A 32-channel modular bi-directional neural interface system with embedded DSP for closed-loop operation

Peng Cong, Piyush Karande, Jonathan Landes, Rob Corey, Scott Stanslaski, Wes Santa, Randy Jensen, Forrest Pape, Dan Moran, Tim Denison

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

22 Scopus citations


A prototype bi-directional neural interface system is presented with closed-loop and embedded DSP capabilities. The system includes 32-electrode stimulation capability, eight multiplexed low-noise low-power bio-potential sensing channels with on-chip digital FFT, and a Cortex M3-based microcontroller for implementing closed-loop algorithms. The stimulation subsystem can provide a maximum stimulation current of 12mA with approximately 3% accuracy per channel. The sensing subsystem uses a fully differential chopping amplifier achieving a noise floor <100nV/rtHz with approximately 1μA current from 2V supply. A 13bit continuous-time sigma-delta ADC is used to sample the amplifier output at the rate of 33kHz. The ADC consumes approximately 100nA while achieving an ENOB of 12b with a 250Hz date rate. A hardware implementation of a cached-FFT is included in the sensing IC to perform spectral analysis of the bio-potential signal. The resulting multiple spectral signatures can be selectively sent to the microcontroller allowing for algorithmic control of the stimulator system. The system partition was designed to minimize overall computational power while providing user flexibility. The sensing performance of the prototype has been demonstrated with 2-D cursor control in a non-human primate brain machine interface (BMI) model using 20 features simultaneously.

Original languageEnglish
Title of host publicationESSCIRC 2014 - Proceedings of the 40th European Solid-State Circuit Conference
EditorsPietro Andreani, Andrea Bevilacqua, Gaudenzio Meneghesso
PublisherIEEE Computer Society
Number of pages4
ISBN (Electronic)9781479956944
StatePublished - Oct 31 2014
Event40th European Solid-State Circuit Conference, ESSCIRC 2014 - Venezia Lido, Italy
Duration: Sep 22 2014Sep 26 2014

Publication series

NameEuropean Solid-State Circuits Conference
ISSN (Print)1930-8833


Conference40th European Solid-State Circuit Conference, ESSCIRC 2014
CityVenezia Lido


  • CMOS circuit
  • embedded DSP
  • implantable system
  • low noise low power amplifier
  • neural interface


Dive into the research topics of 'A 32-channel modular bi-directional neural interface system with embedded DSP for closed-loop operation'. Together they form a unique fingerprint.

Cite this