IMPRESSION TECHNIQUE FOR THE ASSESSMENT OF EDEMA - COMPARISON WITH A NEW TACTILE SENSOR THAT MEASURES PHYSICAL-PROPERTIES OF TISSUE

To measure tissue oedema, the impression technique and a new tactile s ensor technique are compared and evaluated in a silicone rubber model and in an in vivo rat testis model. The principles of the two techniqu es differ in that the impression technique evaluates interstitial flui d flow FT and peak force F(O) when tissue is compressed, whereas the t actile sensor evaluates the hardness/softness or change in resonance f requency Delta f when a vibrating rod is attached to tissue. Both tech niques can detect changes in silicone hardness/softness or in hormone- induced changes of-testis interstitial fluid. Although both F(O) and F T are significantly correlated to Delta f in the experiments, it is co ncluded that F(O) is the most promising impression parameter to give v aluable information about the hardness of living tissue as compared wi th Delta f. The comparison indicates that the impression technique is the most easy to interpret, non-invasive tool to assess tissue oedema so far developed.