Teleoperated tubular continuum robots for transoral surgery - feasibility in a porcine larynx model

Development of a continuum manipulator with variable bending length and piecewise stiffness for transoral laryngeal surgery

PURPOSE

Continuum manipulators (CMs) show great potential in transoral laryngeal surgery due to their flexibility. However, CMs for transoral surgery face several issues: large size, which reduces practicality; intersegment coupling, which causes undesired deflection; and a lack of versatility that limits their applicability across different patient groups.

METHODS

This work combines a rod-driven proximal segment and a cable-driven distal segment to achieve piecewise stiffness, alleviating the issue of intersegment coupling. A rigid constraint tube is integrated into the proximal segment to diversify its bending behavior. Preliminary experiments are conducted to validate the design concept.

RESULTS

The proposed CM has an overall diameter of only 6.5 mm. The proximal segment can achieve a 90° bending with various curvatures. At the working configuration, the coupling error between the proximal segment and the distal segment is less than 1 mm. The effectiveness of the proposed CM is successfully validated using a human model.

CONCLUSION

The proposed continuum manipulator possesses the desirable characteristics of small size, low coupling, and high versatility, indicating its great potentialities for the diagnosis and treatment of laryngeal lesion.

Fiberbots: Robotic fibers for high-precision minimally invasive surgery

Precise manipulation of flexible surgical tools is crucial in minimally invasive surgical procedures, necessitating a miniature and flexible robotic probe that can precisely direct the surgical instruments. In this work, we developed a polymer-based robotic fiber with a thermal actuation mechanism by local heating along the sides of a single fiber. The fiber robot was fabricated by highly scalable fiber drawing technology using common low-cost materials. This low-profile (below 2 millimeters in diameter) robotic fiber exhibits remarkable motion precision (below 50 micrometers) and repeatability. We developed control algorithms coupling the robot with endoscopic instruments, demonstrating high-resolution in situ molecular and morphological tissue mapping. We assess its practicality and safety during in vivo laparoscopic surgery on a porcine model. High-precision motion of the fiber robot delivered endoscopically facilitates the effective use of cellular-level intraoperative tissue identification and ablation technologies, potentially enabling precise removal of cancer in challenging surgical sites.

The State-of-the-Art and Perspectives of Laser Ablation for Tumor Treatment

Tumors significantly impact individuals' physical well-being and quality of life. With the ongoing advancements in optical technology, information technology, robotic technology, etc., laser technology is being increasingly utilized in the field of tumor treatment, and laser ablation (LA) of tumors remains a prominent area of research interest. This paper presents an overview of the recent progress in tumor LA therapy, with a focus on the mechanisms and biological effects of LA, commonly used ablation lasers, image-guided LA, and robotic-assisted LA. Further insights and future prospects are discussed in relation to these aspects, and the paper proposed potential future directions for the development of tumor LA techniques.

Endoscopic image-guided laser treatment system based on fiber bundle laser steering

A miniaturized endoscopic laser system with laser steering has great potential to expand the application of minimally invasive laser treatment for micro-lesions inside narrow organs. The conventional systems require separate optical paths for endoscopic imaging and laser steering, which limits their application inside narrower organs. Herein, we present a novel endoscopic image-guided laser treatment system with a thin tip that can access inside narrow organs. The system uses a single fiber bundle to simultaneously acquire endoscopic images and modulate the laser-irradiated area. The insertion and operation of the system in a narrow space were demonstrated using an artificial vascular model. Repeated laser steering along set targets demonstrated accurate laser irradiation within a root-mean-square error of 28 [Formula: see text]m, and static repeatability such that the laser irradiation position was controlled within a 12 [Formula: see text]m radius of dispersion about the mean trajectory. Unexpected irradiation on the distal irradiated plane due to fiber bundle crosstalk was reduced by selecting the appropriate laser input diameter. The laser steering trajectory spatially controlled the photothermal effects, vaporization, and coagulation of chicken liver tissue. This novel system achieves minimally invasive endoscopic laser treatment with high lesion-selectivity in narrow organs, such as the peripheral lung and coronary arteries.

Development and experiments of a continuum robotic system for transoral laryngeal surgery

PURPOSE

Currently, self-retaining laryngoscopic surgery is not suitable for some patients, and there are dead zones relating to surgical field exposure and operation. The quality of the surgery can also be affected by the long periods of time required to complete it. Teleoperated continuum robots with flexible joints are expected to solve these issues. However, at the current stage of developing transoral robotic surgery systems, their large size affects the precision of surgical operative actions and there are high development and treatment costs.

METHODS

We fabricated a flexible joint based on selective laser melting technology and designed a shallow neural network-based kinematic modeling approach for a continuum surgical robot. Then, human model and animal experiments were completed by master-slave teleoperation to verify the force capability and dexterity of the robot, respectively.

RESULTS

As verified by human model and animal experiments, the designed continuum robot was demonstrated to achieve transoral laryngeal surgical field exposure without laryngoscope assistance, with sufficient load capability to finish the biopsy of vocal fold tissue in living animals.

CONCLUSION

The designed continuum robotic system allows the biopsy of vocal fold tissue without laryngoscope assistance. Its stiffness and dexterity indicate the system's potential for applications in the diagnosis and treatment of vocal fold nodules and polyps. The limitations of this robotic system as shown in the experiments were also analyzed.

μRALP and Beyond: Micro-Technologies and Systems for Robot-Assisted Endoscopic Laser Microsurgery

Laser microsurgery is the current gold standard surgical technique for the treatment of selected diseases in delicate organs such as the larynx. However, the operations require large surgical expertise and dexterity, and face significant limitations imposed by available technology, such as the requirement for direct line of sight to the surgical field, restricted access, and direct manual control of the surgical instruments. To change this status quo, the European project μRALP pioneered research towards a complete redesign of current laser microsurgery systems, focusing on the development of robotic micro-technologies to enable endoscopic operations. This has fostered awareness and interest in this field, which presents a unique set of needs, requirements and constraints, leading to research and technological developments beyond μRALP and its research consortium. This paper reviews the achievements and key contributions of such research, providing an overview of the current state of the art in robot-assisted endoscopic laser microsurgery. The primary target application considered is phonomicrosurgery, which is a representative use case involving highly challenging microsurgical techniques for the treatment of glottic diseases. The paper starts by presenting the motivations and rationale for endoscopic laser microsurgery, which leads to the introduction of robotics as an enabling technology for improved surgical field accessibility, visualization and management. Then, research goals, achievements, and current state of different technologies that can build-up to an effective robotic system for endoscopic laser microsurgery are presented. This includes research in micro-robotic laser steering, flexible robotic endoscopes, augmented imaging, assistive surgeon-robot interfaces, and cognitive surgical systems. Innovations in each of these areas are shown to provide sizable progress towards more precise, safer and higher quality endoscopic laser microsurgeries. Yet, major impact is really expected from the full integration of such individual contributions into a complete clinical surgical robotic system, as illustrated in the end of this paper with a description of preliminary cadaver trials conducted with the integrated μRALP system. Overall, the contribution of this paper lays in outlining the current state of the art and open challenges in the area of robot-assisted endoscopic laser microsurgery, which has important clinical applications even beyond laryngology.

Adding Flexible Instrumentation to a Curved Videolaryngoscope: A Novel Tool for Laryngeal Surgery

OBJECTIVES

Transoral surgery of the larynx with rigid instruments is not always possible. This may result in insufficient therapy or in an increased need for open surgery. For these patients, alternative surgical systems are needed. Here, we demonstrate a curved prototype for laryngeal surgery equipped with flexible instruments.

STUDY DESIGN

Pre-clinical user study in an ex vivo porcine laryngeal model.

METHODS

The prototype was built from established medical devices, namely a hyperangulated videolaryngoscope and modified flexible instruments as well as three-dimensional printed parts. Feasibility of laryngeal manipulation was evaluated in a user study (n = 19) with a porcine ex vivo laryngeal model. Using three different visualization technologies, the participants performed various fine motor skills tasks and rated the usability of the system on a 5-point Likert scale.

RESULTS

Exposure, accessibility, and manipulation of important laryngeal structures were always possible using the new prototype. The participants needed considerably less time (mean, 96.4 seconds ± 6.4 seconds vs. 111.5 seconds ± 4.5 seconds, P = .18), reported significantly better general impression (mean score 3.0 vs. 3.8, P = .041) and significantly lower user head and neck strain (2.6 vs. 1.7, P = .022) using a 40-inch television screen as compared to a standard videolaryngoscope monitor.

CONCLUSION

The results indicate that our curved prototype and large monitor visualization may provide a cost-effective minimally invasive alternative for difficult laryngeal exposure. Its special advantages include avoiding the need for a straight line of sight and a simple and cost-effective construction. The system could be further improved through advances in camera chip technology and smaller instruments. Laryngoscope, 131:E561-E568, 2021.

First Use of a New Robotic Endoscope Guiding System in Endoscopic Orbital Decompression

PURPOSE

Over the last years, robot-assisted surgery gained in importance in head and neck surgery. In our study, we used a new robotic endoscope guiding system in patients undergoing endoscopic balanced orbital decompression. The aim of the study is to evaluate the feasibility and benefit of a robotic arm in endoscopic orbital surgery.

METHODS

The Medineering Robotic Endoscope Guiding System is a robotic arm designed for holding an endoscope during interventions. An endoscope equipped with a 4K camera was attached at the tip of the robotic arm and placed in the surgical field. The surgeon controlled the movements of the endoscope with foot pedal. Eight patients underwent balanced endoscopic orbital decompression showing typical symptoms of Graves' orbitopathy preoperatively. Balanced decompression was performed via a combined approach transnasally and laterally via a small skin incision.

RESULTS

Attaching the endoscope to the robotic guiding system and placing it in the nasal cavity were relatively simple procedures. Setup time was less than 10 minutes. Tool motion and control using the foot pedal were comfortable and adequately precise. Movements of the attached endoscope inside the nose were feasible and allowed 2-hand surgery. The patients did not show any adverse events or complications.

CONCLUSION

The Medineering Robotic Endoscope Guiding System seems to be a safe and effective support in endoscopic skull base surgery especially for orbital decompression, thus allowing 2-hand or even 4-hand settings. To the best of our knowledge, this is the first study describing the successful application of a robotic system in orbital surgery.