Imperial College London

DrLieuweLeene

Faculty of EngineeringDepartment of Electrical and Electronic Engineering

Research Associate
 
 
 
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Contact

 

lieuwe.leene11 CV

 
 
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Location

 

B422Bessemer BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

14 results found

Leene L, Constandinou TG, 2018, Direct digital wavelet synthesis for embedded biomedical microsystems, IEEE Biomedical Circuits and Systems (BioCAS) Conference 2018, Publisher: IEEE, Pages: 77-80

This paper presents a compact direct digital waveletsynthesizer for extracting phase and amplitude data from corticalrecordings using a feed-forward recurrent digital oscillator.These measurements are essential for accurately decoding local-field-potentials in selected frequency bands. Current systemsextensively to rely large digital cores to efficiently performFourier or wavelet transforms which is not viable for manyimplants. The proposed system dynamically controls oscillation togenerate frequency selective quadrature wavelets instead of usingmemory intensive sinusoid/cordic look-up-tables while retainingrobust digital operation. A MachXO3LF Lattice FPGA is used topresent the results for a 16 bit implementation. This configurationrequires 401 registers combined with 283 logic elements andalso accommodates real-time reconfigurability to allow ultra-low-power sensors to perform spectroscopy with high-fidelity.

CONFERENCE PAPER

Leene LB, Constandinou TG, 2018, A 0.006 mm(2) 1.2 mu W Analog-to-Time Converter for Asynchronous Bio-Sensors, IEEE JOURNAL OF SOLID-STATE CIRCUITS, Vol: 53, Pages: 2604-2613, ISSN: 0018-9200

JOURNAL ARTICLE

Leene L, Maslik M, Feng P, Szostak K, Mazza F, Constandinou TGet al., 2018, Autonomous SoC for neural local field potential recording in mm-scale wireless implants, IEEE International Symposium on Circuits and Systems, Publisher: IEEE, Pages: 1-5, ISSN: 2379-447X

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

CONFERENCE PAPER

Williams I, Leene L, Constandinou TG, 2018, Next Generation Neural Interface Electronics, Circuit Design Considerations for Implantable Devices, Editors: Cong, Publisher: River Publishers, Pages: 141-178, ISBN: 978-87-93519-86-2

BOOK CHAPTER

Leene LB, Constandinou TG, 2017, Time Domain Processing Techniques Using Ring Oscillator-Based Filter Structures, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS, Vol: 64, Pages: 3003-3012, ISSN: 1549-8328

JOURNAL ARTICLE

Szostak K, Mazza F, Maslik M, Feng P, Leene L, Constandinou TGet al., 2017, Microwire-CMOS Integration of mm-Scale Neural Probes for Chronic Local Field Potential Recording, IEEE Biomedical Circuits and Systems (BioCAS) Conference, Publisher: IEEE, Pages: 492-495

CONFERENCE PAPER

Leene LB, Constandinou TG, 2017, A 0.016 mm(2) 12b Delta Sigma SAR With 14 fJ/conv. for Ultra Low Power Biosensor Arrays, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS, Vol: 64, Pages: 2655-2665, ISSN: 1549-8328

JOURNAL ARTICLE

Leene LB, Constandinou TG, 2017, A 0.5V Time-Domain Instrumentation Circuit with Clocked and Unclocked Delta Sigma Operation, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 2619-2622, ISSN: 0271-4302

CONFERENCE PAPER

Leene LB, Constandinou TG, 2016, A 2.7 mu W/MIPS, 0.88GOPS/mm(2) Distributed Processor for Implantable Brain Machine Interfaces, 12th IEEE Biomedical Circuits and Systems Conference (BioCAS), Publisher: IEEE, Pages: 360-363, ISSN: 2163-4025

CONFERENCE PAPER

Elia M, Leene LB, Constandinou TG, 2016, Continuous-Time Micropower Interface for Neural Recording Applications, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 534-537, ISSN: 0271-4302

CONFERENCE PAPER

Leene LB, Constandinou TG, 2016, A 0.45V Continuous Time-Domain Filter using Asynchronous Oscillator Structures, 23rd IEEE International Conference on Electronics, Circuits and Systems (ICECS), Publisher: IEEE, Pages: 49-52

CONFERENCE PAPER

Faliagkas K, Leene LB, Constandinou TG, 2015, A Novel Neural Recording System Utilising Continuous Time Energy Based Compression, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 3000-3003, ISSN: 0271-4302

CONFERENCE PAPER

Leene LB, Constandinou TG, 2014, Ultra-low power design strategy for two-stage amplifier topologies, ELECTRONICS LETTERS, Vol: 50, Pages: 583-584, ISSN: 0013-5194

JOURNAL ARTICLE

Leene LB, Luan S, Constandinou TG, 2013, A 890fJ/bit UWB transmitter for SOC integration in high bit-rate transcutaneous bio-implants, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 2271-2274, ISSN: 0271-4302

CONFERENCE PAPER

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