A time-resolved near-infrared spectroscopy based on CMOS image sensor

摘要

Time-resolved (TR) near-infrared spectroscopy (NIRS) offers non-invasive clinical applications in monitoring the bloodoxygenation, where absolute values of oxygenated and deoxygenated hemoglobin, and absorption and scatteringcoefficient, can be obtained. Various detectors have been utilized to realize a TR-NIRS system, such as PMT, SiPM, andSPAD. This paper proposed a prototype NIRS device implemented using a 128 × 128 lock-in pixel CMOS image sensor(CIS) based on the lateral electric field-charge modulator (LEFM) to achieve high time resolution. Preliminaryexperiments based on the reflectance of an agar phantom with varying absorption coefficient have been conducted andthe ability to detect the changes in the absorption coefficient has been demonstrated. The reflectance of the agar phantomis directly observed by the image sensor, which was operated at a time-window of 900 ps with a sensor detection area of2.9mm~2. The results suggest that a NIRS device using CIS is feasible, which opens the potential of a miniature wearabletime-resolved NIRS device.