Multichannel time-resolved tissue oximeter for functional imaging of the brain

This paper reports the development and characterization of a novel multichannel time-resolved (TR) instrument for functional brain imaging studies. The instrument is based on picosecond diode lasers, fiber optics for light injection and delivery, a compact multianode photomultiplier, and a personal computer (PC) board for time-correlated single photon counting (TCSPC). The instrument has been characterized in terms of reproducibility among the nine sources and the 12 collection channels, linearity in the determination of optical properties (absorption and reduced scattering), and stability. Preliminary in vivo measurements were performed on volunteers to monitor the optical response to stimuli following a motor task (finger opposition, 5 Hz).