Miniature Netting System for Endoscopic Object Retrieval From Hard-to-Reach Area

Retrieval of an object from hard-to-reach areas requires the use of instruments of various kinds sent through an endoscope. However, removing a flat object firmly lodged in a narrow space, such as a coin or a button battery in a digestive passageway, causes complications when using existing endoscopic instruments. To address such a difficult situation, this paper reports development of a miniature retrieval device using MEMS technology and implementation of the device in a custom-made endoscope. The MEMS device consists of a circular plastic net 15 mm in diameter and pneumatically operated microjoints integrated under the net to bend it. The endoscope is equipped with a hooking mechanism, which secures the net after it wraps the object, and double imaging systems through which the operator monitors overall endoscopic retrieval procedures. Object retrieval is tested in a lab environment using a coin in a tube.