Portable Medical Recorder

This proposal describes a plan for developing a very small, light-weight, solid-state voice recorder suitable for helping provide improved medical support to injured persons upon playback by subsequent support personnel by providing clear records in the presence of loud background noises. The proposed device will be able to be worn like a dog tag and will be designed to accommodate environmentally challenging conditions. The device will consist of multiple microphones, appropriate signal conditioning electronics, embedded signal processing electronics, voice playback electronics, battery and power supply electronics. The use of multiple microphones will provide for enhanced capabilities of reducing background noise over the use of a single microphone through the use of array signal processing techniques. In particular, a modified version of a highly effective algorithm developed at Radiance technologies for identifying sounds in particular directions while rejecting other noise sources will be used. Other techniques such as band-pass filtering to reduce the effect of spectral content not usually seen in human speech will also be employed to enhance the signal-to-noise ratio and selecting appropriate microphone sensitivities will be performed.