Piyamate Wisanuvej

Effective Manipulation in Confined Spaces of Highly Articulated Robotic Instruments for Single Access Surgery

The field of robotic surgery increasingly advances towards highly articulated and continuum robots, requiring new kinematic strategies to enable users to perform dexterous manipulation in confined workspaces. This development is driven by surgical interventions accessing the surgical workspace through natural orifices such as the mouth or the anus. Due to the long and narrow nature of these access pathways, external triangulation at the fulcrum point is very limited or absent, which makes introducing multiple degrees of freedom at the distal end of the instrument necessary. Additionally, high force and miniaturization requirements make the control of such instruments particularly challenging. This letter presents the kinematic considerations needed to effectively manipulate these novel instruments and allow us their dexterous control in confined spaces. A nonlinear calibration model is further used to map joint to actuator space and improve significantly the precision of the instruments motion. The effectiveness of the presented approach is quantified with bench tests, and the usability of the system is assessed by three user studies simulating the requirements of a realistic surgical task.

A Single-Port Robotic System for Transanal Microsurgery—Design and Validation

This letter introduces a single-port robotic platform for transanal endoscopic microsurgery (TEMS). Two robotically controlled articulated surgical instruments are inserted via a transanal approach to perform submucosal or full-thickness dissection. This system is intended to replace the conventional TEMS approach that uses manual laparoscopic instruments. The new system is based on master–slave robotically controlled tele-manipulation. The slave robot comprises a support arm that is mounted on the operating table, supporting a surgical port and a robotic platform that drives the surgical instruments. The master console includes a pair of haptic devices, as well as a three-dimensional display showing the live video stream of a stereo endoscope inserted through the surgical port. The surgical instrumentation consists of energy delivery devices, graspers, and needle drivers allowing a full TEMS procedure to be performed. Results from benchtop tests, ex vivo animal tissue evaluation, and in vivo studies demonstrate the clinical advantage of the proposed system.

Hands-on reconfigurable robotic surgical instrument holder arm

The use of conventional surgical tool holders requires an assistant during positioning and adjustment due to the lack of weight compensation. In this paper, we introduce a robotic arm system with hands-on control approach. The robot incorporates a force sensor at the end effector which realises tool weight compensation as well as hands-on manipulation. On the operating table, the required workspace can be tight due to a number of instruments required. There are situations where the surgical tool is at the desired location but the holder arm pose is not ideal due to space constraints or obstacles. Although the arm is a non-redundant robot because of the limited degrees of freedom, the pseudo-null-space inverse kinematics can be used to constrain a particular joint of the robot to a specific angle while the other joints compensate in order to minimise the tool movement. This allows operator to adjust the arm configuration conveniently together with the weight compensation. Experimental results demonstrated that our robotic arm can maintain the tool position during reconfiguration significantly more stably than a conventional one.

Implicit gaze-assisted adaptive motion scaling for highly articulated instrument manipulation

Traditional robotic surgical systems rely entirely on robotic arms to triangulate articulated instruments inside the human anatomy. This configuration can be ill-suited for working in tight spaces or during single access approaches, where little to no triangulation between the instrument shafts is possible. The control of these instruments is further obstructed by ergonomic issues: The presence of motion scaling imposes the use of clutching mechanics to avoid the workspace limitations of master devices, and forces the user to choose between slow, precise movements, or fast, less accurate ones. This paper presents a bi-manual system using novel self-triangulating 6-degrees-of-freedom (DoF) tools through a flexible elbow, which are mounted on robotic arms. The control scheme for the resulting 9-DoF system is detailed, with particular emphasis placed on retaining maximum dexterity close to joint limits. Furthermore, this paper introduces the concept of gaze-assisted adaptive motion scaling. By combining eye tracking with hand motion and instrument information, the system is capable of inferring the users destination and modifying the motion scaling accordingly. This safe, novel approach allows the user to quickly reach distant locations while retaining full precision for delicate manoeuvres. The performance and usability of this adaptive motion scaling is evaluated in a user study, showing a clear improvement in task completion speed and in the reduction of the need for clutching.

Three-dimensional robotic-assisted endomicroscopy with a force adaptive robotic arm

Effective in situ, in vivo tumour margin assessment is an important, yet unmet, clinical demand in surgical oncology. Recent advances in probe-based optical imaging tools such as confocal endomicroscopy is making inroads in clinical applications. In practice, maintaining consistent tissue contact whilst ensuring large area surveillance is crucial for its practical adoption and for this reason there is a great demand for robotic assistance so that high-speed endomicroscopes can be combined with autonomous scanning, thus simphfying its incorporation in routine surgical workflows. In this paper, a cooperatively controlled robotic manipulator is developed, which provides a stable mechatronicaUy-enhanced platform for micro-scanning tools to perform local high resolution mosaics over 3D undulating moving surfaces. Detailed kinematic and overall system performance analyses are provided and the results demonstrate the adaptabUity in terms of both contact force and orientation control of the system, and thus its simplicity in practical deployment and value for clinical adoption.

Design of a smart 3D-printed wristed robotic surgical instrument with embedded force sensing and modularity

This paper introduces the design and characterization of a robotic surgical instrument produced mainly with rapid prototyping techniques. Surgical robots have generally complex structures and have therefore an elevated cost. The proposed instrument was designed to incorporate minimal number of components to simplify the assembly process by leveraging the unique strength of rapid prototyping for producing complex, assemble-free components. The modularity, cost-effectiveness and fast manufacturing and assembly features offer the possibility of producing patient or task specific instruments. The proposed robot incorporates an integrated force measurement system, thus allowing the determination of the force exchanged between the instrument and the environment. Detailed experiments were performed to validate the functionality and force sensing capability of the instrument.

3D printing of improved needle grasping instrument for flexible robotic surgery

Suturing is an essential requirement for surgical robots. Current designs of needle drivers require significant forces to be applied so that the needle will not flip or slip between the jaws when inserted into the tissue. The required force implies that most designs are based on rigid instruments with a straight shaft that induces less dexterity. Flexible robotics provides great dexterity to achieve the task, although often it lacks the capability to apply large forces and therefore hold the surgical needle firmly. Solutions can be found in how the needle drivers jaws are designed. This paper presents improved designs for needle grasping tools for flexible robotic instruments, to be produced directly with selective laser melting. Features on the gripping surface were embedded to increase the gripping effectiveness even in the presence of limited grasping force. A detailed characterisation has been performed for each design showing improvements with respect to the state of the art.