A method of in vivo measurement of the elastic properties of skin in radiotherapy patients.

A portable apparatus which measures the force-displacement or elastic characteristics of skin in vivo has been constructed. A displacement transducer between two arms measures the extension of the skin as the arms are driven apart by means of a lead screw, and the force exerted on the skin is measured by means of two electrical resistance strain gauges attached at a reduced section on each of the arms. The apparatus was designed for compactness and lightness to enable it to be hand held. Illustrative results obtained on patients during and after courses of radiotherapy are presented.