Miniaturised Wireless Power Transfer Systems for Neurostimulation: A Review

• Published in: IEEE transactions on biomedical circuits and systems Vol. 14; no. 6; pp. 1160 - 1178
• Main Authors: Barbruni, Gian Luca, Ros, Paolo Motto, Demarchi, Danilo, Carrara, Sandro, Ghezzi, Diego
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.12.2020; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Biomedical materials; Capacitive link; implantable medical device; Implants; Inductive coupling; inductive link; Integrated circuits; Medical equipment; miniaturisation; Miniaturization; Neural engineering; Neural prostheses; neuroengineering; Neurostimulation; ultrasound link; Wireless power transfer; Wireless power transmission
• ISSN: 1932-4545; 1940-9990; 1940-9990
• DOI: 10.1109/TBCAS.2020.3038599

In neurostimulation, wireless power transfer is an efficient technology to overcome several limitations affecting medical devices currently used in clinical practice. Several methods were developed over the years for wireless power transfer. In this review article, we report and discuss the three most relevant methodologies for extremely miniaturised implantable neurostimulators: ultrasound coupling, inductive coupling and capacitive coupling. For each powering method, the discussion starts describing the physical working principle. In particular, we focus on the challenges given by the miniaturisation of the implanted integrated circuits and the related ad-hoc solutions for wireless power transfer. Then, we present recent developments and progresses in wireless power transfer for biomedical applications. Last, we compare each technique based on key performance indicators to highlight the most relevant and innovative solutions suitable for neurostimulation, with the gaze turned towards miniaturisation.