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Al-Gayem Q.,Lancaster University | Richardson A.,Lancaster University | Liu H.,Moor Instruments Ltd.
Proceedings - 2011 IEEE 17th International Mixed-Signals, Sensors and Systems Test Workshop, IMS3TW 2011 | Year: 2011

Lab-on-chip devices are of great interest for analysis in fields including biochemistry, biomedical engineering and bioelectronics. Within these systems, high levels of reliability and robustness are crucial and normally complemented by requirements for extremely low probabilities of false positives or negatives being generated. Optimizing the design of these devices and investigating new methods for validating functionality and integrity of the readings are therefore required. This paper proposes a new fault diagnosis approach using Artificial Neural Network (ANN) for detecting degradation in electrodes that interface to fluidic or biological systems and form the basis of numerous actuation and sensing mechanisms in the biofluidics area. In this approach, the ANN is constructed and trained with a subset of experimental impedance data which was extracted at different degradation levels. New sets of data are used to test the network and the results show that the ANN has the ability to provide an early warning for degradation within the electrode structure. © 2011 IEEE. Source


Al-Gayem Q.,Lancaster University | Liu H.,Moor Instruments Ltd. | Richardson A.,Lancaster University | Burd N.,Lancaster University
Journal of Electronic Testing: Theory and Applications (JETTA) | Year: 2011

Electrode technology is fundamental to numerous actuation and sensing functions in bio-fluidic microsystems that target portable bio-analytical instruments. Within these systems high levels of reliability and robustness are crucial and normally complemented by requirements for extremely low probabilities of false positives or negatives being generated. New methods of validating functionality and integrity of the reading are hence required. Embedded test and condition monitoring are crucial technologies for delivering these capabilities. This paper presents two solutions for detecting degradation in electrodes that interface to fluidic or biological systems. In the first solution, a low frequency, impedance based method for identifying degraded structures within an array is proposed. This method depends on measuring and comparing the impedance of each sensing electrode. This research is backed up by physical measurements from an electrode array for drug testing on cardiac and neuron tissue. In the second solution, a mid-frequency oscillation test technique is proposed that is sensitive to degradation in the bio-fluidic interface capacitance, to contamination and to fouling. © 2010 Springer Science+Business Media, LLC. Source


Binzoni T.,University of Geneva | Boggett D.,Moor Instruments Ltd. | Van De Ville D.,University of Geneva | Van De Ville D.,Ecole Polytechnique Federale de Lausanne
Physiological Measurement | Year: 2011

Laser-Doppler flowmetry (LDF) is an outstanding tool to monitor blood flow in a continuous and non-invasive way. In this work, we study LDF at large interoptode spacing applied to a human bone model (i.e. tibia diaphysis). To that aim, we first performed an extensive set of Monte Carlo (MC) simulations for 10 and 25 mm interoptode spacing. Second, we have assembled a dedicated LDF instrumentation based on an optimized industrial avalanche photo-detector. We performed LDF experimental measurements on human muscle using well-known physiological protocols, which confirmed the reliability of our instrumentation and the relevance of the LDF algorithms tested with the MC simulations. In a second set, we repeated the measurements on human tibia diaphysis. Again, the experiments corroborate the MC simulations and demonstrate the effectiveness of LDF to monitor blood perfusion in bone. The proposed technique has great potential for non-invasive neuro-vascular studies since it will certainly help to reveal the mechanisms underlying the interaction between bone/bone marrow, the circulatory system and the nervous system. © 2011 Institute of Physics and Engineering in Medicine. Source


Al-Gayem Q.,Lancaster University | Liu H.,Moor Instruments Ltd. | Richardson A.,Lancaster University | Burd N.,Lancaster University | Kumar M.,Lancaster University
Proceedings - International Test Conference | Year: 2010

This paper presents a solution for detecting degradation in electrodes that interface to fluidic or biological systems that forms the basis of numerous actuation and sensing mechanisms in the bio-fluidics field. In this solution, a mid-frequency oscillation test strategy is proposed and evaluated experimentally on an array of electrodes. This technique is based on the sensitivity of the bio-fluidic interface capacitance to degradation, contamination and fouling. © 2010 IEEE. Source


Al-Gayem Q.,Lancaster University | Richardson A.,Lancaster University | Liu H.,Moor Instruments Ltd. | Burd N.,Lancaster University
Journal of Electronic Testing: Theory and Applications (JETTA) | Year: 2011

There is significant interest in the use of electrodes for sensing or actuation in bio-fluidic microsystems. Within these systems high levels of reliability are crucial and complimented by requirements for extremely low probabilities of false positive and false negatives. This paper extends previous work on impedance and oscillation based condition monitoring of electrode arrays by investigating the application of oscillation built-in self-test to a microfluidic based electrodes for conductance measurements and a system level implementation for monitoring multiple electrodes on-line. © 2011 Springer Science+Business Media, LLC. Source

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