Pioneering a New Self-Propulsion Technique for Small Bowel Endoscopy

The Applied Dynamics and Control Laboratory in Exeter (ADCE) from the University of Exeter has collaborated with the Royal Devon and Exeter NHS Foundation Trust and the Shangxian Minimally Invasive Inc. to pioneer a novel self-propulsion technique for small-bowel capsule endoscopy.

Capsule endoscopy is a procedure used predominantly to examine the surface lining of the small bowel, an anatomical site previously considered to be inaccessible to clinicians. However, its reliance on peristalsis (a series of wave-like muscle contractions) for passage through the intestine leads to significant limitations, in particular due to the unpredictable speed of movement. Significant abnormalities may be missed, due to intermittent high transit speeds that lead to incomplete visualisation of the intestinal surface. Furthermore, each case produces up to 100,000 still images, from which video footage is generated, taking between 30 and 90 minutes for the clinician to examine in its entirety. The procedure is therefore considered both time-consuming and burdensome for clinicians.

Figure 1: Small-bowel capsule endoscopy (Picture source: Clinical Gastroenterology and Hepatology)

Figure 2: ADCE team

The team has developed a novel, reusable, untethered, self-propelled, endoscopic capsule, named CapScope, for cost-effective small-bowel examination. The prototype, 28 mm in length and 11.5 mm in diameter, consists of an actuation module, a miniaturised camera, LEDs, data antenna, a battery, and a data recorder, offering the potential for a ‘live’ and controllable small-bowel examination taking less than 30 minutes.

Figure 3: Disassembled CapScope

Figure 4: CapScope and the image data recorder

Dr Yang Liu, the lead of ADCE team, said, “ We are exploring an approach to embed the vibro-impact self-propulsion technique into capsule endoscopy, which will provide controllable, reliable, and efficient diagnostic tools for future minimally invasive surgeries. CapScope is particularly suitable when disease is suspected in the small intestine, as it can both overcome peristalsis and speed up diagnostic evaluation. It will be particularly useful in diagnosing inflammatory bowel disease, bleeding vessels, polyps, ulcers, and tumours under the control of a clinician. The expected outcome of this work will have a significant impact on the economy and society, as both NHS hospitals and individual patients will be the ultimate beneficiaries of such an advanced tool and technique.”

Figure 5: Finite element modelling of CapScope in a contractive small bowel

Figure 6: Experimental testing of CapScope in a contractive synthetic small bowel

Dr Shyam Prasad, a Consultant Gastroenterologist and advanced endoscopist at the Royal Devon and Exeter NHS Foundation Trust, says, “The scientific significance and innovation potential of this project is very impressive. The objective of incorporating the resonance-enhanced mechanism into diagnostic capsules to produce self-propelled capsule endoscopy is not only novel and highly relevant to our department, but its application to this and other anatomical sites could potentially revolutionise the diagnosis of gastrointestinal disease. A controllable, wireless, minimally-invasive, diagnostic modality would undoubtedly improve diagnostic accuracy and reduce miss-rates for significant disease, whilst affording patients the prospect of undergoing less disruptive and less painful investigations.”

This project involves two PhD students, one postdoctoral research fellow, a number of academic staffs with expertise in biomechanics and electronics at the University of Exeter, a consultant gastroenterologist at the Royal Devon and Exeter NHS Foundation Trust, and an electronic and a software engineers at the Shangxian Minimally Invasive Inc.

This project has been supported by EPSRC under Grant No. EP/P023983/1 and EP/R043698/1.