Affiliations: [a] Department of Mechatronics and Precision Engineering, Tohoku University, Sendai, Miyagi 980-77, Japan E‐mail: [email protected]
| [b] Department of Urology, Tohoku Kosai Hospital, Sendai, Miyagi 980, Japan
Abstract: This paper is concerned with the development of a soft palpation sensor for detection of prostatic cancer and hypertrophy. The sensor is a layered medium with two polyvinylidene fluoride (PVDF) films embedded in the matrix sponge rubber. It is pressed against the prostates and the output voltage signals from the polymer films are measured. The temporal mean values, {I}_1 and {I}_2, of absolute voltage signals from the films are calculated and their ratio {I}_1/{I}_2 is used as the sensor output. First, the fundamental characteristics of a rectangular sensor with a plane surface are examined. Then, the surface geometry of the sensor was designed so that it clearly indicates the nature on the stiffness of the soft material. Finally, a compact cylindrical sensor attached to the doctor’s forefinger is described and experimental studies of its performance as a palpation sensor are presented. Some representative clinical data on the normal and hardened prostate glands are also presented.
Keywords: palpation sensor, PVDF film, measurement of organic stiffness, prostatic cancer and hypertrophy, diagnosis
