Summary:
UCLA researchers in the Department of Electrical and Computer Engineering have developed a dual-mode, batteryless coil-reuse system for biosensing devices that enables efficient wireless power transfer and long-range data transmission in a compact form.
Background:
A vast majority of wearable and implantable medical devices require two wireless links to perform wireless power transfer and data transmission. Current approaches, such as high-frequency systems or radio frequency recording (RFID) struggle to balance performance with miniaturization. High frequencies increase signal loss and tissue absorption, while RFID limits transmission range. Further, these systems must avoid unwanted coupling, interference, and frequency conflicts. Thus, there is an unmet need for a miniaturized device that allows for reliable data transmission, high sensitivity, minimal power absorption by the body, and broad applicability across medical technologies.
Innovation:
UCLA researchers in the department of Electrical and Computer Engineering have developed an innovative dual-mode system that combines a compact, batteryless design with reliable uplink distances of up to 20 cm. The proposed coil-reuse architecture minimizes power loss and is resilient to variations in the coupling coefficient, key for consistent performance in medical applications. The system outperforms current models, achieving maximum uplink and power transfer distances of 200 mm and 70 mm at 1 kbps and 50 kbps, respectively. Its active telemetry enables real-time, proactive monitoring, while high-frequency radio frequency communication supports longer transmission distances with smaller antennas. This advancement represents a major leap in bioelectronics, paving the way for widespread adoption of miniaturized wearable and implantable medical devices.
Potential Applications:
● EEG systems for monitoring neural activity
● ECG devices for cardiac health tracking
● EMG sensors for muscle and nerve activity
● Compact, wearable biosensors for continuous health monitoring
Advantages:
● Extended data uplink range
● Enhanced wireless power transfer distance
● High-efficiency data transmission
● Reduced signal loss
● Ultra-low power consumption
● Fully battery-free operation
State of Development:
Prototype developed on 180-nm CMOS with circuit board of 5 cm diameter; results of experimentation supporting increased uplink distances.
Related Papers:
1. M. Kiani and M. Ghovanloo, “An rfid-based closed-loop wireless power transmission system for biomedical applications,” IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 57, no. 4, pp. 260–264, 2010.
2. X. Li et al., “A 13.56 mhz wireless power transfer system with reconfigurable resonant regulating rectifier and wireless power control for implantable medical devices,” IEEE Journal of Solid-State Circuits, vol. 50,
no. 4, pp. 978–989, 2015.
3. Y.-P. Lin and K.-T. Tang, “An inductive power and data telemetry subsystem with fast transient low
dropout regulator for biomedical implants,” IEEE Transactions on Biomedical Circuits and Systems, vol. 10,
no. 2, pp. 435–444, 2016.
4. S. Ha et al, "Energy Recycling Telemetry IC With Simultaneous 11.5 mW Power and 6.78 Mb/s Backward
Data Delivery Over a Single 13.56 MHz Inductive Link," in IEEE Journal of Solid-State Circuits, vol. 51, no. 11, pp. 2664-2678, 2016.
5. B. Lee et al, "A Triple-Loop Inductive Power Transmission System for Biomedical Applications," in IEEE
Transactions on Biomedical Circuits and Systems, vol. 10, no. 1, pp. 138-148, 2016.
6. D. Jiang et al., “An integrated passive phase-shift keying modulator for biomedical implants with power
telemetry over a single inductive link,” IEEE Transactions on Biomedical Circuits and Systems, vol. 11, no. 1, pp. 64–77, 2017.
7. C. Kim et al., "A 3 mm × 3 mm Fully Integrated Wireless Power Receiver and Neural Interface System-on-
Chip," in IEEE Transactions on Biomedical Circuits and Systems, vol. 13, no. 6, pp. 1736-1746, 2019.
Reference:
UCLA Case No. 2024-173
Lead Inventor:
Aydin Babakhani