Application of robotics in gastrointestinal endoscopy: A review

Colorectal endoscopic submucosal dissection in the USA: The current state and future perspectives

Endoscopic submucosal dissection (ESD) is a transformative advancement in the endoscopic management of superficial gastrointestinal lesions. Initially conceived for the treatment of early gastric cancer, ESD has demonstrated proficiency in achieving en-bloc resection of superficial gastrointestinal lesions. ESD has experienced widespread acceptance in Japan and East Asia; however, its adoption in the USA remains delayed. This initial hesitancy could be attributed to procedural complexity and training demands; nonetheless, recently, ESD has been gaining popularity in the USA. This is due to the advancements in endoscopic technology, tailored training programs, and cumulative evidence regarding the efficacy and safety of ESDs. This review aimed to deliberate the historical progress, current implementation, and prospective trajectory of ESDs in the USA. With ongoing clinical research, technological integration, and educational efforts, ESD is likely to become the gold standard for managing large gastrointesitinal lesions. This progress marks an imperative step toward less invasive, more precise, and patient-centric approaches regarding advanced therapeutic endoscopy in the USA.

Robotics in interventional endoscopy-evolution and the way forward

The integration of robotics into gastrointestinal (GI) endoscopy represents a transformative advancement and bears the potential to bridge the gap between traditional limitations by offering unprecedented precision and control in diagnostic and therapeutic procedures. This review explores the historical progression, current applications and future potential of robotic platforms in GI endoscopy. Originally designed for surgical applications, robotic systems have expanded their reach into endoscopy, potentially enhancing procedural accuracy and reducing ergonomic strain on practitioners. Natural Orifice Transluminal Endoscopic Surgery (NOTES) emerged as a promising technique, leveraging natural orifices to perform minimally invasive surgeries. Despite its initial potential, several factors, including limitations of the available instrumentations and lack of reliable closure techniques, hindered its widespread adoption and progress. Conventional endoscopic tools often fall short in terms of triangulation, traction and degrees of freedom, necessitating the adoption of robotic interventions. Over recent decades, robotic endoscopy has significantly evolved, focusing on both diagnostic and complex therapeutic procedures such as endoscopic sub-mucosal dissection (ESD) and endoscopic full-thickness resection (EFTR). Various robotic platforms demonstrate enhanced safety and efficiency in GI procedures. As the field progresses, the emphasis on clinical validation, advanced training and the exploration of new applications remains crucial. Continuous innovation in robotic technology and endoscopic techniques promises to overcome existing limitations, further revolutionizing the management of GI diseases and improving patient outcomes.

Multimodal image-guided surgical robot versus 3D-printed template for brachytherapy of malignant tumours in the skull base and deep facial region: a clinical comparative study

This study compared a multimodal image-guided robot and three-dimensionally (3D) printed templates for implanting iodine-125 (I125) radioactive seeds in patients with malignant tumours in the skull base and deep facial region. Seventeen patients who underwent I125 radioactive seed implantation between December 2018 and December 2019 were included. The operation time, intraoperative blood loss, and accuracy of seed implantation were compared between the multimodal image-guided robot-assisted implantation (experimental) group (n = 7) and 3D-printed template-assisted implantation (control) group (n = 10). In total, 291 seeds were implanted in the experimental group and 436 in the control group; the mean error of seed implantation accuracy was 1.95 ± 0.13 mm and 1.90 ± 0.08 mm, respectively (P = 0.309). The preparation time was 26.13 ± 5.28 min in the experimental group and 0 min in the control group, while the average operation time was 34.44 ± 6.39 min versus 43.70 ± 6.06 min, respectively. The intraoperative blood loss was 4.96 ± 1.76 ml (experimental) versus 8.97 ± 2.99 ml (control) (P = 0.123). Multimodal image-guided robot-assisted I125 radioactive seed implantation met the clinical requirements for treating malignant tumours in the skull base and deep facial regions.

Flexible robotic endoscopy for treating gastrointestinal neoplasms

Therapeutic flexible endoscopic robotic systems have been developed primarily as a platform for endoscopic submucosal dissection (ESD) in the treatment of early-stage gastrointestinal cancer. Since ESD can only be performed by highly skilled endoscopists, the goal is to lower the technical hurdles to ESD by introducing a robot. In some cases, such robots have already been used clinically, but they are still in the research and development stage. This paper outlined the current status of development, including a system by the author’s group, and discussed future challenges.

Lap-Endo cooperative surgery (LECS) in gastric GIST: updates and future advances

BACKGROUND

With advancements in the field of laparoscopic and endoscopic techniques leading to improved patient outcomes, open resection has become increasingly outdated for the treatment of gastric gastrointestinal stromal tumours (GIST). This is further superseded with the advent of laparoscopic and endoscopic cooperative surgery (LECS), an amalgamation of the two techniques to further improve results garnered while overcoming prior limitations each had individually.

METHODS

The electronic databases MEDLINE, Embase and PubMed were reviewed up to August 2021, using terms relating to LECS and gastric GIST. Relevant in-article references not returned in the searches were also considered.

RESULTS

Advancements in the field of laparoscopic and endoscopic techniques has led to improved patient outcomes, making open resection a thing of the past for gastric GIST. This has become even more apparent with the advent of LECS, coupling two cutting edge techniques to further improve results garnered while overcoming prior limitations each had individually. LECS has gained much favour by reducing surgical margins due to endoscopic visualisation without being limited to smaller tumours, allowing for better anatomical and functional preservation of prior anatomy. Furthermore, hybrid approaches have improved perioperative outcomes, with reduction in procedure time, post-procedure hospital stay and lesser complications. Additionally, subtypes of LECS such as inverted LECS, closed LECS, non-exposed endoscopic wall-inversion surgery (NEWS) and laparoscopy-assisted endoscopic full-thickness resection (LAEFR) have been developed that allows the abdominal cavity to not be exposed to tumour cells and gastric contents by extracting the lesion transorally.

CONCLUSIONS

LECS and its subtypes being a combination of two advanced techniques shows a synergistic effect that is promising. However, despite all these advantages of enhanced safety and certainty, there remains areas that require further improvement.

A Look into the Future of Endoscopic Submucosal Dissection and Third Space Endoscopy: The Role for Robotics and Other Innovation

Endoscopic resection has been widely applied especially in endoscopic submucosal dissection and third space endoscopy (TSE). Flexible endoluminal robotics allow performance of endoscopic submucosal dissection with exposure of the submucosal plane for precise dissection using two robotic arms. The introduction of TSE revolutionized the horizon of therapeutic endoscopy to the submucosal space beneath and beyond the mucosa. Advantages of TSE include avoidance of full thickness incision in gastrointestinal tract through the submucosal tunneling for performance of peroral endoscopic myotomy and submucosal tunneling endoscopic resection. In future, robotic-driven devices should be developed to enhance performance of complex endoluminal procedures and TSE.

Robotics in therapeutic endoscopy (with video)

Since its inception, endoscopy has evolved from a solely diagnostic procedure to an expanding therapeutic field within gastroenterology. The incorporation of robotics in gastroenterology initially addressed shortcomings of flexible endoscopes in natural orifice transluminal endoscopy. Developing therapeutic endoscopic robotic platforms now offer operators improved ergonomics, visualization, dexterity, precision, and control and the possibility of increasing proficiency and standardization of complex endoscopic procedures including endoscopic submucosal dissection, endoscopic full-thickness resection, and endoscopic suturing. The following review discusses the history, potential applications, and tools currently available and in development for robotics in therapeutic endoscopy.

A novel flexible auxiliary single-arm transluminal endoscopic robot facilitates endoscopic submucosal dissection of gastric lesions (with video)

BACKGROUND

Using conventional endoscope to perform endoscopic submucosal dissection (ESD) is difficult because of the one-handed operation and blind dissection caused by gravity. Poor visualization of the submucosal plane causes ESD to be associated with a high risk of bleeding and perforation. This study aimed to develop a novel ESD-assistive robot system and to evaluate its efficacy.

METHODS

A novel flexible auxiliary single-arm transluminal endoscopic robot (FASTER) was developed. A total of 36 artificial lesions in ex vivo porcine stomachs were removed using the FASTER-assisted ESD method (n = 18) and the conventional ESD method (n = 18). Lesions were 2 cm or 4 cm in diameter, located on the anterior and posterior walls of the antrum. Primary outcome measurements were dissection time and dissection speed.

RESULTS

The dissection time in FASTER-assisted ESD was significantly shorter than that in conventional ESD (7 min vs 13 min, p = 0.012), mainly because of the faster dissection speed (148.6 vs 97.0 mm²/min, p = 0.002). The total procedure time in FASTER-assisted ESD was shorter than that in conventional ESD, but the difference was not significant (16 min vs 24 min, p = 0.252). Complete en bloc resection was achieved in all lesions. No perforations were detected. The FASTER exhibited the ability of regrasp, multidirectional traction, and proper tension control during ESD.

CONCLUSION

FASTER significantly increased the dissection speed by providing proper traction and achieving good submucosal vision. This new device is expected to facilitate ESD in clinical practice.

Endoscopic full-thickness resection of colorectal lesions: a systematic review and meta-analysis

BACKGROUND AND AIMS

Endoscopic full-thickness resection (EFTR) is a novel endoscopic technique for the resection of GI lesions not amenable to standard endoscopic therapy. The primary aim of this study was to perform a systematic review and meta-analysis to evaluate EFTR for the resection of colorectal lesions.

METHODS

Individualized searches were developed through October 2020 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-Analysis of Observational Studies in Epidemiology guidelines. Random-effects models were used to determine pooled technical success, margin-negative (R₀) resection, adverse events, procedure duration, and rate of recurrence at follow-up. Subgroup analysis was used to assess the impact of specific procedure techniques and regression analyses to determine influence of lesion size. Heterogeneity was assessed with I² statistics and publication bias by funnel plots using Egger and Begg tests.

RESULTS

Fourteen studies (1936 subjects; 39.6% women) were included. Most EFTR lesions were located in the colon (75.8%) with the remaining in the rectum. Mean procedure duration was 45.4 ± 11.4 minutes. Pooled technical success was 87.6% (95% confidence interval [CI], 85.1-89.8; I² = 33), R₀ resection rate was 78.8% (95% CI, 75.7-81.5; I² = 33), procedure-associated adverse events occurred in 12.2% (95% CI, 9.3-15.9; I² = 61), and recurrence rate was 12.6% (95% CI, 11.1-14.4; I² = 0) over an average weighted follow-up of 20.1 ± 3.8 weeks. Regression analyses revealed significantly lower R₀ resection (odds ratio, .3; 95% CI, .2-.6; I² = 61; P = .0003) and higher overall procedure-associated adverse event rates (odds ratio, 3.5; 95% CI, 1.8-7.2; I² = 55; P = .0004) for lesions >20 mm.

CONCLUSIONS

EFTR overall appears to be an effective modality with high technical success and R₀ resection rate with a relatively low risk of adverse events and recurrence, with greatest success when lesions are <20 mm.

Improved team communication in endoscopic procedures by digital enhanced telecommunication during the COVID-19 pandemic

Background and study aims  Unbiased communication is crucial for excellent teamwork in high-quality endoscopy. Personal protective equipment (PPE) (FFP-masks and face-shields) worn by endoscopists that are ubiquitous in the current COVID-19 pandemic strikingly impair communication. Digital enhancement approaches to maintain team communication, especially during complex endoscopic procedures, are urgently warranted. Materials and methods  A prospective, two-armed interventional study was performed at an endoscopy unit at a tertiary center in Germany. Two hundred and three endoscopic procedures with PPE se according to pandemic risk level were randomly assigned (1:1) to a group performed by an endoscopy team equipped with digital enhanced cordless telecommunication (DECT) or one without digital-enhanced communication. The primary outcome was the team-reported number of communication-associated events (CAEs) defined as misunderstandings that impaired workflow during endoscopic examination. Secondary outcomes included perceived voice and headphone quality and overall comfort with DECT during endoscopic work. Results  The use of DECT was associated with a significant reduction in communication-associated events in endoscopic procedures and overall, was perceived positively. Conclusions  Digital enhancement of communication is a promising and easy-to- establish tool for improving team communication quality in endoscopy.

Hybrid endoscopic submucosal dissection (ESD) compared with conventional ESD for colorectal lesions: a systematic review and meta-analysis

BACKGROUND

Hybrid endoscopic submucosal dissection (ESD) is increasingly utilized to overcome the complexity of conventional ESD. This systematic review and meta-analysis evaluated the efficacy and safety of hybrid ESD for treatment of colorectal lesions.

METHODS

Search strategies were developed in accordance with PRISMA guidelines. Pooled proportions were calculated with rates estimated using random effects models. Measured outcomes included en bloc resection, procedure-associated complications, recurrence, and need for surgery. Subgroup analyses were performed to compare effectiveness of conventional versus hybrid ESD.

RESULTS

16 studies (751 patients) were included with a mean (standard deviation [SD]) lesion size of 27.96 (10.55) mm. En bloc resection rate was 81.63 % (95 % confidence interval [CI] 72.07 - 88.44; I2  = 80.89). Complications, recurrences, and need for surgery occurred in 7.74 % (95 %CI 4.78 - 12.31; I2  = 65.84), 4.52 % (95 %CI 1.40 - 13.65; I2  = 76.81), and 3.64 % (95 %CI 1.76 - 7.37; I2  = 15.52), respectively. Mean procedure duration was 48.83 (22.37) minutes. On subgroup analyses comparing outcomes for conventional (n = 1703) versus hybrid ESD (n = 497), procedure duration was significantly shorter for hybrid ESD (mean difference 18.45 minutes; P = 0.003), with lower complication rates (P = 0.04); however, hybrid ESD had lower en bloc resection rates (P < 0.001). There was no difference in rates of recurrence or surgery (P > 0.05).

CONCLUSION

While hybrid ESD was safe and effective for removal of colorectal lesions, with shorter procedure duration, fewer complications, and no difference in recurrence versus conventional ESD, hybrid ESD was associated with a lower en bloc resection rate.

A Soft Robotic Sleeve for Safer Colonoscopy Procedures

Colonoscopy is the gold standard for colorectal cancer diagnosis; however, limited instrument dexterity and no sensor feedback can hamper procedure safety and acceptance. We propose a soft robotic sleeve to provide sensor feedback and additional actuation capabilities to improve safety during navigation in colonoscopy. The robot can be mounted around current endoscopic instrumentation as a disposable "add-on", avoiding the need for dedicated or customized instruments and without disrupting current surgical workflow. We focus on design, finite element analysis, fabrication, and experimental characterization and validation of the soft robotic sleeve. The device integrates soft optical sensors to monitor contact interaction forces between the colon and the colonoscope and soft robotic actuators that can be automatically deployed if excessive force is detected, to guarantee pressure redistribution on a larger contact area of the colon. The system can be operated by a surgeon via a graphic user interface that displays contact force values and enables independent or coordinated pressurization of the soft actuators upon demand, in case deemed necessary to aid navigation or distend colon tissue.

Artificial intelligence in gastrointestinal radiology: A review with special focus on recent development of magnetic resonance and computed tomography

Artificial intelligence (AI), particularly the deep learning technology, have been proven influential to radiology in the recent decade. Its ability in image classification, segmentation, detection and reconstruction tasks have substantially assisted diagnostic radiology, and has even been viewed as having the potential to perform better than radiologists in some tasks. Gastrointestinal radiology, an important subspecialty dealing with complex anatomy and various modalities including endoscopy, have especially attracted the attention of AI researchers and engineers worldwide. Consequently, recently many tools have been developed for lesion detection and image construction in gastrointestinal radiology, particularly in the fields for which public databases are available, such as diagnostic abdominal magnetic resonance imaging (MRI) and computed tomography (CT). This review will provide a framework for understanding recent advancements of AI in gastrointestinal radiology, with a special focus on hepatic and pancreatobiliary diagnostic radiology with MRI and CT. For fields where AI is less developed, this review will also explain the difficulty in AI model training and possible strategies to overcome the technical issues. The authors’ insights of possible future development will be addressed in the last section.

Closed-loop control of soft continuum manipulators under tip follower actuation

Continuum manipulators, inspired by nature, have drawn significant interest within the robotics community. They can facilitate motion within complex environments where traditional rigid robots may be ineffective, while maintaining a reasonable degree of precision. Soft continuum manipulators have emerged as a growing subfield of continuum robotics, with promise for applications requiring high compliance, including certain medical procedures. This has driven demand for new control schemes designed to precisely control these highly flexible manipulators, whose kinematics may be sensitive to external loads, such as gravity. This article presents one such approach, utilizing a rapidly computed kinematic model based on Cosserat rod theory, coupled with sensor feedback to facilitate closed-loop control, for a soft continuum manipulator under tip follower actuation and external loading. This approach is suited to soft manipulators undergoing quasi-static deployment, where actuators apply a follower wrench (i.e., one that is in a constant body frame direction regardless of robot configuration) anywhere along the continuum structure, as can be done in water-jet propulsion. In this article we apply the framework specifically to a tip actuated soft continuum manipulator. The proposed control scheme employs both actuator feedback and pose feedback. The actuator feedback is utilized to both regulate the follower load and to compensate for non-linearities of the actuation system that can introduce kinematic model error. Pose feedback is required to maintain accurate path following. Experimental results demonstrate successful path following with the closed-loop control scheme, with significant performance improvements gained through the use of sensor feedback when compared with the open-loop case.

Per-oral Endoscopic Myotomy and Other Applications of Third Space Endoscopy: Current Status and Future Perspectives

INTRODUCTION

The modification of NOTES (natural orifice transluminal endoscopic surgery) by mucosal safety flap has introduced us to the world of third space endoscopy (TSE). POEM (per-oral endoscopic myotomy) for achalasia cardia being its first vista, the realm expanded so that we can now remove en bloc a subepithelial/intramural tumor by POET (per-oral endoscopic tumor resection), perform G-POEM (gastric per-oral endoscopic myotomy) for refractory gastroparesis, restore esophageal continuity in complete obstruction by performing POETRE (per-oral endoscopic tunneling for the restoration of the esophagus), divide the septum in Zenker diverticulum completely with negligible risk of perforation by Z-POEM (Zenker per-oral endoscopic myotomy) and relieve constipation in Hirschsprung disease by PREM (per-rectal endoscopic myotomy). However, the real potential of TSE became evident with the introduction of POEM with fundoplication. TSE has opened the gates of the peritoneal cavity. Improved expertise and equipment will make the role of endoscopist complimentary to the surgeon with the dawn of a new field in therapeutic endoscopy.

AREAS COVERED

This review intends to comprehensively discuss the various aspects of POEM for achalasia studied so far followed by a brief discussion about other applications of TSE and the future perspectives in this exciting field.

Is a Fundamental Design Change for Gastrointestinal Endoscopes Required?

Since the first fiberoptic instruments, gastrointestinal endoscopy has shaped the field of gastroenterology and is now a key diagnostic and therapeutic tool. Compared with the initial fiberoptic endoscopes state-of-the-art optical chips (or charge-coupled device technology) allowed a quantum leap in image quality. Despite these advances, gastrointestinal endoscopy is far from being perfect. The diagnostic yield (eg, for adenoma detection rates) is highly operator dependent and there is still the need for sedation or even anesthesia to address discomfort during the procedure. Despite highly standardized cleaning and high-level disinfection the reuse of contemporary (and difficult to clean) endoscopes with multiple channels exposes patients to the risk of transmission of infections. Artificial intelligence and pattern recognition should eliminate interindividual variability including polyp detection rates, self-propelled, and (potentially remotely controlled) scopes with a soft shaft could reduce the discomfort during procedures and abolish the need for sedation and anesthesia altogether and single-use designs should eliminate the risk of patient-to-patient transmission of infections. While these innovations are feasible and could be implemented rapidly utilizing available technology, they require a paradigm shift affecting all levels of the value chain from the supplier of the instruments to the end-users. Some may negate the need for a paradigm shift, but it is evident that a major redesign of the endoscopic equipment is overdue to fully utilize novel technologies and most importantly ensure the best possible outcomes for patients.

An Accelerated Finite-Time Convergent Neural Network for Visual Servoing of a Flexible Surgical Endoscope With Physical and RCM Constraints

This article designs and analyzes a recurrent neural network (RNN) for the visual servoing of a flexible surgical endoscope. The flexible surgical endoscope is based on a commercially available UR5 robot with a flexible endoscope attached as an end-effector. Most of the existing visual servo control frameworks of the robotic endoscopes or robot arms have not considered either the physical limits of the robot or the remote center of motion (RCM) constraints (i.e., the fulcrum effect). To tackle this issue, this article first conducts the kinematic modeling of the flexible robotic endoscope to achieve automation by visual servo control. The kinematic modeling results in a quadratic programming (QP) framework with physical limits and RCM constraints involved, making the UR5 robot applicable to surgical field. To solve the QP problem and accomplish the visual task, an RNN activated by a sign-bi-power activation function (AF) is proposed. The motivation of using the sign-bi-power AF is to enable the RNN to exhibit an accelerated finite-time convergence, which is more preferred in time-critical applications. Theoretically, the finite-time convergence of the RNN is rigorously proved using the Lyapunov theory. Compared with the previous AFs applied to the RNN, theoretical analysis shows that the RNN activated by the sign-bi-power AF delivers an accelerated convergence speed. Comparative validations are performed, showing that the proposed finite-time convergent neural network is effective to achieve visual servoing of the flexible endoscope with physical limits and RCM constraints handled simultaneously.

Frontiers of Robotic Gastroscopy: A Comprehensive Review of Robotic Gastroscopes and Technologies

Simple Summary

With the rapid advancements of medical technologies and patients’ higher expectations for precision diagnostic and surgical outcomes, gastroscopy has been increasingly adopted for the detection and treatment of pathologies in the upper digestive tract. Correspondingly, robotic gastroscopes with advanced functionalities, e.g., disposable, dextrous and not invasive solutions, have been developed in the last years. This article extensively reviews these novel devices and describes their functionalities and performance. In addition, the implementation of artificial intelligence technology into robotic gastroscopes, combined with remote telehealth endoscopy services, are discussed. The aim of this paper is to provide a clear and comprehensive view of contemporary robotic gastroscopes and ancillary technologies to support medical practitioners in their future clinical practice but also to inspire and drive new engineering developments.

Abstract

Upper gastrointestinal (UGI) tract pathology is common worldwide. With recent advancements in robotics, innovative diagnostic and treatment devices have been developed and several translational attempts made. This review paper aims to provide a highly pictorial critical review of robotic gastroscopes, so that clinicians and researchers can obtain a swift and comprehensive overview of key technologies and challenges. Therefore, the paper presents robotic gastroscopes, either commercial or at a progressed technology readiness level. Among them, we show tethered and wireless gastroscopes, as well as devices aimed for UGI surgery. The technological features of these instruments, as well as their clinical adoption and performance, are described and compared. Although the existing endoscopic devices have thus far provided substantial improvements in the effectiveness of diagnosis and treatment, there are certain aspects that represent unwavering predicaments of the current gastroenterology practice. A detailed list includes difficulties and risks, such as transmission of communicable diseases (e.g., COVID-19) due to the doctor–patient proximity, unchanged learning curves, variable detection rates, procedure-related adverse events, endoscopists’ and nurses’ burnouts, limited human and/or material resources, and patients’ preferences to choose non-invasive options that further interfere with the successful implementation and adoption of routine screening. The combination of robotics and artificial intelligence, as well as remote telehealth endoscopy services, are also discussed, as viable solutions to improve existing platforms for diagnosis and treatment are emerging.

Current state of education and training for endoscopic submucosal dissection: Translating strategy and success to the USA

Endoscopic submucosal dissection (ESD) is a rigorous and technically sophisticated method for removal of lesions within the gastrointestinal tract. Despite having advantages of en-bloc resection of lesions, regardless of size, and widespread use in Japan and Asia, ESD has not become widely adopted in the USA for a variety of reasons. Based upon Japanese education and the master-apprentice model, modification to the education system and additional techniques designed to facilitate broader adoption are required for trainees in the USA. This article will review the current state of education and training for ESD in the USA.

Robotic endoscopy. A review of the literature

Purpose

To present new endoscopic robotic devices in the context of minimally invasive procedures with high precision and automation.

Methods

Review of the literature by December 2018 on robotic endoscopy.

Results

We present the studies and investments for robotic implementation and flexible endoscopy evolution. We divided them into forceps manipulation platforms, active endoscopy and endoscopic capsule. They try to improve forceps handling and stability and to promote active movement.

Conclusion

The implementation and propagation of robotic models depend on doing what the endoscopist is unable to. The new devices are moving forward in this direction.

Steerable OCT catheter for real-time assistance during teleoperated endoscopic treatment of colorectal cancer

When detected early, colorectal cancer can be treated with minimally invasive flexible endoscopy. However, since only specialized experts can delineate margins and perform endoscopic resections of lesions, patients still often undergo colon resections. To better assist in the performance of surgical tasks, a robotized flexible interventional endoscope was previously developed, having two additional side channels for surgical instrument. We propose to enhance the imaging capabilities of this device by combining it with optical coherence tomography (OCT). For this purpose, we have developed a new steerable OCT instrument with an outer diameter of 3.5 mm. The steerable instrument is terminated with a 2 cm long transparent sheath to allow three-dimensional OCT imaging using a side-focusing optical probe with two external scanning actuators. The instrument is connected to an OCT imaging system built around the OCT Axsun engine, with a 1310 nm center wavelength swept source laser and 100 kHz A-line rate. Once inserted in one of the side channels of the robotized endoscope, bending, rotation and translation of the steerable OCT instrument can be controlled by a physician using a joystick. Ex vivo and in vivo tests show that the novel, steerable and teleoperated OCT device enhances dexterity, allowing for inspection of the surgical field without the need for changing the position of the main endoscope.

Analysis of the ‘Endoworm’ prototype’s ability to grip the bowel in in vitro and ex vivo models

Access to the small bowel by means of an enteroscope is difficult, even using current devices such as single-balloon or double-balloon enteroscopes. Exploration time and patient discomfort are the main drawbacks. The prototype ‘Endoworm’ analysed in this paper is based on a pneumatic translation system that, gripping the bowel, enables the endoscope to move forward while the bowel slides back over its most proximal part. The grip capacity is related to the pressure inside the balloon, which depends on the insufflate volume of air. Different materials were used as in vitro and ex vivo models: rigid polymethyl methacrylate, flexible silicone, polyester urethane and ex vivo pig small bowel. On measuring the pressure–volume relationship, we found that it depended on the elastic properties of the lumen and that the frictional force depended on the air pressure inside the balloons and the lumen’s elastic properties. In the presence of a lubricant, the grip on the simulated intestinal lumens was drastically reduced, as was the influence of the lumen’s properties. This paper focuses on the Endoworm’s ability to grip the bowel, which is crucial to achieving effective endoscope forward advance and bowel folding.

Effect of backlash hysteresis of surgical tool bending joints on task performance in teleoperated flexible endoscopic robot

BACKGROUND

The tendon-sheath mechanism provides flexibility but degrades the task performance of the flexible endoscopic robot because of the inherent backlash hysteresis problem. Previous studies have only focused on reducing backlash hysteresis. The goal of this study is to identify the backlash hysteresis criteria of surgical tool bending joints to maintain efficient surgical performance.

METHODS

A test platform for a surgical tool has been developed that has initial backlash hysteresis under 5° and can adjust the backlash hysteresis intentionally. Performance variation has been investigated in three bench-top endoscopic tasks in which various backlash hysteresis conditions were intentionally adjusted.

RESULTS

A clear drop-off in task performance has been observed when the backlash hysteresis of the bending joints was greater than 10° regardless of the type of task and link length.

CONCLUSIONS

The backlash hysteresis of surgical tool bending joints should be reduced to at least 10° to maintain efficient performance in robotic endoscopic surgery.

Robot-assisted endoscopic submucosal dissection versus conventional ESD for colorectal lesions: outcomes of a randomized pilot study in endoscopists without prior ESD experience (with video)

BACKGROUND AND AIMS

Endoscopic submucosal dissection (ESD) is becoming the preferred method for certain early GI malignancies; however, very few U.S. physicians have adopted this technique. This is in part because of the technically challenging nature of the procedure and the long learning curve. Several endoscopic robots are under development to address these complexities.

METHODS

This is a randomized, controlled, pilot study comparing conventional ESD versus robotic-assisted ESD (RESD) in an ex vivo bovine colon model. Five endoscopists without prior ESD or RESD experience were randomized into 2 groups (group 1, RESD after ESD; group 2, RESD before ESD). A standard template was used to create colonic lesions. The primary outcome was completeness of en bloc resection. Secondary outcomes included differences in procedure time, perforation rate, muscle injury rate, and National Aeronautical and Space Administration Task Load Index (NASA-TLX) to assess physical and mental workload.

RESULTS

Five endoscopists each performed 4 tissue resections (2 RESD and 2 ESD), for a total of 20 procedures. Complete en bloc resection was achieved in all RESD and in 50% of ESD (P < .0001). The perforation rate was higher in the ESD group (60% vs 30%, P = .18). Total procedure time (34.1 vs 88.6 min, P = .001) and dissection time (27.8 vs 79.4 minutes, P = .002) were lower for RESD. The NASA-TLX also revealed better results for RESD (28.4 vs 47.4, P = .01).

CONCLUSIONS

RESD appears to be more effective in obtaining en bloc resection with shorter procedure times and a lower perforation rate compared with conventional ESD as performed by ESD novices. RESD is also associated with lower physical and mental workloads.

Development of a Capsule Robot for Exploring the Colon

A tether-less inchworm-like capsule robot (ILCR) is promising to enable a non-invasive exploration of the colon, while existing ILCRs show barely satisfactory movement performance because the colon environment is nonstructural. In this current study, we develop an enhanced ILCR based on a design rule of maximizing the achievable periodic stroke and minimizing the body length, with the aim of improving movement performance. By designing an axial compact expanding mechanism (EM), employing a novel linear mechanism (LM), and integrating a hollow-cylinder-like power source based on wireless power transmission (WPT), the enhanced ILCR achieves a periodic stroke of 38 mm within a small body length of 33 mm. Our experiments show that the EM and LM can work reliably in an ex-vivo colon with a lot of intestinal mucus, and the power source can safely supply a stable working voltage of 3.3 V even in the worst case. Being wirelessly controlled and powered, the enhanced ILCR shows satisfactory movement performance, with velocities of 15.8 cm/min, 12.1 cm/min, and 7.4 cm/min in a transparent tube, a tiled colon, and a suspended colon, respectively, promising to accomplish an exploration for the 1.5-m long colon within 30 min.

Emerging next-generation robotic colonoscopy systems towards painless colonoscopy

Advances in the field of robotics have allowed modern technology to be integrated into medicine and that can minimize patients suffering from the side effects that are inherent to procedures for improving their quality of life. Conventional devices that are used for colonoscopies are rigid and require a high level of expertise from endoscopists to perform the procedure. Advances in robot-assisted colonoscopic systems now produce softer, more slender, automated designs that no longer require the operator to use forceful pushing to advance the colonoscope inside the colon, reducing risks to the patient of perforation and pain. It is challenging to reprocess these scopes for reuse as the materials used can be damaged during decontamination, leading to the possible risks of cross-infection by pathogenic microorganisms when reused by patients. An ideal solution is to eliminate these contamination risks to patients by adopting sterile, single-use scopes straight from the manufacturer's package to the patient. With this idea in mind, emerging developments that push the boundaries in this area will benefit patients and encourage the public to participate in and adhere better to colonoscopy screening to reduce the development of colorectal cancer. Thus, in light of these concerns and challenges, to encourage patients undergoing colorectal screening to comply with colonoscopy procedures that they are less invasive, changes in the design and materials are necessary. One of the more promising technological advances in this area is the advent of robotic colonoscopy.

Robotic-Assisted Transrectal Cholecystectomy in a Porcine Model

Background. With increasing experience and technological advancement in surgical instruments, surgeons have explored the feasibility of single-incision laparoscopic surgery and natural orifice transluminal endoscopic surgery (NOTES). These techniques aim to further reduce surgical trauma, but are not popular due to their inherent pitfalls including clashing of instruments, lack of counter traction, lengthy operating time, and so on. A novel surgical robotic system was designed to overcome the limitations of the existing technologies. Animal trials were conducted to demonstrate its feasibility in performing robotic-assisted transrectal cholecystectomy in a porcine model. Method. The Novel surgical robotic system is a high dexterity, single access port surgical robotic system that enables surgeons to carry out single-port surgical procedure or NOTES. The proposed system’s main features include the ability to perform intraabdominal and pelvic surgeries via natural orifices like the vagina or rectum. The system is equipped with multiple miniaturized (16 mm diameter) internally motorized robotic arms, each with a minimum of 7 degrees of freedom, a dual in vivo camera system, a cannula, and an external swivel system. Results. Robotic-assisted transrectal cholecystectomy was successfully performed in 3 adult male pigs. The estimated blood loss was <10 mL in all 3 cases. There were no intraoperative complications. The system provided good dexterity and clear vision. Conclusions. The trial demonstrated that the system can provide the surgeon a stable platform with adequate spacing for the transrectal insertion of robotic arms, 3-dimensional vision, and enhanced dexterity in performing NOTES cholecystectomy.

Endoworm: A new semi-autonomous enteroscopy device

Using enteroscopes with therapeutic capacity to explore the small intestine entails certain limitations, including long exploration times, patient discomfort, the need for sedation, a high percentage of incomplete explorations and a long learning curve. This article describes the advances and setbacks encountered in designing the new Endoworm enteroscopy system, a semi-autonomous device consisting of a control unit and three cavities that inflate and deflate in such a way that the bowel retracts over the endoscope. The system can be adapted to any commercial enteroscope. Endoworm was tested in different intestine models: a polymethyl methacrylate rigid tube, an in vitro polyester urethane model, an ex vivo pig model and an in vivo animal model. The general behavior of the prototype was evaluated by experienced medical personnel. The mean distance covered through the lumen was measured in each cycle. The system was found to have excellent performance in the rigid tube and in the in vitro model. The ex vivo tests showed that the behavior depended largely on the mechanical properties of the lumen, while the in vivo experiments suggest that the device will require further modifications to improve its performance.

The future of robotic surgery

How robotics could help shape the future of surgical care.

Choledochoscopic Examination of a 3-Dimensional Printing Model Using Augmented Reality Techniques: A Preliminary Proof of Concept Study

BACKGROUND

We applied augmented reality (AR) techniques to flexible choledochoscopy examinations.

METHODS

Enhanced computed tomography data of a patient with intrahepatic and extrahepatic biliary duct dilatation were collected to generate a hollow, 3-dimensional (3D) model of the biliary tree by 3D printing. The 3D printed model was placed in an opaque box. An electromagnetic (EM) sensor was internally installed in the choledochoscope instrument channel for tracking its movements through the passages of the 3D printed model, and an AR navigation platform was built using image overlay display. The porta hepatis was used as the reference marker with rigid image registration. The trajectories of the choledochoscope and the EM sensor were observed and recorded using the operator interface of the choledochoscope.

RESULTS

Training choledochoscopy was performed on the 3D printed model. The choledochoscope was guided into the left and right hepatic ducts, the right anterior hepatic duct, the bile ducts of segment 8, the hepatic duct in subsegment 8, the right posterior hepatic duct, and the left and the right bile ducts of the caudate lobe. Although stability in tracking was less than ideal, the virtual choledochoscope images and EM sensor tracking were effective for navigation.

CONCLUSIONS

AR techniques can be used to assist navigation in choledochoscopy examinations in bile duct models. Further research is needed to determine its benefits in clinical settings.

Flexible robotic endoscopy: current and original devices

Two current major research topics concern the incorporation of flexible robotic endoscopy systems developed for natural-orifice translumenal endoscopic surgery (NOTES), primarily for the purpose of remote forceps operation, into endoscopic submucosal dissection (ESD) and other flexible endoscopic treatments and the use of robots for the manipulation of flexible endoscopes themselves with the aim of enabling the remote insertion of colonoscopes, etc. However, there are still many challenges that remain to be addressed; the ideal robotic endoscope has not yet been realized. This article reviews the ongoing developments and our own efforts in the area of flexible robotic endoscopy.

Robotic Endoscopy

Endoscopes extend the eyes of the physician into the patient's body. They are widely used in gastrointestinal (GI) diagnostics and minimally invasive surgery. Endoscopes can be classified into 3 types: rigid, flexible, and capsule endoscopes. Rigid and flexible endoscopes are traditionally held and manipulated by the physician to visualize the region of interest, while capsule endoscopes move passively along with the GI peristalsis. With the advancement of technology, robotic endoscopy has been increasingly developed and accepted. In this work, robotic endoscopy from 3 categories (robot-assisted rigid endoscopy, robot-assisted flexible endoscopy, and active GI endoscopy including active flexible colonoscopy and active capsule endoscopy) is reviewed by PubMed search with the criteria ('Robotics' OR 'Robot') and ('Endoscopy' OR 'Endoscope').

Technological review on endoscopic submucosal dissection: available equipment, recent developments and emerging techniques

Endoscopic submucosal dissection (ESD) is widely practiced in Japan and the Eastern World and is rapidly expanding in western countries for the management of early malignancies of the upper and lower gastrointestinal tube. In addition, novel therapeutic applications deriving from ESD have emerged including the treatment of achalasia, of submucosal tumors, of diverticula, of strictures and of reflux disease. An ESD procedure necessitates not only skills and specific training, but also familiarization with a vast spectrum of devices (endoscopes, high-frequency generators and their settings, endoknives, hoods, irrigation devices) and techniques (such as countertraction, artificial ulcer closure), that render the procedure faster, more efficient and safer. This technological article gives an overview on current and novel equipment for an ESD and associated techniques.