Luigi Manfredi, PhD, Alfred Cuschieri, Professor. Institute for Medical Science and Technology, University of Dundee, UK
A robotic soft colonoscope able to change its shape to conform to the contours of the individual patient’s colon, will expedite the painless transit form rectum to caecum, essential for completing a colonoscopic inspection, thereby avoiding need for sedation during screening colonoscopy (SC).
However, the design and construction of such a mini robotic device for SC is challenging because of the limited available colonic luminal space (varying from 40 to 90 millimetre) and the length of the colon (circa 1.5 meter). As all the tracts of the colorectal mucosa require inspection, the critical feature in the design of such a mini-robotic device is the choice of mini soft actuators used to control force required and produced with minimal stress reducing the potential for collateral damage to the colonic wall.
METHODS AND PROCEDURES
In contrast to the traditional flexible colonoscope, the authors propose a novel alternative platform, i.e., a Soft hOllow Flexible roboT for Interventional Endoscopy (SOFTIE) equipped with a high resolution camera at the distal section and a channel for a biopsy instrument. The design of SOFTIE is novel as it is based on a patented soft and hollow modular pneumatic actuator, made of soft polymer. This actuator can perform dexterous movements by inflating its chamber with a low pressurised air.
SOFTIE is able to change its form by controlling each segment (mini soft actuator) without any stress or forces on the colonic wall, hence ensuring painless SC, thereby increasing compliance. The mini-soft robot will be manoeuvrable and controlled in its journey through the colorectum via an external simple console, facilitating its navigation inside the colonic lumen, and reducing the long training process required to reach proficiency at expert level.
A preliminary concept of this actuator (Figure 1) has been tested in the lab at IMSaT and has shown high dexterity with a low pressurised air in a tubular device with an external diameter of 20 mm, and an inner lumen of 5 mm. SOFTIE aims to develop a modular actuator, embedding all the required components with external control soft robotic device made up of 5 to 15 soft compartments.
Preliminary experiments have indicated the potential of the proposed soft actuator in the development of a new generation of active soft colonoscopes. Different control strategies can be implemented and further improvements in the design of additional components (e.g. air valves and embedded electronic system) are needed to reduce size of the hardware and produce a modular soft actuator.
Figure 1: Preliminary concept design of a soft pneumatic actuator, developed at IMSaT, University of Dundee, UK. The external diameter is 20 millimetres and preliminary experiments have reported high dexterity and manoeuvrability.
Acknowledgment: CARPE project supported by the EU-FP7, European Research Council, PoC, Grant Agreement n.665696.
Disclosure:  Patent application N. GB 1617934.3, UK, 2016.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 84330
Program Number: ETP745
Presentation Session: Emerging Technology Poster
Presentation Type: Poster