Time resolved optical tomography of the human forearm

A 32-channel time-resolved optical imaging instrument has been developed pr incipally to study functional parameters of the new-born infant brain. As a prelude to studies on infants, the device and image reconstruction methodo logy have been evaluated on the adult human forearm. Cross-sectional images were generated using time-resolved measurements of transmitted light at tw o wavelengths. All data were acquired using a fully automated computer-cont rolled protocol. Images representing the internal scattering and absorbing properties of the arm are presented, as well as images that reveal physiolo gical changes during a simple finger flexion exercise. The results presente d in this paper represent the first simultaneous tomographic reconstruction of the internal scattering and absorbing properties of a clinical subject using purely temporal data, with additional co-registered difference images showing repeatable absorption changes at two wavelengths in response to ex ercise.