Determination of Hemoglobin Oxygen Saturation and Total Hemolgobin Concentration from Turbid Media Using Absorption Spectroscopy

摘要

Oxygen is a versatile molecule involved in a wide range of biological processes. Under physiological conditions, oxygen reacts with hemoglobin to form oxyhemoglobin (OxyHb) at a very high rate. The degree of their combinations is described as blood oxygen saturation (SO2) that has been estimated as well as hemoglobin concentration mostly by Near Infrared Spectroscopy (NIRS) by now. However, the size of the probe used in this technology was too large to apply to the inner body, such as deep brain tissue. The aim of this work was to evaluate the possibility of real-time estimating these parameters from rat cortex by in vivo absorption spectroscopy using a needle-like probe. An artificial neural network (ANN) trained by in vitro data was used. The validity of this approach was studied by decreasing the endogenous OxyHb level with asphyxia. Data indicate that in vivo visible spectroscopy in combination with the ANN fitting method may be a useful tool for gaining real-time insight into SO2 and hemoglobin concentration even from deep brain tissue or small cerebral areas.