Plenary Lecture

Plenary Lecture

ELIN Logarithmic Circuits: Synthesis, Analysis and Applications in Bioengineering

Dr. E. M. Drakakis
Department of Bioengineering
Imperial College London

Abstract: In general implantability and portability of biomedical or not devices is underpinned by the need for low power circuit consumption while preserving high performance. Contrary to conventional circuit design flow techniques which emphasise on the realisation of input-output linear building blocks or elements, unconventional "externally-linear-internally-non-linear" (ELIN) design techniques do not spend power in linearising individual blocks. ELIN logarithmic techniques allow the individual transistors to operate in accordance to their exponential non-linear I-V characteristics dictated by physics. Consequently, such a radical approach increases the mathematical complexity of the design effort but can lead to high dynamic range performance. Moreover, when weakly-inverted MOS devices are employed, ultra low power and high dynamic range designs can be realised. This talk will elaborate on the articulation and validation of a complete transistor-level theoretical framework suitable for the synthesis, analysis and performance evaluation of logarithmic ELIN filters. We will explain how high dynamic range topologies with power consumption ranging from a few nWs to a few Ws can be realised in a systematic manner. We will present results from such state-of-art fabricated and tested microelectronic chips targeting the following bioengineering applications: high- and low-order filters for biosignal acquisition front-ends, biomimetic cochlear implant channels with AGC, current sensing and amplification blocks suitable for amperometric biosensors and Hodgkin-Huxley-type silicon neurons.

Brief Biography of the Speaker:
Dr. Emm. Mic. Drakakis is a Senior Lecturer in the Department of Bioengineering at Imperial College London where he joined in October 2001. Dr. Drakakis has studied Physics (4-year degree - 1st Class Honours) at Aristotle University of Thessaloniki- Macedonia -Greece, Electronic Physics and Radioelectrology (2.5 year MPhil-1st Class Honours) at the same university and earned his PhD in Analogue IC design from the Dept. of Electrical and Electronic Engineering at Imperial in 2000 under the supervision of Dr.A.Payne. In the Dept. of Bioengineering Dr. Drakakis has founded the "Bioinspired VLSI Circuits and Systems Group". The Group's research focuses on circuits and systems "for and from" biology. Dr. Drakakis has been awarded Performance Scholarships from the Foundation of State Scholarship (IKY) -Greece, a Prize by the Hellenic Army's Research & Technology Center (1995) whereas between 1996-1998 he held a scholarship by the Micro-Electronics Research Center (MERC) of LM Ericsson -Kista -Stockholm. His Group have received an IEEE MWSCAS Finalist Award in 2005 and an IEEE ISCAS Live Demo Special Session Award in 2007. In 2006 he received the Imperial Rector's Award for Research Excellence whereas in 2008 he received a Human Frontier Science Program Award. Dr.Drakakis (MIEEE) is a member of the BIOCAS and CNNA IEEE Technical Committees, is past Associate Editor for IEEE Transactions on Circuits and Systems Parts I and II, past Guest Assistant Editor for IEE Electronics Letters and past Subject Editor for the International Journal of Electronics - Taylor & Francis. He has authored or co-authored more than 80 peer-reviewed publications.



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