| In minimally invasive surgery,the tactile sensor can measure the biological tissue information,which can be processed and analyzed,and then transmitted to the doctor,so that the doctor can get a similar sense of contact with the real biological tissue.This technology not only helps the doctor to distinguish whether the biological tissue has pathological changes,but also can effectively optimize the operation plan effectively and improve the safety of the operation.This context,a tactile sensor for measuring elastic modulus of biological tissues is proposed.The paper is devoted to the following research i.e,the design of sensor,the contact problem between sensor and objected tissue,the correction coefficient of sensor and the practicality experiment.In the process of analyzing the contact problem between tactile sensor and biological tissue,first,the overall shape of tactile sensor is designed as a cylindrical,it mainly consists of a rigid annular cylinder,a rigid contact plate,a rigid base plate,a flexible spring and two force sensors.Then,assume the contact surface is frictionless,based on the general Papkovich – Neuber solution satisfying the boundary-value problem,the linear elastic solution of the contact problem is obtained through Combination–of–Harmonics method.Finally,the elastic modulus of the tissue is obtained.In the research on the correction coefficient.The relationship between the correction coefficient of the sensor and the thickness of biological tissue is derived by dimensional analysis of the contact problem through(47)theorem.The contact model is established by using ABAQUS finite element simulation software.After many times of simulation,the concrete expression of dimensionless function is obtained.A scheme for measuring the thickness of the tissue is proposed,so as to accurately find the value of the correction coefficient needed by tactile sensor when measuring different thickness of biological tissue.When conducting the model experiment.The physical model of tactile sensor is made,silica gel is used instead of the tissue.The experimental platform is built andthe experimental scheme is designed to verify the thickness of the tissue,the correction coefficient and the performance of tactile sensor. |
