DEVICE FOR ULTRASONIC EVALUATION IN-VIVO OF RHEOLOGICAL PROPERTIES OFTHE SKIN

In certain dermatoses, the mechanical properties of the skin are marke dly altered. The evaluation of these properties in-vivo requires equip ment which can simultaneously measure the skin's thickness while apply ing a known stress to the site in question. Skin thickness can be meas ured with either A- or B-scan mode ultrasound, the former of which we have incorporated in a device with enables skin elasticity to be deter minated. Essentially, this involves the measurement of the distance be tween transducer (20 Mhz) and the skin structures, before and after de formation by suction, with a resolution of 70 mum. The transducer is l ocated inside a small, cylindrical chamber, which has a 6 mm diameter aperture below the transducer to allow contact with the skin.This devi ce can determine, in a non-invasive way, not only which skin structure s are involved in this deformation, but also the morphological variati on in the subcutaneous layers and their level of involvement at differ ent stresses. With such information, we hope to be able to propose a m echanical model and to define appropriate skin rheological parameters.