脑血红蛋白浓度指数的近红外无损检测与应用

Human cerebral oxygenation and hemodynamics can be estimated by cerebral oxygenation parameters. In this paper, cerebral tissue hemoglobin concentration index (tHI), which was proportional to the cerebral total hemoglobin concentration, was detected non-invasively and in real time using near infrared spectroscopy (NIRS) with two wavelengths and two optical detectors. Cerebral oxygen saturation (rSO2) could also be detected simultaneously. The NIRS oximeter based on the above principle was developed, and eight infants with congenital heart disease were monitored under cardiopulmonary bypass. During modified ultrapurification in the end of cardiopulmonary bypass when the hematocrit was increased by filtering out the redundant water in the blood, the cerebral tHI of all the infants increased significantly at the average speed of 0.0304±0.0136mM/(cmomin)，p<0.001. Comparing the end to the beginning of modified ultrapurification, the cerebral tHI increased for 18.8±7.5%（10.2%~29.2%）, meaning that the total hemoglobin content in the unit volume of brain cortex increased for 18.8±7.5%. During modified ultrapurification, the cerebral rSO2 increased for 5.29±4.05% (p<0.05), which was not so obvious as the increase trend of cerebral tHI. The above results indicate that during modified ultrapurification in the end of cardiopulmonary bypass, the changes of cerebral oxygenation and hemodynamics may be assessed effectively by cerebral tHI.