A wearable repeater relay system for interactive real-time wireless capsule endoscopy

Real-time wireless capsule endoscopy offers more flexibility and more precise screening options over commercially available passive endoscopy systems by allowing physicians to steer endoscopy capsules in real time. Yet, this requires reliable uninterrupted high frame-rate video streaming. In this contribution, we present a wearable repeater relay system that overcomes the impairments of the in-to-out body propagation channel and reliably relays implant data to a remote access point. The system consists of a set of wearable textile repeater nodes, exploiting receive diversity to provide a sufficiently large instantaneous carrier-to-noise ratio for live video streaming. Each wearable node, combining a dedicated receive antenna capturing the implant signal, an amplifier and an off-body transmit antenna, is fully implemented in textile materials, such that the comfort of the patient is not disturbed by the relay system. After outlining the design steps for the wearable relay node, in particular demonstrating stable robust antenna characteristics for the textile receive antenna oriented towards the body, we experimentally verify that a 6th-order diversity system provides the best compromise between user comfort and signal quality.