Full field laser Doppler flowmetry with custom made CMOS sensors

摘要

Recently, full field laser Doppler perfusion imaging has been implemented using a commercial CMOS image sensor coupled with a digital signal processor. The advantage over scanning laser Doppler imaging is that movement artifacts are reduced and the scanning speed of the system is increased due to the absence of moving scanning components.rnA custom made CMOS sensor offers several advantages over commercial cameras as the specifications can be tailored to the signals of interest. An important advantage of custom made sensors is that on-chip processing allows the data bottleneck that exists between the photodetector array and processing electronics to be overcome, as the processed data can be read out from the image sensor to a PC or display at a low data rate.rnWe demonstrate advancements made by our group in this area. In this paper a system is described which combines a 32×32 pixel array with on-chip processing linked to a field programmable gate array. Results are demonstrated using a rotating diffuser, a vibrating test target and blood flow in tissue. Methods for efficiently using silicon when implementing the signal processing on-chip are discussed.