Movement Of Endoscope Research Articles

Experimental measurement on movement of spiral-type capsule endoscope.

Wireless capsule endoscope achieved great success, however, the maneuvering of wireless capsule endoscope is challenging at present. A magnetic driving instrument, including two bar magnets, a stepper motor, a motor driver, a motor controller, and a power supplier, was developed to generate rotational magnetic fields. Permanent magnet ring, magnetized as S and N poles radially and mounted spiral structure on the surface, acted as a capsule. The maximum torque passing to the capsule, rotational synchronization of capsule and motor, and the translational speed of capsule, were measured in ex vivo porcine large intestine. The experimental results illustrate that the rotational movement of the spiral-type capsule in the intestine is feasible and the cost of the magnetic driving equipment is low. As a result, the solution is promising in the future controllability.

Assessment of the endoscopic range of motion for head and neck surgery using the SOLOASSIST endoscope holder.

A 'third hand' is useful for holding the endoscope during surgery. The SOLOASSIST camera holder (AktorMed GmbH, Germany), which is used for abdominal surgery, is supposed to be modified for head and neck surgery. The aim of this study was to determine the intraoperative hand-held endoscopic range of motion for different surgical procedures and to define the required technical changes. The intraoperative movements of the hand-held endoscope during sinus surgery, rigid laryngoscopy, and lateral skull base surgery were measured and calculated. The endoscopic range of motion during surgery revealed diverse geometric bodies and volumes. For use in the ENT area, the system must be expanded by a manual release function for the driven axes and two additional lockable axes at the distal end of the arm. Intraoperative endoscopic range of motions in head and neck surgery are highly specific and, as expected, differ from the endoscopic movements in abdominal surgery.

Adaptive marker-free registration using a multiple point strategy for real-time and robust endoscope electromagnetic navigation

Registration of pre-clinical images to physical space is indispensable for computer-assisted endoscopic interventions in operating rooms. Electromagnetically navigated endoscopic interventions are increasingly performed at current diagnoses and treatments. Such interventions use an electromagnetic tracker with a miniature sensor that is usually attached at an endoscope distal tip to real time track endoscope movements in a pre-clinical image space. Spatial alignment between the electromagnetic tracker (or sensor) and pre-clinical images must be performed to navigate the endoscope to target regions. This paper proposes an adaptive marker-free registration method that uses a multiple point selection strategy. This method seeks to address an assumption that the endoscope is operated along the centerline of an intraluminal organ which is easily violated during interventions. We introduce an adaptive strategy that generates multiple points in terms of sensor measurements and endoscope tip center calibration. From these generated points, we adaptively choose the optimal point, which is the closest to its assigned the centerline of the hollow organ, to perform registration. The experimental results demonstrate that our proposed adaptive strategy significantly reduced the target registration error from 5.32 to 2.59 mm in static phantoms validation, as well as from at least 7.58mm to 4.71mm in dynamic phantom validation compared to current available methods.

Workspace and pivot point for robot-assisted endoscope guidance in functional endonasal sinus surgery (FESS).

For the further development of robot-assisted endoscope guidance in functional endoscopic sinus surgery (FESS), ground data about the workspaces and endoscope movements in conventional FESS are needed. Applying a self-developed marker-based tracking system, we collected the pose data (position and orientation) of the endoscope and all other instruments used in five real sinus surgeries. The automated segmentation of the endoscope poses shows the shape of a hourglass, with a pivot region or pivot point at the 'waistline' of the hourglass, close to the nasal entrance in the nasal dome. We were able to identify a pivot point at the waistline of the segmented endoscope poses. The size of the pivot point corresponds with the diameter of the 4 mm endoscope. Because of the reduction to four degrees of freedom for endoscope motions (three rotations and one translation), easier and safer robot-assisted endoscope guidance becomes feasible.

Endoscopic approaches to enteral feeding and nutrition core curriculum

Endoscopic approaches to enteral feeding and nutrition core curriculum

Computer Modeling of Skull Base Endoscopic Instrument Motion and Surgical Pathway Analysis

Computer Modeling of Skull Base Endoscopic Instrument Motion and Surgical Pathway Analysis

Controlling the Trajectory of a Flexible Ultrathin Endoscope for Fully Automated Bladder Surveillance

During cystoscopy, the urologist manually steers a cyst scope inside a patient's bladder to visually inspect the inner surface. Cystoscopies are performed as part of surveillance for bladder cancer, making it the most expensive cancer to treat over a patient's lifetime. An automated bladder scanning system has been devised to reduce workload and cost by relieving the urologist from performing surveillance. Presented here is a proof-of-concept apparatus that controls the motion of a miniature flexible endoscope. Image-based feedback is used to adjust the endoscope's movement so that captured images overlap with one another, ensuring that the entire inner surface of the bladder is imaged. Within a bladder phantom, the apparatus adaptively created and followed a spherical scan pattern comprised of 13 individual latitudes and 508 captured images, while accepting between 60% and 90% image overlap between adjacent images. The elapsed time and number of captured images were sensitive to the apparatus's placement within the phantom and the acceptable image overlap percentage range. A mosaic of captured images was generated to validate comprehensive surveillance. Overall, a robotically controlled endoscope used in conjunction with image-based feedback may permit fully automated and comprehensive bladder surveillance to be conducted without direct clinician oversight.

Sensor Arrangement Optimization of Wearable Model in Magnetic Localization System

A magnetic localization and orientation system is used to track the movement of the capsule endoscope during the gastrointestinal examination process. The system is made of a magnetic sensors array collecting the intensity of the magnetic field from a magnet in the capsule. In this paper, we try to optimize the sensor arrangement of wearable model that likes elliptical cylinder around the human body, to improve the tracking precision. Different sensor arrangement schemes are evaluated, and the tracking accuracy can be significantly increased with the appropriate arrangement. In addition, we presented a real time localization algorithm to compute uncertain 3D locus for estimating the tracing performance of the capsule.

Multi-view stereo and advanced navigation for transanal endoscopic microsurgery.

Transanal endoscopic microsurgery (TEM), i.e., the local excision of rectal carcinomas by way of a bimanual operating system with magnified binocular vision, is gaining acceptance in lieu of more radical total interventions. A major issue with this approach is the lack of information on submucosal anatomical structures. This paper presents an advanced navigation system, wherein the intraoperative 3D structure is stably estimated from multiple stereoscopic views. It is registered to a preoperatively acquired anatomical volume based on subject-specific priors. The endoscope motion is tracked based on the 3D scene and its field-of-view is visualised jointly with the preoperative information. Based on in vivo data, this paper demonstrates how the proposed navigation system provides intraoperative navigation for TEM1.

Enhanced differential evolution to combine optical mouse sensor with image structural patches for robust endoscopic navigation.

Endoscopic navigation generally integrates different modalities of sensory information in order to continuously locate an endoscope relative to suspicious tissues in the body during interventions. Current electromagnetic tracking techniques for endoscopic navigation have limited accuracy due to tissue deformation and magnetic field distortion. To avoid these limitations and improve the endoscopic localization accuracy, this paper proposes a new endoscopic navigation framework that uses an optical mouse sensor to measure the endoscope movements along its viewing direction. We then enhance the differential evolution algorithm by modifying its mutation operation. Based on the enhanced differential evolution method, these movement measurements and image structural patches in endoscopic videos are fused to accurately determine the endoscope position. An evaluation on a dynamic phantom demonstrated that our method provides a more accurate navigation framework. Compared to state-of-the-art methods, it improved the navigation accuracy from 2.4 to 1.6 mm and reduced the processing time from 2.8 to 0.9 seconds.

Endoscopic Submucosal Dissection Using the “Yo-Yo Technique”

BackgroundEndoscopic submucosal dissection (ESD) has been increasingly used for en bloc resection of gastrointestinal lesions. One of the main difficulties during ESD is to mobilize the partially resected lesion, leading to increased procedure time and complication rates. We developed a new “yo-yo technique”, that allows a fast, cheap and easy way for, not only pulling, but also pushing the lesion during ongoing ESD. AimsTo describe the feasibility and safety of the “yo-yo technique” for ESD. ProcedureAfter marking and lifting the lesion, incision and partial dissection are performed. Then, a hemoclip is placed in the already dissected edge of the lesion. Afterwards, a conventional snare is introduced through the nose into the stomach. Using a forceps, the hemoclip is grabbed with the snare. Due to the moderate stiffness of the snare, the edge of the lesion can be pulled or pushed during ongoing ESD, independently from the endoscope's movements. This increases the visualization of the dissection plane, reducing complications rate and procedure time. ResultsThe pull and push movements of the snare allow easier ESD with better access to the submucosal space and to the lesions' distal margins. Lesions can be successfully and safely removed and en block resection achieved using the “yoyo technique”. The presence of the hemoclip in the resected specimen permits a precise anatomopathological orientation. ConclusionThe “yo-yo technique” for ESD is feasible, cheap and safe allowing full mobilization of the lesion.

Robust Endoscope Motion Estimation Via an Animated Particle Filter for Electromagnetically Navigated Endoscopy

Electromagnetically navigated endoscopy, which is increasingly applied in endoscopic interventions, utilizes an electromagnetic sensor attached at the endoscope tip to measure the endoscope movements and to navigate the endoscope in the region of interest in the body. Due to patient motion and magnetic field distortion, sensor electromagnetic tracking (EMT) measurement inaccuracy and dynamic jitter errors remain challenging for electromagnetic navigation. This paper proposes a new tracking framework of an animated particle filter that integrates adaptive particle swarm optimization into a generic particle filter to significantly boost electromagnetic trackers. We validate our method on a dynamic phantom and compare it to state-of-the-art EMT methods. Our experimental results demonstrate the effectiveness and robustness of our method, which provides position and orientation accuracy of 2.48 mm, 4.69° that significantly outperformed previous methods at least with tracking error of 4.19 mm, 7.75°. The tracking smoothness was improved from 4.09 mm, 3.37° to 1.84 mm, 2.52°. Our method successfully tackled the particle impoverishment better than standard particle filters.

Externally Navigated Bronchoscopy Using 2-D Motion Sensors: Dynamic Phantom Validation

The paper presents a new endoscope motion tracking method that is based on a novel external endoscope tracking device and our modified stochastic optimization method for boosting endoscopy navigation. We designed a novel tracking prototype where a 2-D motion sensor was introduced to directly measure the insertion-retreat linear motion and also the rotation of the endoscope. With our developed stochastic optimization method, which embeds traceable particle swarm optimization in the Condensation algorithm, a full six degrees-of-freedom endoscope pose (position and orientation) can be recovered from 2-D motion sensor measurements. Experiments were performed on a dynamic bronchial phantom with maximal simulated respiratory motion around 24.0 mm. The experimental results demonstrate that our proposed method provides a promising endoscope motion tracking approach with more effective and robust performance than several current available tracking techniques. The average tracking accuracy of the position improved from 6.5 to 3.3 mm, which further approaches the clinical requirement of 2.0 mm in practice.

Real-time computed tomography-based augmented reality for natural orifice transluminal endoscopic surgery navigation

Natural orifice transluminal endoscopic surgery (NOTES) is technically challenging owing to endoscopic short-sighted visualization, excessive scope flexibility and lack of adequate instrumentation. Augmented reality may overcome these difficulties. This study tested whether an image registration system for NOTES procedures (IR-NOTES) can facilitate navigation. In three human cadavers 15 intra-abdominal organs were targeted endoscopically with and without IR-NOTES via both transgastric and transcolonic routes, by three endoscopists with different levels of expertise. Ease of navigation was evaluated objectively by kinematic analysis, and navigation complexity was determined by creating an organ access complexity score based on the same data. Without IR-NOTES, 21 (11·7 per cent) of 180 targets were not reached (expert endoscopist 3, advanced 7, intermediate 11), compared with one (1 per cent) of 90 with IR-NOTES (intermediate endoscopist) (P = 0·002). Endoscope movements were significantly less complex in eight of the 15 listed organs when using IR-NOTES. The most complex areas to access were the pelvis and left upper quadrant, independently of the access route. The most difficult organs to access were the spleen (5 failed attempts; 3 of 7 kinematic variables significantly improved) and rectum (4 failed attempts; 5 of 7 kinematic variables significantly improved). The time needed to access the rectum through a transgastric approach was 206·3 s without and 54·9 s with IR-NOTES (P = 0·027). The IR-NOTES system enhanced both navigation efficacy and ease of intra-abdominal NOTES exploration for operators of all levels. The system rendered some organs accessible to non-expert operators, thereby reducing one impediment to NOTES procedures.

Attitude control system combined with attitude controllable intelligent capsule endoscope for stomach examination

Objective To evaluate the applicable value of attitude control system combined with at- titude controllable intelligent capsule endoscope for stomach examination. Methods A total of 15 patients were recruited to the study. Manipulability of movement and posture change of capsule endoscope, diagnostic efficacy for such locations as gastric cavity, bulb and descending duodenum, image quality and patients＇ compliance were assessed. Results The procedure was completed in 14 patients. One failed due to downfall of the endoscope to duodenum within 5 min. Mean operation time was （23.7 ± 6. 5 ） min （from 5 to 30 min）. Ten cases of superficial gastritis, one case of superficial gastritis with bile regurgitation and 1 case of ulceration of the duodenal bulb were diagnosed. No abnormalities were found in 3 others. Endoscopic ima- ges were of high quality and only a few were influenced by gastrointestinal peristalsis. All patients showed compliance with no discomfort. Capsule endoscopes were discharged within 2 or 3 days. Conclusion Atti- tude control system combined with attitude controllable intelligent capsule endoscope in stomach examination is feasible and valuable in clinic. Key words: Capsule endoscopes; Attitude control; Non invasive; Stomach examination

Magnetic endoscopic imaging saves abdominal compression and patient pain in routine colonoscopies

Magnetic endoscope imaging (MEI) is a technique for the direct visualisation of endoscope configuration within the colon. This method may prevent loop formation by giving visual feedback of endoscope movement. This study aimed to evaluate the efficacy of MEI in improving colonoscopy performance. Overall 1000 consecutive patients who underwent a complete routine colonoscopy were randomized into two groups: in group A with MEI, while in group B without MEI. Sedation was performed according to local standards. In both groups time to reach the cecum, the number of positioning maneuvers and involvement of a second assistant nurse were recorded. Abdominal compression was graded from 1 to 4 according to the duration and intensity of compression was quantified using a scale from 1-3 according to compression form and patient reaction. Patients were randomized (group A with MEI, n = 490; group B without MEI, n = 510) and a total colonoscopy was performed. Time to cecal intubation did not differ between the groups (507 s vs 538 s; NS). The duration of abdominal compression was significantly shorter in MEI guided colonoscopy. The intensity of abdominal compression was lower in group A and fewer turn maneuvers needed per patient. A trend towards a reduced need for assistance in MEI group was seen. Although MEI does not generally accelerate colonoscope advancement, it significantly reduces the force and the duration of abdominal compression by assistant personnel, thus minimizing patient discomfort and decreasing the need for additional staff.

Head or Tail: The Orientation of the Small Bowel Capsule Endoscope Movement in the Small Bowel

The diagnostic accuracy of capsule endoscopy has been suggested to be influenced by the direction of the passage in the intestine. It is currently unknown if a head-first or a tail-first orientation are equally common during the descent through the small bowel. The aim of the study was to identify the orientation of the capsule along the migration through the small bowel. Thirty capsule endoscopies were reviewed by an experienced observer. The direction of the passage through the pylorus and the ileoceccal valve was recorded for all the examinations. In addition, detailed review of the passage of the capsule in different segments of the small bowel was undertaken for all the capsules. The capsule was significantly more likely to pass the pylorus head-first compared to tail-first (25 and 5 out of 30, respectively, OR 5, 95% CI 65-94%, P < 0.001). In 28/30 studies, the capsule exited the ileoceccal valve head-first (OR-14, 95% CI 77-99%, P < 0.001). In an immersion experiment, uneven distribution of weight of the capsule body was demonstrated with the head part (camera tip) being lighter than the tail part. The capsule endoscope usually passes through the pylorus and subsequent segments of the small bowel head-first. This observation suggests that the intestinal peristaltic physiology drives symmetrical bodies with their light part first. The principle of intestinal orientation by weight distribution may bear implications for capsules' design in the future.

A Technique with Manipulator‐Assisted Endoscope Guidance for Functional Endoscopic Sinus Surgery

The goal of this study was to examine the theoretical feasibility of a new manipulator system for endoscope guidance in functional endoscopic sinus surgery. The accuracy of endoscope positioning and time of endoscope movement with an endoscope manipulator system were determined with an artificial sinus model. A laboratory trial was performed. The time for 60 repetitions of manual compared to manipulator-assisted endoscope movements directed at 3 different target positions was evaluated. In addition, the alignment of the position vector for each endoscope movement was examined. A zero-degree Hopkins II telescope with a camera was used to head for the target positions. First, the endoscope movements were done manually, and afterward the endoscope manipulator system was used for endoscope guidance. The alignment of the position vector of the endoscope was measured with a portable measuring arm. There was no statistical difference between the time for manual and manipulator-assisted endoscope movements for all target positions. The alignment of the position vector of the endoscope was statistically different at 2 target positions: anterior ethmoid left side and ostium of maxillary sinus left side. There was no statistical difference at all other positions. The endoscope manipulator system has the potential to be integrated into the operating workflow without extending the time for endoscope guidance. The surgeon will be able to use both hands for the manipulation of the instruments. Less frequent endoscope movements and instrument changes may be expected after technical modification.

A Single Transgastric Access System for NOTES® Is Able to Perform Gastric Access, Gallbladder Resection, and Organ Retrieval

While the ability to safely create transgastric access has been widely reported, the feasibility of performing common peritoneal procedures with simple flexible endoscopic NOTES platform is critical to facilitating NOTES in humans. Aim: To assess the utility of a novel transgastric access system in facilitating access, dissection, and organ retrieval during a NOTES cholecystectomy. Methods: Under general anesthesia a dual channel colonoscope was inserted into the transgastric port included in the prototype access system (Apollo Endosurgery Inc.) and the instruments were advanced in unison into the stomach. The other system device, an over-the-wire gastrotomy dilation balloon, was then introduced into the 3.7 mm scope channel. A peg-like technique was used to orient the dilation balloon in the gastric wall where it was inflated to allow peritoneal access for the scope and overtube. Two cuffs (Peritoneal and gastric) on the port were then inflated to secure the device in the gastrotomy, and the transgastric port was temporarily connected to insufflation. A single 5mm laparoscopic grasper was used for traction while dissection of the gallbladder from the hepatic bed was conducted under endoscopic visualization and control using the electrocautery knife incorporated into the access system's dilation balloon. During dissection the balloon was used to provide precision saline irrigation and coagulation for the control of the minor bleeding encountered. Once dissection was completed an endoscopic polypectomy snare was used to retrieve the organ through the transgastric port. Results: The prototype transgastric peritoneal access system devices were used to create secure transgastric access successfully. The transgastric port enabled both the maintenance of the pneumoperitoneum and free endoscopic movement necessary to perform the cholecystectomy. With assistance from a single laparoscopic grasper the colonoscope and balloon's electrocautery knife were used to dissect approximately the gallbladder from the hepatic bed. The balloon features also effectively controlled the small vessel bleeding encountered. The transgastric access port served as the conduit for en bloc removal of the dissected organ. Conclusion: This prototype transgastric access system was capable of most functions necessary, with the exception of traction, for the dissection and removal of the gallbladder in the porcine model.

CT-based manual segmentation and evaluation of paranasal sinuses

Manual segmentation of computed tomography (CT) datasets was performed for robot-assisted endoscope movement during functional endoscopic sinus surgery (FESS). Segmented 3D models are needed for the robots' workspace definition. A total of 50 preselected CT datasets were each segmented in 150-200 coronal slices with 24 landmarks being set. Three different colors for segmentation represent diverse risk areas. Extension and volumetric measurements were performed. Three-dimensional reconstruction was generated after segmentation. Manual segmentation took 8-10 h for each CT dataset. The mean volumes were: right maxillary sinus 17.4 cm(3), left side 17.9 cm(3), right frontal sinus 4.2 cm(3), left side 4.0 cm(3), total frontal sinuses 7.9 cm(3), sphenoid sinus right side 5.3 cm(3), left side 5.5 cm(3), total sphenoid sinus volume 11.2 cm(3). Our manually segmented 3D-models present the patient's individual anatomy with a special focus on structures in danger according to the diverse colored risk areas. For safe robot assistance, the high-accuracy models represent an average of the population for anatomical variations, extension and volumetric measurements. They can be used as a database for automatic model-based segmentation. None of the segmentation methods so far described provide risk segmentation. The robot's maximum distance to the segmented border can be adjusted according to the differently colored areas.