Design and analysis of a micromachined piezoelectric sensor for measuring the viscoelastic properties of tissues in minimally invasive surgery

In this paper, the design, analysis and fabrication of a micromachined piezoelectric endoscopic tactile sensor to determine the properties of tissues in minimally invasive surgery is presented. The viscoelastic Kelvin model is employed for tissue characterization. A closed form expression is derived to express the relationship between the force ratio, compliance and the equivalent viscous damping of the tissue. The designed sensor uses a PVDF film as its sensing element. The sensor consists of rigid and compliant elements which are mounted on the tip of an endoscopic surgical grasper tool. The relative force between adjacent parts of the contact object is used to measure the viscoelastic properties experimentally.