A Dual-Purpose Microwave-Optical Component for Wireless Capsule Endoscopy - a Feasibility Study by Radio Link Analysis

Wireless capsule endoscopy (WCE) is the only option for non-invasive small intestine disease diagnostics. However, the small size of the capsules poses a major design challenge for engineers since multiple optical and electrical components must reside inside the capsules. This article proposes a space-saving dual-purpose component utilized in both optical image capturing and microwave wireless data transmission of a WCE capsule at the 915 MHz industrial-scientific-medical band. The optical performance is verified through ray-tracing simulations, whereas the microwave operation is demonstrated by full-wave impedance simulations and by conducting a radio link simulation and measurement with an up-scaled prototype. The results show that the proposed component can be utilized in capsule optics to achieve an acceptable imaging quality. Furthermore, the component operates as an antenna, providing adequate link gains for WCE wireless communications.