No abstract

The proposed tactile sensor will help surgeons to characterize different types of cardiac tissues and would facilitate the use of CBT to perform mitral valve annuloplasty.

Minimally invasive sugery (MIS) has increasingly been used in different surgical routines despite having significant shortcomings such as a lack of tactile feedback. Restoring this missing tactile information, particularly the information gained through tissue palpation, would be a significant enhancement to MIS capabilities. Tissue palpation is particularly important and commonly used in locating embedded lumps. The present study is inspired by this major limitation of the MIS procedure and is aimed at developing a system to reconstruct the lost palpation capability of surgeons in an effective way. By collecting necessary information on the size and location of hidden features using MIS graspers equipped with tactile sensors, the information can be processed and graphically rendered to the surgeon. Therefore, using the proposed system, surgeons can identify the presence or absence, location, and approximate size of hidden lumps simply by grasping the target organ with a smart endoscopic grasper. The results of the conducted experiments on the prototyped MIS graspers represented by graphical images are compared with those of the finite element models.

One of the major weaknesses in current endoscopic surgery is the lack of tactile feedback. This paper reports on the design, finite element modeling, and experimental testing of a corrugated tactile sensor. The sensor, a miniaturized and modified form of our previously developed tactile sensor, consists of a 75 µm plate-shaped silicon layer and a 25 µm polyvinylidene fluoride (PVDF) film, patterned on both sides using photolithographic techniques to form three independent sensing elements. The sensor is 15 mm long, 7.5 mm wide, and approximately 3 mm thick, which could make it versatile enough for integration with current endoscopic and medical robotics manipulators. The silicon layer is micromachined in such a way that a U-channel is formed. When a force is applied on the tactile sensor, output voltages from the patterned PVDF-sensing elements are combined to obtain tactile information. Results show that the sensor exhibits high sensitivity and can measure small dynamic loads, comparable to a human pulse, as well as large grasping forces. In addition to measuring the magnitude and position of the applied load, the sensor can determine the modulus of elasticity of the grasped object.

Detection of hard inclusions within soft tissue in robotic assisted minimally invasive surgery (MIS), also referred to as laparoscopic surgery, is of great importance, both in clinical and surgical applications. In clinical applications, surgeons need to detect and precisely identify the location and size of all growths, whether cancerous or benign, that are present within surrounding tissue in order to assess the extent and nature of any future treatment plan. In surgical applications, when any solid matter is being removed, it is important to avoid accidental injury to surrounding tissues and blood vessels since, were this to occur, it could then necessitate the need to resort to open surgery. The present study is aimed at developing a three-dimensional tactile display that provides palpation capability to any surgeon performing robotic assisted MIS. The information is collected from two force sensor/pressure matrices and processed with a new algorithm and graphically rendered. Consequently, the surgeon can determine the presence, location, and the size of any hidden superficial tumor/artery by grasping the target tissue in a quasi-dynamic way. The developed algorithm is presented, and the results for various configurations of embedded tumor/arteries inside the tissue are compared with those of the finite element analysis.