軽量なARグラスの普及に伴い、屋内外を問わず長時間かつ目立たずに操作できるウェアラブル入力インタフェースの重要性が高まっている。
しかし、指輪型デバイスは物理的制約から電池容量が極めて小さく、BLE等の既存無線技術では連続通信時の稼働時間が数時間に留まるため、頻繁な充電が不可欠であった。
本研究は、超小型デバイスの実用的な通信距離を維持しつつ、大幅な低消費電力化によりバッテリー問題を解決することを目的とする。
この課題に対し、磁界バックスキャタ通信に着目し、分散コンデンサを用いた高感度コイルとバランスドブリッジ回路を導入することで、指輪からリストバンドへの中距離通信を実現する「picoRing mouse」を開発した。通信距離を従来の約2.1倍へ拡張し、最大449 μWの超低電力駆動により、27 mAhの電池で約600〜1000時間の連続使用を可能にした。
本成果は、充電の負荷がない常時装用可能な入力手段を提供し、ARグラスの日常利用を加速させるとともに、ウェアラブル通信の新たな設計指針を示すものである。

With the widespread adoption of lightweight AR glasses, there is a growing need for wearable input interfaces that allow subtle, continuous operation in any environment. However, ring-shaped devices are physically constrained to tiny batteries, and conventional wireless technologies like BLE consume excessive power during continuous transmission, limiting operation to just a few hours and requiring frequent charging. This study addresses the challenge of achieving drastic power savings in miniature devices while maintaining a practical communication range. We propose “picoRing mouse,” which utilizes magnetic field backscatter communication enhanced by a high-sensitivity coil with distributed capacitors and a balanced bridge circuit to extend the ring-to-wristband communication range. This approach extends the communication distance by approximately 2.1 times and achieves ultra-low power consumption of maximum 449 uW, enabling 600–1000 hours of continuous use on a single 27 mAh battery charge. These results provide an “always-available” input method free from the burden of frequent charging, significantly improving the daily usability of AR glasses and contributing to the advancement of low-power wearable communications.

Ryo Takahashi, Li Yifan, Masaaki Fukumoto, Mohamed Kari, Hideaki Yamamoto, Akihito Noda, Shigemi Ishida, Tomoyuki Yokota, Takao Someya, Yoshihiro Kawahara, Eric Whitmire, Roger Boldu, Shiu Ng, Wolf Kienzle, Hrvoje Benko

関連論文/Related Publications
Y. Li, M. Fukumoto, M. Kari, S. Ishida, A. Noda, T. Yokota, T. Someya, Y. Kawahara, and R. Takahashi, “Ultra-low-power ring-based wireless tinymouse,” Proceedings of the 38th Annual ACM Symposium on User Interface Software and Technology (ACM UIST), Article 22, 1–12, Busan, Korea, Oct. 2025.
Y. Li, M. Fukumoto, M. Kari, T. Yokota, T. Someya, Y. Kawahara, and R. Takahashi, “Demo of picoRing mouse: ultra-low-powered wireless mouse ring with ring-to-wristband coil-based impedance sensing,” Extended Abstracts of the CHI Conference on Human Factors in Computing Systems (CHI EA ’25), Article 707, pp. 1 – 5, Yokohama, Japan, April 2025.
R. Takahashi, E. Whitmire, R. Boldu, S. Ng, W. Kienzle, and H. Benko, “[招待論文] picoRing: バッテリーレスな指輪型入力デバイス,” 第32回インタラクティブシステムとソフトウェアに関するワークショップ（WISS2024), 国際学会招待発表枠, Dec. 2024.
R. Takahashi, E. Whitmire, R. Boldu, S. Ng, W. Kienzle, and H. Benko, “picoRing: battery-free rings for subtle thumb-to-index input,” Proceedings of the 37rd Annual ACM Symposium on User Interface Software and Technology (UIST ’24), Article No. 13, pp. 1-11, Pittsburgh, Oct. 2024.
R. Takahashi, M. Fukumoto, C. Han, T. Sasatani, Y. Narusue, and Y. Kawahara, “TelemetRing: A Batteryless and Wireless Ring-Shaped Keyboard using Passive Inductive Telemetry,” Proceedings of the 33rd Annual ACM Symposium on User Interface Software and Technology (UIST’20), Pages 1161–1168, Virtual (previously Minneapolis, US), Oct. 2020.

連絡先/Contact
takahashi@akg.t.u-tokyo.ac.jp