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

Swain, Paul; Sadaat, Vahid; Brenneman, Rodney; Ewers, Rolf

doi:10.1016/s0016-5107(04)00711-4

Cited by 5 publications

(2 citation statements)

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“…Crossing two grasping forceps and prior clipping can accomplish tissue approximation with adequate precision and dexterity, but only in the direction of traction and not counter-traction. The reason for this limitation is that endoscopes and their accessories are made to be extremely flexible, in order to avoid tears and perforations inside the gastrointestinal lumen, and therefore cannot transmit force in both direct and sideways directions [3]. Traction (pulling) could prove an exception to this rule insofar as it can be satisfactorily accomplished, provided the two forceps are securely grasped in crossover direction.…”

Section: Resultsmentioning

confidence: 99%

Improving triangulation in notes by triple access

2010

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Background: Triangulation is difficult to perform in flexible endoscopy. Maneuvers required for natural orifice transluminal endoscopic surgery (NOTES) procedures are challenging, if not impossible, even with a double-channel endoscope, mainly because the optical axis and the instruments cannot move independently. The aim of this acute experiment in swine was to investigate whether triangulation can be improved by using three endoscopes inserted through different natural orifices. Method: Fourteen swine were subjected to laparotomy. Three endoscopes were introduced into the peritoneal cavity via the transgastric, transrectal and transvaginal routes, respectively, under direct inspection and assistance, through the open abdomen. The laparotomy was then closed and pneumoperitoneum was created. Using one endoscope for vision [eyes] and two for manipulations [hands] all combinations were performed in relation to the orifice of insertion and the role of each endoscope. The cooperation of the three endoscopes was tested for grasping and manipulating tissues as well as for exposing, dissecting and approximating structures. Results: The most efficient and ergonomic combination for manipulations in the upper abdomen was found to be: endoscope "eyes" and one endoscope "hand" transrectally and the other "hand" transvaginally; the most efficient for manipulations in the lower abdomen involved both endoscope "hands" transgastrically and endoscope "eyes" transrectally or transvaginally, in retroflex position. Conclusions: In NOTES triangulation can be improved for some manipulations by using three endoscopes, inserted through different natural orifices.

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Section: Resultsmentioning

confidence: 99%

Improving triangulation in notes by triple access

2010

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“…Experiments conducted with the Olympus GIF-2T100 reveal a pushing force of approximately 1.3N before the endoscope changes its bent shape [53]. From another study using a different endoscope GIF-140, the maximum pulling force from the endoscope is approximately 2.76N before it changes its original bent shape [54].…”

Section: 23: Force From Manipulatormentioning

confidence: 96%

Analysis and control of tendon-sheath actuation mechanism for a novel surgical robotic system

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Current endoscopic tools are inserted along the body of a flexible endoscope to access the tissue of interest in the patient. Actuated manually by wire ropes at the proximal end, the tool is able to perform simple grasping and cutting tasks. However, these tools possess low number of Degrees of Freedom (DOF) and thus lack the dexterity and maneuverability to perform complicated tasks, like retraction and suturing of tissue, which are required in Natural Orifice Transluminal Endoscopic Surgery (NOTES) and Endoscopic Submucosal Dissection (ESD). A multi DOFs master and slave robotic system is therefore envisaged to better assist the endoscopist in performing these complicated procedures. It is a requirement that the slave manipulator passes through a long, narrow and flexible channel of the endoscope to reach the distal end. Furthermore, due to size constraints, it would be appropriate to house the actuators at the proximal end which is situated outside the patient. As such, the tendon sheath actuation has been proposed for this application. However, shape dependent friction between the tendon and sheath results in undesirable characteristics such as loss of force, backlash, hysteresis and non linearity. For effective closed loop control of the proposed system, issues such as implementation of position control and haptics feedback have to be resolved. It is desired to find the end effector force and elongation of the tendon to control the system but it is not feasible to affix sensors at the end effector due to size constraint, practicability and sterilization issues. It was proposed to utilize the knowledge of the force and position at the proximal end to perceive the distal end force and elongation of the tendon sheath. To realize this, theoretical analysis was conducted to find relations of parameters between the distal and i

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