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

Can single-use versus standard duodenoscope improve ergonomics in ERCP? A comparative, simulation-based pilot study

Background and study aims Musculoskeletal disorders (MSDs) and injuries (MSIs) are frequent in gastrointestinal endoscopy. The aim of this study was to assess potential ergonomic advantages of a lighter single-use duodenoscope compared with a standard reusable one for endoscopists performing endoscopic retrograde cholangiopancreatography (ERCP). Methods Three experienced endoscopists performed an ergonomic, preclinical, comparative protocol-guided simulation study of a single-use and a standard reusable duodenoscope using an anatomic bench model. Surface EMG signals from left forearm and arm muscles were recorded. A commercial inertial sensor-based motion capture system was applied to record body posture as well. Results A significant lowering of root mean square amplitude and amplitude distribution of biceps brachii signal (ranging from 13% to 42%) was recorded in all the participants when using a single-use duodenoscope compared with a reusable one. An overall reduction of muscle activation amplitude and duration was also associated with the single-use duodenoscope for forearm muscles, with different behaviors among subjects. Participants spent most of the time in wrist extension (> 80%) and ulnar deviation (> 65%). A consistent pattern of functional range of motion employed for completing all procedures was observed. Conclusions Our study showed that a lighter scope has a promising effect in reducing upper arm muscle activity during ERCP with potential benefit on musculoskeletal health in the ERCP setting.

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.

Methods for Gastrointestinal Endoscopy Quantification: A Focus on Hands and Fingers Kinematics

Gastrointestinal endoscopy is a complex procedure requiring the mastery of several competencies and skills. This procedure is in increasing demand, but there exist important management and ethical issues regarding the training of new endoscopists. Nowadays, this requires the direct involvement of real patients and a high chance of the endoscopists themselves suffering from musculoskeletal conditions. Colonoscopy quantification can be useful for improving these two issues. This paper reviews the literature regarding efforts to quantify gastrointestinal procedures and focuses on the capture of hand and finger kinematics. Current technologies to support the capture of data from hand and finger movements are analyzed and tested, considering smart gloves and vision-based solutions. Manus VR Prime II and Stretch Sense MoCap reveal the main problems with smart gloves related to the adaptation of the gloves to different hand sizes and comfortability. Regarding vision-based solutions, Vero Vicon cameras show the main problem in gastrointestinal procedure scenarios: occlusion. In both cases, calibration and data interoperability are also key issues that limit possible applications. In conclusion, new advances are needed to quantify hand and finger kinematics in an appropriate way to support further developments.

Autonomous navigation of a magnetic colonoscope using force sensing and a heuristic search algorithm

This paper presents an autonomous navigation system for cost-effective magnetic-assisted colonoscopy, employing force-based sensors, an actuator, a proportional-integrator controller and a real-time heuristic searching method. The force sensing system uses load cells installed between the robotic arm and external permanent magnets to derive attractive force data as the basis for real-time surgical safety monitoring and tracking information to navigate the disposable magnetic colonoscope. The average tracking accuracy on magnetic field navigator (MFN) platform in x-axis and y-axis are 1.14 ± 0.59 mm and 1.61 ± 0.45 mm, respectively, presented in mean error ± standard deviation. The average detectable radius of the tracking system is 15 cm. Three simulations of path planning algorithms are presented and the learning real-time A* (LRTA*) algorithm with our proposed directional heuristic evaluation design has the best performance. It takes 75 steps to complete the traveling in unknown synthetic colon map. By integrating the force-based sensing technology and LRTA* path planning algorithm, the average time required to complete autonomous navigation of a highly realistic colonoscopy training model on the MFN platform is 15 min 38 s and the intubation rate is 83.33%. All autonomous navigation experiments are completed without intervention by the operator.

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.

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.

Biomechanical paradigm and interpretation of female pelvic floor conditions before a treatment

BACKGROUND

Further progress in restoring a woman's health may be possible if a patient with a damaged pelvic floor could undergo medical imaging and biomechanical diagnostic tests. The results of such tests could contribute to the analysis of multiple treatment options and suggest the optimal one for that patient.

AIM

To develop a new approach for the biomechanical characterization of vaginal conditions, muscles, and connective tissues in the female pelvic floor.

METHODS

Vaginal tactile imaging (VTI) allows biomechanical assessment of the soft tissue along the entire length of the anterior, posterior, and lateral vaginal walls at rest, with manually applied deflection pressures and with muscle contraction, muscle relaxation, and Valsalva maneuver. VTI allows a large body of measurements to evaluate individual variations in tissue elasticity, support defects, as well as pelvic muscle function. Presuming that 1) the female pelvic floor organs are suspended by ligaments against which muscles contract to open or close the outlets and 2) damaged ligaments weaken the support and may reduce the force of muscle contraction, we made an attempt to characterize multiple pelvic floor structures from VTI data.

RESULTS

All of the 138 women enrolled in the study were successfully examined with the VTI. The study subjects have had normal pelvic support or pelvic organ prolapse (stages I-IV). The average age of this group of subjects was 60±15 years. We transposed a set of 31 VTI parameters into a quantitative characterization of pelvic muscles and ligamentous structures. Interpretation of the acquired VTI data for normal pelvic floor support and prolapse conditions is proposed based on biomechanical assessment of the functional anatomy.

CONCLUSION

Vaginal tactile imaging allows biomechanical characterization of female pelvic floor structures and tissues in vivo, which may help to optimize treatment of the diseased conditions such as prolapse, incontinence, atrophy, and some forms of pelvic pain.

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.

Sedation practice and comfort during colonoscopy: lessons learnt from a national screening programme

AIM

Medication may be used to manage discomfort during colonoscopy but practice varies. The relationship between medication use and comfort during colonoscopy was examined in the English Bowel Cancer Screening Programme.

METHODS

Data related to patient comfort and medication use from all 113,316 examinations performed within the English Bowel Cancer Screening Programme between 1 January 2010 and 31 December 2012 were analysed. Comfort was rated on the five-point Modified Gloucester Comfort Scale: 1, no discomfort; 5, severe discomfort. Scores of 4 and 5 were considered to indicate significant discomfort. Correlations between the proportion of examinations associated with significant discomfort and the amounts of medication used by colonoscopists were assessed using Spearman's ρ. Logistic regression modelling examined the independent predictors of significant discomfort.

RESULTS

Patients had a mean age of 65.7 years, and 58% were male. Examinations were performed by 290 endoscopists. In 91% of examinations, there was no significant discomfort reported during examination; however, there was considerable variation between individual colonoscopists (range 76.1-99.2%).Intravenous sedation and opiate analgesia were used during most examinations, but there was wide variation between colonoscopists, with a median (range) usage of 95.1% (4.1-100%) and 97.3% (5.6-100%), respectively. There was no association between the amount of sedation and analgesia used and significant discomfort (ρ<0.2). On multivariate analysis, significant discomfort was found to be more common among female individuals [odds ratio (OR)=2.0], on incomplete examinations (OR=6.7), and among patients with diverticulosis (OR=1.4).

CONCLUSION

There was wide variation in medication practice among English screening colonoscopists, but this was unrelated to the occurrence of significant discomfort.

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.

Modeling and in vitro experimental validation for kinetics of the colonoscope in colonoscopy

Colonoscopy is the most sensitive and specific means for detection of colon cancers and polyps. To make colonoscopy more effective several problems must be overcome including: pain associated with the procedure, the risk of perforation, and incomplete intubation colonoscopy. Technically, these problems are the result of loop formation during colonoscopy. Although, several solutions such as modifying the stiffness of the colonoscope, using an overtube and developing image-guided instruments have been introduced to resolve the looping problem, the results of these systems are not completely satisfactory. A new paradigm to overcome loop formation is proposed that is doctor-assistive colonoscopy. In this approach, the endoscopists performance is enhanced by providing using a kinetic model that provides information such as the shape of the scope, direction of the colon and forces exerted within certain sections. It is expected that with the help of this model, the endoscopist would be able to adjust the manipulation to avoid loop formation. In the present studies, the kinetic model is developed and validated using an ex vivo colonoscopy test-bed with a comprehensive kinematic and kinetic data collection. The model utilizes an established colon model based on animal tissue with position tracking sensors, contact force sensors for the intraluminal portion of the scope and a Colonoscopy Force Monitor for the external insertion tube.

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.