1. The Development History of Capsule Endoscope

Human never lose the passion to explore their bodies just as they never stop exploring the outside world. The history of endoscopy is almost as long as that of western medicine.

Back to ancient Greek era, Hippocorates, who is regarded as the father of western medicine, has ever described a type of ¡°rectal specula¡±. Since Philip Bozzini (German) invented the cysto-proctoscope which used candle as light source, the endoscope has been developed with the progress of technology. At present, there is a wide range of endoscope such as hard-tube endoscope, fiber endoscope, ultrasonic endoscope and electronic endoscope. With the help of endoscope, physicians could easily and directly observe patients’ interior organs.

In the recent two decades, with the rapid development of related technology, the gastrointestinal endoscope technology grows dramatically. Especially the endoscope intervention therapy technology has become an indispensable technology in the treatment of digestive diseases, to some extent replacing some traditional surgical operations.

In 1981, a mechanical engineer of Israeli Ministry of Defense G. Iddan learned the process of endoscope examination from a physician. He associated it with the remote control recording equipment in intelligent missile he was familiar with, and got the initial idea of developing wireless endoscope. Since then, under the leadership of Iddan, Israeli experts started the research on wireless endoscope. In 1990s, they gained the first patent in this field. In 2001, Israeli Given Imaging Company, using Iddan’s patent technology, developed the world first capsule endoscope named M2A and put it into clinical application. This new endoscope attracted great attention around the globe.

The invention of capsule endoscope has opened up new field for the medical application of endoscope technology and complemented the gastroscope and enteroscope. It is an important milestone in the development history of gastroenterology.

The capsule endoscope system is belonging to biological chip technology. It is a cross-discipline miniature medical diagnosis system involving nano-biomedical engineering, bio-informatics, microelectronics, semiconductor sensor technology, electrochemistry, RF technology, computer technology, clinical diagnostics and etc. Its huge commercial value and strategic meaning has called high attention of many researchers around the world. Researchers from various countries started the research and development of the capsule gastrointestinal tract diagnosis system, which could provide painless and non-invasive diagnosis and treatment. In recent years, many intelligent capsules with different features has been developed. For example, the ¡°remote control releasing capsule¡± that could release the contained medicine on a fixed point in the gastrointestinal tract; the capsule that could take a tissue sample (biopsy) in the gastrointestinal tract; the Smart pill made by US Diagnostics Ltd. to detect the interior pressure, pH value and other data in the gastrointestinal tract, which could help physicians look for gastrointestinal dynamic disturbances such as gastroesophageal reflux disease; the capsule robot (in the sample test phrase) developed by Korean Ministry of Science and Technology, which through the extracorporeal remote control could accomplish several functions including medicine releasing, image recording, biopsy and treatment; and the Bravo pill developed by Sweden Medtronic Inc.

In Asia, Japan put forward the development plan for NORIKA V3 capsule. The structure of this capsule is as shown in Figure 1.

2. The Features of China-made Capsule Endoscope

Since 2001, Chinese Chongqing Jinshan Science & Technology (Group) Co., Ltd began its research and development of capsule endoscope. In October 2002, this program was listed in the Key International S&T Cooperation Program and in the Advanced Manufacture and Automatization Technology Field MEMS (Micro Electromechanical System) Key Program. After 3 years of hard working, Jinshan Group successfully developed the core technology of the capsule endoscope and produced the prototype. The prototype soon was put into a series of animal tests. In June 2004, the first generation of capsule endoscope passed the appraisement of experts.

The capsule endoscope made by Jinshan Group is named as ¡°OMOM¡±. It is approved by Chinese State Food and Drug Administration (SFDA) for clinical application in March 2004. The OMOM capsule endoscope system is a typical MEMS high-tech product, which integrates technologies such as image processing, information communication, opto-electrical engineering, biomedical engineering and etc. The system consists of three parts: small capsule, image recorder and image workstation (computer and photo analysis software). It is intended to help physicians detect the abnormalities of the gastrointestinal tract, and is widely used in the treatment of digestive diseases.

The working principles of the OMOM capsule endoscope system is as follows: the patient takes the small capsule with water. The capsule acquires video images while moving through the patient’s gastrointestinal tract, and transmits the video images via digital signal to the image recorder worn around the patient’s waist. The whole procedure will last six to eight hours. The capsule will be excreted naturally in the patient’s bowel movement in eight to 72 hours. The physician then views the images recorded by image recorder on image workstation to determine the next step in treatment.

The OMOM capsule endoscope is easy-to-use. The whole procedure only includes three steps: taking small capsule, recording and viewing the results. Physicians could make accurate diagnosis based on the recorded images.

The features of the OMOM capsule endoscope represents in two aspects: First, it allows physicians to take wireless extracorporeal control of the capsule. Its small capsule and image recorder could have communication via wireless duplex multi-channel, as in other capsule endoscopes where the image-recording devices only could receive images passively; Second, the OMOM capsule endoscope enables physicians to conduct real-time observation. A physician could view the real-time color images recorded by the capsule endoscope, meanwhile controlling the capsule working status in gastrointestinal tract. However in other capsule endoscopes a physician only could view the images sent into the workstation after ending the recording procedure.

3. Clinical Application of China-made Capsule Endoscope

The clinical application of capsule endoscope has always been an important issue. At the beginning, the Israeli M2A was originally designed for the examination of the entire gastrointestinal tract. However since the gastral cavity is too large to control the travel time of the capsule endoscope in it and the gastroscope technology has been fully developed, the researchers decided not to use M2A as the tools for the examination of stomach. They chose differentiated positioning strategy. They turned M2A into a specialized tool for the evaluation of the 5-7 meters long small intestine, which has always been regarded as the diagnostic gap in clinical examinations. Chinese manufacturers of OMOM capsule endoscope took a different positioning strategy. They set its clinical value in three aspects. First, the OMOM capsule endoscope could provide safe and comfortable examination for people with low tolerance or from higher levels of society. Second, the OMOM capsule endoscope, as with other investigation methods of gastrointestinal tract, could help physicians increase the accuracy of diagnosis. Third, the OMOM capsule endoscope allows physicians to observe real-time color images of small intestine where physicians can’t directly investigate with conventional methods.

As one of Chinese old sayings says ¡°Prevent the disaster before it happens¡± (nip in the bud). In clinical practice, to achieve this goal, physicians need the help of advanced, safe and comfortable tools. However most of the conventional medical devices can’t meet the requirement of painless and non-invasive detection. The diagnosis of diseases in gastrointestinal tract is often delayed because of the patients’ fear about the pains from the detection procedure. Many patients were diagnosed as serious diseases at a very late stage. As a painless, non-invasive and more acceptable diagnostic method, the OMOM capsule endoscope could reduce patients’ fear about investigations and thus find digestive diseases at an earlier stage. It is a superior diagnostic method for the detection of the digestive diseases.

The clinical statistics show that among examinees taking capsule endoscope examinations some are because of disorders in gastrointestinal tract, and more than half of the examinees take it as part of routine physical examination. This demonstrates that the OMOM capsule endoscope has more potential application. With the improvement of their living standard, people are paying more and more attention on their health. If the OMOM capsule endoscope could be more widely used in routine physical examination, it could be expected that the incidence of late-stage digestive diseases will drop enormously.