Tip Of Endoscope Research Articles

Active constrained motion control for a robot-assisted endoscope manipulator in pediatric minimal access surgery.

Robot-assisted laparoscopic surgery has three main system requirements: safety, simplicity, and intuitiveness. However, accidental movement of the endoscope due to body fatigue and misunderstanding of the verbal orders between the surgeon and assistant will contribute to highly unexpected tool-tissue interactions, particularly in pediatric minimal access surgery with restricted working space. This study introduces a compact, lightweight endoscope manipulator with a mechanical remote-center-motion function. Using a custom-designed human-machine interface, the surgeon can intuitively control the movement of the endoscope manipulator over their view. In addition, an active constrained motion control algorithm is proposed to generate a forbidden-region constraint for avoiding collisions between the endoscope tip and surrounding organs in a pediatric abdominal cavity with restricted space. Simulations and experiments demonstrate the performance of the proposed compact endoscope manipulator and the active constrained surface tracking control scheme.

Flexible endoscope manipulating robot using quad-roller friction mechanism

A robotic system for manipulating a flexible endoscope in surgery can provide enhanced accuracy and usability compared to manual operation. However, previous studies require large-scale, complex hardware systems to implement the rotational and translational motions of the soft endoscope cable. The conventional control of the endoscope by actuating the endoscope handle also leads to undesired slack between the endoscope tip and the handle, which becomes more problematic with long endoscopes such as a colonoscope. This study proposes a compact quad-roller friction mechanism that enables rotational and translational motions triggered not from the endoscope handle but at the endoscope tip. Controlling two pairs of tilted rollers achieves both types of motion within a small space. The proposed system also introduces an unsynchronized motion strategy between the handle and tip parts to minimize the robot’s motion near the patient by employing the slack positively as a control index. Experiments indicate that the proposed system achieves accurate rotational and translational motions, and the unsynchronized control method reduces the total translational motion by up to 88% compared to the previous method.

Use of Snare Tip Endoscopic Submucosal Dissection in the Endoluminal Management of Complex Colon Lesions.

Endoscopic submucosal dissection for advanced colon lesions is typically performed with specialized and costly endoscopic knives, potentially limiting accessibility and increasing procedural cost. Alternatively, the tip of an endoscopic snare, which is inexpensive and universally available, has demonstrated safe and efficient use in gastric lesions but lacks sufficient data for use in colon lesions. This study aimed to assess patient outcomes following endoscopic submucosal dissection of advanced colon lesions using the endoscopic snare tip. A retrospective review of a prospectively maintained database at a single tertiary care center was conducted. This study was conducted at a single tertiary care center. Adult patients with colon lesions that were not amenable to snare polypectomy were evaluated for endoscopic submucosal dissection. Snare tip resection was performed in select patients with lesions that lifted adequately after submucosal injection. Patients who underwent hybrid resections with endoscopic mucosal dissection were excluded. En bloc resection rates, operative time, perioperative complications, and short-term outcomes such as length of stay and lesion recurrence on follow-up colonoscopy were evaluated. A total of 121 patients underwent snare tip endoscopic submucosal dissection, with a mean lesion size of 28.8 ± 9.84 mm. Most procedures were performed in the endoscopy suite (81.8%). The en bloc resection rate was 81.8% with an average procedure time of 37.1 ± 29.8 min. There were two perforations (1.70%), one of which was managed operatively. Recurrence occurred in 6 patients (7.89%) at the time of follow-up colonoscopy. This study was retrospective, conducted by two skilled endoscopists with experience in endoscopic resection, and had short-term follow up. Snare tip endoscopic submucosal dissection for advanced colon lesions demonstrates satisfactory short-term outcomes, suggesting its potential as a safe and accessible alternative to specialized knives, thereby possibly enhancing adoption of endoscopic resection and improving patient accessibility. See Video Abstract.

Validation and efficacy of the Varix Trainer model as a Training device for esophagogastroduodenoscopy.

Background and study aims The Varix Trainer model 1 (VTM1) was created for trainees to safely practice basic endoscope manipulation skills. The VTM1 was tested to see if it could distinguish levels of endoscope manipulation skills (construct validity) and whether training with it could improve these skills faster (content validity). Patients and methods We enrolled 23 novice endoscopists, 18 second-year trainees, and 13 expert endoscopists. They were asked to point with the endoscope tip to 20 numbers in the model as quickly as possible using torque, single-hand small/large wheel manipulation (SHSW), and retroflexion techniques. Their mean times (t20) were compared to determine if the model could distinguish different levels of expertise. Subsequently, 14 novices trained for eight short sessions, and the pre-training and post-training t20 were compared. Nine novice endoscopists received no training and were retested after 4 to 6 weeks (controls). Results Experts had faster t20 than second-year trainees, who were faster than novices, for all three techniques ( P < 0.001). After eight sessions, the mean t20 for novices improved from 112 to 66 seconds for torque, 144 to 72 seconds for SHSW, and 108 to 63 seconds for retroflexion, (all P < 0.001). Their t20 were equivalent to second-year trainees. Improvement in t20 was also seen with the control group, but total reduction was less than for the training group. Conclusions The VTM1 distinguished varying levels of expertise for all techniques, suggesting that it is a valid tool for assessing endoscope manipulation skill. A short curriculum improved novices' manipulation skills faster than traditional practice.

Validation of a White Light and Fluorescence Augmented Panoramic Endoscopic Imaging System on a Bimodal Bladder Wall Experimental Model

Background: Fluorescence visualization of pathologies, primarily neoplasms in human internal cavities, is one of the most popular forms of diagnostics during endoscopic examination in medical practice. Currently, visualization can be performed in the augmented reality mode, which allows to observe areas of increased fluorescence directly on top of a usual color image. Another no less informative form of endoscopic visualization in the future can be mapping (creating a mosaic) of the acquired image sequence into a single map covering the area under study. The originality of the present contribution lies in the development of a new 3D bimodal experimental bladder model and its validation as an appropriate phantom for testing the combination of bimodal cystoscopy and image mosaicking. Methods: An original 3D real bladder-based phantom (physical model) including cancer-like fluorescent foci was developed and used to validate the combination of (i) a simultaneous white light and fluorescence cystoscopy imager with augmented reality mode and (ii) an image mosaicking algorithm superimposing both information. Results: Simultaneous registration and real-time visualization of a color image as a reference and a black-and-white fluorescence image with an overlay of the two images was made possible. The panoramic image build allowed to precisely visualize the relative location of the five fluorescent foci along the trajectory of the endoscope tip. Conclusions: The method has broad prospects and opportunities for further developments in bimodal endoscopy instrumentation and automatic image mosaicking.

An EM-Tracked Approach for Calibrating the 3D Pose of Flexible Endoscopes.

Flexible endoscopes are ideal instruments for visualizing and diagnosing the inner surfaces of organs via a minimally invasive incision. Calibrating a flexible endoscope is a troublesome yet inevitable process in image-based tools tracking. Aiming to simplify the calibration process, we propose an electromagnetic (EM)-tracked calibration approach that does not require any predefined poses of the EM sensor. A three-stage calibration protocol was presented in an extensor. First, the orientation of the endoscope tube was derived by conducting a circular rotation of the endoscope around its axis utilizing a pair of tightly bearing stands. Second, the 3D position of the endoscope tip was acquired by having the tip come into contact with a flat plane. Third, the pose model of the bending section was derived and transformed into the local coordinate system of the EM sensor attached to the endoscope handle. To assess the accuracy of the proposed calibration approach, two experiments were designed and performed. Experimental results indicate accuracies of 0.09 ± 0.06 deg and 0.03 ± 0.19 deg in the estimation of the endoscope tube orientation and 0.52 ± 0.29, 0.33 ± 0.11, and 0.29 ± 0.17 mm in the x,y, and z estimations of the endoscope tip position, respectively. The proposed approach is accurate and easy to operate, does not require the employment of custom calibration markers, and can be used not only in surgical training systems but also in the endoscopic-based tools tracking.

Effective hemostasis under gel immersion endoscopy using inflated balloons on the tip of double balloon endoscope for active bleeding in the small intestine.

Effective hemostasis under gel immersion endoscopy using inflated balloons on the tip of double balloon endoscope for active bleeding in the small intestine.

Specialist consensus of continuous irrigating mode of endoscopic ear surgery

Continuous irrigating mode of endoscopic ear surgery（CIM-EES） solves some pain points and difficulties in the operation of otoscopic surgery to a certain extent, including easily fogging of the endoscopic tip and hemorrhage during the endoscopic operation. In order to illustrate useful information of CIM-EES, including its core conception,generation background, practical operation specification, indications and contraidictions of the mode as well as technical advantages and existing problems, the National Standardized Training and Promotion Collaborative Group for Endoscopic Ear Surgery, in collaboration with otologists nationwide, have discussed and formulated this consensus of CIM-EES.

Assisted teleoperation control of robotic endoscope with visual feedback for nasotracheal intubation

Endoscopic operation is one of the most difficult parts of nasotracheal intubation (NTI), a surgical procedure used to secure the airway of a patient. Due to the requirement of eye–hand coordination, manual operation of a flexible endoscope is challenging, even for an experienced surgeon. To enhance intubation efficiency, this paper developed a master–slave robotic nasotracheal intubation system (RNIS) for endoscopic operation. Movements in three degrees of freedom of the endoscope are controlled by the RNIS. An assisted teleoperation control strategy is designed to assist the operator in remotely controlling the pose, i.e., position and orientation, of the endoscope tip via a joystick. To ensure the efficiency of intubation, visual feedback assistance is hereby proposed, which fine-tunes the orientation of the endoscope tip as needed. The proposed system and methods are experimentally validated on a motion simulator and a phantom. The results demonstrated that the master–slave RNIS can successfully insert the flexible endoscope into the trachea of a phantom through the nasal cavity.

In vitro comparison of simulated intrapelvic pressure in an artificial kidney model during retrograde intrarenal surgery among various single-use ureteroscopes.

This study compares intrapelvic pressure (IPP) during retrograde intrarenal surgery with various single-use flexible ureteroscopes (f-URS) in an artificial kidney model. We created an artificial kidney model with a pressure sensor using a bladder evacuation device. The model was completely closed and the only backflow was on the side of the ureteroscope inside the ureteral access sheath (UAS). We tested five single-use f-URSs (LithoVue, Wiscope, PU3022A, PU3033A, and AXIS) with six different types of UAS (9.5/11.5-14/16 Fr). Using the automatic irrigation system, 30 s of irrigation was performed at various pressures (40-180 mmHg) and steady-state IPP was recorded. IPP was compared between the five single-use f-URSs. IPP cutoff value was determined at 30 mmHg. The diameter of the endoscope tip and the curved and shaft parts were also measured and recorded. The diameters of all parts were significantly different between single-use f-URSs. The maximum IPP tended to be higher in ureteroscopes with larger diameters of the proximal parts (curved part/shaft part). In LithoVue and Uscope PU3022A f-URSs, the maximum IPP did not exceed 30 mmHg when UAS ≥12/14 Fr was used. In AXIS and Wiscope f-URSs, it did not exceed the cutoff value when the UAS ≥11/13 Fr was used. In Uscope PU3033A f-URS, it did not exceed 30 mmHg when the UAS ≥10/12 Fr was used. Maximum IPP tended to be higher in f-URSs with larger diameters of the proximal part and the appropriate size of the UAS differed between various single-use f-URSs.

Nodular regenerative hyperplasia and liver transplantation: a systematic review.

Nodular regenerative hyperplasia (NRH) is a primary disease of the liver that may cause noncirrhotic portal hypertension. Common causes include autoimmune, hematologic, immune deficiency, and myeloproliferative disorders. Given the limited data regarding the development of NRH in contemporary immunosuppressive protocols and the occurrence of NRH post-liver transplantation, we systematically reviewed NRH as it pertains to liver transplantation. We performed a comprehensive search for NRH and transplantation. Nineteen studies were identified with relevant data for NRH as an indication for a liver transplant. Thirteen studies were identified with relevant data pertaining to NRH development after liver transplant. Pooled analysis revealed 0.9% of liver transplant recipients had NRH. A total of 113 patients identified with NRH underwent liver transplantation. Most series report transplants done after the failure of endoscopic banding and TIPS management of portal hypertension. Reported 5-year graft and patient survival ranged from 73%-78% and 73%-90%. The pooled incidence of NRH after liver transplant for all indications was 2.9% and caused complications of portal hypertension. Complications related to portal hypertension secondary to NRH are a rare indication for a liver transplant. NRH can develop at any time after liver transplantation often without an identifiable cause, which may lead to portal hypertension requiring treatment or even re-transplantation.

Actively shielded capacitive proximity sensor for endoscopy

Abstract Flexible endoscopes are widely used for diagnostic and therapeutic procedures on internal organs and tissue surfaces. Accurate positioning of the endoscope tip is critical for obtaining clear images and avoiding tissue damage. Proximity sensors can provide information about the distance to the surrounding tissue, which can help align the endoscope tip and navigate along curved paths. This paper presents a method of proximity measurement using capacitive sensors with active shielding to determine the radial distance between an endoscope and surrounding tissue. The capacitive sensor consists of four copper foil electrodes attached to a 9.5 mm diameter ring. Two different active shielding designs were investigated and compared to reduce the sensing angle and minimize lateral effects. Capacitance was measured as a function of distance using a linear stage. A MATLAB script controlled the linear stage and calculated the distance from the measured capacitance. The results showed that advanced active shielding could be useful to reduce the sensing angle (angular space where capacitance sensor detects capacitance changes.). This method provides a cost-effective solution for radial distance measurement in endoscopy, essential for improving diagnostic and therapeutic procedures.

Closed-loop robust control of robotic flexible endoscopy with neural network-based lumen segmentation

Accurate positioning of the flexible endoscope during clinical procedures is critical for the visualization and success of surgical interventions. However, manual operation of the endoscope is challenging, especially for less-experienced users, due to visual reasoning and hand-eye coordination requirements. To achieve automatic steering of the endoscope, this work proposes a closed-loop robust control method that allows the endoscope to smoothly travel along the upper respiratory tract. First, an attention neural network is introduced to segment the lumen region in endoscopic images, which indicates the moving direction of the endoscope. The segmentation results are optimized by convolutional conditional random field (ConvCRF). In addition, to steer the flexible endoscope, an active disturbance rejection control (ADRC) strategy is proposed to adjust the orientation of the endoscope tip. An external state observer (ESO) is designed to estimate environmental disturbances, enabling the controller to compensate for the positioning error. Finally, the segmentation method achieved the mIOU, accuracy, and Dice values of 85.4%, 97.5%, and 91.4%, respectively, outperforming state-of-the-art methods. The performance of the controller was validated on a real robot showing the ability to automatically steer the flexible endoscope along the upper respiratory tract.

Efficacy of cap-assisted endoscopy for the visualization of the major duodenal papilla: a systematic review and meta-analysis

The current standard of practice is to use a duodenoscope for the evaluation of the major duodenal papilla (MDP). Recently, cap-assisted endoscopy (CAE), which uses a transparent cap at the tip of a standard front-viewing endoscope, has emerged as an alternative. A systematic literature search was performed in several databases from inception to January 2023 to identify studies evaluating the efficacy of CAE for the evaluation of the MDP. Nine studies including 806 patients met our inclusion criteria. The pooled rate of technical success for CAE was 93.2% (95% confidence interval, 85.6-96.9; I2= 84.6%). A subgroup analysis comparing CAE with a standard endoscope showed higher odds for the evaluation of the MDP with CAE (but not a duodenoscope, which was better than CAE) with an odds ratio of 57.294 (95% confidence interval, 17.767-184.755; I2= 45.303%). CAE offers a significant advantage with high rates of complete MDP evaluation compared with standard forward-viewing endoscopy. However, CAE is associated with lower rates of success when compared with side-viewing endoscopes.

Underwater cap-suction pseudopolyp formation for endoscopic mucosal resection: a simple technique for treating flat, appendiceal orifice or ileocecal valve colorectal lesions.

We aimed to evaluate the safety and technical success of an easy-to-use technique that applies underwater cap suction pseudopolyp formation to facilitate the resection of flat lesions or those at the appendiceal orifice or ileocecal valve. We retrospectively analyzed a register of consecutive cap suction underwater endoscopic mucosal resection (CAP-UEMR) procedures performed at two centers between September 2020 and December 2021. Procedures were performed using a cone-shaped cap, extending 7 mm from the endoscope tip, to suction the lesion while submerged underwater, followed by underwater snare resection. Our primary end point was technical success, defined as macroscopic complete resection. We treated 83 lesions (median size 20 mm; interquartile range [IQR] 15-30 mm) with CAP-UEMR: 64 depressed or flat lesions (18 previously manipulated, 9 with difficult access), 11 from the appendix, and 8 from the ileocecal valve. Technical success was 100 %. There were seven intraprocedural bleedings and two delayed bleedings, all managed endoscopically. No perforations or other complications occurred. Among the 64 lesions with follow-up colonoscopy, only one recurrence was detected, which was treated endoscopically. CAP-UEMR was a safe and effective technique for removing nonpolypoid colorectal lesions, including those arising from the appendiceal orifice or ileocecal valve.

Development and application of a spray tip that enables electrocoagulation of a variety of tissues

BackgroundSpray hemostasis is possible using a high-frequency power source from the tip of an electric scalpel; however, the difficulties regarding the uniformity and rapidity of the hemostasis surface remain. This study reports the development of a novel electrocoagulation device tip that can be used in endoscopic and robotic surgeries and can quickly coagulate and hemostat and easily adjust the extent of cauterization and hemostasis while minimizing the depth of thermal injury. MethodsThe safety and efficacy of the hemostatic device were verified in a porcine model. A liver surface transection was conducted in vivo and the rapidity of the hemostatic effect of the device was observed. An extracted stomach, kidney, and liver were cauterized ex vivo by three operators with different surgical skills and the effects were analyzed pathologically. In addition, a sacrificed pig cadaver was used to achieve hemostasis at a renal transection site using the multi-spray endoscope tip. ResultsAn increase in the number of tip terminals expanded the cauterization surface and shortened the cauterization time. In parenchymatous organs, uniform cauterization was possible without increasing the depth of thermal injury. The cauterization depth did not depend on the operator's skill, and the spray coagulation was safe. The variable spray tip allowed for simple hemostasis during open and laparoscopic surgeries. ConclusionsThis novel electrocoagulation device tip can be developed as a forceps that can change the spray range and can be used during laparoscopic and robotic surgeries.

Usefulness of a newly developed endoscope for the observation of the posterior tracheal wall.

Videoendoscopic evaluation of swallowing is an objective swallowing function evaluation method used in dysphagia rehabilitation. However, it is anatomically difficult to detect the entry of foreign substances through the posterior tracheal wall using a conventional endoscope (CE). In this study, we developed an endoscope that can observe the posterior tracheal wall and investigated its reliability and validity in healthy adults. Twenty healthy adults were included. The trachea was observed from inside the larynx using a CE and a portable, flexible two-step angulation endoscope (two-AE) with a two-step curved shaft tip. The visibility of the anterior and posterior walls was recorded. The time from the endoscope tip entering the larynx to the posterior tracheal wall was measured. Additionally, discomfort events were assessed after the examination. McNemar's test and a paired t-test were used for statistical analysis. Kappa coefficients and concordance rates were calculated. The anterior tracheal wall was observed using both endoscopes. The posterior tracheal wall was significantly observed in 18 participants with the two-AE (p < .001), compared to only three of 20 participants with the CE. The time to observation of the posterior tracheal wall for examiners 1 and 2 was 13.3 ± 6.5 and 12.0 ± 6.7 s, respectively, with no difference between groups (p = .400). The kappa coefficients of examiners 1 and 2 and between the examiners were 0.444, 0.643, and 0.643, respectively, with concordance rates of 90%, 95%, and 95%, respectively. Regardless of the examiner's years of experience, we observed that the two-AE could observe the posterior tracheal wall. Step 5.

Automatic endoscopic navigation based on attention-based network for Nasotracheal Intubation

Nasotracheal intubation (NTI) is one of the most commonly performed procedures in anesthesia and is considered the gold standard for securing the airway of patients. Endoscope operation is critical to the success of NTI. However, this operation remains challenging as it requires the surgeon to classify anatomical landmarks and detect heading targets of the endoscope tip in a sequence of monocular images. To alleviate this problem, this study presents a learning-based navigation method that automatically classifies four different anatomical landmarks and detects the heading target of the endoscope tip from endoscopic images. First, an end-to-end multitask network is introduced that consists of a branch for anatomical landmark classification and another for heading target detection. In addition, a convolutional attention module is designed to improve network performance by combining spatial and channel attention. Second, an endoscopic dataset named intuNav is built for network training. The trained network calculates navigation information without image prior knowledge. Finally, extensive experiments on the built dataset and endoscopic videos demonstrate the high performance of our method, achieving classification (94%) and detection (79.4%) accuracies. The results also indicate that the proposed method is effective and efficient in navigation generation during NTI.

The role of endosonography in cardiology: case series and literature review.

Endosonography (EUS) is the diagnostic tool with the highest resolution for the local staging of gastrointestinal tumours and, due to the detailed visualization of the wall layers, is recommended in current guidelines for cancer management. In addition, an endoscope has an ultrasound tip design and balloon insufflation control design, and a 120° bending mechanism to deflect the endoscope tip. These advantages could be beneficial and valuable while investigating the cardiovascular structures during routine gastrointestinal procedures using this diagnostic tool. We present six cases of incidentally diagnosed cardiac pathologies (pulmonary thromboembolism of the main pulmonary artery, patent foramen oval with right to left shunt under Valsalva, left atrial appendage thrombus, aortic dissection, moderate aortic valve stenosis, mitral and aortic valve endocarditis) during routine gastrointestinal endosonographic procedures. These diagnoses influenced changes in management strategies in four cases. The introduction of EUS in cardiovascular medicine allows for a real-time high-resolution assessment of cardiovascular structures and allows early detection of silent cardiac pathologies during routine gastrointestinal procedures. It is the diagnostic tool with the highest resolution for accurate definition of variable gastrointestinal anatomy. Thus, help for accurate definitions of cardiovascular anatomy and pathology, which could influence optimal management strategies with improved safety, efficacy, and economic outcomes.

Adaptive Control of a Master-Slave Based Robotic Surgical System With Haptic Feedback

A master-slave (M-S) based robotic surgical system with haptic feedback is presented in this work for natural orifice transluminal endoscopic surgery (NOTES) using an in-vivo robot. A novel dual-loop control, including closed-loop inverse kinematics (CLIK) and adaptive control with optimal control parameters, is developed for the slave robot to track a random trajectory upon updating the dynamic parameters of the slave robot. The interaction between the slave robot tip position and environment is controlled by an impedance controller that prevents damage to healthy tissues. Upon tracking a given desired 3D trajectory as input for the slave robot by the human operator handling the master robot, the slave robot-tissue interaction force is sensed as haptic feedback at the master side. Lyapunov direct method based stability analysis and performance evaluations involving both simulation and experimental studies prove the efficacy of our novelly developed M-S robotic system aiming NOTES regulated by the proposed adaptive control strategy with optimized control parameters. Note to Practitioners: The M-S based robotic surgical system is developed to perform NOTES using a cable-driven in-vivo robot attached to the tip of a flexible endoscope. It performs tissue manipulation as per the direction given by the operator. The inclusion of haptic imitates the NOTES performed using the in-vivo robot as conventional surgery. The developed system includes the following aspects: a) The adaptive control scheme with optimal control parameters; b) Interaction force between the slave robot and tissue environment is controlled using impedance control and given as haptic feedback to the surgeon; c) The proposed system can be potentially utilized for actual teleoperated surgery and surgical training for NOTES.