Fibre-optic hand held probe for opto-thermal in-vivo skin measurements

The potential of using opto-thermal radiometry for skin measurements is wel l known, but the current bench-top apparatus we use is not suitable for rou tine use and restricts in-vivo measurements to fingers and forearms To over come these shortcomings, we are developing a fibre optic opto-thermal hand held probe, designed for non-invasive, in vivo measurements on any skin sit e of human body. It uses one fibre (hollow waveguide for Q-switched Er:YAG and glass fibre for Q-switched Nd:YAG laser respectively) to deliver the ex citation radiation to the sample surface and another fibre (silver halide) to collect the infrared radiation and send it to the infrared detector. We present details of the design of this probe and the experimental results us ing it on various skin sites, with different laser excitation sources.