A Low-Cost Hybrid Compact Control Hardware for a Soft Colonoscope

Abstract:
Every year about two million new cases of colorectal cancer are diagnosed worldwide, with a mortality close to 50%. Screening and early detection are key to increase the five-year survival rate, which goes above 90% when the cancer is detected at stage 1 and drops below 10% at stage 4. Non-invasive screening, such as FIT (Faecal Immunochemical Test), is adopted in many national bowel screening programs to detect cancer at early stage. Colonoscopy remains the ultimate step to have an optical inspection of the colonic wall and to remove polyps, which may eventually become cancerous. However, this procedure is not well accepted by patients due to pain and discomfort. The pressure of the colonoscope against the colonic wall can damage the mucosa and, in some cases, cause perforation. It is a difficult procedure to learn, and training can take more than 4 years in the UK. This work presents a hybrid and low-cost control hardware including miniaturised valves, with linear actuators and piston-cylinder mechanisms to control a soft colonoscope. The proposed design combines a precise control of the fluid pressure and volumes in each chamber.