Soft robotic devices have been utilized in a number of biomedical applications involving human interaction. An emerging opportunity for soft robotic wearable devices is in mechanotherapeutic applications for the recovery and regeneration of soft tissues. Previous studies have implied that judicious force application during mechanotherapy plays an important role in the functional outcome of tissue regeneration. In this paper, we propose soft robotic devices with closed-loop force control to precisely manipulate muscular tissue. The developed devices incorporate fully soft sensors and actuators using textile-based materials and fabrication methods. The closed-loop force control system is demonstrated in bench studies to regulate massage-magnitude forces at frequencies akin to those expected in manual mechanotherapy practices. Testing of the device on human limbs demonstrates the precision and accuracy of the closed-loop force control methodology across different body shapes and types. When commanded to regulate sinusoidal force profiles (with amplitudes of 30N, 45N and 60N), the soft robotic force control device could regulate peak compressive loads to within 0.7N of the desired force. Conversely, open-loop pressure-based control resulted in up to +/-6.6N force tracking variability between participants. A soft robotic system with independently actuatable modules was also fabricated to demonstrate force-controlled actuation patterns to mimic manual massage techniques.

Increasing demands in endovascular intervention have motivated technical skill training and competency-based measures of performance. However, there are no well-established online metrics for technical skill assessment; few studies have explored operator behavioral patterns from catheter motion and operator hand motions. This paper proposes a platform for active online training and objective assessment of endovascular skills, through learning optimum catheter motions from multiple demonstrations. An ungrounded hand-held haptic device for providing intuitive haptic guidance to novice users based on this learnt information is also proposed. Statistical models are implemented to extract the underlying catheter motion patterns, and utilize them for performance evaluation and haptic guidance. The results show significant improvements in endovascular navigation for inexperienced operators. Finer catheter motions were achieved with the provided haptic guidance. The results suggest that the proposed platform can be integrated into current clinical training setups, and motivate the improvement of endovascular training platforms with better realism.

Despite the increased use of robotic catheter navigation systems, and the growing interest in surgical skill evaluation in the field of endovascular intervention, there is a lack of objective and quantitative metrics for performance evaluation. So far very little research has studied operator behavioral patterns using catheter kinematics, operator forces and motions, and catheter-tissue interactions. This paper proposes a framework for automated and objective assessment of performance by measuring catheter-tissue contact forces and operator motion patterns across different skill levels, and using language models to learn the underlying force and motion patterns that are characteristic of skill. Discrete HMMs are utilized to model operator behavior for varying skill levels performing different catheterization tasks, resulting in cross-validation classification accuracies of 94% (expert) and 98% (novice) using the force-based skill models, as well as 83% (expert) and 94% (novice) using the motion-based models. The results motivate the design of improved metrics for endovascular skill assessment with further applications towards performance evaluation of robot-assisted endovascular catheterization.

The surgical robotics community have developed many different flexible robot designs to address the access problems of minimally invasive surgery. In this paper, we present a hand-held mechatronic tool with a miniaturized distal flexible manipulator incorporating a microscopy probe, camera and a light source for diagnostic arthroscopy. Extensive characterization of the flexible manipulator is provided, including an optimization of the manipulator workspace, hysteresis characteristics and repeatability of the instrument. The lateral stiffness of the flexible manipulator for different bending conditions is assessed along with the overall robustness of the platform. A cadaveric study was performed to demonstrate the potential clinical value of the device.

This paper presents a hand-held microsurgical forceps design with force-feedback capabilities designed for micromanipulation tasks. The device uses a customized force sensor that measures grasping forces over a range of 0-300mN and uses an actuator to exert amplified forces back on to the operator's fingertip in a mechanically-ungrounded setup. This allows perception of low force levels that are otherwise imperceptible to human touch. A customized force sensor design for the forceps grasping measurement is presented and a calibration experiment was conducted to validate its linearity and repeatability. A bench test of the device was conducted to demonstrate its intrinsic force-amplifying capabilities, with amplification factors of up to ×50 reported. A user study was conducted to confirm that the device could significantly improve human perception of grasping forces compared to conventional microsurgical forceps with the results demonstrating an order-of-magnitude improvement in force perception.

In recent years, continuum robots have gained significant momentum in terms of technological maturity and clinical application. Their flexibility allows complex treatment sites to be reached with minimal trauma to the patient. However the reliable control of continuum robots is still an ongoing research issue in the robotics community because their deformable structure makes the modeling of these devices difficult. This motivates the use of external sensors or vision to achieve accurate control. In this paper, a motion control framework based on a vision sensor is proposed in order to perform accurate and controlled movements of a flexible robot that is mounted to an anthropomorphic robotic arm. The vision sensor, which relies on a single camera, provides accurate 3D shape reconstruction and spatial localisation of the flexible robot. This information is used to provide feedback for the real-time control of the flexible robot. The vision sensor detects the robot first in an image stream by modeling its appearance using compressed visual features in an online learning framework. This is combined with the kinematics information from the anthropomorphic robotic arm in order to accurately reconstruct and localise the 3D shape of the flexible robot by minimizing an energy function. Detailed analysis of the framework and a validation are presented in order to demonstrate the practical value of the proposed method.

This paper presents an Implicit Active Constraints control framework for robot-assisted minimally invasive surgery. It extends on current frameworks by prescribing the external constraints implicitly from the operator motion, forgoing the need for pre-operative imaging; the constraints are defined in situ so as to avoid the use of invasive fiducial markers. A hands-on cooperatively-controlled robotic platform, comprising of a surgical instrument and a compliant manipulator, has been designed for an arthroscopic procedure. The surgical platform is capable of constraining the pose of the instrument so as to ensure it passes through the incision point and does not cause trauma to the surrounding tissue. A flexible arthroscopic instrument is designed and its use is investigated to enlarge reachable and dexterous workspace, increasing the accessibility to the target anatomy. The behaviour of the flexible instrument is analysed. A detailed performance analysis is conducted on a group of subjects for validating the control framework, simulating a minimally invasive arthroscopic procedure. Results demonstrate a statistically significant enhancement in the control ergonomics as well as the accuracy and safety of the procedure.

This paper presents an ungrounded, hand-held surgical device that incorporates active constraints and force-feedback. Optical tracking of the device and embedded actuation allow for real-time motion compensation of a surgical tool as an active constraint is encountered. The active constraints can be made soft, so that the surgical tool tip motion is scaled, or rigid, so as to altogether prevent the penetration of the active constraint. Force-feedback is also provided to the operator so as to indicate penetration of the active constraint boundary by the surgical tool. The device has been evaluated in detailed bench tests to quantify its motion scaling and force-feedback capabilities. The combined effects of force-feedback and motion compensation are demonstrated during palpation of an active constraint with rigid and soft boundaries. A user study evaluated the combined effect of motion compensation and force-feedback in preventing penetration of a rigid active constraint. The results have shown the potential of the device operating in an ungrounded setup that incorporates active constraints with force-feedback.

This paper presents a new hand-held device capable of amplifying delicate micromanipulation forces during minimal invasive surgical tasks. It relays force sensing to the user through a simple sliding feature that is coupled to the surgical tool, which translates relative to the casing of the device held by the operator. This forgoes the need of grounding frames or anchoring mechanisms to the body, allowing the device to be used in general surgical environments without affecting the workflow. The device uses a three-phase linear motor that is compact and capable of generating high forces that allow amplification factors of up to ×15. It features a closed-loop force control scheme to perform the required force amplification in which the force exerted on to the user is measured, forming the feedback in the control loop. The device permits interchangeability of instrumentation through a simple docking feature, and thus can be generalized to a range of surgical instruments for micromanipulation tasks. Detailed bench tests and user trials have been performed to validate the accuracy and practical performance of the device. The results have shown a five times reduction of the minimum force threshold perceived by the subjects and ergonomically sound manipulation advantages.

The increasing number of degrees-of-freedom involved in new generations of surgical robotics and the need for incorporating active constraints and haptic feedback, require more intuitive and effective ways of robot control. This paper presents a novel manipulator that allows for ergonomic bimanual joint-level control of an anthropomorphic surgical robot. Through the combined use of bidirectional compressed airflow, the manipulator can operate on nearly zero friction and simulate a range of frictional forces. As a generic platform, the system can withstand large payloads and is able to accommodate a wide range of existing haptic manipulators. The performance of the proposed platform is evaluated with detailed experimental tests and proven to provide negligible friction even at high loads. Its dynamic friction is controllable and positional locking can be flexibly applied. Detailed experimental results demonstrate the practical value of the system.

Robotically assisted catheterisation has attracted significant interest in recent years. However, few designs have made full use of the extensive experience and skills that interventional radiologists have acquired from conventional catheter navigation. Additionally, limited research has been conducted in quantifying the effectiveness of haptic feedback for catheterisation procedures. This paper presents a novel master-slave force feedback system for endovascular catheterisation that can be used in a natural setting with enhanced ergonomics. The system has been validated with detailed laboratory experiments and a comprehensive user study. The performance of the system was compared against manual catheterisation by measuring the forces exerted on a vascular phantom. The results showed a 76% reduction in the mean force applied and a 55% reduction in the maximum force over the course of the study, indicating that the force feedback system reduced the magnitude and duration of force exerted during a simulated endovascular procedure. This research provides important insights into the design of compact and ergonomic robotic catheter manipulators incorporating effective real-time force feedback for intraoperative navigation.

This paper describes a multitasking robotic platform for Minimally Invasive Surgery (MIS). The device is designed to be introduced through a standard trocar port. Once the device is inserted to the desired surgical site, it can be reconfigured by lifting an articulated section, and protruding two tendon driven flexible arms. Each of the arms holds an interchangeable surgical instrument. The articulated section features a 2 Degrees-of-Freedom (DoF) universal joint followed by a single DoF yaw joint. It incorporates an on-board camera and LED light source at the distal end, leaving a Ø3mm channel for an additional instrument. The main shaft of the robot is largely hollow, leaving ample space for the insertion of two tendon driven flexible arms integrated with surgical instruments. The ex-vivo and in-vivo experiments demonstrate the potential clinical value of the device for performing surgical tasks through single incision or natural orifice transluminal procedures.

This paper introduces an articulated robotic device based on universal joints with embedded micro motors for minimally invasive surgery. The device features an articulated distal tip with seven independently controllable degrees-of-freedom (DoF), arranged as two universal joints (intersecting pitch and yaw) and three single DoF joints (yaw only); two Ø3mm internal channels, one for an on-board camera for visualization and the other for passing interventional instruments. The design allows the robot to explore the entire peritoneal cavity from a chosen single incision point. A trans-vaginal procedure using the device to locate the uterine horn, as a model of a human fallopian tube, and apply an endoscopic clip was carried out during a live porcine trial to demonstrate the potential for performing a Natural Orifice Translumenal Endoscopic Surgery (NOTES) tubal ligation procedure.

This paper introduces a modular, mechatronic joint design for a flexible access minimally invasive surgical platform. The design features a hybrid tendon-micromotor actuation scheme coupled via an internal “ring gear”. This configuration transmits the rotary motion of the embedded micromotor to joint rotation in an efficient manner while also providing a hollow lumen through the centre of the joint unit. Detailed analyses of the joint design including tendon path length, positional accuracy and force/torque transmission characteristics are presented. The design has been incorporated into a dexterous, seven degree-of-freedom flexible access platform and its clinical efficacy for performing a Natural Orifice Translumenal Endoscopic Surgery (NOTES) diagnostic peritoneoscopy in an in-vivo environment is presented.