Electromagnetic radiation efficiency of body-implanted devices

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23220%2F18%3A43953801" target="_blank" >RIV/49777513:23220/18:43953801 - isvavai.cz</a>

Výsledek na webu

<a href="https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.9.024033" target="_blank" >https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.9.024033</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevApplied.9.024033" target="_blank" >10.1103/PhysRevApplied.9.024033</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Electromagnetic radiation efficiency of body-implanted devices

Popis výsledku v původním jazyce

Autonomous wireless body-implanted devices for biotelemetry, telemedicine, and neural interfacing constitute an emerging technology providing powerful capabilities for medicine and clinical research. We study the through-tissue electromagnetic propagation mechanisms, derive the optimal frequency range, and obtain the maximum achievable efficiency for radiative energy transfer from inside a body to free space. We analyze how polarization affects the efficiency by exciting TM and TE modes using a magnetic dipole and a magnetic current source, respectively. Four problem formulations are considered with increasing complexity and realism of anatomy. The results indicate that the optimal operating frequency f for deep implantation (with a depth d3 cm) lies in the (108-109)-Hz range and can be approximated as f=2.2×107/d. For a subcutaneous case (d3 cm), the surface-wave-induced interference is significant: within the range of peak radiation efficiency (about 2×108 to 3×109 Hz), the max-to-min ratio can reach a value of 6.5. For the studied frequency range, 80%-99% of radiation efficiency is lost due to the tissue-air wave-impedance mismatch. Parallel polarization reduces the losses by a few percent; this effect is inversely proportional to the frequency and depth. Considering the implantation depth, the operating frequency, the polarization, and the directivity, we show that about an order-of-magnitude efficiency improvement is achievable compared to existing devices.

Název v anglickém jazyce

Electromagnetic radiation efficiency of body-implanted devices

Popis výsledku anglicky

Autonomous wireless body-implanted devices for biotelemetry, telemedicine, and neural interfacing constitute an emerging technology providing powerful capabilities for medicine and clinical research. We study the through-tissue electromagnetic propagation mechanisms, derive the optimal frequency range, and obtain the maximum achievable efficiency for radiative energy transfer from inside a body to free space. We analyze how polarization affects the efficiency by exciting TM and TE modes using a magnetic dipole and a magnetic current source, respectively. Four problem formulations are considered with increasing complexity and realism of anatomy. The results indicate that the optimal operating frequency f for deep implantation (with a depth d3 cm) lies in the (108-109)-Hz range and can be approximated as f=2.2×107/d. For a subcutaneous case (d3 cm), the surface-wave-induced interference is significant: within the range of peak radiation efficiency (about 2×108 to 3×109 Hz), the max-to-min ratio can reach a value of 6.5. For the studied frequency range, 80%-99% of radiation efficiency is lost due to the tissue-air wave-impedance mismatch. Parallel polarization reduces the losses by a few percent; this effect is inversely proportional to the frequency and depth. Considering the implantation depth, the operating frequency, the polarization, and the directivity, we show that about an order-of-magnitude efficiency improvement is achievable compared to existing devices.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20201 - Electrical and electronic engineering

Projekt

<a href="/cs/project/LO1607" target="_blank" >LO1607: RICE – Nové technologie a koncepce pro inteligentní průmyslové systémy</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Physical Review Applied

ISSN

2331-7019

e-ISSN

—

Svazek periodika

9

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

1-12

Kód UT WoS článku

000426346700002

EID výsledku v databázi Scopus

2-s2.0-85043480902