The novel converter design decreases the total power consumption of an implantable 100-channel neural recording microsystem by more than 20%, reducing the patient’s exposure to electromagnetic radiation in the brain tissue when powered wirelessly during the data acquisition of complex brain activity for medical purposes. The converter can also prolong the battery life of other wearable and implantable medical devices and wireless sensor nodes. The ability to extend the battery life and reduce the electromagnetic radiation exposure from implantable devices will significantly reduce the patient’s cost, risk and invasiveness of the surgical procedures involved. Neuroprosthetics, which serve to restore motor functions in paralysed patients due to impaired nervous systems, can potentially benefit from IME’s low power ADC technology.

Elaborating on the research breakthrough, Dr Cheong Jia Hao, the IME scientist who conceptualised and designed the converter integrated circuits (ICs), said, “The ADC employs a tri-level switching scheme to achieve an elegant and simplified digital logic design. By reducing the capacitor charging voltage and the number of complex arithmetic steps in each data conversion cycle, we can boost the energy efficiency to just 19.5 fJ per conversion step, which contributes to significant total power savings without sacrificing data resolution and affecting other hardware features.” The converter is fabricated with 0.18-um CMOS processes, a mature standard processing technology for large volume production.

The ultra low power converter could become one of the key elements in emerging wireless sensor networks, sensor clouds, and sensor fusion for various important applications such as environmental monitoring, industrial monitoring and control, green buildings, smart transportation, and e-health.

Visit Agency for Science, Technology and Research (A*STAR) at www.ime.a-star.edu.sg