DPCM based compressor for capsule endoscopic videos

The main challenge in video capsule endoscopic system is to reduce the area and power consumption while maintaining acceptable video reconstruction. In this paper, a subsample-based data compressor for video endoscopy application is presented. The algorithm is developed around the special features of endoscopic images that consists of a differential pulse-coded modulation (DPCM) followed by Golomb-Rice coding. Based on the nature of endoscopic images, several subsampling schemes on the chrominance components are applied. This video compressor is designed in a way to work with any commercial low-power image sensors that outputs image pixels in a raster scan fashion, eliminating the need of memory buffer and temporary storage (as needed in transform coding schemes). An image corner clipping algorithm is also introduced. The reconstructed images have been verified by five medical doctors for acceptability. The proposed low-complexity design is implemented in a 0.18 μm CMOS technology and consumes 592 standard cells, 0.16 × 0.16 mm silicon area, and 42 μW of power. Compared to other algorithms targeted to video capsule endoscopy, the proposed raster-scan-based scheme performs strongly with a compression ratio of 80% and a very high reconstruction peak signal-to-noise ratio (over 48 dB).

Power efficient ultra-wideband based wireless communication for wireless body area network applications

Purpose: Lubiprostone, a selective activator of type 2 chloride channels, is approved for treatment of chronic idiopathic constipation and constipation predominant IBS. It has been suggested that lubiprostone has a prokinetic effect. This investigation was designed to evaluate lubiprostone as a preparation and propulsive agent for small bowel capsule endoscopy. Methods: The PillCam Small Bowel (SB) capsule endoscopy system (Given Imaging, Yoqneam, Israel) utilizing the PillCam SB1 capsule and Rapid 5 software platform was used. The study was designed as a double blinded placebo-control trial in 40 healthy adults to compare gastric transit time (GTT), small bowel transit time (SBTT), and small bowel cleansing preparation. The study subjects received lubiprostone 24 mcg or placebo 30 minutes prior to PillCam capsule ingestion. Capsule endoscopy studies were read by two independent investigators unaware of the study medication received and differences in interpretation were resolved by consensus. Anatomical landmarks were identified and GTT and SBTT were calculated. Overall preparation assessment of the proximal, mid, and distal small bowel was determined by a 4 step scale. Percentage of visualized bowel was determined by review of 10 minute video segments at 1 hr intervals after the capsule passed through the pylorus. Results: In the lubiprostone group (N = 20), 2 subjects did not pass the capsule through the pylorus in the 8 hr battery time of the capsule. An additional 3 capsules did not pass into the colon. In the placebo group (N = 20), all capsules passed into the small bowel, but 1 did not pass into the colon. The subjects in which the capsules did not pass into the small bowel were excluded from the small bowel analysis. In the subjects that the capsules did not reach the colon, the SBTT was determined by total number of minutes subtracted from the gastric emptying time for each subject. The mean GTT in the lubiprostone group was 126 minutes and 43 minutes in the placebo group (P= 0.0095). The mean SBTT in the lubiprostone group was 208 minutes and 228 minutes in the placebo group (P= 0.249). The overall preparation assessment of the small bowel was not statistically significant between the 2 groups in the proximal, mid or distal small bowel (p- = 0.119-proxmial, 0.118-mid, 0.121-distal). There was no significant difference in lubiprostone vs. placebo in the percentage of visualized small bowel. Conclusion: Lubiprostone had a significant increase in GTT but did not result in a significant decrease in SBTT as compared to placebo. The administration of lubiprostone prior to capsule ingestion did not result in improved overall preparation of the small bowel for capsule endoscopy or increase the percentage of visualized small bowel.

Capsule endoscopy (CE) is a less invasive method of detecting colorectal cancer (CRC) than colonoscopy. Now, a CE system that incorporates a

The goal of this work is to provide a brief review on the image compression algorithms in the wireless capsule endoscopy, which is efficient and simple. This paper also covers the review on each stage of the image compression algorithms and its efficiency. At the latter part of this paper, an ideal algorithm for the image compression with high compression ratio and good image reconstruction quality. The main complication associated with the wireless endoscopy system is the reduction in area and consumed power while preserving the acceptable reconstruction of video with high quality. Most of the existing algorithms are based on DCT algorithms which require more buffer space; thereby it increases the large area and large power for the computation. In this paper, the different data compressor based on DCT is presented. The ideal scheme is based on the subsampling of data. Special features and characteristics of endoscopic images are considered in the stage of algorithm development. The algorithm includes the compression technique differential pulse coded modulation (DPCM) which is lossless followed by simple, efficient and variable length encoding called Golomb-Rice coding. The proposed ideal image compressor is compatible with any image sensors which are low power and commercially available that outputs the pixels of the images in a raster scan manner. It will evict the need of the memory buffer and temporary storage needed in the transform based coding methods. Additional compression acquired by the introduction of the corner clipping algorithm to remove the distorted corners present in the endoscopic images. Compared to other algorithms aims at wireless capsule endoscopy, the proposed ideal algorithm is highly efficient with a high compression ratio as well as very high reconstruction peak signal-to-noise ratio.

Capsule endoscopy (CE) is the first-line diagnostic modality for detecting small bowel lesions. CE is non-invasive and does not require sedation, but its movements cannot be controlled, it requires a long time for interpretation, and it has lower image quality compared to wired endoscopy. With the rapid advancement of technology, several methods to solve these problems have been developed. This article describes the ongoing developments regarding external CE locomotion using magnetic force, artificial intelligence-based interpretation, and image-enhancing technologies with the CE system.

Wireless capsule endoscopy (CE), an image inspection technique, has been an important advancement in the diagnosis of gastrointestinal (GI) tract diseases. A video capsule endoscopy (VCE) system is analyzed in this study. A complementary metal oxide semiconductor (CMOS) analog image sensor is adopted, and other illumination, communication and energy modules are designed for functional realization. Measuring only O11mm × 25 mm, the VCE has a total power consumption of 52.5 mW, which enables it to work continuously for 8 h. The in vivo experiment on a living pig indicates that a clear video with high frame rate of 30 f/s can be obtained.

In this paper, two printed coil antennas for wireless capsule endoscopic (WCE) communication system are proposed. Diagnostic images taken by WCE cameras are sent to an external device and displayed simultaneously. Two resonant frequencies of the proposed antenna are 38.5 and 57.6 MHz. Due to low resonant frequency, signal attenuation inside human body can be decreased, compared to a WCE antenna operating at Medical Implant Communication Systems (MICS) band (402-405 MHz). The receiving antenna size is 64 × 64 × 1.6 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , and the transmitting antenna is 10 mm in diameter and 2 mm thick. A human equivalent phantom is used to evaluate the influence of human body. In addition, the communication link sensitivity with different locations, orientations and misalignments are discussed.

The wireless capsule endoscope system allows clinicians to directly observe the image of the inner wall of the human gastrointestinal tract and obtain the most intuitive information at the lesion. Compared with traditional endoscopic detection technology, its painless, non-invasive, safe and convenient, full gastrointestinal detection features make this technology a research focus in the field of medical devices at home and abroad. As a new non-invasive detection technology for gastrointestinal diseases, the working time, image frame rate and image quality of the existing wireless capsule endoscope system cannot fully meet the needs in clinical applications. The cause of these problems lies in the capsule. The internal space of the speculum is limited, and only the button battery can be used as the energy source. Therefore, it is necessary to design a video capsule endoscope based on wireless energy transmission technology. This article is a review of Zhu Zhanquan, Xue Kaifeng, Lu Ruiqi and other scholars.

In this paper, a new low complexity and lossless image compression system for capsule endoscopy (CE) is presented. The compressor consists of a low-cost YEF color space converter and variable-length predictive with a combination of Golomb-Rice and unary encoding. All these components have been heavily optimized for low-power and low-cost and lossless in nature. As a result, the entire compression system does not incur any loss of image information. Unlike transform based algorithms, the compressor can be interfaced with commercial image sensors which send pixel data in raster-scan fashion that eliminates the need of having large buffer memory. The compression algorithm is capable to work with white light imaging (WLI) and narrow band imaging (NBI) with average compression ratio of 78% and 84% respectively. Finally, a complete capsule endoscopy system is developed on a single, low-power, 65-nm field programmable gate arrays (FPGA) chip. The prototype is developed using circular PCBs having a diameter of 16 mm. Several in-vivo and ex-vivo trials using pig's intestine have been conducted using the prototype to validate the performance of the proposed lossless compression algorithm. The results show that, compared with all other existing works, the proposed algorithm offers a solution to wireless capsule endoscopy with lossless and yet acceptable level of compression.

This article presents the first report of a circularly polarized (CP) omnidirectional radiation antenna for wireless capsule endoscope (WCE) system applications. The proposed antenna incorporates an integrated design concept, and achieves operation at 0.915 GHz Industrial, Scientific, and Medical (ISM) band (0.902-0.928 GHz) with a compact size of π×5.5 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ×22 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The simulation is performed in Ansys HFSS, with the antenna being placed in the center of a cylindrical homogeneous muscle tissue with a size of π×55 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ×80 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The simulated results show that the capsule antenna has an impedance bandwidth (BW) ( |S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> | <; -10 dB) from 0.82 to 0.99 GHz and a CP BW (AR <; 3 dB) from 0.84 to 1.09 GHz. Moreover, the omnidirectional CP radiation properties remain stable for a very wide θ range (49°-144°) in the elevation plane. The robust CP performance and the integrated design concept make the proposed antenna suitable for advanced WCE systems.

In capsule endoscope system, discrete cosine transform (DCT) compression on medical image brings annoying mosaic effect. Previous methods focus more on perfect visual smoothness without considering detail preservation. To address this issue, we integrate ensemble learning model into projection onto convex set (POCS) method. Both structure features and severity of blocking artifacts are evaluated by learning model, and the learning results are used to adaptively modify parameters of constraint convex sets. Finally, we obtain a visually smooth diagnosis image with good detail preservation and an average peak signal to noise radio (PSNR) of 42.90.

The recently established wireless capsule endoscopy promises itself to be a great advancement in the field of medical diagnosis. The amount of data generated due to a single inspection of gastrointestinal tract is huge, and the transmission demands more cost and power. Due to the inherent nature of the capsule, a low complexity and low-power design are highly recommended with the ability to reduce the data. This paper explains the design of a compression module which satisfies the above requirements. The compression algorithm is developed around some features of the endoscopic images with its suitability for hardware implementation. The preprocessing operations followed by two-stage encoder using differential coder and Golomb–Rice coder are implemented on the experimental dataset. The core module in the preprocessing stage is the chroma subsampling which can considerably reduce the data to be transmitted. Several patterns for subsampling have been analyzed in this paper to evaluate the performance of the proposed system. With the help of a suitably designed up-sampler at the receiver, a near-lossless compression with good reconstructed image quality can be achieved. The 22:1:2 pattern yields better results and could bring about an average peak signal-to-noise ratio of 37 dB with compression rate of 70%. The results show that the proposed chroma subsampling patterns performs better than the competing methods towards wireless capsule endoscopy compression.

Capsule endoscopy (CE), which was invented to visualize the entire small intestine in a noninvasive manner was first described in 2000 (Iddan, 2000), was approved for adult patients in 2001 by Food and Drug Administration (FDA). More than 600,000 PillCam SB capsules, which is the first model for CE in the world, have been used worldwide since 2001 (Nakamura, 2009). In pediatric patients, Seidman et al has first described the diagnostic value of CE (Seidman, 2002), and in 2003, FDA approved CE for pediatric patients ages 10 years and older. Emerging number of CE studies in children indicate the great demand for this population ( Tokuhara, 2010; de'Angelis, 2007; Atay, 2009; Fritscher-Ravens, 2009; Moy, 2009; Guilhon de Araujo Sant'Anna, 2005; Thomson, 2010; Ge, 2007; Postgate, 2009; Pinho, 2008; Shamir, 2007; Stiffler, 2003; Arguelles-Arias, 2004; Cohen, 2008 ), but performed number is relatively small (approximately 600, at the time of 2010) compared to adult cases (> 600,000), therefore, informations about indications, obtained results and risk of complications are not fully understood in pediatric patients. In pediatric patients, as well as in adults, CE is a firstline of examination to evaluate the entire small intestine and provides evidence for the diagnosis to the suspected small bowel disease especially in obscure gastrointestinal bleeding (OGIB) and suspected inflammatory bowel disease (IBD), on the other hand, accumulated studies are extending the indication of CE to protein loss, growth failure, abdominal pain, suspected polyp or graft-versus-host disease (GVHD) and regular follow-up for the known small bowel diseases. In this review, we summarize and discuss the capsule endoscopy system, indication, limitation, and future perspective of CE in pediatric patients.

In view of the contradiction between real-time image acquisition and energy restriction in capsule endoscopy design at present, a video capsule endoscopy system based on sleep mode was designed in compromised method. Hardware and software parts inside the system were designed and studied to realize segmented real-time function of the video capsule endoscopy in the way of dormancy and power outages. So the work time of the video capsule endoscopy would be extended. A prototype was developed which total size was just Φ12mmx25mm, so that it was easy to be swallowed. In the vitro test, the video capsule endoscopy system could work over 9h in one second dormancy mode. The video capsule endoscopy prototype could interval real-time acquire the pig intestine internal image clearly in pig intestine experiment instead of human intestine. Tests and experiments show that these scheme and designs were feasible.