Research Projects

Near Infrared light irradiation in tissue absorbs chromophores, such as melanin and hemoglobin, which are biomarkers for various diseases or functional states. Time-domain Near Infrared Spectroscopy (TD-NIRS) offers better accuracy but is expensive due to its complex instrumentation. One challenge in TD-NIRS is achieving better depth-localization, which is not feasible in practice due to factors like low Signal-Noise ratio (SNR), multi-layer tissue, and instrument response inaccuracies. To overcome these challenges, the researchers propose modifying source profiles to obtain more spatial information than conventional point sources. They propose using extended sources like line or combination of lines and acquiring time-resolved data to enhance deep tissue imaging. The proposed system, along with a cerebral blood flow (CBF) measurement system called M-DCS, will be used to achieve accurate CBF measurement in the prefrontal cortex of stroke patients. The researchers have used preliminary data from animal experiments in CW-NIRS using line sources and its different combinations. The proposed TD-NIRS, along with the already developed M-DCS system, will serve as a complete and accurate system to measure CBF in the brain. The novelty of TD-NIRS is that it uses a line source to increase depth of measurement, resulting in high SNR at larger SD separations. The necessity of this method is needed for previous ECRA/SERB projects for CBF measurement in the human brain. The deliverables include a small animal CBF imaging system and bedside monitoring of pre-frontal cortex-CBF for stroke patients.