Next generation ingestible devices: sensing, locomotion and navigation.

There is a significant interest in exploring the human body internal activities and measuring important parameters to understand, treat and diagnose the digestive system environment and related diseases. Wireless capsule endoscopy (WCE) is widely used for the gastrointestinal (GI) tract exploration due to its effectiveness as it provides no pain and totally tolerated by the patient. The current ingestible sensing technology provides a valuable diagnostic tool to establish a platform for monitoring the physiological and biological activities inside the human body. It is also used for visualizing the GI tract to observe the abnormalities by recording the internal cavity while moving. However, the capsule endoscopy is still passive, and there is no successful locomotion method to control its mobility through the whole GI tract. Drug delivery, localization of abnormalities, cost reduction and times consumption are improvements that can be gained from having active ingestible WCEs. In this article, the current technological developments of ingestible devices are explored. Also, as the main feature required to implement an active WCE is the locomotion, useful locomotion methods for WCEs in the literature are discussed and compared. The methods are evaluated in terms of the most important features such as safety, velocity, the complexity of design, the control, and power consumption.