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This article presents a sensorless resistive-based control method to control shape memory alloy wire actuators to be used in the development of a laparoscopic surgical locking system. Shape memory alloy wire electrical resistance is measured to control the martensite phase fraction of shape memory alloy wire. The martensite phase fraction is calculated based on mathematical heating model, resistance models, and the measured resistance. Experiments are conducted to evaluate the validity and performance of the method in the control of the locking system angle. The results show that the sensorless resistive-based control method accurately controls the wire without using any position sensors, resulting in the lower cost, size, and weight of the system. The results show very small steady-state errors, verifying the practicability of this method. The sensorless resistive-based control method has the potential to be used in many applications in which cost and space are limited and the use of an external sensor is impossible or costly.

This article proposes a potential automatic ligation (LigLAP) method to occlude vessels and ducts in several laparoscopic surgical procedures. Currently, stapling devices are widely used for this purpose. However, there are some complications associated with stapling devices, including biliary leak and tissue damage. In this article, we examine the feasibility of an alternative method that uses a double-layer suture to encircle and occlude a vessel. A heating element melts the outer layer of the suture at the cross-point of the suture to create a seal. Several electromechanical mechanisms have been proposed to carry out this ligation process. In addition, some parts have been prototyped for experimental verification and visualization. Several double-layered sutures have been created, and their tensile strength and sealing capabilities have been measured. Moreover, a simple leakage experiment has been performed to verify experimentally the idea of using the double-layer suture. The results show that the new suture and the thermal sealing method provide the required strength to occlude balloons filled with water. Although the results suggest that the proposed method and the double-layer suture may be used in surgical ligation processes, much more rigorous testing of leakage is required.

This paper presents an enhanced haptic-enabled master-slave teleoperation system which can be used to provide force feedback to surgeons in minimally invasive surgery (MIS). One of the research goals was to develop a combined-control architecture framework that included both direct force reflection (DFR) and position-error-based (PEB) control strategies. To achieve this goal, it was essential to measure accurately the direct contact forces between deformable bodies and a robotic tool tip. To measure the forces at a surgical tool tip and enhance the performance of the teleoperation system, an optical force sensor was designed, prototyped, and added to a robot manipulator. The enhanced teleoperation architecture was formulated by developing mathematical models for the optical force sensor, the extended slave robot manipulator, and the combined-control strategy. Human factor studies were also conducted to (a) examine experimentally the performance of the enhanced teleoperation system with the optical force sensor, and (b) study human haptic perception during the identification of remote object deformability. The first experiment was carried out to discriminate deformability of objects when human subjects were in direct contact with deformable objects by means of a laparoscopic tool. The control parameters were then tuned based on the results of this experiment using a gain-scheduling method. The second experiment was conducted to study the effectiveness of the force feedback provided through the enhanced teleoperation system. The results show that the force feedback increased the ability of subjects to correctly identify materials of different deformable types. In addition, the virtual force feedback provided by the teleoperation system comes close to the real force feedback experienced in direct MIS. The experimental results provide design guidelines for choosing and validating the control architecture and the optical force sensor.

A novel multi-port (Triport+) and methodology were designed for single port cholecystectomy (SPC) to replicate the principles found in the gold standard 4-port laparoscopic cholecystectomy. We present the first case series utilizing the Triport+, and methodology through a single 15-mm periumbilical fascial incision.The 4 lumen multi-channel port was placed in the umbilicus through a measured 15-mm fascial incision. Instrument design and placement in the port is specific to the performance of the SPC. Retrospective review of the cases was performed.15 SPCs were performed without complications. No conversions or additional ports were required. Fascial defect size measured was 15 mm. Visualization of the critical view was obtained in each case. The mean total operative time was 36 minutes.The Triport+ and novel SPC methodology successfully replicate the standard of retraction and exposure in traditional 4-port laparoscopic cholecystectomy. This novel technique eliminates both instrument and hand conflict.