DEVELOPMENT OF ADDITIONAL MASTER INTERFACES FOR ENHANCED FUNCTION OF LAPAROSCOPIC SURGICAL ROBOT SYSTEM AND ITS APPLICATIONS

Abstract

Robot-assisted laparoscopic surgery offers several advantages compared to open surgery and conventional minimally invasive surgery. However, important issues which need to be resolved are the complexity of current operation room environment for laparoscopic robotic surgery and demand for a larger operation room. To overcome these issues, additional interfaces based on Hands-On-Throttle-And-Stick (HOTAS) concept which can be simply attached and integrated with master interface of da Vinci surgical robot system were proposed. HOTAS controller is widely used for flight control in the aerospace field which can manipulate hundreds of functions and provide feedback to the pilot on flight conditions. The implementation of HOTAS controller significantly reduced the complexity of flights and reduced the number of pilots required in a cockpit from two to one. In this study, to provide above benefits to the operation room for robotic laparoscopic surgery, two types of additional interfaces are proposed. Proposed additional interfaces can be easily manipulated by the surgeons index finger, which is currently operated only by finger clutch buttons, and therefore enable the surgeon to use multiple functions. Initially, a novel master interface (NMI) was developed. The NMI mainly consists of a 9-way switch and a microprocessor with a wireless communication module. Thus, the NMI can be also regarded as a 9-way compact HOTAS. The performance test, latency, and power consumption of the developed NMI were verified by repeated experiments. Then, an improved novel master interface (iNMI) was developed to provide more intuitive and convenient manipulation. The iNMI was developed based on a capacitive touch sensor array and a wireless microprocessor to intuitively reflect the surgeons decision. Multiple experiments were performed to evaluate the iNMI performance in terms of performance test, latency, and power consumption. In addition, two application systems based on Surgical-Operation-By-Wire (SOBW) concept are proposed in this research to enhance the function of laparoscopic surgical robot system based on clinical needs that are stated below. The size of the additional interface is small enough to be easily installed to the master tool manipulators (MTMs) of da Vinci research kit (dVRK), which was used as an operation robot arm system, to maximize convenience to the surgeon when using the additional interfaces to simultaneously manipulate the application systems with the MTMs. Firstly, a robotic assistant that can be simultaneously manipulated via a wireless controller is proposed to allow the surgeon to control the assistant instrument. This approach not only decreases surgeon fatigue by eliminating communication process with assistants, but also resolves collision between the operation robot arms and the assistant instruments that can be caused by an inexperienced assistant or miscommunication and misaligned intent between the surgeon and the assistant. The system comprises two additional interfaces, a surgical instrument with a gripper actuated by a micromotor and a 6-axis robot arm. The gripping force of the surgical instrument was comparable to that of conventional systems and was consistent even after 1,000 times of gripping motion. The workspace was calculated to be 8,397.4 cm3. Recruited volunteers were able to execute the simple peg task within the cut-off time and successfully performed the in vitro test. Secondly, a wirelessly controllable stereo endoscope system which enables simultaneous control with the operating robot arm system is proposed. This is able to remove any discontinuous surgical flow that occurs when the control is swapped between the endoscope system and the operating robot arm system, and therefore prevent problems such as increased operation time, collision among surgical instruments, and injury to patients. The proposed system consists of two additional interfaces, a four-degrees of freedom (4-DOFs) endoscope control system (ECS) and a simple three-dimensional (3D) endoscope. The 4-DOFs ECS consists of four servo motors and employs a two-parallel link structure to provide translational and fulcrum point motions to the simple 3D endoscope. The workspace was calculated to be 20,378.3 cm3, which exceeds the reference workspace. The novice volunteers were able to successfully execute the modified peg transfer task. Throughout the various verifications, it has been confirmed that the proposed interfaces could make the surgical robot system more efficiently by overcoming its several limitations.