Measurement of Near infrared Spectroscopy based Biomarkers under in-vitro Ischemic stroke condition

Near infrared spectroscopy (NIRS) is an optical method which has been used widely to measure the change in the blood chromophores. Abrupt change in blood chromophore viz, oxyhemoglobin [hbo2] and deoxyhemoglobin [hb] happens in ischemia stroke condition, which occurs due to impairment of the oxygenated compounds viz, oxygen and glucose. The current study presents measurement and analysis of near infrared spectroscopy (NIRS) based regional oxygenation level biomarkers Viz., change in regional blood volume index
$(\Delta \text{rBVI})$
and change in regional oxygen saturation
$(\Delta \text{rSO}2)$
. To measure these NIRS biomarkers dynamic phantom has been designed in such a way that, it mimics the ischemic stroke condition in-vitro by continuously changing (decrease, increase) the oxygenation level of human blood sample in the closed loop arterial system of dynamic phantom. Continuous decline of the
$(\Delta \text{rBVI})\ 22$
%
$(\mathrm{p} < 0.001)$
and
$(\Lambda \text{rSO}2)$
5%
$(\mathrm{p} < 0.001)$
has been observed of the average reading of the samples in an ischemic stroke condition, while 15% and 2% increment has been recorded in reversal of ischemic stroke condition, by increasing the oxygenation level of the arterial system. Correlation between biomarkers in ischemic stroke condition has been found strongly positive (r=56%) and regular residual percentage error in measurement has been measured which has found under 10%. Clinical Relevance— This help in understanding and characterizing the ischemic stroke. Biomarker's trend can be use for classification of stroke types.