Painless Diagnosis Inside The Gastrointestinal Tract Biology Essay

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Many a times we see people saying NO without a doubt for scanning their internal body because of the abhorrence of swallowing the endoscope, a flexible tube with a small camera on its end. Its about 9mm in diameter with flexible tube that travels into body's cavities to inspect digestive tract. Because of the wideness patients are usually sedated before the scan. With the advent of microelectronics the traditional endoscope era has been improvised, we just have to swallow the whole camera.

Yes!!! What you read is absolutely right… Its not just a camera, its "camera in pill".

This endoscopic capsule is a device made up of components for vision, illumination, power supply and telemetry. The wireless capsule comprise a biocompatible capsule, which consists of a chemically resistant polyether-terketone (PEEK) coating, an optical dome, a lens holder, a short focal length lens, four LEDs (Light Emitting Diode) , the four micro-fabricated sensors, two silver oxide batteries, an ASIC radio-frequency transmitter and an external receiving antenna.

Wireless capsule endoscopy is a medical procedure which has revolutionized endoscopy as it has enabled for the first time a painless inspection of the

small intestine. Electronic pills, smart capsules or miniaturized micro systems swallowed by human beings

or animals for various biomedical and diagnostic applications are growing rapidly in the last years. As Wireless capsule endoscopy is a novel breakthrough in the biomedical industry and future progresses in key technologies are expected to drive the development of the next generation of such devices. Therefore, the purpose of this seminar is to make aware of this recent technology and hope soon we get advantage of this In India.


Wireless Capsule endoscopy

Wireless capsule endoscopy (WCE) is a procedure which has enabled for the first time a painless diagnosis inside the gastrointestinal (GI) tract. It was unveiled at the Digestive Disease Week 2000 by Swain and Given Imaging (Yoqneam,Israel), the company which first marketed this device. The pill received approval from Food and Drug Administration (FDA) and was conceived for the inspection of the small intestine mucosa, in particular for the management of GI bleeding, Crohn's disease, celiac disease and small bowel tumors.

The examination requires patients to ingest, after a one night fast, a vitamin-size pill which is carried by peristalsis through the digestive tract. During the transit, the pill takes images which are transmitted to an array of antennas placed externally at the patient's abdomen and recorded into a portable storage unit attached to a belt, around the patient's waist.

The acquisition of images takes eight hours and during this time patients are free to conduct their daily activities. The device is expelled naturally after approximately 24 hours, if no complications arise. Then, patients return to the physician's office to deliver the pill and the rest of the WCE equipment to download the images into the physician's workstation for review and analysis.

This painless procedure has recently extended to the screening of pathologies of esophagus and colon. The success of WCE has sparked the interest among several research groups, in universities and industries, in order to advance the current status of WCE. In fact, at present, the merit of WCE is limited to the visualization of the GI mucosa, while it is not possible to stop at specific sites of the GI tract for performing biopsy or therapy or for moving independently of peristalsis.


The wireless capsule endoscopy system is composed of several key parts: the capsule itself, a portable image receiver/recorder unit and battery pack, and a specially modified computer workstation

Wireless endoscopy Capsule

The imaging capsule is 11 mm by 26 mm, is pill-shaped, and contains these miniaturized elements: a battery, a lens, 4 light emitting diodes, and an antenna/transmitter (fig 2). The capsule is sealed and resistant to decay within the gut. The capsule comes from the manufacturer ready to use and is activated on removal from holding assembly, which contains a magnet that keeps the capsule inactive until use. Once activated, the capsule begins to record images at a rate of 2 per second and transmit them to the belt-pack receiver. The capsule continues to record images at this rate over the course of 7 to 8 hour image acquisition period, yielding a total of approximately 50,000 images per examination. The capsule's lens is hemispheric and yields a 140-degree field of view, similar to that of a standard endoscope. The capsule is disposable and does not need to be recovered by the patient or medical personnel


Receiver/Recorder Unit:

In order for the images obtained and transmitted by the capsule endoscope to be useful, they must be received and recorded for study. Patients undergoing capsule endoscopy wear an antenna array consisting of 8 leads that are connected by wires to the recording unit, worn in standard locations over the abdomen, as dictated by a template for lead placement.(fig 2). The antenna array is very similar in concept and practice to the multiple leads that must be affixed to the chest of patients undergoing standard 12-lead electro-cardiography. The antenna array and battery pack can worn under regular clothing. The recording device to which the leads are attached is capable of recording the thousands of images transmitted by the capsule of recording the thousands of images transmitted by the capsule and received by the antenna array. Ambulatory ( non-vigorous ) patient movement does not interfere with image acquisition and recording. A typical capsule endoscopy takes place approximately in 7 hours.


Computer Workstation:

Once the patient has completed the endoscopy examination, the antenna array and image recording device are returned to the health care provider. The recording device is then attached to a specially modified computer workstation, and the entire examination is downloaded into the computer, where it becomes available to the physician as a digital video. The workstation software allows the viewer to watch the video at varying rates of speed, to view it in both forward and reverse direction , and to capture and label individual frames as well as brief video clips.

Images showing normal anatomy or pathologic findings can be closely examined in full color. A recent addition to the software package is a feature that allows some degree of localization of the capsule within the abdomen and correlation to the video images that correlate with the existence of suspected blood or red areas.



The typical endoscopic procedure begins with the patients fasting after midnight on the day before the examination. No formal bowel preparation is required; however, a surfactant ( eg, simethicone) may be administered prior to the examination to enhance viewing. After a careful medical examination, the patient is fitted with the antenna array and image recorder. The recording device and its battery pack are worn on a special belt that allows the patient to move freely. A fully charged capsule is removed from its holder; once the indicator lights on the capsule and recorder show that data is being transmitted and received, the capsule is swallowed with a small amount of water. At this point, the patient is free to move about ingesting anything other than clear liquids for approximately 2 hours after capsule ingestion (although medications can be taken with water). Patients can eat food approximately 4 hours after they swallow the capsule without interfering with the examination.

Seven to eight hours ingestion, the examination can be considered complete, and the patient can return the antenna array and recording device to the physician. It should be noted that gastrointestinal motility is variable among individuals, and hyper-and hypo motility states affect the free-floating capsule's transit rate through the gut. Download of the data in the recording device to the workstation takes approximately 2.5 to 3 hours. Interpretation of the study takes approximately 1 hour. Individual frames and video clips of normal or pathologic findings can be saved and exported as electronic files for incorporation into procedure reports or patient records. Fig 4 shows examples of images collected during capsule endoscopy.




Preparation before Procedure:

An empty stomach allows for the best and safest examination, so you should have nothing to eat or drink, including water, for approximately twelve hours before the examination. Your doctor will tell you when to start fasting.

Tell your doctor in advance about any medications you take including iron, aspirin, bismuth subsalicylate products and other "over-the-counter" medications. You might need to adjust your usual dose prior to the examination.

Discuss any allergies to medications as well as medical conditions, such as swallowing disorders and heart or lung disease.

Tell your doctor of the presence of a pacemaker, previous abdominal surgery, or previous history of obstructions in the bowel, inflammatory bowel disease, or adhesions.


The wireless capsule comprise a biocompatible capsule, which consists of a chemically resistant polyether-terketone (PEEK) coating, the four micro-fabricated sensors, the ASIC control chip and a discrete component radio transmitter

FIG 3:- CAPSULE OVERVIEW- 1)Optical dome, 2) Lens holder, 3) Lens 4) Illuminating LED's 5) micro fabricated CMOS sensors, 6)Silver oxide batteries, 7)ASIC RF transmitter, 8)Antenna

The unit is powered by two SR44 Ag2O batteries (3.1 V), which provides an operating time of 35 hours at the rated power consumption of 15 mW. The sensors were fabricated on two separate 5x5 mm 2 silicon chips located at the front end of the capsule. The temperature sensor is embedded in the substrate, whereas the conductivity sensor is directly exposed to the surroundings. The pH and oxygen sensors were enclosed in two separate 8 nL electrolyte chambers containing a 0.1M KOH solution retained in a 0.2 % calcium alginate gel. The electrolyte maintains a stable potential of the integrated Ag/AgCl reference electrodes used by the two sensors.

The oxygen and pH sensor are covered by a 12 μm thick film of teflon and nafion respectively, and protected by a 15 μm thick dialysis membrane of polycarbonate. The signals were conditioned by the ASIC and then transmitted to a local receiver (base station) at 40.01 MHz prior to data acquisition on a PC. The applied simplex communication link, based on a direct sequence spread spectrum communication system, can handle data from several pills at the same time.


Capsule endoscopy helps your doctor evaluate the small intestine. This part of the bowel cannot be reached by traditional upper endoscopy or by colonoscopy. The most common reason for doing capsule endoscopy is to search for a cause of bleeding from the small intestine. It may also be useful for detecting polyps, inflammatory bowel disease (Crohn's disease), ulcers, and tumors of the small intestine

As is the case with most new diagnostic procedures, not all insurance companies are currently reimbursing for this procedure. You may need to check with your own insurance company to ensure that this is a covered benefit.

Possible Complications:

Although complications can occur, they are rare when doctors who are specially trained and experienced in this procedure, such as members of the American Society for Gastrointestinal Endoscopy, perform the test. Potential risks include complications from obstruction. This usually relates to a stricture (narrowing) of the intestine from inflammation, prior surgery, or tumor. It's important to recognize early signs of possible complications. If you have evidence of obstruction, such as unusual bloating, pain, and/or vomiting, call your doctor immediately. Also, if you develop a fever after the test, have trouble swallowing or experience increasing chest pain, tell your doctor immediately. Be careful not to prematurely disconnect the system as this may result in loss of image acquisition.


Wireless capsule endoscopy represents a significant technical breakthrough for the investigation of the small bowel, especially in the light of the shortcomings of the other available techniques to image this region. Capsule endoscopy has the potential for the use in a wide range of patients with a variety of illnesses. The definitive role for capsule endoscopy has yet to be determined, and the majority of studies on uses of devices appear only in abstract form to date. At present, capsule endoscopy seems best suited to patients with gastrointestinal bleeding of unclear etiology who have had non diagnostic traditional testing and in whom the distal small bowel needs to be visualized. The ability of the capsule to detect small lesions that could cause recurrent bleeding ( eg, angiectasias, tumors, ulcers) seems ideally suited for this particular role. Therapy ( i.e, medical, surgical, endoscopic, radiologic) for any lesions discovered via capsule endoscopy needs to be tailored to the individual patents, and at this time, the capsule has no therapeutic capabilities. Although a wide variety of indications for capsule endoscopy are being investigated, other uses for the device should be considered experimental at this time and should be performed in the context of clinical trials. Care must taken in patient selection, and the images obtained must be interpreted appropriately and not over-read i.e, not all abnormal findings encountered are the source of the patient's problem. Still in the proper context, capsule endoscopy can provide valuable information and assist in the management of patients with difficult-to-diagnose small bowel disease.