32-Channel Event-Based Analog Front End Compresses Neural Signals Adaptively
Researchers have built a 32-channel event-based analog front-end chip in 180 nm CMOS that encodes biosignals in two modes, pulse frequency modulation and adaptive asynchronous delta modulation. The chip retunes its output data rate in real time to the envelope of the incoming signal, giving high compression and, the authors argue, a route to wireless transmission and online processing of neural signals in brain-computer interfaces.
Why it matters
Radio bandwidth and power, not electrode count, are what cap channel counts in wireless neural implants, so a front end that discards quiet samples before they reach the transmitter is attacking the harder half of the scaling problem.