Characterization of In-Body to On-Body Wireless Radio Frequency Link for Upper Limb Prostheses.

Antonietta Stango,Dario Farina,Francesco Negro,Kamya Yekeh Yazdandoost,Dingguo Zhang

doi:10.1371/journal.pone.0164987

Abstract

Wireless implanted devices can be used to interface patients with disabilities with the aim of restoring impaired motor functions. Implanted devices that record and transmit electromyographic (EMG) signals have been applied for the control of active prostheses. This simulation study investigates the propagation losses and the absorption rate of a wireless radio frequency link for in-to-on body communication in the medical implant communication service (MICS) frequency band to control myoelectric upper limb prostheses. The implanted antenna is selected and a suitable external antenna is designed. The characterization of both antennas is done by numerical simulations. A heterogeneous 3D body model and a 3D electromagnetic solver have been used to model the path loss and to characterize the specific absorption rate (SAR). The path loss parameters were extracted and the SAR was characterized, verifying the compliance with the guideline limits. The path loss model has been also used for a preliminary link budget analysis to determine the feasibility of such system compliant with the IEEE 802.15.6 standard. The resulting link margin of 11 dB confirms the feasibility of the system proposed.

Highlights

In the last decade, there has been an increasing need of acquiring biometric signals for monitoring vital signs and supporting chronically ill patients
We propose a system based on the IEEE 802.15.6 standard [15] composed by two implanted devices that record and transmit wireless EMG signals to an on-body device positioned inside the socket of a hand prosthesis
In this study the wireless RF link between in-body EMG sensors and on-body controller for upper limb prostheses has been investigated with the limitations imposed by the standard for Wireless Body Area Network (WBAN) [15]

Summary

Introduction

There has been an increasing need of acquiring biometric signals for monitoring vital signs and supporting chronically ill patients. Implanted devices can be used to monitor and diagnose cardiac pathologies, cancer, asthma and neurological disorders [1]. More recent applications of wireless implanted systems focus on helping people with physical disabilities [2], e.g. cochlear and retina implants, or active limb prostheses [3]. This study investigates the possibility to use implanted devices able to record and transmit electromyogram (EMG) signals in order to allow amputees to control active myoelectric prostheses.

Methods

Results

Conclusion