Ischemic and bleeding disease monitoring with fNIRS imager: one case report

We detected oxyhemoglobin (HbO2) content change and blood volume of the bleeding model in vivo with NIRS imager. The results showed that the minimum detect limit of NIRS imager is 0.5 ml and the optimum detect depth is 2 - 5 cm under skin. In our test, the imager could detect small change of the blood volume easily, but the HbO2 content in hyperemia location hadn't obvious change. The results suggested that injected blood was venous blood which had lower HbO2 content level. In single channel blood oxygen test, we observed that deoxyhemoglobin, blood volume had significant changes after 0.5 ml venous blood was injected each time. But the oxyhemoglobin hadn't obvious change too. The NIRS imager could determine the location, range and depth of ischemia or bleeding diseases. Because the instrument is cheap, portable, and operate easily, it is promising in family diagnosis and sport medicine.