The measurement of forces exerted during colonoscopy

Artificial intelligence alert system based on intraluminal view for colonoscopy intubation

Mucosal contact of the tip of colonoscopy causes red-out views, and more pressure may result in perforation. There is still a lack of quantitative analysis methods for red-out views. We aimed to develop an artificial intelligence (AI)-based system to assess red-out views during intubation in colonoscopy. Altogether, 479 colonoscopies performed by 34 colonoscopists were analysed using the proposed semi-supervised AI-based system. We compared the AI-based red-out avoiding scores among novice, intermediate, and experienced colonoscopists. The mean AI-based red-out avoiding scores were compared among groups stratified by expert-rated direct observation of procedure or skill (DOPS)-based tip control assessment results. Both the percentage of actual red-out views (p < 0.001) and AI-based red-out avoiding scores (p < 0.001) were significantly different among the novice, intermediate, and experienced groups. Colonoscopists who scored better on the DOPS-based tip control assessment also performed better on the AI-based red-out avoiding skill assessment. AI-based red-out avoiding score was negatively correlated with actual caecal intubation time and actual red-out percentage. Feedback of red-out avoiding score may help remind endoscopists to perform colonoscopy in an effective and safe manner. This system can be used as an auxiliary tool for colonoscopy training.

Design and preliminary evaluation of a track-based robotic colonoscope with a shape-adaptable tip for propulsion

This paper introduces a shape-adaptable robotic endoscope design, which combines an expansion mechanism and external drive system that provide tip insertion force and adjust the tip shape and size to different colon diameters. Expansion rate of 53% has been achieved in the expandable tip size, which corresponds to changes in the colon diameter. We tested the prototype locomotion in a pipe with different friction surface layers, including artificial bowel tissues, to assess propulsion force and normal force on the colon that can be achieved with the current design. The prototype can generate a propulsion force of 2.83 N, and the maximum linear speed of 29.29 mm/s on the artificial tissue surface. It can produce effective propulsion when it passes through pipes of different diameters. The results demonstrate the prototype's ability for shape adaptation that maintains the required traction force on the bowel wall.

MorphGI: A Self-Propelling Soft Robotic Endoscope Through Morphing Shape

Colonoscopy is currently the best method for detecting bowel cancer, but fundamental design and construction have not changed significantly in decades. Conventional colonoscope (CC) is difficult to maneuver and can lead to pain with a risk of damaging the bowel due to its rigidity. We present the MorphGI, a robotic endoscope system that is self-propelling and made of soft material, thus easy to operate and inherently safe to patient. After verifying kinematic control of the distal bending segment, the system was evaluated in: a benchtop colon simulator, using multiple colon configurations; a colon simulator with force sensors; and surgically removed pig colon tissue. In the colon simulator, the MorphGI completed a colonoscopy in an average of 10.84 min. The MorphGI showed an average of 77% and 62% reduction in peak forces compared to a CC in high- and low-stiffness modes, respectively. Self-propulsion was demonstrated in the excised tissue test but not in the live pig test, due to anatomical differences between pig and human colons. This work demonstrates the core features of MorphGI.

Identification of lubricant viscosity to minimize the frictional impact of colonoscopy on colonic mucosa

Applying a lubricant to the colonic mucosa and reducing the dynamic friction coefficient (DFC) between the endoscopic shaft and colonic mucosa may reduce colonoscopy invasiveness. However, the ideal lubricant viscosity remains unknown. Here, we developed a DFC measurement model integrating samples of colonic mucosa from forensic autopsy specimens into a simulated bowel bend and determined the low-friction lubricant viscosity that minimizes the DFC. Carboxymethyl cellulose, xanthan gum, hydroxyethyl cellulose, sodium alginate, and sodium polyacrylate aqueous solutions of various concentrations were used as lubricants. Low-friction lubricants minimized the load on the colonic mucosa during colonoscope insertion and reduced the total endoscopy insertion time. The highest correlation was between the DFC and the lubricant viscosity at a shear rate of 100 1/s. The lowest DFC was almost constant at approximately 0.09, irrespective of the chemical composition of the lubricant, and the low-friction lubricant viscosity (100 1/s) was 0.031–0.086 (median: 0.059). The viscosities of conventional colonoscopic lubricants were suitable for lubricating the anorectal skin owing to their low DFC, but too high for lubricating the colonic mucosa because of their high DFC. The utilization of the low-friction lubricants with the optimal viscosity can reduce the stress on colonic mucosa during colonoscopy.

Watanabe and colleagues investigate the effects of different lubricants on the friction coefficient during colonoscopy. They also develop a corresponding model to measure the dynamic friction coefficient and determine the optimal viscosity for minimizing colonoscopy invasiveness, enhancing patient comfort, and improving surgical efficiency.

Patient Factors Affect Ergonomic Strain of Endoscopists During Colonoscopy

INTRODUCTION

Endoscopic procedures place a great deal of muscular strain on providers, especially over the span of their careers. In this study we quantitatively analyzed the effects of patient factors such as age, body mass index, and sex on the ergonomics of endoscopists performing colonoscopies.

METHODS

Surface electromyography (sEMG) was used to measure ergonomic strain of physicians while performing colonoscopies in several key muscle groups. The percent of the maximum voluntary contraction (%MVC) was used as a measure of muscular strain. Data was then analyzed based on the patient characteristics above.

RESULTS

Endoscopists performing colonoscopies on female patients (n = 47) experienced significantly higher ergonomic strain in their right trapezius and right posterior forearm muscle groups when compared to colonoscopies performed on males (n = 35) (%MVC R-trapezius: Male: 8.2; Female: 8.9; p = 0.048); (%MVC R-posterior forearm: Male: 10.4; Female: 11.6; p = 0.0006). Operators experienced greater strain in the same muscle groups when performing colonoscopies on patients with BMI ≤ 25 (n = 25) when compared to patients with BMI > 25 (n = 57) (%MVC R-trapezius: BMI < 25: 9.7; BMI ≥ 25: 8.2; p = 0.0002); (%MVC R-posterior forearm: BMI < 25: 11.9; BMI ≥ 25: 10.8; p = 0.0001).

CONCLUSION

Physicians experienced greater ergonomic strain when performing colonoscopies on female patients and on patients with a BMI < 25. We believe that these factors potentially impact the tortuosity of the colon and therefore influence the difficulty of navigating the endoscope. These results may aid physicians in gauging the anticipated difficulty of colonoscopies based on patient factors. Increased awareness of their posturing and ergonomics during challenging cases will alleviate musculoskeletal injuries in the long run.

Gastrointestinal endoscopy and work-related injuries: an international survey

Background and study aims  Recently, the awareness of work-related musculoskeletal injuries (MSIs) among gastrointestinal endoscopists has increased because of their effect on the private and work life of clinicians as well as on the health care system. The high injury incidence (reported to range from 37 % to 89 %) has been correlated with the intensive muscular demand required during a procedure. Patients and methods  An online survey with 32 questions was conducted globally. Clinically active endoscopists (doctors and nurses) participated anonymously and voluntarily. The questionnaire included questions about endoscopist anthropometrics, experience of MSI, treatment, and preventive measures such as ergonomic training. Descriptive statistics were used to analyse the data. Results  Of 204 clinicians (78 % males; 81 % > 35 years of age), 107 (53 %) stated to have experienced a work-related MSI. The most frequent locations were in the neck (n = 49), shoulder and thumb (n = 39, both). Female clinicians resulted to be significantly more prone to develop MSI. In addition, endoscopists who performed more than 15 hours of endoscopy or more than 15 procedures per week reported a significantly higher rate of MSI. Conclusions  The high frequency of MSIs among gastrointestinal endoscopists highlights the importance of implementing ergonomic training. Including simple precautions before and during endoscopy may reduce the risk of developing an injury.

Colonic displacement as a marker of endoscopic skill: development of a novel tool for endoscopy training

BACKGROUND

Colonoscopy is a technically challenging procedure. The colonoscope is prone to forming loops in the colon, which can lead patient discomfort and even perforation. We hypothesized that expert endoscopists use techniques to avoid loop formation, identify and straighten loops earlier, and thus exert less force.

METHODS

Using a commercially available physical colon simulator model (Kyoto Kagaku), electromagnetic tracking markers (NDI Medical) were placed along the mobile segments of the colon (sigmoid, transverse) to measure the degree of displacement of the colon as the scope was advanced to the cecum. The colon model was set for each participant to simulate a redundant alpha loop in the sigmoid colon. Gastroenterology and surgical trainees and attendings were assessed. Demographic data were collected for each participant.

RESULTS

Seventy-five participants were enrolled in the study. There were 17 (22.7%) attending physicians, and 58 (77.3%) trainees. Attending physicians advanced the scope to the cecum faster. The mean time required for procedure completion was 360.5 s compared to 178.4 s for the trainee and attending groups respectively (mean difference: 182.1 s, 95% CI: 93.0, 269.7; p = 0.0002). Attending physicians exerted significantly lower mean colonic displacement than trainees. The mean colonic displacement was 79.8 mm for the trainee group and 57.9 mm for the attending group (mean difference: 21.9 mm, 95% CI: 2.6, 41.2; p = 0.04). Those who used torque steering caused lower maximum colonic displacement than those who used knob steering.

CONCLUSION

Attending physicians advance the scope during colonoscopy in a manner that results in significantly less colonic displacement than resident trainees. Although prior studies have shown a difference in force application between endoscopists and inexperienced students, ours is the first to differentiate across varying degrees of endoscopic skill. Future studies will define metrics for incorporation into endoscopic training curricula, focusing on techniques that encourage safety and comfort for patients.

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.

Hydro-jet propelled colonoscopy: proof of concept in a phantom colon

BACKGROUND

Colonoscopy is a widely used and effective procedure, but it often causes patient discomfort and its execution requires considerable skill and training. We demonstrate an alternative approach to colonoscope propulsion with the potential to minimise patient discomfort by reducing the forces exerted on the colonic wall and mesentery, and to reduce the level of skill required for execution.

METHODS

A prototype colonoscopic device is described, consisting of a tethered capsule that is propelled and manoeuvred through a water-filled colon (hydro-colonoscopy) by an array of water jets. As an initial proof of concept, experiments were performed to assess the ability of the device to navigate through a simplified PVA cryogel human colon phantom arranged in various anatomical configurations.

RESULTS

The prototype was capable of successfully navigating through three out of four colon configurations: a simple layout, alpha loop and reverse alpha loop. It was unable to negotiate the fourth configuration involving an "N loop", but this was attributed to problems with the colon phantom. In the successful test replicates, mean complete insertion (i.e. caecal intubation) time was 4.7 min. Measured pressures, temperatures and forces exerted on the colon appeared to be within a physiologically acceptable range. The results demonstrate the viability of propelling a colonoscope through a colon phantom using hydro-jets.

CONCLUSIONS

Results indicate that this approach has the potential to enable rapid and safe caecal intubation. This suggests that further development towards clinical translation is worthwhile.

A Soft Pneumatic Inchworm Double balloon (SPID) for colonoscopy

The design of a smart robot for colonoscopy is challenging because of the limited available space, slippery internal surfaces, and tortuous 3D shape of the human colon. Locomotion forces applied by an endoscopic robot may damage the colonic wall and/or cause pain and discomfort to patients. This study reports a Soft Pneumatic Inchworm Double balloon (SPID) mini-robot for colonoscopy consisting of two balloons connected by a 3 degrees of freedom soft pneumatic actuator. SPID has an external diameter of 18 mm, a total length of 60 mm, and weighs 10 g. The balloons provide anchorage into the colonic wall for a bio-inspired inchworm locomotion. The proposed design reduces the pressure applied to the colonic wall and consequently pain and discomfort during the procedure. The mini-robot has been tested in a deformable plastic colon phantom of similar shape and dimensions to the human anatomy, exhibiting efficient locomotion by its ability to deform and negotiate flexures and bends. The mini-robot is made of elastomer and constructed from 3D printed components, hence with low production costs essential for a disposable device.

ASGE EndoVators Summit: simulators and the future of endoscopic training

Interest in the use of simulation for acquiring, maintaining, and assessing skills in GI endoscopy has grown over the past decade, as evidenced by recent American Society for Gastrointestinal Endoscopy (ASGE) guidelines encouraging the use of endoscopy simulation training and its incorporation into training standards by a key accreditation organization. An EndoVators Summit, partially supported by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health, (NIH) was held at the ASGE Institute for Training and Technology from November 19 to 20, 2017. The summit brought together over 70 thought leaders in simulation research and simulator development and key decision makers from industry. Proceedings opened with a historical review of the role of simulation in medicine and an outline of priority areas related to the emerging role of simulation training within medicine broadly. Subsequent sessions addressed the summit's purposes: to review the current state of endoscopy simulation and the role it could play in endoscopic training, to define the role and value of simulators in the future of endoscopic training and to reach consensus regarding priority areas for simulation-related education and research and simulator development. This white paper provides an overview of the central points raised by presenters, synthesizes the discussions on the key issues under consideration, and outlines actionable items and/or areas of consensus reached by summit participants and society leadership pertinent to each session. The goal was to provide a working roadmap for the developers of simulators, the investigators who strive to define the optimal use of endoscopy-related simulation and assess its impact on educational outcomes and health care quality, and the educators who seek to enhance integration of simulation into training and practice.

Musculoskeletal injuries in gastrointestinal endoscopists: a systematic review

Gastrointestinal(GI) endoscopy forms a significant proportion of clinicians' workloads. However, little attention is given to the ergonomic aspects of endoscopy. This systematic review of musculoskeletal pain and/or injuries in GI endoscopists aims to better understand the types of occupational injuries resulting from endoscopic procedures and associated risk factors. Areas covered: Systematic literature search conducted for articles evaluating prevalence, risk factors and mechanism of musculoskeletal pain and/or injuries related to GI endoscopy. In 13 included studies, 39-89% of surveyed endoscopists reported pain and/or injuries related to endoscopy. Common areas of pain were the back(15-57%), neck(9-46%), shoulders(9-19%), elbows(8-15%) and hands/fingers(14-82%). Risk factors included procedure volume, time spent doing endoscopy, cumulative time in practice and endoscopist age. Experimental studies showed that forces and loads placed on endoscopists' bodies during procedures place them at risk of occupational injury. Areas of pain differed between novice and experienced endoscopists implying separate mechanisms of injury. Expert commentary: Comprehensive investigation into the prevalence, types, pathophysiology and methods to minimise endoscopy-related musculoskeletal injuries is vital to ensure the continued efficient provision of endoscopy services in the face of rising demands worldwide. A paradigm shift is required in endoscopic devices and techniques to improve safety and comfort.

Design and preliminary evaluation of a self-steering, pneumatically driven colonoscopy robot

Colonoscopy is a diagnostic procedure to detect pre-cancerous polyps and tumours in the colon, and is performed by inserting a long tube equipped with a camera and biopsy tools. Despite the medical benefits, patients undergoing this procedure often complain about the associated pain and discomfort. This discomfort is mostly due to the rough handling of the tube and the creation of loops during the insertion. The overall goal of this work is to minimise the invasiveness of traditional colonoscopy. In pursuit of this goal, this work presents the development of a semi-autonomous colonoscopic robot with minimally invasive locomotion. The proposed robotic approach allows physicians to concentrate mainly on the diagnosis rather than the mechanics of the procedure. In this paper, an innovative locomotion approach for robotic colonoscopy is addressed. Our locomotion approach takes advantage of longitudinal expansion of a latex tube to propel the robot's tip along the colon. This soft and compliant propulsion mechanism, in contrast to minimally invasive mechanisms used in, for example, inchworm-like robots, has shown promising potential. In the preliminary ex vivo experiments, the robot successfully advanced 1.5 metres inside an excised curvilinear porcine colon with average speed of 28 mm/s, and was capable of traversing bends up to 150 degrees. The robot creates less than 6 N of normal force at its tip when it is pressurised with 90 kPa. This maximum force generates pressure of 44.17 mmHg at the tip, which is significantly lower than safe intraluminal human colonic pressure of 80 mmHg. The robot design inherently prevents loop formation in the colon, which is recognised as the main cause of post procedural pain in patients. Overall, the robot has shown great promise in an ex vivo experimental setup. The design of an autonomous control system and in vivo experiments are left as future work.

Development of a Robotic Colonoscopic Manipulation System, Using Haptic Feedback Algorithm

PURPOSE

Colonoscopy is one of the most effective diagnostic and therapeutic tools for colorectal diseases. We aim to propose a master-slave robotic colonoscopy that is controllable in remote site using conventional colonoscopy.

MATERIALS AND METHODS

The master and slave robot were developed to use conventional flexible colonoscopy. The robotic colonoscopic procedure was performed using a colonoscope training model by one expert endoscopist and two unexperienced engineers. To provide the haptic sensation, the insertion force and the rotating torque were measured and sent to the master robot.

RESULTS

A slave robot was developed to hold the colonoscopy and its knob, and perform insertion, rotation, and two tilting motions of colonoscope. A master robot was designed to teach motions of the slave robot. These measured force and torque were scaled down by one tenth to provide the operator with some reflection force and torque at the haptic device. The haptic sensation and feedback system was successful and helpful to feel the constrained force or torque in colon. The insertion time using robotic system decreased with repeated procedures.

CONCLUSION

This work proposed a robotic approach for colonoscopy using haptic feedback algorithm, and this robotic device would effectively perform colonoscopy with reduced burden and comparable safety for patients in remote site.

The efficacy of training insertion skill on a physical model colonoscopy simulator

Background and study aims: Prior research supports the validity of performance measures derived from the use of a physical model colonoscopy simulator - the Kyoto Kagaku Colonoscope Training Model (Kyoto Kagaku Co. Ltd., Kyoto, Japan) - for assessing insertion skill. However, its use as a training tool has received little research attention. We assessed the efficacy of a brief structured program to develop basic colonoscope insertion skill through unsupervised practice on the model. Participants and methods: This was a training study with pretesting and post-testing. Thirty-two colonoscopy novices completed an 11-hour training regime in which they practiced cases on the model in a colonoscopy simulation research laboratory. They also attempted a series of test cases before and after training. For each outcome measure (completion rates, time to cecum and peak force applied to the model), we compared trainees' post-test performance with the untrained novices and experienced colonoscopists from a previously-reported validation study. Results: Compared with untrained novices, trained novices had higher completion rates and shorter times to cecum overall (Ps < .001), but were out-performed by the experienced colono-scopists on these metrics (Ps < .001). Nevertheless, their performance was generally closer to that of the experienced group. Overall, trained novices did not differ from either experience-level comparison group in the peak forces they applied (P > .05). We also present the results broken down by case. Conclusions: The program can be used to teach trainees basic insertion skill in a more or less self-directed way. Individuals who have completed the program (or similar training on the model) are better prepared to progress to supervised live cases.

Development of a Haptic Interface for Natural Orifice Translumenal Endoscopic Surgery Simulation

Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive procedure, which utilizes the body's natural orifices to gain access to the peritoneal cavity. The NOTES procedure is designed to minimize external scarring and patient trauma, however flexible endoscopy based pure NOTES procedures require critical scope handling skills. The delicate nature of the NOTES procedure requires extensive training. Thus, to improve access to training while reducing risk to patients, we have designed and developed the VTEST, a virtual reality NOTES simulator. As part of the simulator, a novel decoupled 2-DOF haptic device was developed to provide realistic force feedback to the user in training. A series of experiments were performed to determine the behavioral characteristics of the device. The device was found capable of rendering up to 5.62N and 0.190 Nm of continuous force and torque in the translational and rotational DOF, respectively. The device possesses 18.1 and 5.7 Hz of force bandwidth in the translational and rotational DOF, respectively. A feedforward friction compensator was also successfully implemented to minimize the negative impact of friction during the interaction with the device. In this work, we have presented the detailed development and evaluation of the haptic device for the VTEST.

Ex vivo comparison of the lumen-apposing properties of EUS-specific stents (with video)

BACKGROUND AND AIMS

Several EUS-specific stents have become available. It has been claimed that some of these stents have lumen-apposing properties, but objective data measuring such properties are not available. The aim of this study is to measure the lumen-apposing force (LAF) of these stents.

METHODS

The LAF of 3 EUS-specific metallic stents (stents A, N, and S) were compared in an ex vivo setting. Four types of anastomoses were performed with the stents including cholecysto-duodenal, cholecysto-gastric, gastro-gastric, and gastro-jejunal and compared with a hand-sewn (HS) equivalent of the anastomosis. The outcome parameter was the LAF created by each type of stent.

RESULTS

Sixty-four anastomoses were created. The overall mean (standard deviation) LAFs were significantly higher for stents A and S (P < .001). This difference persisted regardless of the type of anastomosis: gastro-gastric (P = .002), gastro-jejunal (P = .005), cholecysto-gastric (P = .002), and cholecysto-jejunal (P = .003). The differences in LAF created by each type of stent across different types of anastomoses were also compared. A trend to significance was observed in the anastomoses created by stent N (P = .064) and stent A (P =.052); a significant difference in LAF was observed among different anastomoses created by stent S (P = .015). The LAF created by HS anastomosis was significantly higher than that for all stents across all anastomoses.

CONCLUSIONS

Stents A and S had a higher LAF. The use of these stents should be considered when performing EUS-guided transmural luminal anastomoses in non-adherent organs. Further studies are required to confirm the clinical efficacies of these EUS-specific stents.

A Response Surface Model Exploration of Dosing Strategies in Gastrointestinal Endoscopies Using Midazolam and Opioids

Classical midazolam-opioid combination for gastrointestinal endoscopy sedation has been adopted for decades. Dosing regimens have been studied but most require fixed dosing intervals. We intend to use a sophisticated pharmacodynamic tool, response surface model (RSM), to simulate sedation using different regimens. RSM can predict patient's response during different phases of the examination and predict patient's wake-up time with precision and without the need for fixed dosing intervals. We believe it will aid physicians in guiding their dosing strategy and timing.The study is divided into 2 parts. The first part is the full Greco RSMs development for 3 distinct phases: esophagogastroduodenoscopy (EGD), colonoscopy, and intersession (the time lapse between procedures). Observer's Assessment of Alertness Score (OAA/S) is used to assess patient response. The second part simulates 6 regimens with different characteristics using the RSMs: midazolam only, balanced midazolam and opioids, high-dose opioids and midazolam, low-dose midazolam with high-dose opioids, high-dose midazolam and low-dose opioids, and finally midazolam with continuous opioid infusion. Loss of response at 95% probability for adequate anesthesia during examination and return of consciousness at 50% probability during intersession was selected for simulation purposes.The average age of the patient population is 49.3 years. Mean BMI is 21.9 ± 2.3 kg/m. About 56.7% were females and none received prior abdominal surgery. The cecal intubation rate was 100%. Only 1 patient (3%) developed temporary hypoxemia, which was promptly managed with simple measures. The RSMs for each phase showed significant synergy between midazolam and alfentanil. The balanced midazolam and alfentanil combination provided adequate anesthesia and most rapid return of consciousness. The awakening time from the final drug bolus was 7.4 minutes during EGD and colonoscopy stimulation, and 9.1 minutes during EGD simulation.Simulation of regimens with different characteristics gives insights on dosing strategies. A balanced midazolam-alfentanil regimen is adequate in providing good anesthetic depth and most rapid return of consciousness. We believe with the aid of our RSM, clinicians can perform sedation with more flexibility and precision.

In-training gastrointestinal endoscopy competency assessment tools: Types of tools, validation and impact

The ability to perform endoscopy procedures safely, effectively and efficiently is a core element of gastroenterology practice. Training programs strive to ensure learners demonstrate sufficient competence to deliver high quality endoscopic care independently at completion of training. In-training assessments are an essential component of gastrointestinal endoscopy education, required to support training and optimize learner's capabilities. There are several approaches to in-training endoscopy assessment from direct observation of procedural skills to monitoring of surrogate measures of endoscopy skills such as procedural volume and quality metrics. This review outlines the current state of evidence as it pertains to in-training assessment of competency in performing gastrointestinal endoscopy as part of an overall endoscopy quality and skills training program.

Training and Assessment in Pediatric Endoscopy

A key aspect of pediatric gastroenterology practice is the ability to perform endoscopy procedures safely, effectively, and efficiently. Similar to adult endoscopy, performance of pediatric endoscopy requires the acquisition of related technical, cognitive, and integrative competencies to effectively diagnose and manage gastrointestinal disorders in children. However, the distinctive requirements of pediatric patients and their families and the differential spectrum of disease highlight the need for a pediatric-specific training curriculum and assessment framework to ensure endoscopic procedures are performed safely and successfully in children. This review outlines the current state of evidence as it pertains to pediatric endoscopy training and assessment.

Design of a New Haptic Interface for Endoscopy Simulation

This paper reports a novel haptic interface to provide haptic feedback during endoscopy simulation. The proposed haptic interface combines two independent mechanisms to provide two decoupled degrees-of-freedom in the translational and the rotational directions. Effects of the apparent inertia–mass and apparent friction to the user's hand are measured in the form of resistive force and torque. The forces and torques that can be manifested by the developed haptic interface are compared with the exerted force data during actual endoscopy.

Kinematic analysis of wrist motion during simulated colonoscopy in first-year gastroenterology fellows

BACKGROUND AND STUDY AIMS

Gastroenterology trainees acquire skill and proficiency in performing colonoscopies at different rates. The cause for heterogeneous competency among the trainees is unclear. Kinematic analysis of the wrist joint while performing colonoscopy can objectively assess the variation in wrist motion. Our objective was to test the hypothesis that the time spent by the trainees in extreme ranges of wrist motion will decrease as the trainees advance through the fellowship year.

SUBJECTS AND METHODS

Five first-year gastroenterology fellows were prospectively studied at four intervals while performing simulated colonoscopies. The setting was an endoscopy simulation laboratory at a tertiary care center. Kinematic assessment of wrist motion was done using a magnetic position/orientation tracker held in place by a custom-made arm sleeve and hand glove. The main outcome measure was time spent performing each of four ranges of wrist motion (mid, center, extreme, and out) for each wrist degree of freedom (pronation/supination, flexion/extension, and adduction/abduction).

RESULTS

There were no statistically significant differences in the time spent for wrist movements across the three degrees of freedom throughout the study period. However, fellows spent significantly less time in extreme range (1.47 ± 0.34 min vs. 2.44 ± 0.34 min, P = 0.004) and center range (1.02 ± 0.34 min vs 1.9 ± 0.34 min, P = 0.01) at the end of the study compared to the baseline evaluation. The study was limited by the small number of subjects and performance of colonoscopies on a simulator rather than live patients.

CONCLUSIONS

Gastroenterology trainees alter the time spent at the extreme range of wrist motion as they advance through training. Endoscopy training during the first 10 months of fellowship may have beneficial effects on learning ergonomically correct motion patterns.

Assessment of competence in pediatric gastrointestinal endoscopy

Gastrointestinal endoscopy is an invaluable tool for the diagnosis and treatment of upper and lower gastrointestinal diseases in children. Pediatric and adult endoscopy differ in several respects including differences in procedural indications, sedation practices, pre-procedure preparation, equipment, and the importance of routine tissue sampling and terminal ileum intubation. In the same way that performance of endoscopy in children requires pediatric-specific training, assessment of pediatric endoscopists requires an approach that is tailored to pediatric practice and the use of assessment methods and measures that have been developed and validated specifically within the pediatric context.

Review of musculoskeletal injuries and prevention in the endoscopy practitioner

Practitioners of endoscopy often experience musculoskeletal pain and injury (most often in the back, neck, shoulders, hands, wrists, and thumbs) that are associated with the minute and repetitive strain that is placed on these areas during endoscopic procedures. This review of the current documentation of endoscopy-related pain and injuries among practitioners finds that such problems are widespread and specific in kind as well as strongly correlated with high procedure volume and procedure duration. Research on the nature and impact of cumulative trauma and overuse syndromes in other professions such as dentistry, pianists, production labor, and athletics is brought to bear on the work of the endoscopist. A more thorough understanding of the nature and prevalence of work-related pain and injury sustained by endoscopists should inform further development of ergonomic practices and equipment design. This article reviews current recommendations for ergonomic design in the endoscopy procedure space and finds that reported compliance with those recommendations is quite low. Strategies for the management of the risk of musculoskeletal injuries related to the practice of endoscopy include compliance with currently recommended ergonomic practices, education of trainees in ergonomic technique when practicing endoscopy, and research toward the modification and development of more ergonomic endoscopes and procedure spaces.

Monitoring salivary amylase activity is useful for providing timely analgesia under sedation

AIM

To detect the criteria and cause of elevated salivary amylase activity (sAMY) in patients undergoing endoscopic submucosal dissection (ESD) under sedation.

METHODS

A total of 41 patients with early gastric cancer removed via ESD under deep sedation (DS) were enrolled. The perioperative sAMY, which was shown as sympathetic excitements (SE), was measured. The time at which a patient exhibited a relatively increased rate of sAMY compared with the preoperative baseline level (IR, %) ≥ 100% (twice the actual value) was assumed as the moment when the patient received SE. Among the 41 patients, we focused on 14 patients who exhibited an IR ≥ 100% at any time that was associated with sAMY elevation during ESD (H-group) and examined whether any particular endoscopic procedures can cause SE by simultaneously monitoring the sAMY level. If a patient demonstrated an elevated sAMY level above twice the baseline level, the endoscopic procedure was immediately stopped. In the impossible case of discontinuance, analgesic medicines were administered. This study was performed prospectively.

RESULTS

A total of 26 episodes of sAMY eruption were considered moments of SE in the H-group. The baseline level of sAMY significantly increased in association with an IR of > 100% at 5 min, with a significant difference (IR immediately before elevation/IR at elevation of sAMY = 8.72 ± 173/958 ± 1391%, P < 0.001). However, effective intervention decreased the elevated sAMY level immediately within only 5 min, with a significant difference (IR at sAMY elevation/immediately after intervention = 958 ± 1391/476 ± 1031, P < 0.001). The bispectral indices, systolic blood pressure and pulse rates, which were measured at the same time, remained stable throughout the ESD. Forceful endoscopic insertion or over insufflation was performed during 22 of the 26 episodes. Release of the gastric wall tension and/or the administration of analgesic medication resulted in the immediate recovery of the elevated sAMY level, independent of body movement.

CONCLUSION

By detecting twice the actual sAMY based on the preoperative level, the release of the gastric wall tension or the administration of analgesic agents should be considered.

Effect of propofol anesthesia on force application during colonoscopy

BACKGROUND

Sedation is frequently used during colonoscopy to control patient discomfort and pain. Propofol is associated with a deeper level of sedation than is a combination of a narcotic and sedative hypnotic and, therefore, may be associated with an increase in force applied to the colonoscope to advance and withdraw the instrument.

OBJECTIVE

To compare force application to the colonoscope insertion tube during propofol anesthesia and moderate sedation.

DESIGN

An observational cohort study of 13 expert and 12 trainee endoscopists performing colonoscopy in 114 patients. Forces were measured by using the colonoscopy force monitor, which is a wireless, handheld device that attaches to the insertion tube of the colonoscope.

SETTING

Community ambulatory surgery center and academic gastroenterology training programs.

PATIENTS

Patients undergoing routine screening or diagnostic colonoscopy with complete segment force recordings.

MAIN OUTCOME MEASUREMENTS

Axial and radial forces and examination time.

RESULTS

Axial and radial forces increase and examination time decreases significantly when propofol is used as the method of anesthesia.

LIMITATIONS

Small study, observational design, nonrandomized distribution of sedation type and experience level, different instrument type and effect of prototype device on insertion tube manipulation.

CONCLUSIONS

Propofol sedation is associated with a decrease in examination time and an increase in axial and radial forces used to advance the colonoscope.

Mechanical analysis of insertion problems and pain during colonoscopy: why highly skill-dependent colonoscopy routines are necessary in the first place... and how they may be avoided

BACKGROUND

Colonoscopy requires highly skill-dependent manoeuvres that demand a significant amount of training, and can cause considerable discomfort to patients, which increases the use of sedatives. Understanding the underlying fundamental mechanics behind insertion difficulties and pain during colonoscopy may help to simplify colonoscopy and reduce the required extent of training and reliance on sedatives.

METHODS

A literature search, anatomical studies, models of the colon and colonoscope, and bench tests were used to qualitatively analyze the fundamental mechanical causes of insertion difficulties and pain. A categorized review resulted in an overview of potential alternatives to current colonoscopes.

RESULTS

To advance a colonoscope through the colon, the colon wall, ligaments and peritoneum must be stretched, thus creating tension in the colon wall, which resists further wall deformation. This resistance forces the colonoscope to bend and follow the curves of the colon. The deformations that cause insertion difficulties and pain (necessitating the use of complex conventional manoeuvres) are the stretching of ligaments, and stretching of colon wall in the transverse and longitudinal directions, and the peritoneum.

CONCLUSIONS

Four fundamental mechanical solutions to prevent these deformations were extracted from the analysis. The current results may help in the development of new colonoscopy devices that reduce - or eliminate - the necessity of using highly skill-dependent manoeuvres, facilitate training and reduce the use of sedatives.

Evaluation of Feedback Enabled Active Colonoscopy Training Model

The objective of this research is to evaluate the efficacy of an active colonoscopy training model (ACTM). Colonoscopy is a widely utilized procedure for diagnosing diseases of the lower gastrointestinal tract. Since colonoscopy is a difficult procedure to teach, as well as learn, simulators are often used to teach and practice the procedure. To make learning and assessing the procedural skills easy and interactive, an active training model was developed and evaluated. To measure the applied force and the time to complete the procedure, load cells and light detecting sensors were installed in the training model and were interfaced with a data acquisition system. The user interface was programmed in LabVIEW to record the force data and time taken to complete the procedure. Thirty medical students were recruited to perform a series of three colonoscopies on the ACTM. These students were instructed how to handle the equipment and perform the colonoscopy. The procedure was also performed by experienced endoscopists to establish a benchmark. The collected data were analyzed to determine the effectiveness of the device to (1) distinguish between the participants based on their level of expertise, and (2) to detect improvement in skill of the students with repetitive sessions with the device. The results of this research may be useful to show that the ACTM may be an effective tool to integrate in to the medical training program of medical studies. It can be possibly used for evaluating the skill sets, as well as practicing the procedure before a novice surgeon performs the procedure on a patient.

Segmental increases in force application during colonoscope insertion: quantitative analysis using force monitoring technology

BACKGROUND

Colonoscopy is a frequently performed procedure that requires extensive training and a high skill level.

OBJECTIVE

Quantification of forces applied to the external portion of the colonoscope insertion tube during the insertion phase of colonoscopy.

DESIGN

Observational cohort study of 7 expert and 9 trainee endoscopists for analysis of colonic segment force application in 49 patients. Forces were measured by using the colonoscopy force monitor, which is a wireless, handheld device that attaches to the insertion tube of the colonoscope.

SETTING

Academic gastroenterology training programs.

PATIENTS

Patients undergoing routine screening or diagnostic colonoscopy with complete segment force recordings.

MAIN OUTCOME MEASUREMENTS

Axial and radial force and examination time.

RESULTS

Both axial and radial force increased significantly as the colonoscope was advanced from the rectum to the cecum. Analysis of variance demonstrated highly significant operator-independent differences between segments of the colon (zones) in all axial and radial forces except average torque. Expert and trainee endoscopists differed only in the magnitude of counterclockwise force, average push/pull force rate used, and examination time.

LIMITATIONS

Small study, observational design, effect of prototype device on insertion tube manipulation.

CONCLUSION

Axial and radial forces used to advance the colonoscope increase through the segments of the colon and are operator independent.

Construct validation of a physical model colonoscopy simulator

BACKGROUND

Previous studies have demonstrated the construct validity of virtual reality colonoscopy simulators by showing that they can distinguish between users according to their level of endoscopic experience. Although physical model simulators are known to simulate looping more realistically than these devices, they lack published validation evidence.

OBJECTIVE

To assess the construct validity of a physical model simulator, the Kyoto Kagaku Colonoscope Training Model (Kyoto Kagaku Co. Ltd, Kyoto, Japan) and to determine its suitability for assessing the insertion skill of trainee colonoscopists.

DESIGN

Validation study; 21 experienced colonoscopists and 18 novices made 2 attempts at each of 4 standard cases on the Kyoto Kagaku physical model simulator, and we compared their performance on each case.

SETTING

A medical simulation center in a large tertiary hospital.

MAIN OUTCOME MEASUREMENTS

Completion rates, times to cecum, and peak forces applied to the colon model.

RESULTS

Compared with novices, experienced colonoscopists had significantly higher completion to cecum rates and shorter times to cecum for each of the 4 cases (all P < .005). For 2 cases, experienced colonoscopists also exerted significantly lower peak forces than did novices (both P = .01).

LIMITATIONS

Two of the model's 6 "standard cases" were not included in the study.

CONCLUSIONS

The 4 cases included in the study have construct validity in that they can distinguish between the performance of experienced colonoscopists and novices, reproducing experienced/novice differences found in real colonoscopy. These cases can be used to validly assess the insertion skill of colonoscopy trainees.

Advanced technologies for gastrointestinal endoscopy

The gastrointestinal tract is home to some of the most deadly human diseases. Exacerbating the problem is the difficulty of accessing it for diagnosis or intervention and the concomitant patient discomfort. Flexible endoscopy has established itself as the method of choice and its diagnostic accuracy is high, but there remain technical limitations in modern scopes, and the procedure is poorly tolerated by patients, leading to low rates of compliance with screening guidelines. Although advancement in clinical endoscope design has been slow in recent years, a critical mass of enabling technologies is now paving the way for the next generation of gastrointestinal endoscopes. This review describes current endoscopes and provides an overview of innovative flexible scopes and wireless capsules that can enable painless endoscopy and/or enhanced diagnostic and therapeutic capabilities. We provide a perspective on the potential of these new technologies to address the limitations of current endoscopes in mass cancer screening and other contexts and thus to save many lives.

Does a fitted abdominal corset makes colonoscopy more tolerable?

BACKGROUND AND AIM

  The present study evaluated the usefulness of a fitted abdominal corset for colonoscopy, enabling proper compression of the abdomen during the entire examination.

METHODS

  Patients undergoing colonoscopy were subjected to either traditional methods or to using a fitted abdominal corset. Two hundred and sixteen patients were divided into two groups: group 1 (conventional colonoscopy) and group 2 (colonoscopy with abdominal corset). Cecal intubation rate and time need for manual compression and change of position were recorded. At the end of each colonoscopic examination, the patient evaluated pain by an 11-point visual analog scale from 0 to 10 (0: no pain, 10: worst pain).

RESULTS

  Cecal intubation time was shorter, the need for extra manual compression and change of position decreased and patients felt less pain during the procedure as denoted by lower visual analog scale scores in the group using a fitted abdominal corset, when compared to the group without a corset, in a statistically proven manner.

CONCLUSION

  Our data confirm the usefulness of the abdominal corset in decreasing the degree of patient pain and it makes colonoscopy easier and quicker with less manipulation, so we propose using a fitted abdominal corset during routine colonoscopic procedures.

Design and Evaluation of a Novel Haptic Interface for Endoscopic Simulation

Inspection of the colon with an endoscope for early signs of cancer (colonoscopy) has become an extremely widespread procedure, since early treatment radically improves the outlook of patients. The procedure requires a close coordination between the sense of touch and vision to navigate the endoscope along the colon. This raises the need to develop efficient training methods for physicians. Training simulators based on virtual reality, where realistic graphics are combined with a mechatronic system providing haptic feedback, are alternative to traditional training methods. To provide physicians with realistic haptic sensations of an endoscopic procedure, we have designed a haptic interface, instrumented a clinical endoscope and combined them with a simulation software for colonoscopy. In this contribution, we present the mechatronic components of the simulator. The haptic interface is able to generate high forces using the combination of electrical motors and brakes in a compact design. Experiments were performed to determine the characteristics of the device. A model-based control has been implemented and the results show that the control successfully compensates for the device nonlinearities, such as friction. The proposed haptic interface, together with the virtual reality, form a highly realistic training simulator for endoscopic surgeons, applicable not only to colonoscopy, but also to similar interventions.

Minimizing occupational hazards in endoscopy: personal protective equipment, radiation safety, and ergonomics

The ASGE Technology Committee provides reviews of existing, new, or emerging endoscopic technologies that have an impact on the practice of GI endoscopy. Evidence-based methodology is used, by using a MEDLINE literature search to identify pertinent clinical studies on the topic and a MAUDE (U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported complications of a given technology. Both are supplemented by accessing the "related articles" feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Controlled clinical trials are emphasized, but in many cases, data from randomized, controlled trials are lacking. In such cases, large case series, preliminary clinical studies, and expert opinions are used. Technical data are gathered from traditional and Web-based publications, proprietary publications, and informal communications with pertinent vendors. Technology Status Evaluation Reports are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the committee as a whole, and approved by the Governing Board of the ASGE. When financial guidance is indicated, the most recent coding data and list prices at the time of publication are provided. For this review, the MEDLINE database was searched through August 2009 for articles related to personal protection equipment by using the key words "personal protection equipment" (exp Protective Clothing/ or exp Protective Devices/ or exp Masks/ or exp Occupational Exposure/'') "infection control" paired with "Endoscopy." For the radiation section, the following key words were used: "radiation and endoscopy," "radiation and ERCP," and "radiation safety." For the ergonomics section, the following key words were used: "ergonomics of endoscopy," "endoscopist injury," "medical ergonomics," "endoscopy and musculoskeletal strain," "musculoskeletal injury and endoscopists," "occupational diseases and endoscopy," "cumulative trauma disorder and endoscopy," "repetitive strain injury and endoscopy." Technology Status Evaluation Reports are scientific reviews provided solely for educational and informational purposes. Technology Status Evaluation Reports are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

Characterization of forces applied by endoscopists during colonoscopy by using a wireless colonoscopy force monitor

BACKGROUND

To perform a colonoscopy, the endoscopist maneuvers the colonoscope through a series of loops by applying force to the insertion tube. Colonoscopy insertion techniques are operator dependent but have never been comprehensively quantified.

OBJECTIVE

To determine whether the Colonoscopy Force Monitor (CFM), a device that continually measures force applied to the insertion tube, can identify different force application patterns among experienced endoscopists.

DESIGN

Observational study of 6 experienced endoscopists performing routine diagnostic and therapeutic colonoscopy in 30 patients.

SETTING

Outpatient ambulatory endoscopy center.

PATIENTS

Adult male and female patients between 30 and 75 years of age undergoing routine colonoscopy.

INTERVENTIONS

CFM monitoring of force applied to the colonoscope insertion tube during colonoscopy.

MAIN OUTCOME MEASUREMENTS

Maximum and mean linear and torque force, time derivative of force, combined linear and torque vector force, and total manipulation time.

RESULTS

The CFM demonstrates differences among endoscopists for maximum and average push/pull and mean torque forces, time derivatives of force, combined push/torque force vector, and total manipulation time. Endoscopists could be grouped by force application patterns.

LIMITATIONS

Only experienced endoscopists using conscious sedation in the patients were studied. Sample size was 30 patients.

CONCLUSIONS

This study demonstrates that CFM allows continuous force monitoring, characterization, and display of similarities and differences in endoscopic technique. CFM has the potential to facilitate training by enabling trainees to assess, compare, and quantify their techniques and progress.

Minor adverse events of colonoscopy on ambulatory patients: the impact of moderate sedation

BACKGROUND

Minor complications in colonoscopy, such as pain, distension, headache, dizziness, etc. are an important cause for the rejection of colonoscopy procedure. Their incidence, however, has not been established.

OBJECTIVE

To determine minor complication rates in outpatient colonoscopy procedures and the effect of sedation on these complications.

PATIENTS

A prospective randomized cohort study was performed on 1250 adults selected randomly among patients referred to our endoscopy unit. Complications and undesirable affects related to the colonoscopy were reordered during the patients' stay in the endoscopy unit (early complications) and 30 days postprocedure (late complications).

RESULTS

One thousand one hundred and twenty-six patients were enrolled (mean age 50.43+/-13.7 years; 54.5% female), of which 875 (78%) were sedated and 251 (22%) were not. No difference between groups was observed. Thirty-one percent of the patients had early minor complications (25% among sedated patients; 52% of nonsedated patients; P<0.001 chi2); 23% had late minor complications (16% of sedated patients vs. 51% nonsedated patients; P<0.001 chi2). The most common undesirable effects were pain and abdominal distension. The risk of experiencing complications - odds ratio - was 1.013 times higher per year of age [confidence interval (CI) 95%: 1.004-1.022]; 1.953 times higher per increase in American Society of Anesthesiologists classification (95% CI: 1.524-2.504); and 0.116 times lower when sedation was used (95% CI: 0.079-0.170).

CONCLUSION

Minor complications of colonoscopy are common. Their incidence increases with age and American Society of Anesthesiologists class and decreases with the use of sedation.

Sightline ColonoSight system for a disposable, power-assisted, non-fiber-optic colonoscopy (with video)

BACKGROUND

The Sightline ColonoSight (CS) colonoscopy system presents 3 technologic advances: (1) disposable components protect the reusable parts from contact with colonic contents, eliminating the need for disinfection between procedures, (2) an air-pressure-powered engine assists in colonoscope advancement, (3) light emitting diode (LED) illumination eliminates the need for fiber optics and an external light source.

OBJECTIVES

To study the operation, performance, and safety of the Sightline CS colonoscopy system.

DESIGN

The system was tested during colonoscopy in animals and in human pilot studies. An in vitro dye diffusion test, and bacterial cultures (obtained after using the colonoscope in animals and humans) were performed to ascertain the protective integrity of the disposable components.

SETTING

Animal centers, hospitals in Israel and Italy, and office endoscopy centers in the United States.

PATIENTS

Thirty-three volunteers and 145 patients who required a colonoscopy for various indications.

INTERVENTIONS

Colonoscopy, polypectomy, biopsy, and coagulation.

MAIN OUTCOME MEASURES

Complications, system function, cecal intubation, and colonoscopy time.

RESULTS

The Sightline CS system performed well during a colonoscopy in 19 animals and 178 patients, without complications. Dye studies and bacterial cultures showed no transfer of dye molecules or bacterial organisms across the protective, disposable components.

LIMITATIONS

This is an observational pilot study, with no comparative group.

CONCLUSIONS

The new Sightline CS colonoscopy system performed well. The disposable components eliminated the need for disinfection of the colonoscope between procedures. Advancement of the colonoscope in the colon was helped by self propulsion of the instrument affected by an air-pressure-powered engine. LED illumination eliminated the need for fiber optics and an external light source.

Factors affecting abdominal pain during colonoscopy

OBJECTIVE

The actual degree of pain or discomfort experienced during colonoscopy varies between patients. This prospective study was conducted to determine what variables, apart from the endoscopist's skill, are associated with a patient's discomfort during this procedure.

DESIGN/METHODS

From December 2003 to September 2004, 646 colonoscopy examinations performed by three experienced endoscopists were analysed. Midazolam and meperidine were administered intravenously 10 min before the procedure. The degree of patient discomfort was assessed by asking more than five times during the procedure and by using a visual analogue pain scale (0-10) examined up to 7 days after the procedure. Patients were divided into sub-groups as follows: (1) comfortable group (n=304), no complaint during the procedure; and (2) uncomfortable group (n=342), more than one complaint during the procedure.

RESULTS

The correlation between the degree of patient discomfort and the results of the visual analogue pain scale was statistically significant (r2=0.118, P<0.01). Chi-squared analyses demonstrated that female gender, younger age (<or=40 years), presence of symptoms of inflammatory bowel syndrome, history of previous abdomino-pelvic surgery, poorer bowel preparation, longer insertion time (>480 s), technically difficult insertion, and lower body mass index (BMI) are factors associated with uncomfortable procedure. Multivariate analysis demonstrated that younger age, female gender, lower BMI, difficulty of examination, and previous gynaeco-pelvic surgery in female gender are independent factors associated with discomfort during colonoscopy.

CONCLUSIONS

An uncomfortable colonoscopic procedure will be expected in younger, female patients with a history of gynaeco-pelvic surgery.

Computer-assisted colonoscopy (the NeoGuide Endoscopy System): results of the first human clinical trial ("PACE study")

OBJECTIVES

Unsedated colonoscopy is an uncomfortable procedure for most patients. Discomfort during colonoscopy is largely related to looping of the colonoscope, which displaces the colon from its native configuration and stretches attachments to the mesentery. A novel computer-assisted colonoscope utilizes a fully articulated, computer-controlled insertion tube. On manual insertion of the colonoscope, the position and angle of the scope's tip are encoded into a computer algorithm. As the colonoscope is advanced, the computer directs each successive segment to take the same shape that the tip had at a given insertion depth. The insertion tube thus changes its shape at different insertion depths in a "follow-the-leader" manner.

METHODS

This initial clinical trial with this novel colonoscopy system was designed as a prospective, nonrandomized, unblinded, feasibility study. Three physicians of varying levels of experience participated in the study.

RESULTS

Eleven consecutive patients (seven men, four women, age range 19-80) meeting inclusion criteria for screening or diagnostic colonoscopy were enrolled in the study. The cecum was reached in 10 consecutive patients (100%). Findings included diverticular disease in two cases and multiple colonic polyps in two cases. Postprocedure assessment at discharge, 48 h, and 30 days revealed no complications or adverse effects. Physician satisfaction and patient acceptance of this new technique were high.

CONCLUSIONS

In this limited, first of its kind feasibility study, the computer-assisted colonoscope was shown to perform colonoscopy safely and effectively. The colonoscope's unique design limited loop formation during colonoscopy. Large-scale clinical trials are indicated.

Improved haptic interface for colonoscopy simulation

This paper presents an improved haptic interface of the KAIST-Ewha colonoscopy simulator II. The haptic interface enables the distal portion of the colonoscope to be freely bent while guaranteeing enough workspace and reflective forces for colonoscopy simulation. Its force-torque sensor measures profiles of the user. Manipulation of the colonoscope tip is monitored by four deflection sensors, and triggers computation to render accurate graphic images corresponding to the angle knob rotation. Tack switches are attached on the valve-actuation buttons of the colonoscope to simulate air-injection or suction, and the corresponding deformation of the colon.