8-GHz band implantable UWB communications for wireless brain-machine interfaces

This paper presents a wireless data transmission technology using ultra wideband (UWB) signals in order to realize ultra multi-channel neural recoding system for wireless brain-machine interface (BMI). In order to show feasibility of the use of UWB signals in the application, a testbed has been developed, which consists of a liquid phantom and UWB radio system. The liquid phantom has been developed as to provide electrical constants equivalent to tissues of human body. The UWB radio system which occupies bandwidth of 1800 MHz to send 133 × 10⁶ pulses per second. A small-size UWB has been employed, which was fabricated for this application. As a result of experiment with the testbed, it has been demonstrated that bit error ratio (BER) at distance of 20 mm between an implanted device and on-body antenna becomes less than 10^-4.