A new depth-sense esthesiometer. A comparative study on sensitivity.

The structure and functions of a depth-sense esthesiometer have been described. Unlike the prototype designed by Renfrew, the new instrument is so fabricated that the speed and the directions of its movements, and the pressure applied by the finger, can be constantly controlled. In addition, it provides an automatic measurement of depth-sense thresholds with greater accuracy. Thirty-three normal subjects and nine patients were examined with both instruments. With the new esthesiometer all normal hands, as expected, showed normal results, but, with the Renfrew instrument, 12 of these 66 hands (18%) showed abnormal results. Similarly, on examination of the hands of the nine patients, the new instrument showed equally improved reliability.