Investigation of optical wireless power transmission across biological tissue using NIR light considering safe irradiance level

Presently, implantable electronic devices (IEDs) are becoming integral choices in medical applications, still their reliance on nonrechargeable batteries limits their longevity. This challenge has driven worldwide interest in developing rechargeable IEDs. While energy transfer based on radio-frequen...

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Main Authors: Syifaul Fuada, Mariella Särestöniemi, Marcos Katz
Format: Article
Language:English
Published: Elsevier 2025-05-01
Series:Results in Optics
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Online Access:http://www.sciencedirect.com/science/article/pii/S266695012500029X
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author Syifaul Fuada
Mariella Särestöniemi
Marcos Katz
author_facet Syifaul Fuada
Mariella Särestöniemi
Marcos Katz
author_sort Syifaul Fuada
collection DOAJ
description Presently, implantable electronic devices (IEDs) are becoming integral choices in medical applications, still their reliance on nonrechargeable batteries limits their longevity. This challenge has driven worldwide interest in developing rechargeable IEDs. While energy transfer based on radio-frequency (RF) has been clinically employed to address the challenge of IEDs running out of battery power, research into alternative methods, such as near-infrared (NIR) light-based energy transfer schemes, is advancing rapidly. The key advantages of optical systems are security, privacy, safety, interference-free operation, etc. The properties of NIR light are attractive for optical wireless power transmission (OWPT) across biological tissue due to minimal scattering and absorption effect. NIR light has been widely employed for various therapeutic applications, such as photobiomodulation (PBM) therapy. When using power transfer, ensuring that do not exceed safety regulations to avoid damage to the tissue is important. In this study, we investigate OWPT under safe level irradiance referring to the typical PBM applications, i.e., 20 mW/cm2, 25 mW/cm2, and 200 mW/cm2. The OWPT system is tested on an experimental testbed, consisting of an 810 nm NIR LED and a photovoltaic (PV) cell as transmitter and receiver, respectively. A tissue-mimicking optical phantom was employed as a propagation media that has long-lasting stability at a room temperature around the testbed, thus suitable for prolonged experiments. We measure the time it takes to charge an energy-storing supercapacitor under three different safe irradiance levels to assess the feasibility of safely charging an IED’s storage. In addition, we compare the results with the maximum irradiance of NIR LED, i.e., 527 mW/cm2. Comparing 527 mW/cm2 to PBM irradiance revealed a trade-off between supercapacitor charging time and tissue safety. Charging limitations and other related issues are also elaborated in this paper.
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spelling doaj-art-a021b850d03f4097b93671dcc77c0c452025-08-20T02:11:54ZengElsevierResults in Optics2666-95012025-05-011910080110.1016/j.rio.2025.100801Investigation of optical wireless power transmission across biological tissue using NIR light considering safe irradiance levelSyifaul Fuada0Mariella Särestöniemi1Marcos Katz2Centre for Wireless Communications, Faculty of Information Technology and Electrical Engineering, University of Oulu, Oulu, Finland; InfoTech Oulu, University of Oulu, Oulu, Finland; Corresponding author.Centre for Wireless Communications, Faculty of Information Technology and Electrical Engineering, University of Oulu, Oulu, Finland; InfoTech Oulu, University of Oulu, Oulu, Finland; Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, FinlandCentre for Wireless Communications, Faculty of Information Technology and Electrical Engineering, University of Oulu, Oulu, FinlandPresently, implantable electronic devices (IEDs) are becoming integral choices in medical applications, still their reliance on nonrechargeable batteries limits their longevity. This challenge has driven worldwide interest in developing rechargeable IEDs. While energy transfer based on radio-frequency (RF) has been clinically employed to address the challenge of IEDs running out of battery power, research into alternative methods, such as near-infrared (NIR) light-based energy transfer schemes, is advancing rapidly. The key advantages of optical systems are security, privacy, safety, interference-free operation, etc. The properties of NIR light are attractive for optical wireless power transmission (OWPT) across biological tissue due to minimal scattering and absorption effect. NIR light has been widely employed for various therapeutic applications, such as photobiomodulation (PBM) therapy. When using power transfer, ensuring that do not exceed safety regulations to avoid damage to the tissue is important. In this study, we investigate OWPT under safe level irradiance referring to the typical PBM applications, i.e., 20 mW/cm2, 25 mW/cm2, and 200 mW/cm2. The OWPT system is tested on an experimental testbed, consisting of an 810 nm NIR LED and a photovoltaic (PV) cell as transmitter and receiver, respectively. A tissue-mimicking optical phantom was employed as a propagation media that has long-lasting stability at a room temperature around the testbed, thus suitable for prolonged experiments. We measure the time it takes to charge an energy-storing supercapacitor under three different safe irradiance levels to assess the feasibility of safely charging an IED’s storage. In addition, we compare the results with the maximum irradiance of NIR LED, i.e., 527 mW/cm2. Comparing 527 mW/cm2 to PBM irradiance revealed a trade-off between supercapacitor charging time and tissue safety. Charging limitations and other related issues are also elaborated in this paper.http://www.sciencedirect.com/science/article/pii/S266695012500029XOWPTNIR lightImplantable Electronic DevicePhotobiomodulationSafe irradiance level
spellingShingle Syifaul Fuada
Mariella Särestöniemi
Marcos Katz
Investigation of optical wireless power transmission across biological tissue using NIR light considering safe irradiance level
Results in Optics
OWPT
NIR light
Implantable Electronic Device
Photobiomodulation
Safe irradiance level
title Investigation of optical wireless power transmission across biological tissue using NIR light considering safe irradiance level
title_full Investigation of optical wireless power transmission across biological tissue using NIR light considering safe irradiance level
title_fullStr Investigation of optical wireless power transmission across biological tissue using NIR light considering safe irradiance level
title_full_unstemmed Investigation of optical wireless power transmission across biological tissue using NIR light considering safe irradiance level
title_short Investigation of optical wireless power transmission across biological tissue using NIR light considering safe irradiance level
title_sort investigation of optical wireless power transmission across biological tissue using nir light considering safe irradiance level
topic OWPT
NIR light
Implantable Electronic Device
Photobiomodulation
Safe irradiance level
url http://www.sciencedirect.com/science/article/pii/S266695012500029X
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AT mariellasarestoniemi investigationofopticalwirelesspowertransmissionacrossbiologicaltissueusingnirlightconsideringsafeirradiancelevel
AT marcoskatz investigationofopticalwirelesspowertransmissionacrossbiologicaltissueusingnirlightconsideringsafeirradiancelevel