Autonomous SoC for neural local field potential recording in mm-scale wireless implants
File(s)iscas2018.pdf (2.19 MB)
Accepted version
Author(s)
Type
Conference Paper
Abstract
Next generation brain machine interfaces fundamentally need to improve the information transfer rate and chronic consistency when observing neural activity over a long period of time. Towards this aim, this paper presents a novel System-on-Chip (SoC) for a mm-scale wireless neural recording node that can be implanted in a distributed fashion. The proposed self-regulating architecture allows each implant to operate autonomously and adaptively load the electromagnetic field to extract a precise amount of power for full-system operation. This can allow for a large number of recording sites across multiple implants extending through cortical regions without increased control overhead in the external head-stage. By observing local field potentials (LFPs) only, chronic stability is improved and good coverage is achieved whilst reducing the spatial density of recording sites. The system features a ΔΣ based instrumentation circuit that digitises high fidelity signal features at the sensor interface thereby minimising analogue resource requirements while maintaining exceptional noise efficiency. This has been implemented in a 0.35 μm CMOS technology allowing for wafer-scale post-processing for integration of electrodes, RF coil, electronics and packaging within a 3D structure. The presented configuration will record LFPs from 8 electrodes with a 825 Hz bandwidth and an input referred noise figure of 1.77μVrms. The resulting electronics has a core area of 2.1 mm2 and a power budget of 92 μW
Date Issued
2018-05-04
Date Acceptance
2018-01-15
Citation
2018 IEEE International Symposium on Circuits and Systems (ISCAS), 2018, pp.1-5
ISSN
2379-447X
Publisher
IEEE
Start Page
1
End Page
5
Journal / Book Title
2018 IEEE International Symposium on Circuits and Systems (ISCAS)
Copyright Statement
© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Grant Number
EP/M020975/1
Source
IEEE International Symposium on Circuits and Systems
Publication Status
Published
Start Date
2018-05-27
Finish Date
2018-05-30
Coverage Spatial
Florence, Italy