Passive UHF RFID Voice Prosthesis Mounted Sensor for Microbial Growth Detection

Aaron J. R. Hillier,Viktorija Makarovaite,John C. Batchelor,Simon J. Holder,Campbell W. Gourlay

doi:10.1109/jrfid.2020.3011900

Aaron J. R. Hillier, Viktorija Makarovaite + Show 3 more

Open Access

https://doi.org/10.1109/jrfid.2020.3011900

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Abstract

Capacitive loading due to human tissue can lead to low efficiency for implantable Passive Radio Frequency Identification (RFID) antennas. The presented passive UHF antenna sensor provides read distances above 0.5 meters (within a body phantom) by utilizing a convoluted half-wave dipole design. It is able to detect simulated early to mature Candida albicans biofilm growth when mounted upon a voice prosthesis (up to a $30~\mu \text{m}$ biofilm thickness). Depending on the propagation frequency of interest, as early 4-hour growth (5 to $10~\mu \text{m}$ biofilm thickness) equivalent could be detected and before any device failure could occur due to the colonization. This was accomplished by utilising thin layers of polyurethane to decouple the saliva from the presented UHF sensor (biofilm growth is known to increase layer hydrophobicity). This presented sensor has better functionality within the U.S. UHF frequency band as it detects changes above $5~\mu \text{m}$ . If there is a need for implantation within additional tissues with variable dielectric properties, a shunt capacitance of 2.6 pF could allow the system functionality within the permittivity range of 21 to 58. Allowing for immediate medical intervention before medical prosthesis failure.

Highlights

T HERE is a global market projected increase of U.S $3.9 billion in the ‘ generation implants’ by 2023 worth an estimated U.S $141 billion [1], [2]
When looking at the CST simulations, an increase in C. albicans biofilm thickness resulted in a noticeable frequency shift
As this is a first attempt to understand the effect of saliva and microbial growth on ultra-high frequency (UHF) Radio Frequency Identification (RFID) sensor design, further study is necessary

Summary

Introduction

T HERE is a global market projected increase of U.S $3.9 billion in the ‘ generation implants’ by 2023 worth an estimated U.S $141 billion [1], [2]. Increased global utilization of medical implants should be coupled with an increase in expected implant complications of which the majority (20 to 25%) is composed of microorganism colonization of device surfaces (or adjacent host tissues) [3]. The overall infection rate for medical implants (when grouped together) is only near 2%; the infection rate exponentially increases (near 50%) for temporary devices such as catheters [4]. Microorganism colonisation on medical devices often leads to device failure necessitating implant removal (and often replacement), increasing costs and straining often underfunded healthcare organizations [3]. Manuscript received March 9, 2020; revised June 7, 2020; accepted July 8, 2020. Date of publication July 27, 2020; date of current version November 23, 2020. Engineering and Physical Science Research Council (EPSRC). (Corresponding author: Viktorija Makarovaite.)

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