Endoscopic End-Effector for Foreign Body Retrieval Using Shape Memory Alloy

Foreign body retrieval is potentially needed when a patient ingests foreign objects; while many of these will pass naturally, intervention may be required. The retrieval process can be done endoscopically or surgically. This paper covers the novel use of shape memory alloy to assist in endoscopic foreign body removal. Six closure methods were constructed and tested for percentage contraction. These ranged from linear actuation and memorized simple shapes to shape-set springs. Of these closure methods, a spring based architecture yielded the greatest percentage contraction but tangled during the contraction process. The design presented in this paper will enable faster and less invasive gastroenterological foreign body retrieval from the stomach.