Integrated probes containing a VCSEL and a multidetector chip for laser Doppler tissue perfusion monitoring

An integrated probe has been developed containing the essential optoelectronic components necessary for monitoring tissue perfusion using the laser Doppler principle. The device includes a VCSEL for illumination, and a chip containing photodetectors, analog amplifiers for signal enhancement, and digital circuitry for external probe control. VCSEL and detector chip are mounted on a common ceramic platform, which also includes an integrated temperature sensor. A Peltier element may be included for temperature stabilization, or thermal cycling for physiological purposes. Two special chips have been developed: one containing an array of five detectors, at various distances from the laser, which will allow for some degree of depth discrimination, and a single detector chip. In this paper the multidetector chip and the probe design are presented