arXiv subjects

Nikita J. Greenidge

Publications and source records attributed to Nikita J. Greenidge.

3 recordsLinked to original sources

arXiv2026

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

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.

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arXiv2025

In vivo validation of Wireless Power Transfer System for Magnetically Controlled Robotic Capsule Endoscopy

This paper presents the in vivo validation of an inductive wireless power transfer (WPT) system integrated for the first time into a magnetically controlled robotic capsule endoscopy platform. The proposed system enables continuous power delivery to the capsule without the need for onboard batteries, thus extending operational time and reducing size constraints. The WPT system operates through a resonant inductive coupling mechanism, based on a transmitting coil mounted on the end effector of a robotic arm that also houses an external permanent magnet and a localization coil for precise capsule manipulation. To ensure robust and stable power transmission in the presence of coil misalignment and rotation, a 3D receiving coil is integrated within the capsule. Additionally, a closed-loop adaptive control system, based on load-shift keying (LSK) modulation, dynamically adjusts the transmitted power to optimize efficiency while maintaining compliance with specific absorption rate (SAR) safety limits. The system has been extensively characterized in laboratory settings and validated through in vivo experiments using a porcine model, demonstrating reliable power transfer and effective robotic navigation in realistic gastrointestinal conditions: the average received power was 110 mW at a distance of 9 cm between the coils, with variable capsule rotation angles. The results confirm the feasibility of the proposed WPT approach for autonomous, battery-free robotic capsule endoscopy, paving the way for enhanced diagnostic in gastrointestinal medicine.

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arXiv2024

External Steering of Vine Robots via Magnetic Actuation

This paper explores the concept of external magnetic control for vine robots to enable their high curvature steering and navigation for use in endoluminal applications. Vine robots, inspired by natural growth and locomotion strategies, present unique shape adaptation capabilities that allow passive deformation around obstacles. However, without additional steering mechanisms, they lack the ability to actively select the desired direction of growth. The principles of magnetically steered growing robots are discussed, and experimental results showcase the effectiveness of the proposed magnetic actuation approach. We present a 25 mm diameter vine robot with integrated magnetic tip capsule, including 6 Degrees of Freedom (DOF) localization and camera and demonstrate a minimum bending radius of 3.85 cm with an internal pressure of 30 kPa. Furthermore, we evaluate the robot's ability to form tight curvature through complex navigation tasks, with magnetic actuation allowing for extended free-space navigation without buckling. The suspension of the magnetic tip was also validated using the 6 DOF localization system to ensure that the shear-free nature of vine robots was preserved. Additionally, by exploiting the magnetic wrench at the tip, we showcase preliminary results of vine retraction. The findings contribute to the development of controllable vine robots for endoluminal applications, providing high tip force and shear-free navigation.

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