A Micro Mobile Robot with Suction Cups in the Abdominal Cavity for NOTES

NOTES (Natural Orifice Translumenal Endoscopic Surgery), in which forceps are put through a natural orifice, such as the mouth, anus or vagina, and a hole is cut at the site to reach intra-abdominal cavity. Because this surgery is able to minimize incision size and the amount of pain, thus greatly improve the quality of life of patients. Although the NOTES approach may hold tremendous potential, there are difficulties that should be overcome before this technique is introduced into clinical care. The most serious one is that since the distance from the surgeon’s fingertip to the targeted site is generally longer than that of the usual endoscopic operations, manipulation of forceps is much more difficult, which brings more burdens on the surgeons; meanwhile, there are few surgical devices that could be specifically used for NOTES. The aim of this study is to develop surgical devices that could facilitate high manipulability and high functionality (cut, hold tissues, hold camera) for NOTES. The biggest issue when developing an device for NOTES support use is that it has to show both flexibility and rigidity. On one hand, in order to pass a long pathway (i.e., the esophagus) to reach a site (i.e., the stomach) it should be flexible enough. On the other hand, after reaching its target site (i.e., the abdominal cavity), it should show sufficient rigidity which could stay at the site steadily and perform its tasks, such as holding a camera for inspection, and/or a soft forceps in operations. The first type expanded the traditional flexible endoscope for single port access surgery (Xu. et. al., 2009), which has built-in camera, forceps, and electric scalpel, all folded in a small cylinder before and during insertion, then deployed after reaching its targeted site. This type of device owns sufficient flexibility, however, since the fulcrum of the manipulation (a point to provide support of manipulation) is outside the port, as the distance between the fulcrum and targeted site increases, its rigidity of system will be reduced by its inherent flexibility, and force will be even more difficult to transmitted to the endeffector usually located at the detail portion of the device. The robot type goes to another extreme. The robot moves around the targeted site, after being inserted through the port. The fulcrum of manipulation is usually near the endeffector, thus the Robot Type usually has good manipulability. It has been reported that a wheeled surgical robot system could move on the surface of liver (Rentschler & Reid, 2009). However, the mobile mechanism could not provide mobility to cover whole abdominal cavity for NOTES support usage. Moreover, not all the surface of inner organs