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  • Conference paper
    Hu Y, Liu Y, Constandinou TG, Toumazou Cet al., 2011,

    A 5s-Time-Constant Temperature-Stable Integrator for a Tuneable PID Controller in LOC Applications

    , IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 1387-1390

    In this paper, we present a novel, ultra-long-time-constant analog integrator circuit as part of an analogue signal processing block. By employing transconductance reduction techniques a time constant of up to 5s is achievable using only a 35pF capacitor. This is achieved by introducing a R-2R current divider network in the feedback loop, additionally allowing the transconductance to be digitally-tuned within a range of 0.2 to 5 seconds to 4-bit resolution. Furthermore, through internal compensation, the clockless integrator achieves a temperature dependance of under 1.2\% over the 0$^oC$ to 100$^oC$ range.

  • Conference paper
    Goh ZDC, Georgiou P, Constandinou TG, Prodromakis T, Toumazou Cet al., 2011,

    A CMOS-Based Lab-on-Chip Array for Combined Magnetic Manipulation and Opto-Chemical Sensing

    , IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 1997-2001

    This paper presents a CMOS-based lab-on-chip platform for combined magnetic manipulation and opto-chemical sensing. Within each pixel, a Programmable Gate (PG) ISFET chemical sensor is combined with an active pixel sensor, and is encompassed within an inductive coil. The integrated pixel is tesselated to form an 8×8 array. Fabricated in a commercially available 0.35um CMOS technology, the system can be used for simultaneous optical imaging and pH sensing, and includes auto- calibration mechanisms for eliminating sensor non-idealities. A spatiotemporal magnetic field pattern generator has also been embedded for micro-scale magnetic manipulation. Controlled via a MATLAB based graphical user interface, the system achieves real time data acquisition at 6fps, a pH sensitivity of 57mV/pH and demonstrates magnetic manipulation of micro-beads.

  • Conference paper
    Banks D, Morris C, Omeru J, Wei W, Georgiou P, Toumazou Cet al., 2011,

    A CMOS Pancreatic Islet of Langerhans for Automatic Glycemic Regulation

    , Annual IEEE Biomedical Circuits and Systems Conference (BioCAS) - Engineering Tomorrow's Healthcare, Publisher: IEEE, Pages: 261-264, ISSN: 2163-4025
  • Journal article
    Morris C, Banks DJ, Gaweda L, Scott S, Zhu XX, Panico M, Georgiou P, Toumazou Cet al., 2011,

    A Robust Microfluidic <i>in vitro</i> Cell Perifusion System

    , 2011 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC), Pages: 8412-8415, ISSN: 1557-170X
  • Conference paper
    Prodromakis T, Liu Y, Yang J, Hollinghurst D, Toumazou Cet al., 2011,

    A Novel Design Approach for Developing Chemical Sensing Platforms Using Inexpensive Technologies

    , Proceedings of the IEEE Biomedical Circuits and Systems (BioCAS) Conference
  • Conference paper
    Prodromakis T, Liu Y, Toumazou C, 2011,

    Low-cost Implementations of pH Monitoring Platforms

    , IEEE Sensors
  • Conference paper
    Grossman N, Nikolic K, Grubb MS, Burrone J, Toumazou C, Degenaar Pet al., 2011,

    High-frequency limit of neural stimulation with ChR2

    , 33rd Annual International Conference of the IEEE Engineering-in-Medicine-and-Biology-Society (EMBS), Publisher: IEEE, Pages: 4167-4170, ISSN: 1557-170X
  • Patent
    Georgiou P, Thay LK, Toumazou C, 2010,

    A Glucagon Pump Controller

    , TW201113058(A); GB2471066A; WO2010142734 (A1); US2012232519 (A1)

    According to a first aspect of the present invention there is provided a controller for controlling a glucagon pump. The controller comprises an input 8 for receiving an input signal indicative of a measured blood glucose concentration, an output 9 for providing a pulsed glucagon pump drive signal, each pulse being arranged to cause a glucagon pump to deliver a volume of glucagon, and a processing unit 10 for setting the pulse frequency of the pump drive signal in dependence upon the input signal, such that when the input signal indicates that the measured blood glucose concentration is above a threshold concentration the pulse frequency is zero and when the input signal indicates that the measured blood glucose concentration is below the threshold concentration the pulse frequency is increased as the measured blood glucose concentration decreases.

  • Conference paper
    Prodromakis T, Toumazou C, 2010,

    A Review on Memristive Devices and Applications

    , IEEE International Conference on Electronics, Circuits, and Systems

    Recent discovery of the memristor has sparked a new wave of enthusiasm and optimism in revolutionising circuit design, marking a new era for the advancement of neuromorphic and analogue applications. In this work, we consider practical applications in which the highly non-linear dynamic response of the memristor can be employed. It is shown that the device can be utilised as a non-volatile memory element and/or a programmable dynamic load, with particular emphasis given into bio-inspired analog implementations that typically exploit the ability of the memristor to support both logic and memory simultaneously. Finally, a novel concept is presented demonstrating the capacity of memristive networks in realising demanding image processing algorithms and more specifically edge detection.

  • Conference paper
    Zain WSW, Prodromakis T, Toumazou C, 2010,

    A Bulk-Driven ISFET-Based Chemical Mixer

    , Proceedings of the IEEE Biomedical Circuits and Systems (BioCAS) Conference, Publisher: IEEE

    In this work the concept of the chemical mixerfor comparing the pH of two aqueous solutions is introduced. Ionic concentrations are sensed via a pair of ISFETs, which are then translated into signals with frequencies that correspond to the pH values of the solutions. Using the bulk-driven single balanced topology, the number of transistors is significantly reduced, making it suitable for applications where a low supply voltage and low power consumption are essential. Finally, it is demonstrated that the output frequency of the mixer depends on the ΔpH of the solutions under test.

  • Journal article
    Chan WP, Premanode B, Toumazou C, 2010,

    An Integrated ISFETs Instrumentation System in Standard CMOS Technology

    , IEEE Journal of Solid-State Circuits, Vol: 45, Pages: 1923-1934, ISSN: 0018-9200
  • Conference paper
    Prodromakis T, Michelakis K, Toumazou C, 2010,

    Fabrication and Electrical Characteristics of Memristors with TiO2/TiO2+x active layers

    , IEEE International Symposium on Circuits and Systems

    We report on the fabrication and electrical characterisation of memristors with TiO2/TiO2+x active layer. This active layer is deposited at room temperature with RF-sputtering and consists of two sub-layers, the top one of which containsexcess oxygen atoms. Electrical characterisation of the devices demonstrates similar switching characteristics as previously reported for nano-scale memristors with TiO2/TiO2−x active cores.

  • Conference paper
    Nikolic K, Toumazou C, 2010,

    A bio-inspired ultrasensitive imaging chip — Phase one: Design paradigm

    , Proceedings of the IEEE International Symposium on Circuits and Systems (ISCAS), 2010, Pages: 345-348
  • Journal article
    Prodromakis T, Liu Y, Constandinou TG, Georgiou P, Toumazou Cet al., 2010,

    Exploiting CMOS Technology to Enhance the Performance of ISFET Sensors

    , IEEE Electron Device Letters, Vol: 31, Pages: 1053-1055, ISSN: 0741-3106

    This paper presents a novel method for fabricating ISFET devices in unmodified CMOS technologies. Conventional CMOS ISFETs utilise the protective passivation coating as the sensing membrane, with the sensed potential being coupled down to the floating MOS gate via a stack of conducting and insulating layers. The proposed structure minimises the use of these layers by exploiting the passivation opening mask, normally intended for bondpad openings. Parasitic effects such as reduced transconductance and trapped charge within the floating gate structure are minimised, resulting in a lower VT and improved chemical transconductance efficiency. Other characteristics including chemical sensitivity, reference leakage current and noise power are at comparable levels with conventional CMOS-based ISFET devices.

  • Patent
    Toumazou C, Premanode B, Shepherd L, 2010,

    Ion Sensitive Field Effect Transistors

    , US2010/0159461A1

    According to a first aspect of the present invention there is provided a digital signal processing circuit, one or more switches of the circuit being provided by an ion sensitive field effect transistor.

  • Patent
    Toumazou C, Purushothaman S, 2010,

    Sensing Apparatus and Method

    , US2010151479(A1); GB20010005831 20010309; US20100711249 20100223; WO2002GB00965 20020311; US20040471197 20040302

    A sensing apparatus comprising an ion sensitive field effect transistor arranged to generate an electrical output signal in response to localised fluctuations of ionic charge at or adjacent the surface of the transistor, and means for detecting the electrical output signal from the ion sensitive field effect transistor, the localised fluctuations of ionic charge indicating events occurring during a chemical reaction.

  • Patent
    Degennaar P, Hankins M, Drakakis E, Toumazou C, Nikolic K, Kennard Cet al., 2010,

    Retinal Prosthetic Devices

    , US2010/0152849A1

    A retinal prosthetic device comprises image capture means (20) arranged to capture an image, light producing means (30) arranged to define a plurality of light paths along each of which a light beam can be directed towards a respective position on a retina, and control means (24) arranged to process the captured image and control the light producing means so as to produce a stimulating array of light beams along a group of the light paths, the group being dependent upon the captured image.

  • Journal article
    Prodromakis T, Konstantinidis G, Papavassiliou C, Toumazou Cet al., 2010,

    Interfacial polarisation on gallium arsenide membranes

    , Micro & Nano Letters, IET, Vol: 5, Pages: 178-180, ISSN: 1750-0443

    An investigation on the dielectric properties of gallium arsenide membranes is presented. Particularly, the authors exploit the interfacial polarisation effect of microstrip and coplanar transmission lines on multilayered membrane structures. Such structures are in favour with the Maxwell-Wagner polarisation, which can be used for resembling the dielectric characteristics of high-k materials. The authors demonstrate a technique for attaining large slowing factors while the corresponding dielectric losses are significantly reduced.

  • Journal article
    Juffali W, Georgiou P, Toumazou C, 2010,

    ISFET based Urea:Creatinine translinear sensor

    , ELECTRONICS LETTERS, Vol: 46, Pages: 746-U29, ISSN: 0013-5194
  • Journal article
    Constandinou TG, Hafliger P, 2010,

    Guest Editorial - Special Issue on Selected Papers from ISCAS 2009

    , IEEE Transactions on Biomedical Circuits and Systems, Vol: 4, Pages: 137-138, ISSN: 1932-4545

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