Dear Visitor,
Welcome to the Bioinspired VLSI Circuits & Systems (BioCAS) Group of the Department of Bioengineering Imperial College London website. Our Group focuses on the conception, synthesis, realisation and evaluation of Circuits For and From Biology.
Our Group is fully committed to serving Imperial’s mission statement. It was founded in 2004 and since then it has grown thanks to competitively secured research funding from various sources. Its activities constitute an integral part of the “Biomedical Devices, Sensors and Circuits” Research Theme of our Department. We want to believe that our research trancedes what is traditionally referred to as “circuits for biomedical applications”.
More specifically: not only do we seek to apply well-established electrical & (micro)-electronic engineering techniques to healthcare aiming at the development of new, clinically relevant modalities and bioinstrumentation, but also we study the principles of operation of naturally encountered systems, try to translate and occasionally abstract their behaviour in meaningful engineering terms, draw inspiration from and apply them in a critical manner upon useful artificial systems. We hope that our systems will inherit some of the enviable properties of their physical prototype counterparts; namely their computational prowess and power efficiency despite the use of imperfect bioengineering “components”.
In other words, our research is inspired both by the instrumentation needs encountered in particular fields of biology and medicine (”Engineering for Biology”) and by the exquisite anatomy & operation properties of naturally encountered systems and/or processes (”Engineering from Biology”). Typical examples of our bioinstrumentation research philosophy include: our intelligent stem cell culture systems monitoring platform, our traumatic brain injury instrumentation, our optobionic chips, our fly-dies (chips implantable into the brain of blowflies), our ultra-low-power integrated pulse oximetry front-end, our ultra-high-dynamic range and ultra-low-power (log-domain and hyperbolic sine) frequency shaping networks for bioengineering applications, microprobes for medicine and biology and others. Typical examples of our biomimetics research approach include our recent cytomimetic circuits (microelectronic circuits which compute in real-time computationally demanding non-linear cellular and molecular dynamics consuming only minute amounts of power), our high-performance microelectronic topologies which mimic the operation of a segment of the basilar membrane matching the performance and power consumption of their natural counterpart, our bioinspired, ultra-low-power and noise-robust cochlear processor of increased spectral-contrast, our “temporal diffusion/derivative” Cellular Non-linear Networks (CNNs) (a novel CNN paradigm, termed TDCNN, which realises non-separable, discrete-space, continuous-time spatiotemporal transfer functions resembling spatiotemporal receptive fields encountered in the visual cortex), auditory processing elements inspired by insects (e.g. Ormia Ochracea) and others.
The above two axis of research philosophy are underpinned by several strands of theoretical research ranging from computational studies of the ribbon synapse and its application to novel software tools for the design of patient-specific cochlear implants, to transistor-level performance and non-ideality analysis (a sine qua non activity if useful/practical microelectronic topologies are to be built), non-linear transistor-level synthesis and analysis techniques and memristor research.
Key terms which underpin our research activities: ultra-low-power, non-linear, analogue, ultra high-dynamic range, integrated circuits, bioinstrumentation, physiological monitoring platforms and modalities, microprobes, mathematics, bioinspiration, biomimetics, high-performance analysis and limitations, synthesis/design, PCB design, embedded systems, chip layout, fabrication and testing.
For some of our research activities central role is played by the Bernoulli Cell Formalism introduced as part of my PhD research some time ago. The formalism enables the systematic monolithic realisation of both linear and non-linear dynamical systems: it facilitates not only the analysis and synthesis of nanopower or not “externally linear internally non-linear” linear time invariant topologies, but also enables, for the first time in a systematic manner, the realisation of non-linear, generic biological dynamics such as the celebrated nerve membrane Hodgkin-Huxley dynamics or cellular and molecular cytomimetic dynamics. In a nutshell Bernoulli Dynamics are realised by means of appropriate, simple combinations of exponential transconductors (e.g. nanopower MOS transistors) and capacitors, the “bread and butter” of IC technology. This particular form of dynamics should be viewed as a continuous-time continuous-value nanopower computational kernel capable of morphing on silicon linear or non-linear, bioinspired or not, spatiotemporal or not dynamics expressed in the form of intertwined differential equations. It is intriguing to note that neuromorphic silicon synaptic circuits and ideal memristors obey Bernoulli Dynamics.
If you happen to be a strong graduate (ideally 1st Class or strong 2.1) in Engineering (particularly Electrical & Electronic) with a keen interest in cross-fertilising healthcare or biology with (micro)-electronic technology do contact us. If you happen to be a strong graduate in Physics, Mathematics or Computing with a keen interest in biomathematics and/or biophysical modelling do contact us since challenging engineering projects in those areas are available. If you deliberate whether to conduct research in one of the above fields or if you have a specific project in mind do contact us. Do not contact us unless you are prepared to work hard and creatively, flexing your mental abilities and stretching your technical skills. Over the years it has become clear to me that our culture of mostly “walking the walk” keeping a low profile rather than “talking the talk” aligns well with independent thinkers/students who are intellectually strong, technically competent and not impressionable. Having said the above we always aspire not only to do research but also have fun! After all
life is short, no?
Of course one might wonder “why join this Group and not opt for a more traditional Department”? The answer could not be simpler: the uniqueness of our growing Department lies in its cross-, inter-, and multi-disciplinarity. Members of staff share a strong esprit de corps while the atmosphere among PhD candidates is truly synergistic fostering in-depth understanding. In other words, by joining our research Group, you will also benefit from an ambient “think laterally”, “do differently” and “challenge constructively” bioengineering research practice permeating at departmental level.
If you have reached this point in the foreword then I am sure that you would be tempted to check upon our activities in other parts of the site. I can only hope that you find them interesting and thought provoking. Manos