Dobromir Filip

Self-Stabilizing Colonic Capsule Endoscopy: Pilot Study of Acute Canine Models

Video capsule endoscopy (VCE) is a noninvasive method for examining the gastrointestinal tract which has been successful in small intestine studies. Recently, VCE has been attempted in the colon. However, the capsule often tumbles in the wider colonic lumen, resulting in missed regions. Self-stabilizing VCE is a novel method to visualize the colon without tumbling. The aim of the present study was to comparatively quantify the effect of stabilization of a commercially available nonmodified capsule endoscope (CE) MiroCam and its modified self-stabilizing version in acute canine experiments. Two customized MiroCam CEs were reduced in volume at the nonimaging back-end to allow the attachment of a self-expanding, biocompatible stabilizing device. Four mongrel dogs underwent laparotomy and exteriorization of a 15-cm segment of the proximal descending colon. A single CE, either self-stabilizing or nonmodified was inserted through an incision into the lumen of the colon followed by phar macologically induced colonic peristalsis. The inserted capsule was propelled distally through the colon and expelled naturally through the anus. Novel signal processing method was developed to quantify the video stabilization based on camera tracking a pre determined target point (locale). The average locale trajectory, the average radius movement of the locale, and the maximum rate of change of the locale for sequential images were significantly lower for the stabilized capsules compared to the nonstabilized ones (p <; 0.05). The feasibility of self-stabilized capsule endoscopy has been demonstrated in acute canine experiments.

Rotary in-drilling alignment using an autonomous MEMS-based inertial measurement unit for measurement- while-drilling processes

The severe conditions of the drilling environment greatly limit technical options available to the equipment designer. Some desirable options cannot be used simply because they are too large for the restricted diameters available in drilling tools. Drilling would greatly benefit from inertial navigation solutions, but suitable conventional components cannot be used because of their physical size. This article describes work directed to the provision of improved navigation solutions for MWD applications.

Transcutaneous Intraluminal Impedance Measurement for Minimally Invasive Monitoring of Gastric Motility: Validation in Acute Canine Models

Transcutaneous intraluminal impedance measurement (TIIM) is a new method to cutaneously measure gastric contractions by assessing the attenuation dynamics of a small oscillating voltage emitted by a battery-powered ingestible capsule retained in the stomach. In the present study, we investigated whether TIIM can reliably assess gastric motility in acute canine models. Methods. Eight mongrel dogs were randomly divided into 2 groups: half received an active TIIM pill and half received an identically sized sham capsule. After 24-hour fasting and transoral administration of the pill (active or sham), two force transducers (FT) were sutured onto the antral serosa at laparotomy. After closure, three standard cutaneous electrodes were placed on the abdomen, registering the transluminally emitted voltage. Thirty-minute baseline recordings were followed by pharmacological induction of gastric contractions using neostigmine IV and another 30-minute recording. Normalized one-minute baseline and post-neostigmine gastric motility indices (GMIs) were calculated and Pearson correlation coefficients (PCCs) between cutaneous and FT GMIs were obtained. Statistically significant GMI PCCs were seen in both baseline and post-neostigmine states. There were no significant GMI PCCs in the sham capsule test. Further chronic animal studies of this novel long-term gastric motility measurement technique are needed before testing it on humans.

Suture marker lesion detection in the colon by self-stabilizing and unmodified capsule endoscopes: pilot study in acute canine models

BACKGROUND Capsule endoscopy is a noninvasive method for examining the small intestine. Recently, this method has been used to visualize the colon. However, the capsule often tumbles in the wider colon lumen, resulting in potentially missed pathology. In addition, the capsule does not have the ability to distend collapsed segments of the organ. Self-stabilizing capsule endoscopy is a new method of visualizing the colon without tumbling and with the ability to passively distend colon walls. OBJECTIVE To quantitatively compare the detection rate of intraluminal suture marker lesions for colonoscopy by using a custom-modified, self-stabilizing capsule endoscope (SCE); an unmodified capsule endoscope (CE) of the same brand; and a standard colonoscope. DESIGN Four mongrel dogs underwent laparotomy and the implantation of 5 to 8 suture markers to approximate colon lesions. Each dog had both capsule endoscopy and self-stabilizing capsule endoscopy, administered consecutively in random order. In each case, the capsule was inserted endoscopically into the proximal lumen of the colon followed by pharmacologically induced colon peristalsis to propel it distally through the colon. Blinded standard colonoscopy was performed by an experienced gastroenterologist after the capsule endoscopies. SETTING Experimental study in a live canine model. SUBJECTS Four dogs. INTERVENTION Laparotomy, capsule endoscopy, colonoscopy. MAIN OUTCOME MEASUREMENTS Comparison of the marker detection rate of the SCE to that of the unmodified MiroCam CE and a colonoscope. RESULTS The average percentages of the marker detection rate for unmodified capsule endoscopy, self-stabilizing capsule endoscopy, and colonoscopy, respectively, were 31.1%, 86%, and 100% (P < .01), with both self-stabilizing capsule endoscopy and colonoscopy performing significantly better than the unmodified capsule endoscopy. LIMITATIONS Acute canine model, suture markings poorly representative of epithelial polyps, limited number of animals. CONCLUSION The proposed self-stabilizing capsule endoscope delivered a significant improvement in detection rates of colon suture markings when compared with the unmodified capsule endoscope.

Improved Video Quality and Reliability With Self-Stabilizing Colon Capsule Endoscopy: Pilot Study in Acute Canine Models

previous investigations. Results: A total of 580 double-balloon enteroscopy procedures were carried out. Anterograde (oral) and retrograde (anal) route double-balloon enteroscopies were performed in 359 and 221 patients, respectively. A total of 48 patients were found to have neoplastic disease/masses. Thirty-five tumours were detected prior to DBE (33 by capsule enteroscopy and 2 by Computer tomography), 9 were suspected by CE but found only at DBE and 2 cases were missed by CE altogether. Twenty-one tumours were found at retrograde DBE, whilst 27 were found at antegrade DBE. 46 patients presented with OGIB, where 2 presented with abdominal pain. The distribution of lesions was duodenum 5, jejunum 22, mid small bowel 16 and ileum 5. Morphologically, 2 were infiltrative, 7 were pedunculated, and the remainder were sub mucosal. At DBE 13 were inspected only, 25 were biopsied, 6 were tattooed for potential surgery and 4 were resected endoscopically. The final pathology was: 9 small sub mucosal lesions with normal biopsy (normal histology), 4 adenomas , 3 lymphomas , 3 lymphangitic cysts, 2 adenocarcinomas , 1 Meckels diverticulum, 1 hamartoma, 1 lymphoid hyperplasia, 1 lipoma, and 1 metastatic melanoma. Eighteen patients avoided surgery (diagnosis made and observation only), 4 resected by endoscopy, 3 underwent surgery (adenocarcinoma with invasive infiltration), and 3 underwent chemotherapy for lymphoma. Conclusions: Our analysis shows that small bowel tumours are a significant finding at double-balloon enteroscopy and that this procedure has a therapeutic impact on the management of suspected or documented small bowel neoplasia.

Progress in self-stabilizing capsules for imaging of the large intestine

This work reports on the progress and development advances in the design of self-stabilizing capsules for imaging the lower part of the gastro-intestinal tract, namely the large intestine (the colon). Macro-level design is reviewed, and the new miniaturized design and its components are described. Preliminary performance results are discussed.

Electronic Stool (e-Stool): A Novel Self-Stabilizing Video Capsule Endoscope for Reliable Non-Invasive Colonic Imaging

Video capsule endoscopy (VCE) has become a popular non-invasive technique to study the small intestine. However, colonic VCE has been problematic due to capsule tumbling in the larger lumen of this organ. Self-stabilizing VCE is a novel method to visualize the colon without tumbling utilizing a biomimetic approach. The proposed design uses the free energy of the body’s natural processes employed to move chyme, and imitates the formation and propagation of stool. In its final stage, it physically and mechanically mimics natural feces. The process starts by administering the capsule orally. The capsule size, shape, and material were chosen to provide a smooth transit throughout the gastrointestinal (GI) tract. Once it reaches the colon, its special outer casing enzymatically dissolves. A stabilizing component that is attached to the back end of the capsule starts quickly expanding in the cecum by osmosis. This increase of the volumetric size of the expandable component (stabilizing component) invokes natural peristalsis by colonic mass reflex. Since the expansion process takes place very quickly, the capsule gets stabilized before the expansion-provoked peristalsis starts. At the final stage, the artificially created expanded component (behaving like an artificial stool) centralizes the capsule during its voyage in the colon, allowing a very smooth transit due to its viscosity. The aim of the present study is to present the design of the capsule from a biomimetic perspective and to comparatively quantify the mechanical properties of the design with those of actual human stool.Copyright

Mo1302 Gastric-Retentive Transcutaneous Intraluminal Impedance Measurement (TIIM): Sham Controlled, Minimally-Invasive Assessment of Gastric Motility in Acute Canine Models

the 2009 dataset for validation. Results: In 2008, there were 53.4 million (95% CI 45.4 million 61.6 million) visits for T2DM. Of these, 658,767 (95% CI 234,319 1,083,215) were for hypoglycemia and 152,751 (95% CI: 0-350,141) were for gastroparesis. When adjusted for payor status, age, gender, comorbidities and medication use, gastroparesis was associated with a significantly lower risk of hypoglycemia. Validation with 2009 data revealed a concordance of 88% between predicted and observed hypoglycemia events. Conclusions: T2DM patient visits with gastroparesis were associated with a significantly lower risk of hypoglycemia compared to those without gastroparesis. Due to sampling design and the rarity of gastroparesis, there were very few sampled visits with gastroparesis, resulting in large confidence intervals. Thus, the results need to be confirmed in larger samples. Another limitation is that these analyses are based on cross-sectional data and laboratory confirmation of hypogyemia was not available. While gastoparesis is often associated with labile glycemic control, these results are consistent with the mechanism of action of GLP-1 receptor agonists, which blunt postprandial hyperglycemia by slowing gastric emptying without causing hypoglycemia.