sCAM: An Untethered Insertable Laparoscopic Surgical Camera Robot

Fully insertable robotic imaging devices represent a promising future of minimally invasive laparoscopic vision. Emerging research efforts in this field have resulted in several proof-of-concept prototypes. One common drawback of these designs derives from their clumsy tethering wires which not only cause operational interference but also reduce camera mobility. Meanwhile, these insertable laparoscopic cameras are manipulated without any pose information or haptic feedback, which results in open loop motion control and raises concerns about surgical safety caused by inappropriate use of force.This dissertation proposes, implements, and validates an untethered insertable laparoscopic surgical camera (sCAM) robot. Contributions presented in this work include: (1) feasibility of an untethered fully insertable laparoscopic surgical camera, (2) camera-tissue interaction characterization and force sensing, (3) pose estimation, visualization, and feedback with sCAM, and (4) robotic-assisted closed-loop laparoscopic camera control. Borrowing the principle of spherical motors, camera anchoring and actuation are achieved through transabdominal magnetic coupling in a stator-rotor manner. To avoid the tethering wires, laparoscopic vision and control communication are realized with dedicated wireless links based on onboard power. A non-invasive indirect approach is proposed to provide real-time camera-tissue interaction force measurement, which, assisted by camera-tissue interaction modeling, predicts stress distribution over the tissue surface. Meanwhile, the camera pose is remotely estimated and visualized using complementary filtering based on onboard motion sensing. Facilitated by the force measurement and pose estimation, robotic-assisted closed-loop control has been realized in a double-loop control scheme with shared autonomy between surgeons and the robotic controller.The sCAM has brought robotic laparoscopic imaging one step further toward less invasiveness and more dexterity. Initial ex vivo test results have verified functions of the implemented sCAM design and the proposed force measurement and pose estimation approaches, demonstrating the technical feasibility of a tetherless insertable laparoscopic camera. Robotic-assisted control has shown its potential to free surgeons from low-level intricate camera manipulation workload and improve precision and intuitiveness in laparoscopic imaging

Development of A Soft Robotic Approach for An Intra-abdominal Wireless Laparoscopic Camera

In Single-Incision Laparoscopic Surgery (SILS), the Magnetic Anchoring and Guidance System (MAGS) arises as a promising technique to provide larger workspaces and field of vision for the laparoscopes, relief space for other instruments, and require fewer incisions. Inspired by MAGS, many concept designs related to fully insertable magnetically driven laparoscopes are developed and tested on the transabdominal operation. However, ignoring the tissue interaction and insertion procedure, most of the designs adopt rigid structures, which not only damage the patients\u27 tissue with excess stress concentration and sliding motion but also require complicated operation for the insertion. Meanwhile, lacking state tracking of the insertable camera including pose and contact force, the camera systems operate in open-loop control. This provides mediocre locomotion precision and limited robustness to uncertainties in the environment. This dissertation proposes, develops, and validates a soft robotic approach for an intra-abdominal wireless laparoscopic camera. Contributions presented in this work include (1) feasibility of a soft intra-abdominal laparoscopic camera with friendly tissue interaction and convenient insertion, (2) six degrees of freedom (DOF) real-time localization, (3) Closed-loop control for a robotic-assisted laparoscopic system and (4) untethering solution for wireless communication and high-quality video transmission. Embedding magnet pairs into the camera and external actuator, the camera can be steered and anchored along the abdominal wall through transabdominal magnetic coupling. To avoid the tissue rapture by the sliding motion and dry friction, a wheel structure is applied to achieve rolling motion. Borrowing the ideas from soft robotic research, the main body of the camera implements silicone material, which grants it the bendability to passively attach along the curved abdominal wall and the deformability for easier insertion. The six-DOF pose is estimated in real-time with internal multi-sensor fusion and Newton-Raphson iteration. Combining the pose tracking and force-torque sensor measurement, an interaction model between the deformable camera and tissue is established to evaluate the interaction force over the tissue surface. Moreover, the proposed laparoscopic system is integrated with a multi-DOF manipulator into a robotic-assisted surgical system, where a closed-loop control is realized based on a feedback controller and online optimization. Finally, the wireless control and video streaming are accomplished with Bluetooth Low Energy (BLE) and Analog Video (AV) transmission. Experimental assessments have been implemented to evaluate the performance of the laparoscopic system

Magnetic Surgical Instruments for Robotic Abdominal Surgery.

This review looks at the implementation of magnetic-based approaches in surgical instruments for abdominal surgeries. As abdominal surgical techniques advance toward minimizing surgical trauma, surgical instruments are enhanced to support such an objective through the exploration of magnetic-based systems. With this design approach, surgical devices are given the capabilities to be fully inserted intraabdominally to achieve access to all abdominal quadrants, without the conventional rigid link connection with the external unit. The variety of intraabdominal surgical devices are anchored, guided, and actuated by external units, with power and torque transmitted across the abdominal wall through magnetic linkage. This addresses many constraints encountered by conventional laparoscopic tools, such as loss of triangulation, fulcrum effect, and loss/lack of dexterity for surgical tasks. Design requirements of clinical considerations to aid the successful development of magnetic surgical instruments, are also discussed

Closed-Loop Control of Local Magnetic Actuation for Robotic Surgical Instruments

We propose local magnetic actuation (LMA) as an approach to robotic actuation for surgical instruments. An LMA actuation unit consists of a pair of diametrically magnetized single-dipole cylindrical magnets, working as magnetic gears across the abdominal wall. In this study, we developed a dynamic model for an LMA actuation unit by extending the theory proposed for coaxial magnetic gears. The dynamic model was used for closed-loop control, and two alternative strategies-using either the angular velocity at the motor or at the load as feedback parameter-were compared. The amount of mechanical power that can be transferred across the abdominal wall at different intermagnetic distances was also investigated. The proposed dynamic model presented a relative error below 7.5% in estimating the load torque from the system parameters. Both the strategies proposed for closed-loop control were effective in regulating the load speed with a relative error below 2% of the desired steady-state value. However, the load-side closed-loop control approach was more precise and allowed the system to transmit larger values of torque, showing, at the same time, less dependence from the angular velocity. In particular, an average value of 1.5 mN·m can be transferred at 7 cm, increasing up to 13.5 mN·m as the separation distance is reduced down to 2 cm. Given the constraints in diameter and volume for a surgical instrument, the proposed approach allows for transferring a larger amount of mechanical power than what would be possible to achieve by embedding commercial dc motors

Design, analysis and trajectory tracking control of underactuated mobile capsule robots.

The research on capsule robots (capsubots) has received attraction in recent years because of their compactness, simple structure and their potential use in medical diagnosis (e.g. capsule endoscopy), treatment and surgical assistance. The medical diagnostic capability of a capsule endoscope - which moves with the aid of visceral peristalsis - in the GI (gastro-intestinal) tract can be improved by adding propulsion to it e.g. legged, magnetic or capsubot-type propulsion. Driven by the above needs this thesis presents the design, analysis, trajectory tracking control and implementation of underactuated mobile capsule robots. These capsule robots can be modified and used in in-vivo medical applications. Researches on the capsubottype underactuated system focus on the stabilization of the robot and tracking the actuated configuration. However trajectory tracking control of an unactuated configuration (i.e. the robotmotion)was not considered in the literature though it is the primary requirement of any mobile robot and also crucial for many applications such as in-vivo inspection. Trajectory tracking control for this class of underactuated mechanical systems is still an open issue. This thesis presents a strategy to solve this issue. This thesis presents three robots namely a one-dimensional (1D) capsule robot, a 2D capsule robot and a 2D hybrid capsule robot with incremental capability. Two new acceleration profiles (utroque and contrarium) for the inner mass (IM) - internal moving part of the capsule robot - are proposed, analysed and implemented for the motion generation of the capsule robots. This thesis proposes a two-stage control strategy for the motion control of an underactuated capsule robot. A segment-wise trajectory tracking algorithm is developed for the 1D capsule robot. Theoretical analysis of the algorithm is presented and simulation is performed in the Matlab/Simulink environment based on the theoretical analysis. The algorithm is implemented in the developed capsule robot, the experimentation is performed and the results are critically analyzed. A trajectory tracking control algorithm combining segment-wise and behaviour-based control is proposed for the 2D capsule robot. Detailed theoretical analysis is presented and the simulation is performed to investigate the robustness of the trajectory tracking algorithm to friction uncertainties. A 2D capsule robot prototype is developed and the experimentation is performed. A novel 2D hybrid robot with four modes of operation - legless motion mode, legged motion mode, hybrid motion mode and anchoring mode - is also designed which uses one set of actuators in all operating modes. The theoretical analysis, modelling and simulation is performed. This thesis demonstrates effective ways of propulsion for in-vivo applications. The outer-shape of the 1D and 2D capsule robots can be customized according to the requirement of the applications, as the propulsion mechanisms are completely internal. These robots are also hermetically sealable (enclosed) which is a safety feature for the in-vivo robots. This thesis addresses the trajectory tracking control of the capsubot-type robot for the first time. During the experimentation the 1D robot prototype tracks the desired position trajectory with some error (relative mean absolute error: 16%). The trajectory tracking performance for the 2D capsubot improves as the segment time decreases whereas tracking performance declines as the friction uncertainty increases. The theoretical analysis, simulation and experimental results validate the proposed acceleration profiles and trajectory tracking control algorithms. The designed hybrid robot combines the best aspects of the legless and legged motions. The hybrid robot is capable of stopping in a suspected region and remain stationary for a prolonged observation for the in-vivo applications while withstanding the visceral peristalsis

Cable-driven parallel mechanisms for minimally invasive robotic surgery

Minimally invasive surgery (MIS) has revolutionised surgery by providing faster recovery times, less post-operative complications, improved cosmesis and reduced pain for the patient. Surgical robotics are used to further decrease the invasiveness of procedures, by using yet smaller and fewer incisions or using natural orifices as entry point. However, many robotic systems still suffer from technical challenges such as sufficient instrument dexterity and payloads, leading to limited adoption in clinical practice. Cable-driven parallel mechanisms (CDPMs) have unique properties, which can be used to overcome existing challenges in surgical robotics. These beneficial properties include high end-effector payloads, efficient force transmission and a large configurable instrument workspace. However, the use of CDPMs in MIS is largely unexplored. This research presents the first structured exploration of CDPMs for MIS and demonstrates the potential of this type of mechanism through the development of multiple prototypes: the ESD CYCLOPS, CDAQS, SIMPLE, neuroCYCLOPS and microCYCLOPS. One key challenge for MIS is the access method used to introduce CDPMs into the body. Three different access methods are presented by the prototypes. By focusing on the minimally invasive access method in which CDPMs are introduced into the body, the thesis provides a framework, which can be used by researchers, engineers and clinicians to identify future opportunities of CDPMs in MIS. Additionally, through user studies and pre-clinical studies, these prototypes demonstrate that this type of mechanism has several key advantages for surgical applications in which haptic feedback, safe automation or a high payload are required. These advantages, combined with the different access methods, demonstrate that CDPMs can have a key role in the advancement of MIS technology.Open Acces