Modeling of a New Sma Microactuator for Active Endoscopy Applications

Abstract

Shape Memory Alloys (SMA) are good candidates to actuate endoscope heads but the cooling problem must be solved particularly in confined situations. For these reasons, a new SMA micro-actuator specially designed for active endoscopy applications has been developed in our laboratory. This work is a new step in the approach of using integrated thermoelectric cooling with SMA actuators. In fact, the Peltier effect is very attractive in such a case because this reversible phenomenon reduces the overheating of the external environment and provides forced cooling that decreases the response time. In this paper the actuator design and its working principle are presented. A fine modeling of the coupled mechanical and thermal behaviors gives a better understanding of the physical phenomenon involved in the actuator. Finally an experimental prototype has been developed and tested in order to verify the model predictions.

A survey on actuators-driven surgical robots

“…The comparisons for all actuators in terms of size, power consumption, force/torque ranges, and scaling possibilities are given in Table 9. Table 9 Comparisons for all actuators in terms of size, power consumption, force/torque ranges, and scaling possibilities with references from 34,153,1,2,30,36,44,49,71,80,89,92,93,106,131,141,149,171,177,188,189,203 <H1> Conclusion This study serves as one of the most comprehensive review on the actuators-driven surgical robots in terms of design, modelling, control problems, and proposed potential future research directions. While there have been multiple developed categories such as cable, flexible fluidic, smart material, and magnetic actuators, every candidate still holds both disadvantages and advantages.…”

“…Mechanical structure of hand-held instrument (a) Systematic view of the hybrid tool with tendon-gear and tendon-sheath mechanism, (b) Detail presentation of end-effector 97 <Figure>Fig. 13 49,69,72,172,181,203 <Table>Table 8: Highlight the different approaches for the modelling and control of magnetic actuators with references from 15, 182 <Table>Table 9: Comparisons for all actuators in terms of size, power consumption, force/torque ranges, and scaling possibilities with references from 34,153,1,2,30,37,45,50,72,81,90,93,94,107,132,142,150,172,178,189,190,204 24,212 Entirely appropriate for discrete structures and good approximation for continuous structures 86 Easy to apply and compute 86 Require configuration information for the modelling 86 Represent continuum robot geometry with a finite number of mutually tangent curved segments 24,212 Most well-known kinematic framework for continuum robots 24,212 Complex identification 86  Configuration information is not required 86 High accuracy and noise reduction 86 Able deal with disturbances and uncertainties due to the use of adaptive control …”

Actionneurs non conventionnels pour la robotique

“…Cette forme est obtenue par exemple par découpe laser dans une plaque. L'actionneur est alors composé d'un agencement de poutres en parallèle ou en série travaillant principalement en flexion plane [81] (Figure 43d). Enfin, le matériau AMF peut être déposé en couche mince sur un substrat souple.…”

Proposal and fundamental experiments of a novel pneumatic film actuator for assisting colonoscope insertion

“…However this high stiffness brings pain and discomfort felling to patients. To solve the problem, various endoscopes and mechanisms have been developed [1][2][3][4][5][6][7]. Nevertheless, many of these mechanisms have some weak points for actual usage, for examples, complexity of the structure, possibility of damage of the colon, and demand of new operation skill for doctors, etc.…”