Shape sensing of miniature snake-like robots using optical fibers

Snake like continuum robots are increasingly used for minimally invasive surgery. Most robotic devices of this sort that have been reported to date are controlled in an open loop manner. Using shape sensing to provide closed loop feedback would allow for more accurate control of the robot's position and, hence, more precise surgery. Fiber Bragg Gratings, magnetic sensors and optical reflectance sensors have all been reported for this purpose but are often limited by their cost, size, stiffness or complexity of fabrication. To address this issue, we designed, manufactured and tested a prototype two-link robot with a built-in fiber-optic shape sensor that can deliver and control the position of a CO 2 -laser fiber for soft tissue ablation. The shape sensing is based on optical reflectance, and the device (which has a 4 mm outer diameter) is fabricated using 3D printing. Here we present proof-of-concept results demonstrating successful shape sensing - i.e. measurement of the angular displacement of the upper link of the robot relative to the lower link - in real time with a mean measurement error of only 0.7°

Modelling & characterization of a compliant tethered microgripper for microsurgical applications

The development of microscale surgical tools could pave the way for truly minimally invasive microsurgical procedures. This work demonstrates the application of direct laser writing (DLW) using two-photon polymerization (TPP), a rapid prototyping microfabrication technique, to create a tethered, passively actuated three-dimensional gripper with potential applications in microbiopsy. A microgripper design was devised, modelled and optimized. The gripper was then fabricated and characterized for validation of the theoretical model. The results demonstrate that modelling the behavior of compliant microtools provides a useful approximation for the observed trends and, thus, can be utilized in the design of TPP tools. Future work on the incorporation of viscoelastic material into the model will further improve agreement between the predicted and experimental performance

Rolling-joint design optimization for tendon driven snake-like surgical robots

The use of snake-like robots for surgery is a popular choice for intra-luminal procedures. In practice, the requirements for strength, flexibility and accuracy are difficult to be satisfied simultaneously. This paper presents a computational approach for optimizing the design of a snake-like robot using serial rolling-joints and tendons as the base architecture. The method optimizes the design in terms of joint angle range and tendon placement to prevent the tendons and joints from colliding during bending motion. The resulting optimized joints were manufactured using 3D printing. The robot was characterized in terms of workspace, dexterity, precision and manipulation forces. The results show a repeatability as low as 0.9mm and manipulation forces of up to 5.6N

3D Printed Microfluidic Device with Integrated Biosensors for Online Analysis of Subcutaneous Human Microdialysate

We thank the EPSRC (EP/H009744/1) and Wellcome Trust DOH (HICF-0510-080) for fundin

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

Robotics in keyhole transcranial endoscope-assisted microsurgery: a critical review of existing systems and proposed specifications for new robotic platforms

BACKGROUND: Over the past decade, advances in image guidance, endoscopy, and tube-shaft instruments have allowed for the further development of keyhole transcranial endoscope-assisted microsurgery, utilizing smaller craniotomies and minimizing exposure and manipulation of unaffected brain tissue. Although such approaches offer the possibility of shorter operating times, reduced morbidity and mortality, and improved long-term outcomes, the technical skills required to perform such surgery are inevitably greater than for traditional open surgical techniques, and they have not been widely adopted by neurosurgeons. Surgical robotics, which has the ability to improve visualization and increase dexterity, therefore has the potential to enhance surgical performance. OBJECTIVE: To evaluate the role of surgical robots in keyhole transcranial endoscope-assisted microsurgery. METHODS: The technical challenges faced by surgeons utilizing keyhole craniotomies were reviewed, and a thorough appraisal of presently available robotic systems was performed. RESULTS: Surgical robotic systems have the potential to incorporate advances in augmented reality, stereoendoscopy, and jointed-wrist instruments, and therefore to significantly impact the field of keyhole neurosurgery. To date, over 30 robotic systems have been applied to neurosurgical procedures. The vast majority of these robots are best described as supervisory controlled, and are designed for stereotactic or image-guided surgery. Few telesurgical robots are suitable for keyhole neurosurgical approaches, and none are in widespread clinical use in the field. CONCLUSION: New robotic platforms in minimally invasive neurosurgery must possess clear and unambiguous advantages over conventional approaches if they are to achieve significant clinical penetration

The i2Snake robotic platform for endoscopic surgery

Endoscopic procedures have transformed minimally invasive surgery as they allow the examination and intervention on a patient's anatomy through natural orifices, without the need for external incisions. However, the complexity of anatomical pathways and the limited dexterity of existing instruments, limit such procedures mainly to diagnosis and biopsies. This paper proposes a new robotic platform: the Intuitive imaging sensing navigated and kinematically enhanced ([Formula: see text]) robot that aims to improve the field of endoscopic surgery. The proposed robotic platform includes a snake-like robotic endoscope equipped with a camera, a light-source and two robotic instruments, supported with a robotic arm for global positioning and for insertion of the [Formula: see text] and a master interface for master-slave teleoperation. The proposed robotic platform design focuses on ergonomics and intuitive control. The control workflow was first validated in simulation and then implemented on the robotic platform. The results are consistent with the simulation and show the clear clinical potential of the system. Limitations such as tendon backlash and elongation over time will be further investigated by means of combined hardware and software solutions. In conclusion, the proposed system contributes to the field of endoscopic surgical robots and could allow to perform more complex endoscopic surgical procedures while reducing patient trauma and recovery time

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 instrument's 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