A stiffness probe based on force and vision sensing for soft tissue diagnosis

This paper introduces a novel approach of stiffness measurement based on force and vision sensing for tissue diagnosis. The developed probe is mainly composed of a force sensor and an image acquisition unit capable of obtaining contact area of probe-soft tissue interaction. By measuring the change of diameter of contact area during indentation test, the indentation depth can be determined. The stiffness of target soft tissue then can be evaluated by measuring indentation force and depth simultaneously. The probe can generalize a mechanical image to visualize the stiffness distribution for localization of abnormalities when sliding over soft tissue. The performance of the developed probe was validated by experiments on multiple materials including silicone phantoms and pork organs. The results show that the probe can perform stiffness measurement effectively when the probe indents or slides on the tissue surface.