A Miniaturized Wi-Fi HaLow-Based Wireless Imaging Transfer System for Capsule Endoscopy

Abstract

Wireless capsule endoscopy is constrained by severe limitations in size, available power, and reliable data transmission through biological tissues. Although recent advances in miniature imaging sensors have improved image quality, the wireless transmission of color images at practical frame rates remains a challenging task under the tight capsule constraints. We present the design and the experimental validation of a miniaturized Wireless Imaging Transfer (WIT) system for capsule endoscopy based on a sub-GHz IEEE 802.11ah (Wi-Fi HaLow) wireless link. In addition, a preliminary in-vivo validation of Wi-Fi HaLow communication is reported, showing that a stable through-body wireless link can be established across biological tissues in a clinically relevant porcine model. These in-vivo results provide direct experimental support for the adoption of sub-GHz Wi-Fi HaLow for capsule endoscopy applications. Experimental results demonstrate stable wireless image transmission at a resolution of 320x320 pixels, with measured end-to-end data rates above 12 Mbps and a transmission energy efficiency of 20.7 nJ/bit. We also report a detailed power consumption analysis, with a breakdown of the contributions from the imaging sensor, illumination, digital processing, and RF transmission. When all active subsystem contributions are considered, including the camera, digital processing, RF transmission, and illumination at 60% LED brightness, the total power consumption is approximately 477 mW, corresponding to a complete-chain energy consumption of approximately 39.6 nJ/bit. Overall, the measured performance confirms that sub-GHz Wi-Fi HaLow provides a promising trade-off among throughput, robustness, and energy efficiency for wireless imaging in capsule endoscopy.