2013 13th Inteational Conference on Control, Automation and Systems (ICCAS 2013) Oct. 20-23, 2013 in Kimdaejung Convention Center, Gwanu, Korea Prototype Modular Capsule Robots for Capsule Endoscopies Laehyun Kim l * , Sai Chun Tang 2 , and Seung-Schik Yoo 3 i Center for Bionics, Korea Institute of Science and Technology, Seoul, 136-791, Korea (Tel: +82-2-958-6726; E-mail: laehyunk@kist.re.kr) * Corresponding auor 2 Department of Radiology, Harvard Medical School / Brigham and Women's Hospital, Boston, 02115, USA (Tel: +1-617-278-0606; E-mail sct@bwh.harvard.edu ) 3 Department of Radiology, Harvard Medical School / Brigham and Women's Hospital, Boston, 02115, USA (Tel: +1-617-732-9464; E-mail yoo@bwh.harvard.edu ) Abstract: Capsule endoscopy allows clinicians to wirelessly examine the small intestine using a capsule equipped with a miniscule camera. However, it has intrinsic limitations such as a lack of controlled capsule locomotion and limited therapeutic nctions inside the gastrointestinal (GI) track. Recently, several researches have been conducted to prototype robotic capsules that have a self-propelling mechanism by integrating mode technologies. To routinely use in a clinical setting, several technical challenges, including size constraint of the capsule, locomotion mechanism, and stable power source, should be addressed. In this paper, we introduce a prototype of a modular robotic capsule system, which is designed to distribute the nctional burdens among multiple robotic capsule modules. For example, active locomotion can be achieved via a collaborative actuation among multiple modules aſter self-assembly. This novel design was also supplemented with inductive power transmission techniques to wirelessly power the modules. The presented modular, miniature robotic platform may provide a new paradigm for developing multi-function capsule endoscope, with future implications in minimally invasive surgery. Keywords: Capsule robot, Modular robot, Endoscopy, Wireless power transmission. 1. INTRODUCTION Endoscopies are a standard medical procedure for diagnosing and treating abnormalities inside the GI track. They are more accurate than indirect methods, such as angiographies, ultrasonographies, and X-rays, in detecting abnormalities, because the doctor can directly view these areas using a wired endoscope with a small camera. An upper endoscopy is used to view inside of the upper digestive tract, including the esophagus, stomach, and first part of the small intestine, called the duodenum, and it enters the patient through the mouth. Meanwhile, a lower endoscopy, which is called a colonoscopy, is used to look at the large intestine (rectum and colon) and it enters through the patient's anus. During a colonoscopy, tissue samples can be collected (biopsy) and abnormal growths can be removed. However, the conventional endoscopy oſten requires sedation, because it may cause patients significant discomfort and intense pain, which may also increase the risk of intestinal perforation during the procedure. Furthermore, an endoscopy cannot inspect the small intestine, which is the middle portion of the gastrointestinal (GI) tract. Capsule endoscopy allows the doctor to view the small intestine in order to wirelessly diagnose bleeding and abnormalities, and it is painless unlike a conventional endoscopy [I]. There are commercial capsule endoscopy products for clinical use, including PiIICam (Yoqneam, Israel), Endo capsule (Olympus, Japan), MicroCam (IntroMedic, Korea), and SmartPill (SmartPill, USA) [2]. A typical endoscopy capsule is the size of a large vitamin tablet (approximately 11 mm in diameter and 27 mm in length) and contains a camera, LED lights, battery, and a telemetry module. The patient swallows the capsule with a glass of water and the camera inside the capsule captures and wirelessly 978-89-93215-05-295560/13/$15 @rCROS 350 transmits images to exteal data storage during its jouey through the GI tract. The procedure is patient-iendly, because it is noninvasive and painless, and does not require sedation. Capsule endoscopy usually requires long examination times (approximately 6�8 hours) and aſter the procedure, doctors evaluate the suspected small intestine diseases based on the captured images [3]. Unfortunately, capsule endoscopy has limitations; for example, doctors cannot control the capsule because it moves passively through the natural bowel movement (peristalsis), which is caused by muscle contractions that ordinarily move food during digestion. As a result, the capsule cannot change its speed, position, or direction, and it cannot stay in a specific location for a more detailed examination. This passive movement can fail to detect suspicious lesions or to collect sufficient information about detected lesions. In addition, capsule endoscopy is only used for diagnosis and cannot perform biopsies or therapeutic procedures. If the abnormalities are identified, the capsule endoscopy should be followed by a conventional endoscopy m order to treat the abnormalities [4]. The integration of robot technology into capsule endoscopies could address some of these limitations. Capsule robots or robotic capsules have an active actuation mechanism so that they can move forward or backward along the GI tract and remain in position for a longer period of time. In addition, some capsule robots have been designed to perform medical functions, such as biopsies, drug deliveries, and surgical operations [5-7]. However, the single capsule robot has an intrinsic limitation: the small size of the single capsule robot limits the number of components and degree of eedom. Thus, complicated surgical operations cannot be performed using a single capsule robot.