentrations (29,70,116,144,152).…”

Long-Term In Vivo Oxygen Sensors for Peripheral Artery Disease Monitoring

“…While techniques exist to assess perfusion and capillary hemoglobin oxygenation [7], a more direct measurement of tissue (interstitial) oxygen availability may provide a better indicator of tissue health and enable earlier intervention. Transcutaneous oxygen tension (TCOM or TcpO 2 ) and ankle-brachial index (ABI) are two techniques commonly used to monitor PAD patients.…”

Low Tissue Oxygen Saturation Is Associated with Requirements for Transfusion in the Rural Trauma Population

“…Tissue hemoglobin oxygen saturation (StO 2 ) measured by near infrared spectroscopy is a rapid and noninvasive method of measuring tissue perfusion that quantifies muscle oxygenation [7]. StO 2 has been evaluated in various clinical settings including monitoring cerebral perfusion in patients with stroke and subarachnoid hemorrhage, lower extremity wound healing, peripheral arterial disease, organ failure, and septic shock [8][9][10][11][12][13][14][15]. In the trauma population, several studies have assessed the use of StO 2 to guide resuscitation, predict the development of organ dysfunction, and determine the need for blood transfusion within 24 h after injury.…”