Control of a Robotic Flexible Endoscope Holder for Laparoscopic Surgery

In this paper, we present an integrated robotic arm with a flexible endoscope for laparoscopy. The endoscope holder is built to mimic a human operator that reacts to the surgeon's push while maintaining both the incision opening through the patient's body and the center of the endoscopic image. An impedance control algorithm is used to react to the surgeon's push when the robotic arm gets in the way. A modified software remote center-of-motion (RCM) constraint formulation then enables simultaneous RCM and impedance control. We derived the kinematic relationship between the robotic arm and line of sight of the flexible endoscope for image center control. Using this kinematic model, we integrated the task control for RCM and surgeon cooperation and the endoscope image centering into a semi-autonomous system. Implementation of the control algorithm with both matlab simulation and the HIWIN RA605-710 robotic arm with a MitCorp F500 flexible endoscope demonstrated the feasibility of the proposed algorithm.

Magnetic flexible endoscope for colonoscopy: an initial learning curve analysis

Background and study aims Colonoscopy is a technically challenging procedure that requires extensive training to minimize discomfort and avoid trauma due to its drive mechanism. Our academic team developed a magnetic flexible endoscope (MFE) actuated by magnetic coupling under supervisory robotic control to enable a front-pull maneuvering mechanism, with a motion controller user interface, to minimize colon wall stress and potentially reduce the learning curve. We aimed to evaluate this learning curve and understand the user experience. Methods Five novices (no endoscopy experience), five experienced endoscopists, and five experienced MFE users each performed 40 trials on a model colon using 1:1 block randomization between a pediatric colonoscope (PCF) and the MFE. Cecal intubation (CI) success, time to cecum, and user experience (NASA task load index) were measured. Learning curves were determined by the number of trials needed to reach minimum and average proficiency—defined as the slowest average CI time by an experienced user and the average CI time by all experienced users, respectively. Results MFE minimum proficiency was achieved by all five novices (median 3.92 trials) and five experienced endoscopists (median 2.65 trials). MFE average proficiency was achieved by four novices (median 14.21 trials) and four experienced endoscopists (median 7.00 trials). PCF minimum and average proficiency levels were achieved by only one novice. Novices’ perceived workload with the MFE significantly improved after obtaining minimum proficiency. Conclusions The MFE has a short learning curve for users with no prior experience—requiring relatively few attempts to reach proficiency and at a reduced perceived workload.

Endoscopic Retroperitoneal Necrosectomy for Infected Pancreatic Necrosis Using a Self-Expandable Metal Stent

Infected walled-off pancreatic necrosis (WOPN) is a severe complication of acute pancreatitis. Surgery in these critically ill patients can be associated with increased morbidity and mortality. Hence, minimally invasive therapies have emerged as an alternative to surgery. Herein, we report a case of severe acute pancreatitis with WOPN which was treated percutaneously with a flexible endoscope through an esophageal self-expanding metal stent using a total retroperitoneal approach. Percutaneous direct endoscopic necrosectomy (p-DEN) using the retroperitoneal route improved the patient’s parameters dramatically with resolution of sepsis without the need for surgery. p-DEN using a flexible endoscope passed through a large bore metal stent shows promise in selected patients with WOPN and can be used in patients who are not ideal candidates for transmural or surgical drainage.

Surgical Robot for Intraluminal Access: An Ex Vivo Feasibility Study

Early-stage gastrointestinal cancer is often treated by endoscopic submucosal dissection (ESD) using a flexible endoscope. Compared with conventional percutaneous surgery, ESD is much less invasive and provides a high quality of life for the patient because it does not require a skin incision, and the organ is preserved. However, the operator must be highly skilled because ESD requires using a flexible endoscope with energy devices, which have limited degrees of freedom. To facilitate easier manipulation of these flexible devices, we developed a surgical robot comprising a flexible endoscope and two articulating instruments. The robotic system is based on a conventional flexible endoscope, and an extrapolated motor unit moves the endoscope in all its degrees of freedom. The instruments are thin enough to allow insertion of two instruments into the endoscope channel, and each instrument has a bending section that allows for up–down, right–left, and forward–backward motion. In this study, we performed an ex vivo feasibility evaluation using the proposed robotic system for ESD in a porcine stomach. The procedure was successfully performed by five novice operators without complications. Our findings demonstrated the feasibility of the proposed robotic system and, furthermore, suggest that even operators with limited experience can use this system to perform ESD.