Publications
410 results found
Dassau E, Hennings T, Fazio J, et al., 2013, Closing the Loop, DIABETES TECHNOLOGY & THERAPEUTICS, Vol: 15, Pages: S29-S39, ISSN: 1520-9156
Reddy M, Herrero P, Oliver N, et al., 2013, Clinical Assessment of the Imperial College Bio-inspired Artificial Pancreas (BiAP) in Subjects With Type 1 Diabetes Mellitus, Advanced Technologies & Treatments for Diabetes, 2013
Herrero P, Georgiou P, Oliver N, et al., 2013, In-Silico Comparison of a Bio-Inspired Glucose Controller vs. a PID controller with Insulin Feedback, Advanced Technologies & Treatments for Diabetes (ATTD)
A recently developed bio-inspired glucose controller (BIAP) based on a model of β-cell physiology is compared against a recently published PID controller with insulin feedback (PID-IF) using the UVa/Padova T1DM metabolic simulator.Both controllers were tuned using a 24-hour scenario containing a 40g(10am) carbohydrates meal and initial blood glucose of 160mg/dl. A single tuning parameter was adjusted to stabilize glucose around 100mg/dl, avoiding dropping below 80mg/dl. To compare controllers, a 24-hour scenario containing 3 meals (30g(6am), 40g(2pm), 20g(10pm)) was employed. In both controllers, a partial bolus corresponding to 50% of the required insulin to cover a meal was delivered at the time of ingestion. Standard metrics provided by the simulator were employed for comparison purposes.See table for results of BIAP and PID-IF in n=10 adult, n=10 adolescent and n=10 children in-silico subjects. Mean blood glucose with PID-IF was lower than with BIAP in the adult cohort, percentage of time below target with BIAP was lower in the children cohort, percentage of time within target with BIAP was higher in the adolescents cohort and risk index was lower with BIAP in the adult and adolescent groups.The tuning parameter in BIAP correlated very well with the insulin sensitivity factor of the test subjects (R2=0.9), while the correlation observed within PID-IF was lower (R2=0.6).The BIAP glucose controller performed comparably to the PID-IF controller in in-silico setting with superior metrics in an adolescent cohort. The BIAP controller can be easily tuned by using a simple correlation with the insulin sensitivity factor.
Sohbati M, Georgiou P, Toumazou C, 2013, A Piecewise Linear Approximating ISFET Readout, IEEE Biomedical Circuits and Systems Conference (BioCAS), Publisher: IEEE, Pages: 37-40, ISSN: 2163-4025
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- Citations: 3
Sohbati M, Georgiou P, Toumazou C, 2013, REFET Replication for ISFET-based SNP Detection Arrays, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 185-188, ISSN: 0271-4302
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- Citations: 6
Hu Y, Georgiou P, 2013, A direct-capacitive feedback ISFET interface for pH reaction monitoring, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 189-192, ISSN: 0271-4302
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- Citations: 3
Hu Y, Georgiou P, 2013, A study of the partitioned dynamic programming algorithm for genome comparison in FPGA, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 1897-1900, ISSN: 0271-4302
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- Citations: 1
Reddy M, Herrero P, Oliver N, et al., 2012, Clinical Assessment of a Novel Bio-inspired Artificial Pancreas (B-iAP) in Subjects With Type 1 Diabetes Mellitus, Diabetes Technology Society, Diabetes Technology Meeting, 2012
Herrero P, Georgiou P, Delaunay B, et al., 2012, Robust Parameter Estimation of Glucose-Insulin Minimal Models using Interval Analysis, Diabetes Technology Society, Diabetes Technology Meeting, 2012
Herrero P, Yoong WK, Georgiou P, et al., 2012, A Bio-Inspired Insulin Bolus, Diabetes Technology Society, Diabetes Technology Meeting, 2012
Herrero P, Delaunay B, Jaulin L, et al., 2012, An Efficient Implementation of the SIVIA Algorithm in a High-Level Numerical Programming Language, Reliable Computing, Pages: 239-251
High-level, numerically oriented programming languages such as Mat-lab, Scilab or Octave are popular and well-established tools in the sci-enti c and engineering communities. However, their computational e -ciency sometimes limits their use in certain areas where intensive numer-ical computations are required, such as interval analysis. In this paper,we present an e cient implementation of the well known Set Inverter viaInterval Analysis (SIVIA) algorithm in Matlab that has a computationale ciency comparable to its C++ counterpart. Such implementation aimsat promoting and facilitating the use of SIVIA algorithm by the afore-mentioned communities. The source code of a Matlab implementation isfreely distributed.
Herrero P, Calm R, Vehi J, et al., 2012, Robust Fault Detection System For Insulin Pump Therapy using Continuous Glucose Monitoring, Journal of Diabetes Science and Technology, Vol: 6, Pages: 1131-1141
Background:The popularity of continuous subcutaneous insulin infusion (CSII), or insulin pump therapy, as a way to deliver insulin more physiologically and achieve better glycemic control in diabetes patients has increased. Despite the substantiated therapeutic advantages of using CSII, its use has also been associated with an increased risk of technical malfunctioning of the device, which leads to an increased risk of acute metabolic complications, such as diabetic ketoacidosis. Current insulin pumps already incorporate systems to detect some types of faults, such as obstructions in the infusion set, but are not able to detect other types of fault such as the disconnection or leakage of the infusion set. Methods:In this article, we propose utilizing a validated robust model-based fault detection technique, based on interval analysis, for detecting disconnections of the insulin infusion set. For this purpose, a previously validated metabolic model of glucose regulation in type 1 diabetes mellitus (T1DM) and a continuous glucose monitoring device were used. As a first step to assess the performance of the presented fault detection system, a Food and Drug Administration-accepted T1DM simulator was employed.Results:Of the 100 in silico tests (10 scenarios on 10 subjects), only two false negatives and one false positive occurred. All faults were detected before plasma glucose concentration reached 300 mg/dl, with a mean plasma glucose detection value of 163 mg/dl and a mean detection time of 200 min.Conclusions:Interval model-based fault detection has been proven (in silico) to be an effective tool for detecting disconnection faults in sensor-augmented CSII systems. Proper quantification of the uncertainty associated with the employed model has been observed to be crucial for the good performance of the proposed approach.
Liu Y, Al-Ahdal A, Georgiou P, et al., 2012, Minimal readout scheme for ISFET sensing arrays based on pulse width modulation, ELECTRONICS LETTERS, Vol: 48, Pages: 548-U28, ISSN: 0013-5194
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- Citations: 9
Herrero P, Georgiou P, Oliver N, et al., 2012, Simulation For Bihormonal Glucose ControllerTesting, Incorporating Intra-Day Variability And A Meal Library, Advanced Technologies & Treatments for Diabetes, 2012
Kalofonou M, Georgiou P, Ou C-P, et al., 2012, An ISFET based translinear sensor for DNA methylation detection, SENSORS AND ACTUATORS B-CHEMICAL, Vol: 161, Pages: 156-162
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- Citations: 28
Herrero P, Bondia J, Palerm CC, et al., 2012, A simple robust method for estimating the glucose rate of appearance from mixed meals., J Diabetes Sci Technol, Vol: 6, Pages: 153-162
BACKGROUND: Estimating the rate of glucose appearance (R(a)) after ingestion of a mixed meal may be highly valuable in diabetes management. The gold standard technique for estimating R(a) is the use of a multitracer oral glucose protocol. However, this technique is complex and is usually not convenient for large studies. Alternatively, a simpler approach based on the glucose-insulin minimal model is available. The main drawback of this last approach is that it also requires a gastrointestinal model, something that may lead to identifiability problems. METHODS: In this article, we present an alternative, easy-to-use method based on the glucose-insulin minimal model for estimation of R(a). This new technique avoids complex experimental protocols by only requiring data from a standard meal tolerance test. Unlike other model-based approaches, this new approach does not require a gastrointestinal model, which leads to a much simpler solution. Furthermore, this novel technique requires the identification of only one parameter of the minimal model because the rest of the model parameters are considered to have small variability. In order to account for such variability as well as to account for errors associated to measurements, interval analysis has been employed. RESULTS: The current technique has been validated using data from a United States Food and Drug Administration-accepted type 1 diabetes simulator [root mean square error (RMSE) = 0.77] and successfully tested with two clinical data sets from the literature (RMSE = 0.69). CONCLUSIONS: The presented technique for the estimation of R(a) showed excellent results when tested with simulated and actual clinical data. The simplicity of this new technique makes it suitable for large clinical research studies for the evaluation of the role of R(a) in patients with impairments in glucose metabolism. In addition, this technique is being used to build a model library of mixed meals that could be incorporated into diabetic su
Al-Ahdal A, Georgiou P, Toumazou C, 2012, ISFET’s threshold voltage control using bidirectional electron tunnelling, Pages: 172-175
Dayan O, Spulber I, Eftekhar A, et al., 2012, Applying EMG spike and peak counting for a real-time muscle fatigue monitoring system, Pages: 41-44
Wang K, Liu Y, Toumazou C, et al., 2012, A TDC based ISFET readout for large-scale chemical sensing systems, Pages: 176-179
Hu Y, Liu Y, Toumazou C, et al., 2012, A CMOS architecture allowing parallel DNA comparison for on-chip assembly, IEEE International Symposium on Circuits and Systems, Publisher: IEEE, Pages: 1544-1547, ISSN: 0271-4302
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- Citations: 2
Spulber I, Georgiou P, Eftekhar A, et al., 2012, Frequency analysis of wireless accelerometer and EMG sensors data: Towards discrimination of normal and asymmetric walking pattern, Circuits and Systems (ISCAS), 2012 IEEE International Symposium on, Pages: 2645-2648
This preliminary study reports on the combined use of wireless accelerometers and wireless EMG sensors for monitoring walking patterns. The sensor data was analyzed in frequency domain through FFT, PSD and time-frequency spectrogram analysis. Accelerometer spectra was found to shift towards lower frequencies (<3 Hz) while EMG spectra of selected muscles shifted towards higher frequencies (>50 Hz) during asymmetric walking. Median frequency was used to quantify the spectral shifts. The combined wireless accelerometer/EMG system showed potential for discrimination between the normal and asymmetric walking.
Herrero P, Georgiou P, Oliver N, et al., 2012, A Bio-Inspired Glucose Controller Based on the Pancreatic β-Cell Physiology, Journal of Diabetes Science and Technology, Vol: 6
Sohbati M, Liu Y, Georgiou P, et al., 2012, An ISFET design methodology incorporating CMOS passivation, Pages: 65-68
Georgiou P, Toumazou C, 2011, Semiconductors for early detection and therapy, ELECTRONICS LETTERS, Vol: 47, Pages: S4-S6, ISSN: 0013-5194
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- Citations: 7
Toumazou C, Georgiou P, 2011, Semiconductors in Personalised Medicine, ELECTRONICS LETTERS, Vol: 47, Pages: S1-S2, ISSN: 0013-5194
Toumazou C, Georgiou P, Bergveld P, 2011, Piet Bergveld-40 years of ISFET technology: From neuronal sensing to DNA sequencing, ELECTRONICS LETTERS, Vol: 47, Pages: S7-S12, ISSN: 0013-5194
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- Citations: 24
Kalofonou M, Georgiou P, Toumazou C, 2011, An ISFET based chemical Gilbert Cell, IEEE Biomedical Circuits and Systems Conference (BioCAS) 2011, Publisher: IEEE, Pages: 365-368
This paper presents an ISFET based chemical Gilbert Cell capable of differential measurement of pH signals during thermocycling reactions. Such a process is important for DNA analysis during PCR, with the capability to be applied in Lab-On-Chip (LOC) topologies. The proposed circuit is capable of measuring the difference between two reaction chambers allowing stable drift reduction. The system has been designed and fabricated in a typical 0.35μm CMOS process, with the resulting topology achieving differential measurement, tunable gain of up to 40dB, temperature stability, with a variation of just 0.7% within the range of 0 to 100°C and a low power consumption of 198nW. © 2011 IEEE.
Toumazou C, Georgiou P, 2011, Bio-inspired semiconductors for early detection and therapy, Pages: 129-132
This paper presents an overview of how semiconductor technology is now being used for early detection and therapy of disease. Specifically three areas are described which are currently utilising CMOS technology with tremendous benefit in healthcare. The first being in mobile health whereby CMOS technology enables implementation of a low power intelligent wireless solution. The second being in Genomics, whereby advances in CMOS based ISFET technology is now allowing implementation of Point-of-Care diagnostic systems as well as genetic sequencing systems which are scalable, miniature and fabricated at low cost, and the final being in bio-inspired prosthetics, whereby low-power CMOS based systems can be designed to replicate biology to provide implantable and portable devices for personalised therapy of conditions such as Diabetes. © 2011 IEEE.
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