Conventional Flexible Endoscope Research Articles

Flexible Chip-on-the-tip-Endoskopie zur Larynxdiagnostik

Laryngoscopic procedures can be performed either with rigid or with flexible endoscopes (FE). While the benefit of FEs is a better reflection of the physiological situation, rigid endoscopes (RE) usually offer better image quality. Modern flexible 'chip-on-the-tip' endoscopes promise to combine the advantages of both procedures. A total of 38 patients with dysphonia were examined with RE, conventional FE, and"chip-on-the-tip" endoscopes (TCE). Image quality was assessed and compared and procedures were evaluated with regard to patient contentment. In all cases image quality of TCE and RE was better than conventional FE. In 55% of cases image quality of TCE and RE was comparable, in 24% RE was judged to be better and in 21% TCE was better. Patient contentment was higher for FE in comparison with RE. 'Chip-on-the-tip' endoscopes combine the advantages of both RE and FE with respect to a physiological examination and high image quality.

A paddling based locomotive mechanism for capsule endoscopes

Diagnosis and treatment using the conventional flexible endoscope in gastro-intestinal tract are very common since advanced and instrumented endoscopes allow diagnosis and treatment by introducing the human body through natural orifices. However, the operation of endoscope is very labor intensive work and gives patients some pains. As an alternative, therefore, the capsule endoscope is developed for the diagnosis of digestive organs. Although the capsule endoscope has conveniences for diagnosis, it is passively moved by the peristaltic waves of gastro-intestinal tract and thus has some limitations for doctor to get the image of the organ and to diagnose more thoroughly. As a solution of these problems, various locomotive mechanisms for capsule endoscopes are introduced. In our proposed mechanism, the capsule-type microrobot has synchronized multiple legs that are actuated by a linear actuator and two mobile cylinders inside of the capsule. For the feasibility test of the proposed microrobot, a series of in-vitro experiments using small intestine without incision were carried out. From the experimental results, our proposed microrobot can advance along the 3D curved and sloped path with the velocity of about 3.29–6.26 mm/sec and 35.1–66.7% of theoretical velocity. Finally, the proposed locomotive mechanism can be not only applicable to micro capsule endoscopes but also effective to advance inside of gastro-intestinal tract.

Removal of a foreign body from the upper gastrointestinal tract with a flexible endoscope: a prospective study.

There have so far been no prospective studies on the value of flexible endoscopy for removing foreign bodies in the upper gastrointestinal tract. This study presents a clinical analysis of accidents with foreign bodies and prospectively evaluates the effectiveness of flexible endoscopy for removing them. A total of 105 cases of foreign-body ingestion in the upper gastrointestinal tract were evaluated, 29 (27.6 %) in children and 76 (72.4 %) in adults. Thirty patients (28.5 %) had esophageal strictures. Thirty-nine of the foreign bodies (37.1 %) consisted of food and 66 (62.9 %) were not food-related. The success rate of foreign-body extraction using only a conventional flexible endoscope and accessories for treatment was 98.0 %, and with only a polypectomy snare and rat-toothed forceps it was 91.2 %. Complications at the moment of foreign-body removal occurred in nine patients (8.6 %); there was only one (1 %) esophageal perforation. The incidence of complications related to the duration of foreign-body impaction was six (10.5 %) with foreign bodies impacted for up to 24 h, 13 (52.0 %) for those impacted for 24-48 h, and three (60.0 %) for those impacted for 48-72 h ( P < 0.05). The flexible endoscope is an effective and safe device for removing foreign bodies from the upper gastrointestinal tract, with a high success rate using only the polypectomy snare and the rat-toothed forceps as accessories. If foreign-body impaction lasts for more than 24 h, there is a significant increase in the incidence of complications.

Force Transmission at Flexible Endoscopy with Conventional Endoscopes and Shape Locking Endoscope Guide Catheter

Background: A major limitation to the development of flexible endoscopic surgery is the limitation of force, which can be exerted on needles, catheters and endosurgical surgical instruments in a forwards and sideways direction. The flexibility of the endoscopes and the instruments passing through them reduces precision and control when compared with rigid surgical instruments. Aim: To compare the forces exerted by instruments during endosurgical maneuvers through flexible endoscopes and using shape-locking technology (SLT). Methods: We compared forces exerted pushing needles through tissue using 1: flexible endoscopic grasping forceps holding a threaded needle, 2: needles of 21,19,17 Guage, 3: stents of 5, 7, 10, F over a guide wire which were passed through the wall of a porcine stomach. Studies were performed on the bench with postmortem tissue and were then in live experiments. Push, pull and lateral force were measured with a force gauge. Measurements (n=10 each) were made using instruments in postmortem pig stomach passed through a gastroscope (Olympus 140) and the same gastroscope constrained in SLT guide catheter SG1. Results: In live pig studies, maximum pushing force exerted on the wall of the stomach by forceps passed through the accessory channel of an endoscope in a live pig stomach held at an intragastric angle of 90 degrees(d) was 94.9 grams. When the SLT catheter was locked over the endoscope the force was increased to 431 grams (365% increase in force). Pull force in the opposite direction again at 90d to the cephalad-caudad axis of the animal was 281 without and 691 grams with SLT (146% increase) (p<0.05). Peak pushing force of the endoscope, positioned in the duodenum in a live pig with a 90d turn into duodenum after entering the pylorus) was 470 without and 1094 grams with the shape locking technology (135% increase in force) (p<0.05). SLT allowed the passage of stents, and needles through the wall of the unsupported stomach which could not be accomplished without. Conclusions: The forces exerted at flexible endoscopy, especially push and lateral 90 degree force were substantially reduced compared with laparoscopic instruments. Lateral force was very limited when using flexible biopsy forceps through flexible endoscopes. Using SLT to restrain the flexible endoscope, a four-fold increase in pushing force was measured. This allowed endosurgical maneuvers to be accomplished, which could not be performed by conventional flexible endoscopes alone.

Use of Gas Jet Appositional Pressurization in Endoscopic Laser Photocoagulation

A hybrid optical fiber catheter has been developed which is capable of simultaneously emitting from its distal end 20 W of continuous laser radiation and a jet stream of CO2 gas. The catheter can be readily inserted into the biopsy channel of conventional flexible endoscopes for control of gastric bleeding. Experiments on bleeding animal ulcers and an artificial bleeding vessel model show that a catheter which delivers a simultaneous jet of gas with laser radiation is much more effective in achieving hemostasis than laser radiation alone. The laser/gas catheter also incorporates other improvements in device durability. Results of controlled animal trials are discussed.

A high-power gastric photocoagulator for fiberoptic endoscopy.

A single quartz fiber delivery system capable of remotely depositing in excess of 9 watts of continuous laser radiation has been developed and tested. Of particular interest in this development was the achievement of a catheter that can be inserted into the biopsy channel of a conventional flexible endoscope for noninvasive control of gastric bleeding. In animal testing, the prototype device was found capable of producing a large useful area of superficial tissue coagulum, effectively controlling gastric hemorrhage. Future clinical application is highly encouraging.