A 2.4GHz Low Power ASK Transmitter for Wireless Capsule Endoscope Applications

A 2.4GHz ASK transmitter suitable for a low power wireless capsule endoscope system is presented. A mixer-based frequency up-conversion transmitter architecture is employed to achieve a high data rate. A pseudodifferential stacked class-A power amplifier using the current reuse technique is proposed to save power. The transmitter mainly includes two parts： a 20MHz ASK modulator based on a constant amplitude phase lock loop （PLL） and a direct up-conversion RF circuit. This design, implemented in a TSMC 0.25μm CMOS process, achieves a - 23. 217dBm output power with a data rate of 1Mbps and dissipates 3.17mA of current with a single 2.5V power supply.

Wireless capsule endoscopy

Wireless capsule endoscopy is a new technique that allows complete exploration of the small bowel without exlemal wires. Its role has been analyzed in many small bowel diseases such as obscure gastrointestinal bleeding, Crohn＇s disease and gastrointestinal polyposis syndromes with promising results. Studies on other pathologies （i.e. small bowel tumour, celiac disease） are under evaluation to define the role of this technique.

Wireless capsule endoscopy in the investigation of patients with chronic renal failure and obscure gastrointestinal bleeding (preliminary data)

AIM： To investigate the role of wireless capsule endoscopy （WCE） in detection of small bowel （SB） pathology in patients with chronic renal failure （CRF） and obscure bleeding. METHODS： Consecutive CRF patients with obscure bleeding were prospectively studied. Patients with normal renal function and obscure bleeding, investigated during the same period with WCE, were used for the interpretation of results. RESULTS： Seventeen CRF patients （11 overt, 6 occult bleeding） and 51 patients （33 overt, 18 occult bleeding） with normal renal function were enrolled in this study. Positive SB findings were detected in 70.6% of CRF patients and in 41.2% of non-CRF patients （P〈0.05）. SB angiodysplasia was identified in 47% of CRF patients and in 17.6% of non-CRF patients. Univariate logistic regression revealed CRF as a significant predictive factor for angiodysplasia （P〈0.05）. Therapeutic measures were undertaken in 66% of the patients with the positive findings. CONCLUSION： According to our preliminary results, SB angiodysplasia was found in an increased prevalence among CRF patients with obscure bleeding. WCE is useful in diagnosis of gastrointestinal pathologies and in planning appropriate therapeutic intervention and, therefore, should be included in the work-up of this group of patients.

Wireless capsule endoscopy and proximal small bowel lesions in Crohn’s disease

AIM: To investigate the prevalence of proximal small bowel (SB) lesions detected by wireless capsule endoscopy (WCE) in Crohn's disease (CD). METHODS: WCE was performed in 64 patients: 32 with CD of the distal ileum, and 32 controls with iron-deficiency anemia (IDA) or diarrhea. WCE was performed using the Given SB-WCE, followed by small intestine contrast ultrasonography (SICUS). Findings compatible with CD by using WCE included erosions, aphthoid or deep ulcers, and strictures/stenosis. RESULTS: WCE detected proximal SB lesions in 16/32 (50%) patients (14 aphthoid ulcers, 2 deep ulcers, one stricture), which appeared not to be related to clinical parameters [epigastric pain, age, smoking, non-steroidalanti-inflammatory drugs (NSAIDs), IDA]. Among patients with proximal SB lesions, 6 (37%) were smokers, 3 (19%) NSAID users, 3 (19%) had epigastric pain and 4 (25%) had IDA. SICUS detected proximal SB lesions in 3/32 patients (19%) also showing lesions with WCE. No correlations were observed between proximal SB lesions assessed by WCE or by SICUS (χ2 = 1.5, P = 0.2). CONCLUSION: The use of WCE allows the detection of previously unknown upper SB lesions in a high proportion of patients with a previous diagnosis of CD involving the distal ileum.

RF characteristics of wireless capsule endoscopy in human body

The wireless capsule endoscope,as a small electronic device,has conquered some limitations of traditional wired diagnosing tools,such as the uncomfortableness of the cables for the patient and the inability to examine the very convoluted small intestine section.However,this technique is still encountering a lot of practical challenges and is looking for feasible improvements.This work investigates the RF performance of the wireless capsule endoscope system by studying the electromagnetic(EM) wave propagation within the human body.A wireless capsule endoscopy transmission channel model is constructed to serve the purpose of investigating signal attenuations according to the relative position between the transmitter and the receiver.Within 300-500 MHz,the S_(21) results are regular and do not display any sudden changes,which allows a suitable expression to be derived for S_(21) in terms of frequency and offset.The results provide useful information for capsule localization.

Wireless capsule endoscopy in detecting small-intestinal polyps in familial adenomatous polyposis

AIM:To detect the prevalence of small bowel polyps by wireless capsule endoscopy(WCE)in patients with familial adenomatous polyposis(FAP).METHODS:We examined prospectively 14 patients with FAP to assess the location,size and number of small-intestinal polyps.Patients'age,sex,years of observation after surgery,type of surgery,duodenal polyps and colorectal cancer at surgery were analyzed.RESULTS:During WCE,polyps were detected in 9/14(64.3%)patients.Duodenal adenomatous polyps were found in nine(64.3%)patients,and jejunal and ileal polyps in seven(50%)and eight(57.1%),respectively.The Spigelman stage of duodenal polyposis was associated with the presence of jejunal and ileal polyps.Identification of the ampulla of Vater was not achieved with WCE.Importantly,the findings of WCE had no immediate impact on the further clinical management of FAP patients.No procedure-related complications were observed in the patients.CONCLUSION:WCE is a promising noninvasive new method for the detection of small-intestinal polyps.Further investigation is required to determine which phenotype of FAP is needed for surveillance with WCE.

Role of wireless capsule endoscopy in inflammatory bowel disease

Capsule endoscopy(CE) offers state-of-the-art imaging of the small bowel.In Crohn's disease its clinical role is still uncertain.This report analyses the usefulness of CE in patients with suspected Cronh's disease,in patients with established Crohn's disease(when assessing severity,occult gastrointestinal bleeding and/or as a guide to therapy),in patients with inflammatory bowel disease unclassified(IBDU),and in individuals with ulcerative colitis.The first item in this group is the most important although there is no strong evidence to establish the position of CE in the diagnostic workup.In patients with established Crohn's disease,recently developed activity scores are promising tools for an accurate assessment of severity.As a guide to therapy,CE should be focused on patients with unexplained symptoms when other investigations are inconclusive.In postoperative Crohn's Disease,international consensus recommended considering CE only ifileocolonoscopy is contraindicated or unsuccessful.In the case of IBDU,studies have shown a significant proportion of patients reclassified with Crohn's disease.In this setting,CE could have a role determining small bowel involvement.The role of CE in ulcerative colitis is limited.Some authors advocate CE before colectomy for refractory cases in order to exclude Crohn's disease.In summary,CE offers a new horizon in inflammatory bowel disease,and a better knowledge of mucosal abnormalities that could offer a paradigm shift:changing from symptombased disease activity estimation to direct mucosal healing monitoring.Nevertheless,randomized controlled studies are still needed to provide stronger evidence in this setting.

Wireless capsule endoscopy: Perspectives beyond gastrointestinal bleeding

Wireless capsule endoscopy(CE) is a technology developed for the endoscopic exploration of the small bowel. The first capsule model was approved by the Food and Drug Administration in 2001, and its first and essential indication was occult gastrointestinal(GI) bleeding. Over subsequent years, this technology has been refined to provide superior resolution, increased battery life, and capabilities to view different parts of the GI tract. Indeed, cases for which CE proved useful have increased significantly over the last few years, with new indications for the small bowel and technical improvements that have expanded its use to other parts of the GI tract, including the esophagus and colon. The main challenges in the development of CE are new devices with the ability to provide therapy, air inflation for a better vision of the small bowel, biopsy sampling systems attached to the capsule and the possibility to guide and move the capsule with an external motion control. In this article we review the current and new indications of CE, and the evolving technological changes shaping this technology, which has a promising potential in the coming future of gastroenterology.

Detection of small bowel tumor in wireless capsule endoscopy images using an adaptive neuro-fuzzy inference system

Automatic diagnosis tool helps physicians to evaluate capsule endoscopic examinations faster and more accurate.The purpose of this study was to evaluate the validity and reliability of an automatic post-processing method for identifying and classifying wireless capsule endoscopic images, and investigate statistical measures to differentiate normal and abnormal images. The proposed technique consists of two main stages, namely, feature extraction and classification. Primarily, 32 features incorporating four statistical measures(contrast, correlation, homogeneity and energy) calculated from co-occurrence metrics were computed. Then, mutual information was used to select features with maximal dependence on the target class and with minimal redundancy between features. Finally, a trained classifier, adaptive neuro-fuzzy interface system was implemented to classify endoscopic images into tumor, healthy and unhealthy classes. Classification accuracy of 94.2% was obtained using the proposed pipeline. Such techniques are valuable for accurate detection characterization and interpretation of endoscopic images.

Wireless Capsule Cystoscopy: How Near? How Far?

It is a fact that performing endoscopy using conventional methods requires substantial time and development of alternative diagnostic modalities. Replacement of rigid endoscopes with flexible and digital devices in time, faster performance of the procedures and reduced time for them to turn back to work brought about the expectancy. It was possible that easier and more reliable methods could exist. Idea of capsule endoscopy was born following examination of the gastrointestinal tract with an endoscope with shape of a capsule. Although idea of capsule endoscopy was suggested long years ago, it fell behind the advances in conventional step of the endoscopy, especially developmental speed of the flexible devices. Furthermore, three-dimensional (3D) organ views can be processed digitally by means of sophisticated software in the fields of computerized tomography and magnetic resonance imaging. Thus, virtual cystoscopy of high resolution and specificity is possible by means of both methods. Wireless capsule endoscopy is still in the experimental stage. “Steerable independent intracorporeal endoscope” with feature of consecutive instillation in addition to its diagnostic utility is not a dream.

Bleeding Detection from Wireless Capsule Endoscopy Images Using Improved Euler Distance in CIELab

Bleeding in the digestive tract is one of the most common gastrointestinal (GI) tract diseases,as well as the complication of some fatal diseases. Wireless capsule endoscopy (WCE),which is widely applied in the clinical field,allows physicians to noninvasively examine the entire GI tract. However,it is very laborious and timeconsuming to detect the huge amount of WCE images,and limits its wider application. It is urgent and necessary to develop the automatic and intelligent computer aided bleeding detection technique. This paper improves the Euler distance with the covariance matrix of image to measure the colour similarity in CIELab colorimetric system,and proposes a novel method of bleeding detection in WCE images. The experiments demonstrate that the bleeding region in WCE images can be correctly recognized and marked out,and the sensitivity of this method is 92%,the specificity is 95%.

Wireless esophageal pH capsule for patients with gastroesophageal reflux disease: A multicenter clinical study

AIM: To investigate the feasibility and safety of pH capsule to monitor pH in patients with gastroesophageal reflux disease (GERD).

Meckel's diverticulum diagnosis by video capsule endoscopy: A case report and review of literature

BACKGROUND Meckel’s diverticulum （MD） occurs predominantly in chil-dren and adolescents. It is rarely diagnosed in adults. Preoperative diagnosis is diffcult due to low sensitivity of the radiological imaging studies. The role of video capsule endoscopy （VCE） in the diagnosis of MD is unknown, and the endoscopic patterns are not defned. We will describe four of our cases of MD evaluated with VCE and make a review of the literature focusing on the endoscopic characteristics.CASE SUMMARYWe present four cases of MD confirmed by surgery. They were all adult males with ages going from 18 to 50 years, referred to our service from 2004 to 2018, due to obscure gastrointestinal bleeding （OGIB）. TheyGarcía-Compeán D et al . Merckel’s diverticulum diagnosis by VCEhad a history of 1 mo to 10 years of overt and occult bleeding episodes. Laboratory blood test showed an iron-deficiency anemia from 4 to 9 g/dL of hemoglo-bin that required multiple hospitalizations and blood transfusions in all cases. Repeated upper digestive endoscopies and colonoscopies were negative. Small bowel was examined with VCE, which revealed double lumen images in all cases, one with polyps and three with circumferential ulcers in the diverticulum. However, based on VCE findings, preoperative diagnosis of MD was suggested only in two patients. Capsule was retain-ed in one patient, which was recovered with surgery. The anatomopathological report revealed ulcerated ectopic gastric mucosa in all cases.CONCLUSIONVCE is useful for the diagnosis of MD. However, endo-scopic characteristics must be recognized in order to establish preoperative diagnosis.

QI-BRiCE: Quality Index for Bleeding Regions in Capsule Endoscopy Videos

With the advent in services such as telemedicine and telesurgery,provision of continuous quality monitoring for these services has become a challenge for the network operators.Quality standards for provision of such services are application specic as medical imagery is quite different than general purpose images and videos.This paper presents a novel full reference objective video quality metric that focuses on estimating the quality of wireless capsule endoscopy(WCE)videos containing bleeding regions.Bleeding regions in gastrointestinal tract have been focused in this research,as bleeding is one of the major reasons behind several diseases within the tract.The method jointly estimates the diagnostic as well as perceptual quality of WCE videos,and accurately predicts the quality,which is in high correlation with the subjective differential mean opinion scores(DMOS).The proposed combines motion quality estimates,bleeding regions’quality estimates based on support vector machine(SVM)and perceptual quality estimates using the pristine and impaired WCE videos.Our method Quality Index for Bleeding Regions in Capsule Endoscopy(QI-BRiCE)videos is one of its kind and the results show high correlation in terms of Pearson’s linear correlation coefcient(PLCC)and Spearman’s rank order correlation coefcient(SROCC).An F-test is also provided in the results section to prove the statistical signicance of our proposed method.

Understanding deep learning in capsule endoscopy: Can artificial intelligence enhance clinical practice?

Wireless capsule endoscopy(WCE)enables physicians to examine the gastrointestinal tract by transmitting images wirelessly from a disposable capsule to a data recorder.Although WCE is the least invasive endoscopy technique for diagnosing gastrointestinal disorders,interpreting a WCE study requires significant time effort and training.Analysis of images by artificial intelligence,through advances such as machine or deep learning,has been increasingly applied to medical imaging.There has been substantial interest in using deep learning to detect various gastrointestinal disorders based on WCE images.This article discusses basic knowledge of deep learning,applications of deep learning in WCE,and the implementation of deep learning model in a clinical setting.We anticipate continued research investigating the use of deep learning in interpreting WCE studies to generate predictive algorithms and aid in the diagnosis of gastrointestinal disorders.

Optimized Identification with Severity Factors of Gastric Cancer for Internet of Medical Things

The Internet of Medical Things (IoMT) emerges with the visionof the Wireless Body Sensor Network (WBSN) to improve the health monitoringsystems and has an enormous impact on the healthcare system forrecognizing the levels of risk/severity factors (premature diagnosis, treatment,and supervision of chronic disease i.e., cancer) via wearable/electronic healthsensor i.e., wireless endoscopic capsule. However, AI-assisted endoscopy playsa very significant role in the detection of gastric cancer. Convolutional NeuralNetwork (CNN) has been widely used to diagnose gastric cancer based onvarious feature extraction models, consequently, limiting the identificationand categorization performance in terms of cancerous stages and gradesassociated with each type of gastric cancer. This paper proposed an optimizedAI-based approach to diagnose and assess the risk factor of gastric cancerbased on its type, stage, and grade in the endoscopic images for smarthealthcare applications. The proposed method is categorized into five phasessuch as image pre-processing, Four-Dimensional (4D) image conversion,image segmentation, K-Nearest Neighbour (K-NN) classification, and multigradingand staging of image intensities. Moreover, the performance of theproposed method has experimented on two different datasets consisting ofcolor and black and white endoscopic images. The simulation results verifiedthat the proposed approach is capable of perceiving gastric cancer with 88.09%sensitivity, 95.77% specificity, and 96.55% overall accuracy respectively.

Comment on “Artificial intelligence in gastroenterology: A state-ofthe- art review”

Colon capsule endoscopy(CCE)was introduced nearly two decades ago.Initially,it was limited by poor image quality and short battery time,but due to technical improvements,it has become an equal diagnostic alternative to optical colonoscopy(OC).Hastened by the coronavirus disease 2019 pandemic,CCE has been introduced in clinical practice to relieve overburdened endoscopy units and move investigations to out-patient clinics.A wider adoption of CCE would be bolstered by positive patient experience,as it offers a diagnostic investigation that is not inferior to other modalities.The shortcomings of CCE include its inability to differentiate adenomatous polyps from hyperplastic polyps.Solving this issue would improve the stratification of patients for polyp removal.Artificial intelligence(AI)has shown promising results in polyp detection and characterization to minimize incomplete CCEs and avoid needless examinations.Onboard AI appears to be a needed application to enable near-real-time decision-making in order to diminish patient waiting times and avoid superfluous subsequent OCs.With this letter,we discuss the potential and role of AI in CCE as a diagnostic tool for the large bowel.

Double balloon enteroscopy in children:Diagnosis,treatment,and safety

AIM:To assess the feasibility and utility of double balloon enteroscopy(DBE)in the management of small bowel diseases in children. METHODS:Fourteen patients(10 males)with a median age of 12.9 years(range 8.1-16.7)underwent DBE; 5 for Peutz-Jeghers syndrome(PJ syndrome),2 for chronic abdominal pain,4 for obscure gastrointestinal (GI)bleeding,2 with angiomatous malformations(1 blue rubber bleb nevus syndrome)having persistent GI bleeding,and 1 with Cowden's syndrome with multiple polyps and previous intussusception.Eleven procedures were performed under general anesthesia and 3 with deep sedation. RESULTS:The entire small bowel was examined in 6 patients,and a length between 200 cm and 320 cm distal to pylorus in the remaining 8.Seven patients had both antegrade(trans-oral)and retrograde(transanal and via ileostomy)examinations.One patient underwent DBE with planned laparoscopic assistance.The remaining 6 had trans-oral examination only.The median examination time was 118 min(range 95-195). No complications were encountered.Polyps were detected and successfully removed in all 5 patients with PJ syndrome,in a patient with tubulo-villous adenoma of the duodenum,in a patient with significant anemia and occult bleeding,and in a patient with Cowden's syndrome.A diagnosis was made in a patient with multiple angiomata not amenable to endotherapy,and in 1 with a discrete angioma which was treated with argon plasma coagulation.The source of bleeding was identified in a further patient with varices.DBE was normal or revealed minor mucosal friability in the remaining 3 patients.Hence a diagnostic yield of 11/14 with therapeutic success in 9/14 was achieved. CONCLUSION:Double balloon enteroscopy can be a useful diagnostic and therapeutic tool for small bowel disease in children,allowing endo-therapeutic intervention beyond the reach of the conventional endoscope.

Gastroparesis:New insights into an old disease

Gastroparesis(Gp)is a chronic disease characterized by a delayed gastric emptying in the absence of mechanical obstruction.Although this condition has been reported in the literature since the mid-1900s,only recently has there been renewed clinical and scientific interest in this disease,which has a potentially great impact on the quality of life.The aim of this review is to explore the pathophysiological,diagnostic and therapeutical aspects of Gp according to the most recent evidence.A comprehensive online search for Gp was carried out using MEDLINE and EMBASE.Gp is the result of neuromuscular abnormalities of the gastric motor function.There is evidence that patients with idiopathic and diabetic Gp may display a reduction in nitrergic inhibitory neurons and in interstitial cells of Cajal and/or telocytes.As regards diagnostic approach,99-Technetium scintigraphy is currently considered to be the gold standard for Gp.Its limits are a lack of standardization and a mild risk of radiation exposure.The C13 breath testing is a valid and safe alternative method.13C acid octanoic and the 13C Spirulina platensis recently approved by the Food and Drug Administration are the most commonly used diagnostic kits.The wireless motility capsule is a promising technique,but its use is limited by costs and scarce availability in many countries.Finally,therapeutic strategies are related to the clinical severity of Gp.In mild and moderate Gp,dietary modification and prokinetic agents are generally sufficient.Metoclopramide is the only drug approved by the Food and Drug Administration for Gp.However,other older and new prokinetics and antiemetics can be considered.As a second-line therapy,tricyclic antidepressants and cannabinoids have been proposed.In severe cases the normal nutritional approach can be compromised and artificial nutrition may be needed.In drug-unresponsive Gp patients some alternative strategies(endoscopic,electric stimulation or surgery)are available.

Smart Image Sensor with Integrated Low Complexity Image Processing for Wireless Endoscope Capsules

A smart image sensor was developed which integrates a digital pixel image sensor array with an image processor, designed for wireless endoscope capsules. The camera-on-a-chip architecture and its on-chip functionality facilitate the design of the packaging and power consumption of the integrated capsule. The power reduction techniques were carried out at both the architectural and circuit level. Gray coding and power gating in the sensor array to eliminate almost 50% of the switch activity on the data bus and more than 99% of the power dissipation in each pixel at a transmitting rate of 2 frames per second. Filtering and compression in the processor reduces the data transmission by more than 2/3. A parallel fully pipelined architecture with a dedicated clock management scheme was implemented in the JPEG-LS engine to reduce the power consumption by 15.7%. The smart sensor has been implemented in 0.18 μm CMOS technology.