Byron F. Smith

Wireless Insufflation of the Gastrointestinal Tract

Despite clear patient experience advantages, low specificity rates have thus far prevented swallowable capsule endoscopes from replacing traditional endoscopy for diagnosis of colon disease. One explanation for this is that capsule endoscopes lack the ability to provide insufflation, which traditional endoscopes use to distend the intestine for a clear view of the internal wall. To provide a means of insufflation from a wireless capsule platform, in this paper we use biocompatible effervescent chemical reactions to convert liquids and powders carried onboard a capsule into gas. We experimentally evaluate the quantity of gas needed to enhance capsule visualization and locomotion, and determine how much gas can be generated from a given volume of reactants. These experiments motivate the design of a wireless insufflation capsule, which is evaluated in ex vivo experiments. These experiments illustrate the feasibility of enhancing visualization and locomotion of endoscopic capsules through wireless insufflation.

Toward tetherless insufflation of the GI Tract

Toward increasing the diagnostic ability of wireless capsule endoscopy, we propose a method to wirelessly insufflate the Gastrointestinal Tract. By increasing the viewable surface area, it appears likely that capsule-based insufflation may reduce the number of false negative diagnoses made by endoscopic capsules. Our approach to wireless insufflation is to utilize controlled phase transition of a small volume of fluid stored onboard the capsule to a large volume of gas that is then emitted into the intestine. We begin by describing experiments designed to evaluate the amount of gas a capsule must produce to have a beneficial impact on visualization in the colon. We then describe experiments evaluating how much gas can be generated from a given volume of fluid, using Hydrogen Peroxide as our working fluid. We also evaluate thermal effects of the Hydrogen Peroxide reaction. The cumulative result of these experiments is an illustration of the feasibility of carrying a sufficient volume of fluid onboard a wireless capsule to generate a beneficial enhancement in visualization of the interior of the Gastrointestinal Tract, and specifically the colon.

Controlled colonic insufflation by a remotely triggered capsule for improved mucosal visualization

BACKGROUND AND STUDY AIMS Capsule endoscopy is an attractive alternative to colorectal cancer screening by conventional colonoscopy, but is currently limited by compromised mucosal visibility because of the lack of safe, controlled colonic insufflation. We have therefore developed a novel system of untethered, wireless-controlled carbon dioxide (CO2) insufflation for use in colonic capsule endoscopy, which this study aims to assess in vivo. MATERIAL AND METHODS This observational, nonsurvival, in vivo study used five Yorkshire-Landrace cross swine. A novel insufflation capsule was placed in the porcine colons, and we recorded volume of insufflation, time, force, visualization, and a pathologic assessment of the colon. RESULTS The mean (standard deviation [SD]) diameter of insufflation was 32.1 (3.9) mm. The volume of CO2 produced successfully allowed complete endoscopic visualization of the mucosa and safe proximal passage of the endoscope. Pathologic examination demonstrated no evidence of trauma caused by the capsule. CONCLUSIONS These results demonstrate the feasibility of a novel method of controlled colonic insufflation via an untethered capsule in vivo. This technological innovation addresses a critical need in colon capsule endoscopy.

Novel approach for colonic insufflation via an untethered capsule (with video).

would alter the angle of the pulled papilla. With minor adjustments, cannulation can be achieved. In conclusion, when a hooded major papilla is encountered at ERCP, traction of the papilla by the use of forceps may be useful. Application of clips during ERCP: a new anchoring method for redundant Kerckrings fold covering the duodenal papilla. Capsule endoscopy has quickly become a cornerstone for evaluation of the small intestine. Implementing this technology successfully for evaluation of the human colon has been challenging because of numerous factors. One factor is the need for safe, controlled, reliable insufflation. Carbon dioxide (CO 2) for the purpose of colonic insuffla-tion has been advantageous over traditional air insufflation because it is readily absorbed through the colon, thereby reducing patient discomfort caused by the effect of colonic distention. Our team has developed a novel approach for untethered controlled CO 2 insufflation for use in colon capsule endoscopy. To create CO 2 for wireless untethered colon insuffla-tion, a safe and controlled chemical reaction was developed. This reaction uses sodium bicarbonate (NaHCO 3) and citric acid (C 6 H 8 O 7) in the presence of water (H 2 O) to yield the products of sodium citrate (Na 3 C 6 H 5 O 7), carbon dioxide (CO 2), and water. All the reactants and products are described as safe for human use/consumption by the US Food and Drug Administration. 1 Although the required amount of water can be found within the intestine in physiologic conditions, sodium bi-carbonate and citric acid, in solid state, can be loaded inside a swallowable capsule with a magnetic controlled drug release system (internal volume 2 mL). 2 To quantify the quantity of gas generated and the dynamics of the proposed reactions under ideal conditions, bench-top tests were performed under conditions similar to those in vivo (T ϭ 37°C). Ten trials at 37°C yielded a mean CO 2 volume of 455.30 Ϯ 10.17 mL at 4 minutes (t 50). The pH of the reaction was 6.5. Ex-vivo trials were then performed by use of a fresh porcine colon that was submerged in a tank of 9 L water maintained at 37°C. No animals were killed specifically for the purpose of obtaining tissues. A total of 9 fiducials were spaced at 2-cm intervals along the colon wall and sutured in place. The reactants were then loaded into the swal-lowable capsule, which was activated inside the …

809 In Vivo Colonic Insufflation via a Disposable CO2 Insufflation System

Background: One of the major obstacles (~30%) of screening colonoscopy is the hurdle of preparation. The standard technologies demands aggressive bowel cleansing that hamper patients compliance. Aim: To test the safety and proof of concept of a novel prep-less XRay imaging capsule (Check Cap Ltd, Israel) for colon cancer screening. Material and Methods: The capsule (approximately 34 mm in length and 11.5 mm in diameter, similar in size to optical imaging capsules) utilizes a novel ultra-low dose (0.03 mSv) low energy (56 70 Kev) X-ray-based imaging technology to safely generate high resolution 3-D imagery of the colon without bowel cleansing or other aggressive preparation. 10 capsules were swallowed by volunteers (M=7, F=3) (ages 37 66) and were tracked during the whole passage of the capsule in the body using radio frequency telemetry and an Electromagnetic Localization System (ELS). The capsules were programed to perform scans when movement in the colon is detected and transmit the imaging data to an external recorder unit worn by the patients. The study was approved by the IRB of the Tel Aviv Medical Center. Total transit time and total X-ray exposure to the patients were calculated to assess the safety profile of the x-ray capsule imaging technology in human subjects. Results: All capsules were swallowed and naturally exerted by the volunteers without any minor or major side effect. The average transit time of 68 ±31 hours. The volunteers were exposed to an ultralow total radiation dose (Average total exposure (0.03 ± 0.007 mSv), two orders of magnitude less than CTC (with 1 outlier due to manufacturing fault). Data from scans in the colon combined with ELS positioning information was used to reconstruct 3D colon segments in un-prepped colon. Fig1 and Fig.2 are examples of such 3D scans. Laboratory data form synthetic colon phantoms with and without polyps as well as data from cow colon phantom with induced tissue made polyp Fig.3 and Fig.4 have shown reconstruction accuracy of 2 3 mm in colon diameter measurements. (All figure dimensions in mm) Conclusions: A safety and proof of concept study has been performed using a novel prep-less x-ray imaging capsule for colon cancer screening. Quantitative ultra-low dose x-ray 3D imaging was achieved in the colon of human subjects. The efficacy will be confirmed in a multi-center study.