AN ULTRASOUND INDENTATION SYSTEM FOR BIOMECHANICAL PROPERTIES ASSESSMENT OF SOFT-TISSUES IN-VIVO

An ultrasound indentation system for biomechanical assessment of soft tissues in vivo was developed. The pen-size, hand-held probe was compo sed of an ultrasound transducer and a load cell. The ultrasound transd ucer was at the tip of the probe serving also as the indentor. The thi ckness and deformation of the soft tissue layer were determined from t he ultrasound echo. A compressive load cell was connected in series wi th the ultrasound transducer to record the force response, A validatio n experiment was performed on porcine tissues. Force and deformation a cquired with the present system was in good comparison with those obta ined from a Housfield material testing machine. Material constants wer e obtained via a curve-fitting procedure by predicting the force trans ient response from the deformation-time data using a quasilinear visco elastic model. In addition, deformation in the fat and in the muscle c ould be differentiated. The potential applications of this type of ind entation probes are many. The specific application of this current dev elopment is for stump tissue assessment in the design of prosthetics.