Chung-Kwong Yeung, MBBS, MD, PhD1, Chi-Chung Foo, MBBS, FRCSEd, FHKAM1, Wai-Lun Law, MBBS, MS, FRCSEd, FHKAM1, Biji Sreedhar, Msc, PhD2, JLK Cheung, PhD2. 1The University of Hong Kong, 2Bio-Medical Engineering (HK) Limited
Objective: Conventional colonoscopy is considered the gold standard for colorectal screening due to its ability to serve as both diagnostic and therapeutic modality. However, the disadvantages of this technology include high cost, invasiveness, pain and discomfort for patients. Moreover, there is major risk of cross-infection from ineffective sterilization between patient use.We therfore propose a state -of – the – art soft robotic colonoscopy (SRC) system which enables endoscopists to carryout next generation of non-invasive diagnostic and therapeutic colonoscopy procedures.
Description of technology: The key features of the system include i) a pneumatic/hydraulic-driven soft elastomeric active bending mechanism that allows omni-directional bending of the scope towards areas of interest while performing the procedure ii) a novel twin-ballon anchoring mechanism to provide secure anchorage of the colonoscope to the colonic wall and thereby straighten the colonoscope to allow unobstructed advancement and reduce loop formation and/or entanglement iii) a double-tube trailing design to enable rapid movement of the device through the colon and, iv) endoscopic 3D HD vision to enable 180 o omnidirectional visulaization and v) a disposable scope, eliminating the risk of cross-infection and avoiding the need for expensive sterilization. We evaluated the functionality and effectiveness of locomotion mechanism and dynamics of bendable section of the proposed SRC system in performing colonoscopy in human cadaver.
Methods: Cadaver was positioned in lithotomy position with arms tucked and secured at the sides; legs apart and placed on to the padded leg holders. Laparotomy was performed to gain access to the colon and cecum for the placement of the Foley catheter inorder to cleanse the colon. Abdominal incison was was then sutured, retaining the Foley catheter inside. At first, a standard colonoscopy was performed using the Olympus colonoscope to evaluate the cleansing conditions and any potential abnormalities of the colon. The SRC system was then inserted into the rectum of the cadaver to perform the procedure.
Results: Three soft embalmed human cadavers (1M and 2F) were used for the pilot feasibility study. Both conventional and robotic colonoscopies were performed in all 3 cases. The SRC system was successfully inserted into the rectum of the cadaver and colon insufflation was sucessfully achived. The camera delivered clear views of the colonic mucosa and colonic lumen in all cases. The novel twin-ballon anchoring mechanism enabled precise orientation, dynamic anchoring and navigation of the scope to traverse the sigmoid colon, splenic flexure and transverse colon. However, before reaching the cecum, the bending section of the SRC system curled up and multiple attempts were necessary to further advance the scope to the cecum to achieve cecal intubation.
Conclusion and future direction: Our results demonstrated that the overall performance of the SRC prototype was satisfactory. However, further modification of the design is warranted to optimize the functionality and variable level of stiffness, which will enhance the advancement of the scope towards the cecum without any loop formation. Further cadaveric studies are required to refine and examine the functionality of the modified system.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 91209
Program Number: ETP886
Presentation Session: Emerging Technology iPoster Session (Non CME)
Presentation Type: Poster