An Inexpensive System for Measuring the Dielectric Properties of Biological Tissues Using an Open-Ended Coaxial Probe

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21460%2F25%3A00383432" target="_blank" >RIV/68407700:21460/25:00383432 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1109/TIM.2025.3561426" target="_blank" >https://doi.org/10.1109/TIM.2025.3561426</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1109/TIM.2025.3561426" target="_blank" >10.1109/TIM.2025.3561426</a>

Jazyk výsledku

angličtina

Název v původním jazyce

An Inexpensive System for Measuring the Dielectric Properties of Biological Tissues Using an Open-Ended Coaxial Probe

Popis výsledku v původním jazyce

Knowledge of the dielectric parameters of biologicaltissues is important in a wide range of medical applications ofelectromagnetic fields. Commercial systems using high-qualityvector network analyzers (VNAs) are expensive and can be abarrier to the development of existing and emerging applications.Therefore, the main objective of this work was to investigatethe potential of using inexpensive VNAs, which is available onthe market, to measure the dielectric parameters of biologicaltissues. To accomplish this task, a system for the measurementof dielectric properties of biological tissues in the frequency rangefrom 70 MHz to 3 GHz using inexpensive VNAs was developedand presented. The system consists of pocketVNA 2.0 and acustom-made coaxial reflection probe with a diameter of 2.2 mm.The virtual line model of the coaxial probe was used to convertthe measured reflection coefficients to the complex permittivity.A total of five ex vivo tissues (heart, muscle, liver, kidney cortex,and fat) and two standard liquids (isopropanol and ethanol) weremeasured. The lower accuracy and lower signal-to-noise ratio ofthe inexpensive VNA were compensated for by postprocessingof the measured data, including a time-domain gating andfitting of the evaluated dielectric properties to the Cole-Coleand Debye models for tissues and standard liquids, respectively.The measurement results were compared to the results obtainedwith a commercial measurement system, and both the standarddeviation and mean absolute percentage error (MAPE) wereevaluated and presented. The lowest achieved MAPE of biologicaltissues was for fit relative permittivity 4.35% (fat,f<200 MHz)and 0.66% (kidney cortex, f > 200 MHz) and for fit equivalentelectrical conductivity 2.58% (heart,f<200 MHz) and 3.83%(heart, f > 200 MHz)

Název v anglickém jazyce

An Inexpensive System for Measuring the Dielectric Properties of Biological Tissues Using an Open-Ended Coaxial Probe

Popis výsledku anglicky

Knowledge of the dielectric parameters of biologicaltissues is important in a wide range of medical applications ofelectromagnetic fields. Commercial systems using high-qualityvector network analyzers (VNAs) are expensive and can be abarrier to the development of existing and emerging applications.Therefore, the main objective of this work was to investigatethe potential of using inexpensive VNAs, which is available onthe market, to measure the dielectric parameters of biologicaltissues. To accomplish this task, a system for the measurementof dielectric properties of biological tissues in the frequency rangefrom 70 MHz to 3 GHz using inexpensive VNAs was developedand presented. The system consists of pocketVNA 2.0 and acustom-made coaxial reflection probe with a diameter of 2.2 mm.The virtual line model of the coaxial probe was used to convertthe measured reflection coefficients to the complex permittivity.A total of five ex vivo tissues (heart, muscle, liver, kidney cortex,and fat) and two standard liquids (isopropanol and ethanol) weremeasured. The lower accuracy and lower signal-to-noise ratio ofthe inexpensive VNA were compensated for by postprocessingof the measured data, including a time-domain gating andfitting of the evaluated dielectric properties to the Cole-Coleand Debye models for tissues and standard liquids, respectively.The measurement results were compared to the results obtainedwith a commercial measurement system, and both the standarddeviation and mean absolute percentage error (MAPE) wereevaluated and presented. The lowest achieved MAPE of biologicaltissues was for fit relative permittivity 4.35% (fat,f<200 MHz)and 0.66% (kidney cortex, f > 200 MHz) and for fit equivalentelectrical conductivity 2.58% (heart,f<200 MHz) and 3.83%(heart, f > 200 MHz)

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20601 - Medical engineering

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

IEEE Transactions on Instrumentation and Measurement

ISSN

0018-9456

e-ISSN

1557-9662

Svazek periodika

74

Číslo periodika v rámci svazku

4008011

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

11

Strana od-do

—

Kód UT WoS článku

001479467200034

EID výsledku v databázi Scopus

2-s2.0-105002771390