Preliminary Analysis of Burn Degree Using Non-invasive Microwave Spiral Resonator Sensor for Clinical Applications

Pramod K B Rangaiah; Bappaditya Mandal; Erik Avetisyan; Arvind Selvan Chezhian; Bobins Augustine; Mauricio David Perez; Robin Augustine

doi:10.3389/fmedt.2022.859498

Preliminary Analysis of Burn Degree Using Non-invasive Microwave Spiral Resonator Sensor for Clinical Applications

Front Med Technol. 2022 Apr 5:4:859498. doi: 10.3389/fmedt.2022.859498. eCollection 2022.

Authors

Pramod K B Rangaiah¹, Bappaditya Mandal¹, Erik Avetisyan¹, Arvind Selvan Chezhian¹, Bobins Augustine^{1

2}, Mauricio David Perez¹, Robin Augustine¹

Affiliations

¹ Ångström Laboratory, Department of Engineering Sciences, Microwaves in Medical Engineering Group, Solid State Electronics, Uppsala University, Uppsala, Sweden.
² Ångström Laboratory, Division of Computer Systems, Department of Information Technology, Uppsala Networked Objects (UNO), Uppsala University, Uppsala, Sweden.

Abstract

The European "Senseburn" project aims to develop a smart, portable, non-invasive microwave early effective diagnostic tool to assess the depth(d) and degree of burn. The objective of the work is to design and develop a convenient non-invasive microwave sensor for the analysis of the burn degree on burnt human skin. The flexible and biocompatible microwave sensor is developed using a magnetically coupled loop probe with a spiral resonator (SR). The sensor is realized with precise knowledge of the lumped element characteristics (resistor (R), an inductor (L), and a capacitor (C) RLC parameters). The estimated electrical equivalent circuit technique relies on a rigorous method enabling a comprehensive characterization of the sensor (loop probe and SR). The microwave resonator sensor with high quality factor (Q) is simulated using a CST studio suite, AWR microwave office, and fabricated on the RO 3003 substrate with a standard thickness of 0.13 mm. The sensor is prepared based on the change in dielectric property variation in the burnt skin. The sensor can detect a range of permittivity variations (ε _r 3-38). The sensor is showing a good response in changing resonance frequency between 1.5 and 1.71 GHz for (ε _r 3 to 38). The sensor is encapsulated with PDMS for the biocompatible property. The dimension of the sensor element is length (L) = 39 mm, width (W) = 34 mm, and thickness (T) = 1.4 mm. The software algorithm is prepared to automate the process of burn analysis. The proposed electromagnetic (EM) resonator based sensor provides a non-invasive technique to assess burn degree by monitoring the changes in resonance frequency. Most of the results are based on numerical simulation. We propose the unique circuit set up and the sensor device based on the information generated from the simulation in this article. The clinical validation of the sensor will be in our future work, where we will understand closely the practical functioning of the sensor based on burn degrees. The senseburn system is designed to support doctors to gather vital info of the injuries wirelessly and hence provide efficient treatment for burn victims, thus saving lives.

Keywords: circuit analysis; flexible sensor; loop probe; microwave sensor; spiral resonator (SR).