In-Vivo Evaluation of Microultrasound and Thermometric Capsule Endoscopes.

Holly S Lay,Sandy Cochran,Rachael Mcphillips,Marc P Y Desmulliez,Gerard Cummins,Ciaran Connor,Rachael Gregson,Eddie Clutton,Mihnea Vlad Turcanu,Benjami F Cox,Yongqiang Qiu

doi:10.1109/tbme.2018.2852715

Abstract

Clinical endoscopy and colonoscopy are commonly used to investigate and diagnose disorders in the upper gastrointestinal tract and colon, respectively. However, examination of the anatomically remote small bowel with conventional endoscopy is challenging. This and advances in miniaturization led to the development of video capsule endoscopy (VCE) to allow small bowel examination in a noninvasive manner. Available since 2001, current capsule endoscopes are limited to viewing the mucosal surface only due to their reliance on optical imaging. To overcome this limitation with submucosal imaging, work is under way to implement microultrasound (μUS) imaging in the same form as VCE devices. This paper describes two prototype capsules, termed Sonocap and Thermocap, which were developed respectively to assess the quality of μUS imaging and the maximum power consumption that can be tolerated for such a system. The capsules were tested in vivo in the oesophagus and small bowel of porcine models. Results are presented in the form of μUS B-scans as well as safe temperature readings observed up to 100mW in both biological regions. These results demonstrate that acoustic coupling and μUS imaging can be achieved in vivo in the lumen of the bowel and the maximum power consumption that is possible for miniature μUS systems.

Highlights

G ASTROINTESTINAL (GI) pathologies, such as Barrett’s oesophagus, coeliac disease, inflammatory bowel disease, and colorectal cancer are recognized as a significant public health issues, leading to a growing number of GI-related endoscopic procedures performed worldwide, including in the UK
Three of the transducers were placed along the longitudinal axis of the Sonocap surface with the fourth transducer situated at a 180° rotation from the others at the front of the capsule, distally with respect to the tether
The highest surface temperature observed was in the non-saline cooled oesophagus, where one test reached a temperature of 41.5 °C

Summary

Introduction

G ASTROINTESTINAL (GI) pathologies, such as Barrett’s oesophagus, coeliac disease, inflammatory bowel disease, and colorectal cancer are recognized as a significant public health issues, leading to a growing number of GI-related endoscopic procedures performed worldwide, including in the UK. Manuscript received March 23, 2018; revised May 18, 2018; accepted June 30, 2018. Date of publication July 5, 2018; date of current version February 18, 2019. Cochran are with the School of Engineering, University of Glasgow

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