Search

Constipation is a common yet distressing disease that has high rates of morbidity and impacts patients' quality of life. However, there is no perfect method to distinguish costive patients from healthy subjects. Is there chaos in human colonic activities? Are there any differences for the chaos indicators of colonic activities between healthy and costive subjects? Can these indicators distinguish patients with constipation from healthy subjects? To answer these questions, colonic pressure data from 16 healthy subjects and 48 patients with constipation were analyzed using the chaos theory. Three chaotic indicators [i.e., the largest Lyapunov exponent (LyE), correlation dimension (CorDim), and Kolmogorov entropy (KoEn)] were calculated and compared between groups with the Wilcoxon rank sum test. As a result, the LyE was greater than zero and the CorDim was fractioned, which showed that human colonic activities have clear chaotic characteristics. Statistically significant differences were observed between groups for CorDim (p < 0.05), whereas LyE did not show statistically significant differences between groups. The chaotic indicator of CorDim was able to differentiate between patients with constipation and healthy subjects. The chaos theory provides a new method for learning the nonlinear dynamics of human gastrointestinal activities.

Fluorescence Imaging (FI) is a powerful technique in biological science and clinical medicine. Current FI devices that are used either for in-vivo or in-vitro studies are expensive, bulky and consume substantial power, confining the technique to laboratories and hospital examination rooms. Here we present a miniaturised wireless fluorescence endoscope capsule with low power consumption that will pave the way for future FI systems and applications. With enhanced sensitivity compared to existing technology we have demonstrated that the capsule can be successfully used to image tissue autofluorescence and targeted fluorescence via fluorophore labelling of tissues. The capsule incorporates a state-of-the-art complementary metal oxide semiconductor single photon avalanche detector imaging array, miniaturised optical isolation, wireless technology and low power design. When in use the capsule consumes only 30.9 mW, and deploys very low-level 468 nm illumination. The device has the potential to replace highly power-hungry intrusive optical fibre based endoscopes and to extend the range of clinical examination below the duodenum. To demonstrate the performance of our capsule, we imaged fluorescence phantoms incorporating principal tissue fluorophores (flavins) and absorbers (haemoglobin). We also demonstrated the utility of marker identification by imaging a 20 μM fluorescein isothiocyanate (FITC) labelling solution on mammalian tissue.

Introduction: Capsule endoscopy (CE) has become a first-line tool for small bowel (SB) examination. However, adverse events (AEs), such as CE retention or aspiration, may occur. The aims of this study were to evaluate incidence, clinical outcomes and therapeutic approaches of CE-related AEs in the largest series published to date., Methods: Data from 5428 procedures performed at 12 institutions between August 2001 and January 2012 were retrospectively analyzed. Baseline patient characteristics; procedure; type, localization and symptoms before/after AEs; previous patency tests performed; therapeutic management and patient's outcome were recorded., Results: The overall incidence of CE-related AEs was 1.9%: 2.0% for SB, 0.9% for esophageal and 0.5% for colon CE. The incidence of capsule retention was significantly higher than capsule aspiration (1.87% vs. 0.003%; p < 0.05), in patients suffering from inflammatory bowel disease (IBD) than in obscure GI bleeding (OGIB) (3.3% vs. 1.5%; p < 0.05) and in patients with the combination of nausea/vomiting, abdominal pain and distension. The SB was the most frequent localization of retention (88.2%). The use of patency tests -except for Patency© capsule- before CE was not a good predictor for AEs. Most of the patients with AEs developed no or mild symptoms (97%) and were managed by non-surgical methods (64.4%)., Conclusions: CE-related AEs are uncommon and difficult to predict by imagiological examinations. SB retention, that is usually asymptomatic, is the most frequent AE. In absence of symptoms, non-surgical management of CE-related AEs is recommended.

Noninvasive imaging with CT and magnetic resonance enterography or direct visualization with wireless capsule endoscopy can provide valuable diagnostic information and direct therapy. Enteroscopy technology and techniques have evolved significantly and allow diagnosis and therapy deep within the small bowel, previously attainable only with intraoperative enteroscopy. Push enteroscopy, readily available in most endoscopy units, plays an important role in the evaluation and management of lesions located up to the proximal jejunum. Currently available device-assisted enteroscopy systems, DBE, SBE, and spiral enteroscopy each have their technical nuances, clinical advantages, and limitations. Newer, on-demand enteroscopy systems appear promising, but further studies are needed. Despite slight differences in parameters such as procedural times, depths of insertion, and rates of complete enteroscopy, the overall clinical outcomes with all overtube-assisted systems appear to be similar. Endoscopists should therefore master the enteroscopy technology based on institutional availability and their level of technical expertise.

The paper presents an overview of endoscopic capsules with particular emphasis on technical aspects. It indicates common problems in capsule endoscopy such as: (1) limited wireless communication (2) the use of capsule endoscopy in the case of partial patency of the gastrointestinal tract, (3) limited imaging area, (4) external capsule control limitations. It also presents the prospects of capsule endoscopy, the most recent technical solutions for biopsy and the mobility of the capsule in the gastrointestinal tract. The paper shows the possibilities of increasing clinical usefulness of capsule endoscopy resulting from technological limitations. Attention has also been paid to the current role of capsule endoscopy in screening tests and the limitations of its effectiveness. The paper includes the author's recommendations concerning the direction of further research and the possibility of enhancing the scope of capsule endoscopy.

Aim: To analyze therapeutic changes in Crohn's disease (CD) patients following video capsule endoscopy (VCE) and to assess the usefulness of Lewis score and the Patency Capsule., Methods: Patency Capsule was performed in every patient that had indication for VCE, and those with negative patency did not undergo VCE. Patients with established CD that underwent VCE between January 2011 and February 2014 were selected for this study; those with suspected CD were excluded, independent of VCE results, since our purpose was to address differences in therapeutic regimen in CD patients before and after VCE. Patients with inconclusive VCE were also excluded. Patients had to be free of non-steroidal anti-inflammatories for at least 1 mo. Those patients who met these criteria were allocated into one of three groups: Staging group (asymptomatic CD patients that underwent VCE for staging of CD), Flare group (patients with active CD), or Post-op group (CD patients evaluated for post-operative recurrence). Lewis score was calculated for every VCE procedure. Statistical analysis was performed to address the impact of VCE findings on the therapeutic management of CD patients and to evaluate the utility of the Lewis score., Results: From a total of 542 VCEs, 135 were performed in patients with CD. Patency capsule excluded nearly 25% of the patients who were supposed to undergo VCE. No videocapsule retention during VCE was reported. From these 135 patients, 29 were excluded because CD diagnosis was not established at the time of VCE. Therefore, a total of 106 patients were included in the final analysis. From these, the majority were in the Staging group (n = 73, 69%), and the remaining were in the Flare (n = 23, 22%) or Post-op (n = 10, 9%) group. Median time between diagnosis and VCE was 5.5 years. Overall, VCE determined changes in the treatment of 40% of patients: only 21% remained free of immunosuppressors after VCE compared to 44% before VCE (P < 0.001). The differences in therapy before and after VCE achieved statistical significance in the Staging and Flare groups. In addition, patients were significantly different when stratified regarding time since diagnosis to the date of VCE. A higher Lewis score was associated with therapeutic modifications (P < 0.0001); where a score higher than 1354 was related to 90% probability of changing therapy [area under the receiver operative characteristic (AUROC) 0.80 (95%CI: 0.69-0.88)]., Conclusion: VCE significantly changed the therapeutic management of CD patients, even in those with long-term disease. Systematic use of Patency capsule allowed for no videocapsule retention.

Background: Video capsule endoscopy is a useful tool for noninvasive intestinal detection, but it is not capable of active movement; wireless power is an effective solution to this problem., Methods: The research in this paper consists of two parts: the mechanical structure which enables the robot to move smoothly inside the intestinal tract, and the wireless power supply which ensures efficiency. First, an intestinal robot with leg architectures was developed based on the Archimedes spiral, which mimics the movement of an inchworm. The spiral legs were capable of unfolding to an angle of approximately 155°, which guaranteed stability of clamping, consistency of surface pressure, and avoided the risk of puncturing the intestinal tract. Secondly, the necessary power to operate the robot was far beyond the capacity of button batteries, so a wireless power transmission (WPT) platform was developed. The design of the platform focused on power transfer efficiency and frequency stability. In addition, the safety of human tissue in the alternating electromagnetic field was also taken into consideration. Finally, the assembled robot was tested and verified with the use of the WPT platform., Results: In the isolated intestine, the robot system successfully traveled along the intestine with an average speed of 23 mm per minute. The obtained videos displayed a resolution of 320 × 240 and a transmission rate of 30 frames per second. The WPT platform supplied up to 500 mW of energy to the robot, and achieved a power transfer efficiency of 12%., Conclusion: It has been experimentally verified that the intestinal robot is safe and effective as an endoscopy tool, for which wireless power is feasible. Proposals for further improving the robot and wireless power supply are provided later in this paper., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

We report a case of a 57-year-old woman with an obscure gastrointestinal bleed who was found to have an extramural gastrointestinal stromal tumour (GIST), detected by capsule endoscopy, and confirmed by laparoscopically-assisted enteroscopy and resection. Currently, major modalities used for detection of GISTs include double-balloon enteroscopy, capsule endoscopy and CT. Endoscopic measures, including capsule endoscopy, are limited in their ability to detect GISTs with extramural growth, as these typically do not demonstrate obvious luminal abnormalities. This case report illustrates a case in which an extraluminal GIST causing recurrent gastrointestinal bleeding presented as an ulcer, as seen on capsule endoscopy., (2015 BMJ Publishing Group Ltd.)

Background: We have been developing the Self-Propelling Capsule Endoscope (SPCE) that allows for controllability from outside of the body and real-time observation. What kind of capsule endoscope (CE) is suitable for a controllable SPCE is unclear and a very critical point for clinical application. We compared observing ability of three kinds of SPCEs with different viewing angles and frame rates., Methods: Eleven buttons were sewed in an excised porcine stomach. Four examiners controlled the SPCE using PillCamSB2, -ESO2, and -COLON2 (Given Imaging Ltd., Israel), for 10 minutes each with the aim of detecting as many buttons and examining them as closely as possible. The ability to find lesions was assessed based on the number of detected buttons. The SPCE-performance score (SPS) was used to evaluate the ability to examine the lesions in detail., Results: The SPCE-ESO2, -COLON2, and -SB2 detected 11 [interquartile range (IQR): 0], 10.5 (IQR, 0.5), and 8 (IQR, 1.0) buttons, respectively. The SPCE-ESO2 and -COLON2 had a significantly better ability to detect lesions than the -SB2 (p < 0.05). The SPCE-ESO2, -COLON2, and -SB2 had significantly different SPS values of 22 (IQR, 0), 16.5 (IQR, 1.5), and 14 (IQR, 1.0), respectively (p < 0.05 for all comparisons; SPCE-SB2 vs. -ESO2, -SB2 vs. -COLON2, and -ESO2 vs. -COLON2)., Conclusions: PillCamESO2 is most suitable in different three CEs for SPCE for examining lesions in detail of the stomach.

Although many groups have attempted to develop an automated computerized method to detect pathology of the small intestinal mucosa caused by celiac disease, the efforts have thus far failed. This is due in part to the occult presence of the disease. When pathological evidence of celiac disease exists in the small bowel it is visually often patchy and subtle. Due to presence of extraneous substances such as air bubbles and opaque fluids, the use of computerized automation methods have only been partially successful in detecting the hallmarks of the disease in the small intestine-villous atrophy, fissuring, and a mottled appearance. By using a variety of computerized techniques and assigning a weight or vote to each technique, it is possible to improve the detection of abnormal regions which are indicative of celiac disease, and of treatment progress in diagnosed patients. Herein a paradigm is suggested for improving the efficacy of automated methods for measuring celiac disease manifestation in the small intestinal mucosa. The suggestions are applicable to both standard and videocapsule endoscopic imaging, since both methods could potentially benefit from computerized quantitation to improve celiac disease diagnosis., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Examination of the upper gastrointestinal tract by a standard endoscope is often thought as a daunting experience to many who have undertaken or are about to undergo the procedure. The overall perceived size of the gastroscope, unpleasantness of stimulation of the gag reflex and the need often for sedation is discouraging to many. A method to visualise the upper gastrointestinal mucosa which negates the need for sedation, the associated expensive decontamination costs and the possibility of having a community based examination would be particularly welcoming to this endoscopy field. Since the first swallow of a capsule endoscope by a human volunteer in 1999, their usage for examining the small bowel has exponentially grown to that of over a million patients worldwide. More recently, innovation in this field have shown plausibility for its use to visualise the upper gastrointestinal tract, with the integration of magnets within the capsule the most promising method., (Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.)

Wireless capsule endoscopy (WCE) enables the non-invasive examination of the gastrointestinal (GI) tract by a swallowable device equipped with a miniature camera. Accurate localization of the capsule in the GI tract enables accurate localization of abnormalities for medical interventions such as biopsy and polyp resection; therefore, the optimization of the localization outcome is important. Current approaches to endoscopic capsule localization are mainly based on external sensors and transit time estimations. Recently, we demonstrated the feasibility of capsule localization based-entirely-on visual features, without the use of external sensors. This technique relies on a motion estimation algorithm that enables measurements of the distance and the rotation of the capsule from the acquired video frames. Towards the determination of an optimal visual feature extraction technique for capsule motion estimation, an extensive comparative assessment of several state-of-the-art techniques, using a publicly available dataset, is presented. The results show that the minimization of the localization error is possible at the cost of computational efficiency. A localization error of approximately one order of magnitude higher than the minimal one can be considered as compromise for the use of current computationally efficient feature extraction techniques., (Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.)

In this paper, we present a smart capsule for location-specific drug release in the gastrointestinal tract. Once activated through a magnetic proximity fuse, the capsule opens up and releases its powdered payload in a location specified by an implanted miniature magnetic marker or an externally worn larger magnet. The capsule (9 mm × 26 mm) comprises of two compartments: one contains a charged capacitor and a reed switch, while the second one houses the drug reservoir capped by a taut nylon thread intertwined with a nichrome wire. The nichrome wire is connected to the capacitor through the reed switch. The capacitor is charged to 2.7 V before ingestion and once within the proximity of the permanent magnet; the reed switch closes, discharging the capacitor through the nichrome wire, melting the nylon thread, detaching the cap, and emptying the drug reservoir.

To achieve long-term attachment of capsule endoscopes (CEs) and miniature biosensors in the human gastrointestinal (GI) tract, a tissue attachment mechanism (TAM) was designed, optimized and tested for safety and adhesive capabilities on excised tissue in vitro and in vivo on a live pig model. Six TAMs were tested for their attachment strength in an in vitro attachment tensile experiment in which each TAM was tested on three different proximal intestine tissue samples. The maximum strength and average value are 8.09 N and 4.54 N respectively. The initial attachment damage was tested for 10 min using a sine wave pull force on the TAM with a 0.4 N peak value and 6 s period, which represents typical human intestinal traction force from peristalsis. The in vitro attachment tensile test verified that the tissue was not visually damaged nor perforated by the attachment process. In the in vivo experiment, four TAMs were placed in the intestine of a pig through individual longitudinal enterotomies. X-ray images were taken each hour after the surgery and showed zero migration of the TAMs after 24 h of adhesion. X-ray images taken each day indicated the attachment duration of this mechanism lasted up to 6 days. Post experiment inspection confirmed the attachment did not cause visible damage to tissue. These results confirmed the reliability of the TAM in vivo and demonstrated preliminary feasibility of long-term sensor adhesion to the GI tract.

Background and Study Aims: Capsule endoscopy is well tolerated but control of its movement is needed in order to visualize the whole gastric surface. Technological developments have produced an external magnet to allow manipulation of the capsule within the gastric cavity. The aim of this study was to compare magnetically steerable gastric capsule endoscopy (MSGCE) with flexible endoscopy for the detection of beads in a porcine stomach., Materials and Methods: Beads were sewn onto the mucosal surface of 12 ex vivo porcine stomachs. Each model was examined by flexible endoscopy and MSGCE by two blinded investigators. MSGCE was performed according to a protocol using positional changes and magnetic steering. Outcome measures were number and location of beads identified, and duration of procedure., Results: Flexible endoscopy identified 79 /90 beads (88 %), and MSGCE identified 80 /90 (89 %). The difference in sensitivities was 1.11 (95 % confidence interval 0.06 - 28.26). Thus, MSGCE was noninferior to flexible endoscopy. Mean examination times for flexible endoscopy and MSGCE were 3.34 minutes and 9.90 minutes, respectively., Conclusion: MSGCE was equivalent to conventional flexible endoscopy in the detection of beads in a porcine stomach model., (© Georg Thieme Verlag KG Stuttgart · New York.)

Aim: To evaluate mucosal healing in patients with small bowel plus colonic Crohn's disease (CD) with a single non-invasive examination, by using PillCam COLON 2 (PCC2)., Methods: Patients with non-stricturing nonpenetrating small bowel plus colonic CD in sustained corticosteroid-free remission were included. At diagnosis, patients had undergone ileocolonoscopy to identify active CD lesions, such as ulcers and erosions, and small bowel capsule endoscopy to assess the Lewis Score (LS). After ≥ 1 year of follow-up, patients underwent entire gastrointestinal tract evaluation with PCC2. The primary endpoint was assessment of CD mucosal healing, defined as no active colonic CD lesions and LS < 135., Results: Twelve patients were included (7 male; mean age: 32 years), and mean follow-up was 38 mo. The majority of patients (83.3%) received immunosuppressive therapy. Three patients (25%) achieved mucosal healing in both the small bowel and the colon, while disease activity was limited to either the small bowel or the colon in 5 patients (42%). It was possible to observe the entire gastrointestinal tract in 10 of the 12 patients (83%) who underwent PCC2., Conclusion: Only three patients in sustained corticosteroid-free clinical remission achieved mucosal healing in both the small bowel and the colon, highlighting the limitations of clinical assessment when stratifying disease activity, and the need for pan-enteric endoscopy to guide therapeutic modification.

Wireless capsule endoscopy (CE) for the diagnosis of small-bowel disease has been in clinical use for more than a decade, and is no longer an emerging technology, but rather one that has reached fruition. This noninvasive technology has been readily embraced by both physicians and patients. Used in the diagnosis of inflammatory bowel disease, for locating sources of obscure gastrointestinal bleeding, and for assessing small-bowel polyp burden in polyposis syndromes as well as for less common indications, CE has transformed the diagnostic algorithms of small-bowel investigations. Although already in widespread use, the technology incorporated into the various CE platforms continues to improve and expand. Here, we briefly review the indications, limitations, and advances in video capsule technology, with an emphasis on its use in pediatrics.

Background and Study Aims: We developed a novel magnetic-controlled capsule endoscopy (MCE) system for use in the human stomach. The aim of the current study was to compare the diagnostic accuracy of MCE with that of standard gastroscopy for gastric diseases., Patients and Methods: A total of 68 patients were enrolled in this self-controlled trial. Patients were evaluated by both MCE and gastroscopy. Gastroscopy was performed 4 – 24 hours after completion of the MCE examination., Results: The positive percent agreement between MCE and gastroscopy was 96.0 %, and the negative percent agreement was 77.8 %. The overall agreement was 91.2 % with a kappa value of 0.765 (P < 0.001). A total of 68 pathological findings were detected, of which 53 were identified by both methods. The MCE and standard gastroscopy missed seven and eight findings, respectively., Conclusions: MCE showed a diagnostic accuracy similar to that of standard gastroscopy. These results suggest that MCE is a promising alternative to gastroscopy for noninvasive screening of gastric diseases.Clinical trial registration number: NCT01903629.

Aim: To evaluate the completion rate and diagnostic yield of the PillCam SB2-ex in comparison to the PillCam SB2., Methods: Two hundred cases using the 8-h PillCam SB2 were retrospectively compared to 200 cases using the 12 h PillCam SB2-ex at a tertiary academic center. Endoscopically placed capsules were excluded from the study. Demographic information, indications for capsule endoscopy, capsule type, study length, completion of exam, clinically significant findings, timestamp of most distant finding, and significant findings beyond 8 h were recorded., Results: The 8 and 12 h capsule groups were well matched respectively for both age (70.90 ± 14.19 vs 71.93 ± 13.80, P = 0.46) and gender (45.5% vs 48% male, P = 0.69). The most common indications for the procedure in both groups were anemia and obscure gastrointestinal bleeding. PillCam SB2-ex had a significantly higher completion rate than PillCam SB2 (88% vs 79.5%, P = 0.03). Overall, the diagnostic yield was greater for the 8 h capsule (48.5% for SB2 vs 35% for SB2-ex, P = 0.01). In 4/70 (5.7%) of abnormal SB2-ex exams the clinically significant finding was noted in the small bowel beyond the 8 h mark., Conclusion: In our study, we found the PillCam SB2-ex to have a significantly increased completion rate, though without any improvement in diagnostic yield compared to the PillCam SB2.

Wireless capsule endoscopy (WCE) has been a great breakthrough in visually detecting the pathological changes of gastrointestinal (GI) wall, but the limit of viewing angle and power by batteries still hinder the wide application of WCE. In order to address these shortcomings, a dual-head video capsule system based on new type of receiving coils is presented. First, the dual-head video capsule system is designed, which could capture images of the whole GI tract in two channels, transforming the images into NTSC videos at a frame rate of 30 f s(-1) and transmitting the signals outside the body. Second, the wireless power transmission platform with new type of receiving coils is established to provide at least 108 mW of continuous, stable energy for the capsule. Then a prototype was fabricated and applied in animal experiments. The designed dual-head video capsule system is proved to be feasible and a potential solution for future clinical application.

Background: The completion rate (CR) of small bowel capsule endoscopy (SBCE) has been reported at 81.3% to 84.8%. Prokinetic agents are used to increase CR and (theoretically) diagnostic yield (DY). Domperidone has not been widely used in SBCE; unlike metoclopramide, it lacks extrapyramidal adverse effects., Objectives: This was a retrospective study. This study aimed to assess gastric transit time (GTT), small bowel transit time (SBTT), and the CR of SBCE when using domperidone. Furthermore, we aimed to compare the CR of 2 different SBCE systems (MiroCam, PillCam). Consecutive SBCE examinations (January 2008 to October 2012) from a tertiary referral center were analyzed., Results: In the aforementioned period, a total of 635 SBCE examinations were performed: 379/635 (59.7%) with PillCamSB and 256 (40.3%) with MiroCam. In 437/635 (68.8%) examinations, liquid domperidone (5 mg) was administered for capsule ingestion, whereas 198 (31.2%) ingested the capsule without any domperidone. Although the 2 groups were comparable, the median age of patients who received domperidone was higher compared with patients who did not receive (58 vs. 48 y, P=0.027). In our cohort, the overall CR of SBCE was 88.9%. The 2 SBCE systems showed equivalent CR (PillCamSB 88.9%, MiroCam 89.1%; P =0.96). The use of liquid domperidone increased CR (91.1% vs. 84.3%; P =0.042). Interestingly, the use of domperidone with PillCamSB was associated with reduced DY for vascular, inflammatory, and polyps/mass-type lesions. This effect was not seen in the MiroCam group. Furthermore, the median GTT and the median SBTT did not differ between the 2 groups (GTT/SBTT with domperidone 26.0'/221.0' and without 29.0'/228.0', respectively; P=0.461/P=0.477). A higher CR was noted when domperidone was used with PillCamSB (93.0% vs. 89.5%, P=0.012) than with MiroCam (84.4% vs. 83.3%, P=0.08)., Limitations: The major limitations of this study were the retrospective design of the study and limited numbers on MiroCam with no domperidone., Conclusions: In conclusion, the use of domperidone increases the CR of SBCE with PillCamSB. However, this increase does not translate into higher DY. A smart, tailored approach, which may include domperidone, purgatives, and real-time viewers, may be used in the clinical practice to improve DY until technology delivering capsules with much longer battery time becomes available.

In some biomedical applications such as wireless capsule endoscopy, the localization of an in-body radio-frequency (RF) source is important for the positioning of any abnormality inside the gastrointestinal tract. With knowledge of the location, therapeutic operations can be performed precisely at the position of the abnormality. Electrical properties (relative permittivity and conductivity) of the tissues and their distribution are utilized to estimate the position. This paper presents a method for the localization of an in-body RF source based on microwave imaging. The electrical properties of the tissues and their distribution at 403.5 MHz are found from microwave imaging and the position of an RF source is then estimated based on the image. The method is applied on synthetic noisy data, obtained after the addition of white Gaussian noise to simulated data of a simple circular phantom, and a realistic phantom in a 2-D case. The root-mean-square of the error distance between the actual and the estimated position is found to be within 10 and 4 mm for the circular and the realistic phantom, respectively, showing the capability of the proposed algorithm to work with a good accuracy even in the presence of noise for the localization of the in-body RF source.

Background: Patients with gastrointestinal (GI) dysmotility often experience overlapping upper and lower GI symptoms suggestive of multiregional involvement. Wireless motility capsule (WMC) provides a full GI tract transit profile and may be able to detect and diagnose multiregional dysmotility., Aim: To determine the clinical utility and diagnostic yield of WMC in patients with upper and lower GI symptoms suggestive of multiregional GI dysmotility., Methods: Retrospective chart review of all patients who had undergone WMC testing for suspected multiregional GI dysmotility from January 2009 to December 2012 at our institution was performed. Information regarding demographics, symptoms, medication use, prior diagnostic studies, and results of WMC testing was collected., Results: A total of 161 patients were included in the analysis. Mean age was 43 ± 15 years, and 83 % were female. WMC was abnormal in 109 (67.7 %) subjects. Of these, 17 (15.6 %) patients had isolated delayed gastric emptying, 13 (11.9 %) patients had isolated delayed small bowel transit, and 25 (22.9 %) patients had isolated delayed large bowel transit. Multiregional dysmotility was diagnosed in 54 (49.5 %) patients. There was no significant difference in past medical or past surgical history between patients with isolated regional versus multiregional involvement. The presence or absence of various patient-reported symptoms by history did not predict an abnormal WMC study., Conclusions: Patients' symptoms are poor predictors of GI dysmotility and its anatomical extent. WMC can be a useful diagnostic test in these patients as it provides a comprehensive evaluation of the motility profile of the entire GI tract and provides objective evidence of multiregional involvement.

Gastric cancer is the second leading cause of cancer death worldwide and screening programs have had a significant impact on reducing mortality. The majority of cases occur in low- and middle-income countries (LMIC), where endoscopy resources are traditionally limited. In this paper, we introduce a platform designed to enable inexpensive gastric screening to take place in remote areas of LMIC. The system consists of a swallowable endoscopic capsule connected to an external water distribution system by a multichannel soft tether. Pressurized water is ejected from the capsule to orient the view of the endoscopic camera. After completion of a cancer screening procedure, the outer shell of the capsule and the soft tether can be disposed, while the endoscopic camera is reclaimed without needing further reprocessing. The capsule, measuring 12 mm in diameter and 28 mm in length, is able to visualize the inside of the gastric cavity by combining waterjet actuation and the adjustment of the tether length. Experimental assessment was accomplished through a set of bench trials, ex vivo analysis, and in vivo feasibility validation. During the ex vivo trials, the platform was able to visualize the main landmarks that are typically observed during a gastric cancer screening procedure in less than 8 min. Given the compact footprint, the minimal cost of the disposable parts, and the possibility of running on relatively available and inexpensive resources, the proposed platform can potentially widen gastric cancer screening programs in LMIC.

Background and Aims: This study used computed tomography modelling of the abdomen to determine the optimal placements of a magnetic capsule endoscope in the stomach that allows complete mucosal visualization and determined the optimal placement of the handheld magnet to aid pyloric traversing., Materials and Methods: Using multiplanar reformatting, 100 abdominal computed tomography scans were analysed to assess gastric luminal visualization by a capsule endoscope from five fixed stations throughout the stomach. From each station, we assessed the ability of a capsule endoscope to visualize six gastric landmarks. The pyloric canal angles were calculated to create a vector. We mapped the position of this vector on the patient to determine the optimal placement of the magnet that would aid pyloric traversing., Results: Complete visualization of the stomach (viewing all landmarks) was only achievable in up to 29% of cases when viewed from a sole station. Maximal visualization required combining stations. Fundal dependent (station 1) and opposite antral dependent (station 4) was the best, achieving visualization in 85% (P<0.01). The optimal positioning of the magnet to aid pyloric traversing was posteriorly between vertebrae T5 and L2 in an area 10 cm to the left and 18 cm to the right (83% cases). Age older than 55 years (P=0.03) and the ability to view the pylorus from station 3 (P=0.04) were associated with an extreme pyloric vector., Conclusion: Although there is some extreme variation in the upper gastrointestinal anatomy, the majority of cases will allow the use of a single standard method in performing MACE, which may be very useful for screening purposes.

Colon capsule endoscopy (CCE) is a minimally invasive technique specifically designed to explore the colon without sedation and air insufflation. CCE may overcome some of the limitations of colonoscopy. Second-generation CCE (CCE-2) was proved accurate in detecting colonic neoplastic lesions when used in average-risk individuals. The evidence to date supports the use of CCE-2 in cases of colonoscopy failure, in patients unwilling to undergo colonoscopy, and when colonoscopy is contraindicated. Other potential applications, such as colorectal cancer screening or diagnostic surveillance of inflammatory bowel disease, require clarification., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Aim: To determine if longer battery life improves capsule endoscopy (CE) completion rates., Methods: A retrospective study was performed at a tertiary, university-affiliated hospital in Vancouver, Canada. Patients who underwent CE with either PillCam™ SB2 or SB2U between 01/2010 and 12/2013 were considered for inclusion. SB2 and SB2U share identical physical dimensions but differ in their battery lives (8 h vs 12 h). Exclusion criteria included history of gastric or small bowel surgery, endoscopic placement of CE, interrupted view of major landmarks due to technical difficulty or significant amount of debris, and repeat CE using same system. Basic demographics, comorbidities, medications, baseline bowel habits, and previous surgeries were reviewed. Timing of major landmarks in CE were recorded, and used to calculate gastric transit time, small bowel transit time, and total recording time. A complete CE study was defined as visualization of cecum. Transit times and completion rates were compared., Results: Four hundred and eight patients, including 208 (51.0%) males, were included for analysis. The mean age was 55.5 ± 19.3 years. The most common indication for CE was gastrointestinal bleeding (n = 254, 62.3%), followed by inflammatory bowel disease (n = 86, 21.1%). There was no difference in gastric transit times (group difference 0.90, 95%CI: 0.72-1.13, P = 0.352) and small bowel transit times (group difference 1.07, 95%CI: 0.95-1.19, P = 0.261) between SB2U and SB2, but total recording time was about 14% longer in the SB2U group (95%CI: 10%-18%, P < 0.001) and there was a corresponding trend toward higher completion rate (88.2% vs 93.2%, OR = 1.78, 95%CI 0.88-3.63, P = 0.111). There was no statistically significant difference in the rates of positive findings (OR = 0.98, 95%CI: 0.64-1.51, P = 0.918)., Conclusion: Extending the operating time of CE may be a simple method to improve completion rate although it does not affect the rate of positive findings.

Recently, capsule endoscopes have been used for diagnosis in digestive organs. However, because a capsule endoscope does not have a locomotive function, its use has been limited to small tubular digestive organs, such as small intestine and esophagus. To address this problem, researchers have begun studying an active locomotive intestine capsule endoscope as a medical instrument for the whole gastrointestinal tract. We have developed a capsule endoscope with a small permanent magnet that is actuated by an electromagnetic actuation system, allowing active and flexible movement in the patient's gut environment. In addition, researchers have noted the need for a biopsy function in capsule endoscope for the definitive diagnosis of digestive diseases. Therefore, this paper proposes a novel robotic biopsy device for active locomotive intestine capsule endoscope. The proposed biopsy device has a sharp blade connected with a shape memory alloy actuator. The biopsy device measuring 12 mm in diameter and 3 mm in length was integrated into our capsule endoscope prototype, where the device's sharp blade was activated and exposed by the shape memory alloy actuator. Then the electromagnetic actuation system generated a specific motion of the capsule endoscope to extract the tissue sample from the intestines. The final biopsy sample tissue had a volume of about 6 mm(3), which is a sufficient amount for a histological analysis. Consequently, we proposed the working principle of the biopsy device and conducted an in-vitro biopsy test to verify the feasibility of the biopsy device integrated into the capsule endoscope prototype using the electro-magnetic actuation system., (© IMechE 2015.)

Objectives: Upper gastrointestinal endoscopy is mostly performed under sedation and has a low yield of relevant gastric lesions in patients without alarm symptoms. Simpler screening tests such as capsule endoscopy could be helpful, but gastric visualization is insufficient with the current passive capsules. A magnetically guided gastric capsule was prospectively evaluated in patients with routine indications for gastroscopy., Methods: A total of 189 symptomatic patients (105 male; mean age 53 y) from 2 French centers subsequently and blindly underwent capsule and conventional gastroscopy by 9 and 6 examiners, respectively. The final gold standard was unblinded conventional gastroscopy with biopsy under propofol sedation. Main outcome was accuracy (sensitivity/specificity) of capsule gastroscopy for diagnosis of major gastric lesions, defined as those lesions requiring conventional gastroscopy for biopsy or removal., Results: Twenty-three major lesions were found in 21 patients. Capsule accuracy was 90.5% [95% confidence interval (CI), 85.4%-94.3%] with a specificity of 94.1% (95% CI, 89.3%-97.1%) and a sensitivity of 61.9% (95% CI, 38%-82%). Accuracy did not correlate with lesion location, gastric luminal visibility, examiner case volume, or examination time. Of the remaining 168 patients, 94% had minor and mostly multiple lesions; the capsule made a correct diagnosis in 88.1% (95% CI, 82.2%-92.6%), with gastric visibility and lesion location in the proximal stomach having significant influence. All patients preferred capsule gastroscopy., Conclusions: In a prospective and strictly blinded study, magnetically guided capsule gastroscopy was shown to be feasible in clinical practice and was clearly preferred by patients. Improvements in capsule technology may render this technique a future alternative to gastroscopy.

With the development of capsule endoscopy, developing active capsule endoscopy robot becomes a growing trend. Although stomach diagnosis with robot has been put into clinical test, the realization of the complete intestinal capsule endoscopy is still a difficulty. This paper reports the status quo of the research process for intestinal capsule endoscopy robot, and analyzes their advantages, defects and prospects for development, which provides reference for the research of intestinal capsule endoscopy robot.

Combining ASIC and multiple microsensors low-power wireless electronic capsule was developed for the long-term monitoring of the entire human gastro-intestinal (GI) tract. To meet the system requirements, several low-power designs were used in the wireless electronic capsule. The capsule measured 11 × 22 mm including batteries (45mAh). The capsule system's lifetime was 233 h, and it could meet the requirements of almost all clinical applications. A wireless electronic capsule, portable data recorder, and workstation comprised the human GI physiological parameters monitoring system. In this paper, this system was used in a clinical trial to compare colon peristaltic pressure between patients with constipation and healthy people.

Wireless capsule endoscopy (WCE) enables the detection and diagnosis of inflammatory bowel diseases such as Crohn's disease and ulcerative colitis. However treatment of these pathologies can only be achieved through conventional means. This paper describes the next generation WCE with increased functionality to enable targeted drug delivery in the small intestinal tract. A prototype microrobot fabricated in Nylon 6 is presented which is capable of resisting peristaltic pressure through the deployment of an integrated holding mechanism and delivering targeted therapy. The holding action is achieved by extending an "anchor" spanning a 60.4 mm circumference, for an 11.0 mm diameter WCE. This function is achieved by a mechanism that occupies only 347.0 mm(3) volume, including mechanics and actuator. A micropositioning mechanism is described which utilises a single micromotor to radially position and then deploy a needle 1.5 mm outside the microrobot's body to deliver a 1 mL dose of medication to a targeted site. An analysis of the mechanics required to drive the holding mechanism is presented and an overview of microactuators and the state of the art in WCE is discussed. It is envisaged that this novel functionality will empower the next generation of WCE to help diagnose and treat pathologies of the GI tract.

This paper presents an analysis of H-field generated by a simple solenoid, pair of solenoids, pair of double-layer solenoids, segmented-solenoid, and Helmholtz power transmission coils (PTCs) to power an endoscopic wireless capsule (WC). The H-fields were computed using finite element analysis based on partial differential equations. Three parameters were considered in the analysis: i) the maximum level of H-field (Hmax) to which the patient's body would be exposed, ii) the minimum level of H-field (Hmin) effective for power transmission, and iii) uniformity of H-field. We validated our analysis by comparing the computed data with data measured from a fabricated Helmholtz PTC. This analysis disclosed that at the same excitation power, all the PTCs are able to transfer same amount of minimum usable power since they generated almost equal value of Hmin. The level of electromagnetic exposure and power transfer stability across all the PTCs would vary significantly which is mainly due to the different level of Hmax and H-field uniformity. The segmented solenoid PTC would cause the lowest exposure and this PTC can transfer the maximum amount of power. The Helmholtz PTC would be able to transfer the most stable power with a moderate level of exposure.

Aim: Is to evaluate technical aspects and feasibility of colon capsule endoscopy (CCE) in the daily clinical practice., Materials and Methods: From I.2014 to VIII.2014 we performed 36 (97.3%) CCE from 37 patients (m-19, f-17, mean age 43.9 ± 14.2 years, range 22-72)., Results: Total CCE was performed in 33 (89.2%) patients. In all patients we were able to register anatomy and to evaluate the lumen and the wall of large bowel; to explore and identify mucosal abnormality as well as epithelial lesions., Conclusion: The article demonstrates our own experience of colon capsule endoscopy (n = 36); the principal possibilities to evaluate colon anatomy and to detect wide range of abnormality.

Video capsule endoscopy is being increasingly used to investigate the esophagus and colon as well as the small bowel. With the advancement of technology used in capsule endoscopy there have been marked improvements in diagnostic rates for colon capsule endoscopy in the detection of colonic polyps and colorectal cancer. It is also being increasingly used in the field if inflammatory bowel disease to investigate for mucosal inflammation and could potentially be used to assess mucosal healing. It also has role in completing the evaluation of colonic pathology in those in whom colonoscopy is incomplete. Esophageal capsule is preferred by patients over esophagogastroduodenoscopy (EGD) but as yet does not rival EGD in terms of diagnostic accuracy however the advent of magnetically steerable capsules may improve this. This review covers advances in the field of colon and esophageal capsule endoscopy; it covers diagnostic capabilities of these 2 tools as well as technical aspects of both procedures and preparation.

In this paper, we propose a platform to achieve accurate localization of small-bowel lesions and endoscopic video stabilization in wireless capsule endoscopy. Current research modules rely on the use of external magnetic fields and triangulation methods to calculate the position vector of the capsule, leading to considerable error margins. Our platform, entitled OdoCapsule (a synthesis of the words Odometer and Capsule), provides real-time distance information from the point of duodenal entry to the point of exit from the small bowel. To achieve this, OdoCapsule is equipped with three miniature legs. Each leg carries a soft rubber wheel, which is made with human-compliant material. These legs are extendable and retractable thanks to a micromotor and three custom-made torsion springs. The wheels are specifically designed to function as microodometers: each rotation they perform is registered. Hence, the covered distance is measured accurately in real time. Furthermore, with its legs fully extended, OdoCapsule can stabilize itself inside the small-bowel lumen thus offering smoother video capture and better image processing. Recent ex vivo testing of this concept, using porcine small bowel and a commercially available (custom-modified) capsule endoscope, has proved its viability.

Background and Aim: The Agile patency capsule (PC; Given Imaging Ltd, Yoqneam, Israel) is used as a dummy prior to capsule endoscopy (CE) to avoid retention of the CE capsule. However, impaction of the PC's inner radio frequency identification (RFID) tag in a stricture could cause small-bowel ileus. Recently, the RFID tag-less PC was introduced into clinical practice. Herein, we aimed to retrospectively evaluate the usefulness of the tag-less PC., Methods: Of 154 patients who were scheduled to undergo CE, 100 consecutive patients (65%) who underwent PC evaluation were enrolled in the present study. Primary study end point was the retention rate of the CE capsule after successful passage of the PC. Secondary end point was analysis of the significant factors affecting the passage of the PC., Results: In total, 87 patients (87%) had bowel patency confirmed by PC evaluation. There was no capsule retention in any of these 87 patients during CE. Abnormal findings were obtained from 60 CE, and 41 patients received new or modified treatment. Multivariate analysis of factors related to the confirmation of patency demonstrated that stenosis on imaging was the most influential factor (P = 0.002, odds ratio 16.387). The results confirmed that passage of the PC depends on stenosis on imaging., Conclusions: Use of the tag-less PC confirmed gastrointestinal tract patency for most of the patients who did not have stenosis on imaging and allowed estimation of the patency for patients who did have stenosis on imaging., (© 2014 The Authors. Digestive Endoscopy © 2014 Japan Gastroenterological Endoscopy Society.)

Simulation of a wireless communication link for a capsule endoscopy is presented for monitoring of small intestine in humans. The realized communication link includes the transmitting capsule antenna, the outside body receiving antenna and the model of the human body. The capsule antenna is designed for operating at the frequency band of 600 MHz with an impedance bandwidth of 10 MHz and omnidirectional radiation pattern. The quality of the communication link is improved by using directive antenna outside body inside matching layer for electromagnetic wave tuning to the body. The outside body antenna has circular polarization that guaranteeing the communication link for different orientations of the capsule inside intestine. It is shown that the path loss for the capsule in 60 mm from the abdomen surface varies between 37-47 dB in relation to the antenna orientation. This link can establish high data rate wireless communications for capsule endoscopy.

Background/aims: A patency capsule (PC) is used to safely perform capsule endoscopy. When the PC is not excreted within the defined time frame, radiography often cannot localize the PC. Computed tomography (CT) localizes a PC more definitively than radiography. We evaluated the localization of PCs using low-dose (LD)-CT., Methodology: Forty-nine patients received a PC and 33 did not excrete the PC within the defined time frame and underwent radiography and LDCT with a 90% exposure reduction., Results: LDCT localized the PC in 31 patients (93.9%), whereas radiography localized it in 7 (21.2%), indicating a significantly higher detection rate with LDCT (P<0.0001). PC retention in the small intestine was confirmed by LDCT in 4 patients. Retention was not observed during capsule endoscopy in the patients with confirmed patency of the gastrointestinal tract. In 21 patients who underwent LDCT with the conventional photographing area, the effective radiographic exposure dose associated with LDCT was 1.43±1.08 mSv. Conversely, in the 12 patients who underwent LDCT with a reduced photographing area, the effective dose was reduced to 0.62±0.27 mSv (P<0.05)., Conclusion: LDCT with a reduced exposure dose can definitively localize a PC. Therefore, this method may allow capsule endoscopy to be performed for more diseases.

Video capsule endoscopy (VCE) was launched in 2000 and has revolutionized direct endoscopic imaging of the gut. VCE is now a first-line procedure for exploring the small bowel in cases of obscure digestive bleeding and is also indicated in some patients with Crohn's disease, celiac disease, and polyposis syndrome. A video capsule has also been designed for visualizing the esophagus in order to detect Barrett's esophagus or esophageal varices. Different capsules are now available and differ with regard to dimensions, image acquisition rate, battery life, field of view, and possible optical enhancements. More recently, the use of VCE has been extended to exploring the colon. Within the last 5 years, tremendous developments have been made toward increasing the capabilities of the colon capsule. Although colon capsule cannot be proposed as a first-line colorectal cancer screening procedure, colon capsule may be used in patients with incomplete colonoscopy or in patients who are unwilling to undergo colonoscopy. In the near future, new technological developments will improve the diagnostic yield of VCE and broaden its therapeutic capabilities.

Background: PillCam patency capsule (PC) is a novel and radiofrequency identification tag-free device that remains intact in the gastrointestinal tract for 30-33 h after ingestion and then disintegrates. The aim of this study was to determine the clinical relevance of PC combined with abdominal ultrasonography as a reliable indicator of functional patency., Patients and Methods: The study was prospective and PillCam PC was administered to consecutive patients with known or suspected small bowel strictures. PC was verified if it was excreted intact in 33 h after administration. Following excretion failure and radiograph detection in the pelvic cavity, ultrasonography was used to detect the PC in relation to the stricture., Results: The participants were 52 patients with known or suspected small bowel strictures (58% women, mean age 51 years, including 32 with or suspected Crohn's disease). Twenty-two patients (42.3%) retrieved PC in the stool within 33 h after ingestion. Radiograph identified the four PCs in the colon and eight were not observed. Ultrasonography precisely judged all 17 PCs retained including six PCs at the proximal side of small bowel stricture in the patients considered ineligible for capsule endoscopy (CE). In all eligible patients, CE passed through the small intestine without incident., Conclusion: PillCam PC combined with ultrasonography before CE appears to be a reliable indicator of functional patency to predict and minimize the risk of impaction in suspected or even known cases with small bowel stricture.

Background and Objective: The reading of capsule endoscopy (CE) is time-consuming. Thus, several time-saving features have been added to the CE software by different CE companies. However, the similar pictures elimination mode in the OMOM capsule endoscopy software has not been evaluated yet. Our aim is to evaluate the sensitivity and specificity of the similar pictures elimination mode., Methods: We retrospectively studied 200 consecutive capsule endoscopy procedures in Nanfang Hospital between April 2012 and July 2012, among which 52 cases were excluded for poor bowel preparation, failure to reach the colon or data missing. All images of the small-bowel were re-evaluated with four different reading modes (conventional mode and three levels of similar pictures elimination mode) by four experienced endoscopists. Then, the reading time, the number of detected lesions, κ value, sensitivity and specificity were compared between 4 methods., Results: The mean reading time with levels I to III, respectively, was significantly shorter than with conventional mode (P<0.001, conventional mode 33.25min, level I 24.90min, level II 20.54min, level III 14.96min). The sensitivity between conventional mode and level I were similar (93.8% vs. 87.7%, P=0.073), while the sensitivity of levels II and III was significantly lower than conventional mode (77.8% vs. 93.8%, 70% vs. 93.8%, respectively). The specificity between all 4 modes were similar (100% for conventional mode, 98.5% for levels I to III)., Conclusions: Level I reading mode was as efficient as the conventional mode and less time-consuming. Its sensitivity and specificity were similar compared with the conventional mode., (Copyright © 2014. Published by Elsevier Masson SAS.)

Colon capsule endoscopy (CCE; PillCam Colon; Given Imaging; Yoqneam, Israel) is a minimally invasive wireless technique for the visualization of the colon. With the recent introduction of the second generation colon capsule the diagnostic accuracy of CCE for polyp detection has significantly improved and preliminary data suggest it may be useful to monitor mucosal inflammation in patients with inflammatory bowel disease. Limitations include the inability to take biopsies and the procedural costs. However, given the potentially higher acceptance within an average risk colorectal cancer (CRC) screening population, its usefulness as a screening tool with regard to CRC prevention should be further evaluated.