Publications
551 results found
Zuliani C, Ng FS, Alenda A, et al., 2016, An array of individually addressable micro-needles for mapping pH distributions, Analyst, Vol: 141, Pages: 4659-4666, ISSN: 1364-5528
This work describes the preparation of an array of individually addressable pH sensitive microneedles which are sensitized by electrodepositing iridium oxide. The impact of the deposition potential, storage conditions and interferents on the sensor characteristics such as slope, offset, intra- and inter-batch reproducibility is investigated. The device may be a useful tool for carrying out direct pH measurements of soft and heterogeneous samples such as tissues and organs. For example, we demonstrated that the microneedle array can be employed for real-time mapping of the cardiac pH distribution during cycles of global ischemia and reperfusion.
El Sharkawy M, Herrero P, Reddy M, et al., 2016, A LOW-POWER BIO-INSPIRED ARTIFICIAL PANCREAS, Publisher: MARY ANN LIEBERT, INC, Pages: A54-A54, ISSN: 1520-9156
Pesl P, Herrero P, Reddy M, et al., 2016, AUGMENTING AN ADVANCED BOLUS CALCULATOR WITH CONTINUOUS GLUCOSE MONITORING AND A SMARTWATCH, Publisher: MARY ANN LIEBERT, INC, Pages: A97-A97, ISSN: 1520-9156
Pesl P, Herrero P, Reddy M, et al., 2016, GLUCOSE RATE-OF-CHANGE AT MEAL TIMES FOR INSULIN DOSING DECISION SUPPORT, Publisher: MARY ANN LIEBERT, INC, Pages: A97-A97, ISSN: 1520-9156
Herrero P, Bondia J, Amparo G, et al., 2016, A BIHORMONAL GLUCOSE CONTROLLER BASED ON THE PARACRINE INTERACTION BETWEEN BETA CELL AND ALPHA CELL, Publisher: MARY ANN LIEBERT, INC, Pages: A57-A58, ISSN: 1520-9156
Seechurn S, Reddy M, Jugnee N, et al., 2016, Does the addition of glucagon to a closed loop system impact on post exercise glycaemia?, ATTD 2016 9th International Conference on Advanced Technologies & Treatments for Diabetes, Publisher: Mary Ann Liebert, Pages: A60-A60, ISSN: 1520-9156
Reddy M, Pesl P, Xenou M, et al., 2016, CLINICAL SAFETY AND FEASIBILITY OF THE ADVANCED BOLUS CALCULATOR FOR TYPE 1 DIABETES BASED ON CASE-BASED REASONING: A 6-WEEK NON-RANDOMISED SINGLE-ARM PILOT STUDY, DIABETES TECHNOLOGY & THERAPEUTICS, Vol: 18, Pages: A34-A35, ISSN: 1520-9156
Herrero P, Delaunay B, Jaulin L, et al., 2016, Robust set-membership parameter estimation of the glucose minimal model, INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Vol: 30, Pages: 173-185, ISSN: 0890-6327
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- Citations: 4
Murphy O, Bahmanyar MR, McLeod CN, et al., 2016, Beyond RF ablation other uses for RF within the body, Pages: 1362-1364
The use of high frequencies within the body is commonplace for treatment and imaging, but, other than a few examples very little exists in terms of RF sensors and for communication deep into the body. This paper will give an overview of an RF powered implantable blood pressure sensor for continuous monitoring and in doing so demonstrate the use of RF within the body.
Ma D, Georgiou P, Toumazou C, 2016, A weak inversion ISFET current mirror for differential bio-sensing, 12th IEEE Biomedical Circuits and Systems Conference (BioCAS), Publisher: IEEE, Pages: 42-45, ISSN: 2163-4025
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- Citations: 3
Murphy O, Bahmanyar MR, McLeod CN, et al., 2016, Beyond RF Ablation Other uses for RF within the body., 11th European Microwave Integrated Circuits Conference (EuMIC), Publisher: IEEE, Pages: 433-435
Pesl P, Herrero P, Reddy M, et al., 2016, Live Demonstration: Smartwatch Implementation of an Advanced Insulin Bolus Calculator for Diabetes, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 2370-2370, ISSN: 0271-4302
Ma D, Georgiou P, Toumazou C, 2016, An ISFET-based switched current DNA integrator, IEEE International Symposium on Circuits and Systems (ISCAS), Publisher: IEEE, Pages: 329-332, ISSN: 0271-4302
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- Citations: 1
Pesl P, Herrero P, Reddy M, et al., 2015, An Advanced Bolus Calculator for Type 1 Diabetes: System Architecture and Usability Results., IEEE Journal of Biomedical and Health Informatics, Vol: 20, Pages: 11-17, ISSN: 2168-2208
This paper presents the architecture and initial usability results of an advanced insulin bolus calculator for diabetes (ABC4D), which provides personalized insulin recommendations for people with diabetes by differentiating between various diabetes scenarios and automatically adjusting its parameters over time. The proposed platform comprises two main components: a smartphone-based patient platform allowing manual input of glucose and variables affecting blood glucose levels (e.g., meal carbohydrate content and exercise) and providing real-time insulin bolus recommendations; and a clinical revision platform to supervise the automatic adaptations of the bolus calculator parameters. The system implements a previously in silico validated bolus calculator algorithm based on case-based reasoning, which uses information from similar past events (i.e., cases) to suggest improved personalized insulin bolus recommendations and automatically learns from new events. Usability of ABC4D was assessed by analyzing the system usage at the end of a six-week pilot study (n = 10). Further feedback on the use of ABC4D has been obtained from each participant at the end of the study from a usability questionnaire. On average, each participant requested 115 ± 21 insulin recommendations, of which 103 ± 28 (90%) were accepted. The clinical revision software proposed a total of 754 case revisions, where 723 (96%) adaptations were approved by a clinical expert and updated in the patient platform.
Hernandez-Silveira M, Ahmed K, Ang SS, et al., 2015, Assessment of the feasibility of an ultra-low power, wireless digital patch for the continuous ambulatory monitoring of vital signs., BMJ Open, Vol: 5, Pages: e006606-e006606, ISSN: 2044-6055
BACKGROUND AND OBJECTIVES: Vital signs are usually recorded at 4-8 h intervals in hospital patients, and deterioration between measurements can have serious consequences. The primary study objective was to assess agreement between a new ultra-low power, wireless and wearable surveillance system for continuous ambulatory monitoring of vital signs and a widely used clinical vital signs monitor. The secondary objective was to examine the system's ability to automatically identify and reject invalid physiological data. SETTING: Single hospital centre. PARTICIPANTS: Heart and respiratory rate were recorded over 2 h in 20 patients undergoing elective surgery and a second group of 41 patients with comorbid conditions, in the general ward. OUTCOME MEASURES: Primary outcome measures were limits of agreement and bias. The secondary outcome measure was proportion of data rejected. RESULTS: The digital patch provided reliable heart rate values in the majority of patients (about 80%) with normal sinus rhythm, and in the presence of abnormal ECG recordings (excluding aperiodic arrhythmias such as atrial fibrillation). The mean difference between systems was less than ±1 bpm in all patient groups studied. Although respiratory data were more frequently rejected as invalid because of the high sensitivity of impedance pneumography to motion artefacts, valid rates were reported for 50% of recordings with a mean difference of less than ±1 brpm compared with the bedside monitor. Correlation between systems was statistically significant (p<0.0001) for heart and respiratory rate, apart from respiratory rate in patients with atrial fibrillation (p=0.02). CONCLUSIONS: Overall agreement between digital patch and clinical monitor was satisfactory, as was the efficacy of the system for automatic rejection of invalid data. Wireless monitoring technologies, such as the one tested, may offer clinical value when implemented as part of wider hospital systems that integrate and supp
Herrero P, Pesl P, Reddy M, et al., 2015, Advanced insulin bolus advisor based on run-to-run control and case-based reasoning, IEEE Journal of Biomedical and Health Informatics, Vol: 19, Pages: 1087-1096, ISSN: 2168-2194
This paper presents an advanced insulin bolus advisor for people with diabetes on multiple daily injections or insulin pump therapy. The proposed system, which runs on a smartphone, keeps the simplicity of a standard bolus calculator while enhancing its performance by providing more adaptability and flexibility. This is achieved by means of applying a retrospective optimization of the insulin bolus therapy using a novel combination of run-to-run (R2R) that uses intermittent continuous glucose monitoring data, and case-based reasoning (CBR). The validity of the proposed approach has been proven by in-silico studies using the FDA-accepted UVa-Padova type 1 diabetes simulator. Tests under more realistic in-silico scenarios are achieved by updating the simulator to emulate intrasubject insulin sensitivity variations and uncertainty in the capillarity measurements and carbohydrate intake. The CBR(R2R) algorithm performed well in simulations by significantly reducing the mean blood glucose, increasing the time in euglycemia and completely eliminating hypoglycaemia. Finally, compared to an R2R stand-alone version of the algorithm, the CBR(R2R) algorithm performed better in both adults and adolescent populations, proving the benefit of the utilization of CBR. In particular, the mean blood glucose improved from 166 ± 39 to 150 ± 16 in the adult populations (p = 0.03) and from 167 ± 25 to 162 ± 23 in the adolescent population (p = 0.06). In addition, CBR(R2R) was able to completely eliminate hypoglycaemia, while the R2R alone was not able to do it in the adolescent population.
Herrero P, Pesl P, Bondia J, et al., 2015, Method for automatic adjustment of an insulin bolus calculator: In silico robustness evaluation under intra-day variability, COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE, Vol: 119, Pages: 1-8, ISSN: 0169-2607
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- Citations: 27
Sohbati M, Toumazou C, 2015, Dimension and Shape Effects on the ISFET Performance, IEEE SENSORS JOURNAL, Vol: 15, Pages: 1670-1679, ISSN: 1530-437X
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- Citations: 31
Herrero P, Chen Z, Bondia J, et al., 2015, INTERVAL-BASED MODEL PREDICTIVE CONTROL FOR AN ARTIFICIAL PANCREAS, Publisher: MARY ANN LIEBERT, INC, Pages: A99-A99, ISSN: 1520-9156
Reddy M, Herrero P, El Sharkawy M, et al., 2015, CLINICAL EVALUATION OF THE BIO-INSPIRED ARTIFICIAL PANCREAS (BIAP) WITHOUT MEAL ANNOUNCEMENT IN ADULTS WITH TYPE 1 DIABETES, Publisher: MARY ANN LIEBERT, INC, Pages: A45-A46, ISSN: 1520-9156
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- Citations: 1
Pesl P, Herrero P, Reddy M, et al., 2015, ACCEPTABILITY OF A PATIENT AND CLINICAL PLATFORM OF AN ADVANCED BOLUS CALCULATOR FOR TYPE 1 DIABETES (ABC4D), Publisher: MARY ANN LIEBERT, INC, Pages: A130-A130, ISSN: 1520-9156
Reddy M, Pesl P, Xenou M, et al., 2015, CLINICAL SAFETY EVALUATION OF AN ADVANCED BOLUS CALCULATOR FOR TYPE 1 DIABETES (ABC4D), Publisher: MARY ANN LIEBERT, INC, Pages: A130-A131, ISSN: 1520-9156
Kaufman N, Bian RR, 2015, Using Health Information Technology to Prevent and Treat Diabetes, DIABETES TECHNOLOGY & THERAPEUTICS, Vol: 17, Pages: S53-S66, ISSN: 1520-9156
Reddy M, Herrero P, El Sharkawy M, et al., 2015, METABOLIC CONTROL WITH THE BIO-INSPIRED ARTIFICIAL PANCREAS (BIAP) IN ADULTS WITH TYPE 1 DIABETES: A 24-HOUR RANDOMISED CONTROLLED CROSSOVER STUDY, Publisher: MARY ANN LIEBERT, INC, Pages: A20-A21, ISSN: 1520-9156
Paraskevopoulou SE, Eftekhar A, Kulasekeram N, et al., 2015, A Low-Noise Instrumentation Amplifier with DC Suppression for Recording ENG Signals, 2015 37TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC), Pages: 2693-2696, ISSN: 1557-170X
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- Citations: 3
Kalofonou M, Toumazou C, 2014, Early screening of breast cancer recurrence by monitoring DNA methylation based biomarkers using semiconductor technology, MEC Annual Meeting and Bioengineering14, Cancer Engineering and Technologies
Breast cancer is one of the most common cancer types in women, with 1 in 8 women having a lifetime risk of incidence. From the cases of primary breast cancer, more than 30% of diagnosed and treated cases will most likely lead to a metastasis, also known as cancer recurrence, within a period of 5-15 years from time of first diagnosis, dependent on the aggressiveness and rate of disease progression. From the stage of first detection of primary breast cancer to the point of a metastatic recurrence, certain tumour-specific genetic and epigenetic changes occur. The use of epigenetic markers, specifically DNA methylation, as a biomarker for cancer has shown great potential due to its role in the initiation, progression and recurrence of the disease. Given that the time of the event of a metastasis can vary from the moment of initial diagnosis, the use of markers that could monitor tumour progression by detecting tumour-specific DNA methylation based changes would provide significant insight in estimating the risk of recurrence, so that the right therapy is being addressed at the right time, in a more personalised way. Current screening methods of breast cancer have shown that more newly developed/recurred breast cancer cases can now be diagnosed but with the risk of more false-positive findings which could further lead to unnecessary treatment due to the possible misinterpretation of the imaging result (low/high risk lesions). Studies have shown that DNA methylation patterns found in blood can be used as reliable markers for distinguishing breast cancer patients from healthy subjects as well as for assessing the progression of breast cancer after therapy. Detection of DNA methylation changes could therefore offer a very promising alternative approach to early screening of breast cancer recurrence, providing with a more individualised clinical assessment and management of cancer as a chronic disease. A Point-of-Care system using the methylation profile of carefully selecte
Reddy M, Herrero P, El Sharkawy M, et al., 2014, Feasibility study of a bio-inspired artificial pancreas in adults with type 1 diabetes, Diabetes Technology and Therapeutics, Vol: 16, Pages: 550-557, ISSN: 1520-9156
Background: This study assesses proof of concept and safety of a novel bio-inspired artificial pancreas (BiAP) system in adults with type 1 diabetes during fasting, overnight, and postprandial conditions. In contrast to existing glucose controllers in artificial pancreas systems, the BiAP uses a control algorithm based on a mathematical model of β-cell physiology. The algorithm is implemented on a miniature silicon microchip within a portable hand-held device that interfaces the components of the artificial pancreas.Materials and Methods: In this nonrandomized open-label study each subject attended for a 6-h fasting study followed by a 13-h overnight and post-breakfast study on a separate occasion. During both study sessions the BiAP system was used, and microboluses of insulin were recommended every 5 min by the control algorithm according to subcutaneous sensor glucose levels. The primary outcome was percentage time spent in the glucose target range (3.9–10.0 mmol/L).Results: Twenty subjects (55% male; mean [SD] age, 44 [10] years; duration of diabetes, 22 [12] years; glycosylated hemoglobin, 7.4% [0.7%] [57 (7) mmol/mol]; body mass index, 25 [4] kg/m2) participated in the fasting study, and the median (interquartile range) percentage time in target range was 98.0% (90.8–100.0%). Seventeen of these subjects then participated in the overnight/postprandial study, where 70.7% (63.9–77.4%) of time was spent in the target range and, reassuringly, 0.0% (0.0–2.3%) of time was spent in hypoglycemia (<3.9 mmol/L).Conclusions: The BiAP achieves safe glycemic control during fasting, overnight, and postprandial conditions.
Reddy M, Agha-Jaffar R, Herrero P, et al., 2014, The impact of glycaemic variability on quality of life in adults with type1 diabetes, Publisher: SPRINGER, Pages: S429-S429, ISSN: 0012-186X
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- Citations: 7
Kalofonou M, Toumazou C, 2014, A Low Power Sub-μW Chemical Gilbert Cell for ISFET Differential Reaction Monitoring, IEEE Transactions on Biomedical Circuits and Systems, Pages: 1-1, ISSN: 1932-4545
This paper presents a low power current-mode method for monitoring differentially derived changes in pH from ion-sensitive field-effect transistor (ISFET) sensors, by adopting the Chemical Gilbert Cell. The fabricated system, with only a few transistors, achieves differential measurements and therefore drift minimisation of continuously recorded pH signals obtained from biochemical reactions such as DNA amplification in addition to combined gain tunability using only a single current. Experimental results are presented, demonstrating the capabilities of the front-end at a microscopic level through integration in a lab-on-chip (LoC) setup combining a microfluidic assembly, suitable for applications that require differential monitoring in small volumes, such as DNA detection where more than one gene needs to be studied. The system was designed and fabricated in a typical 0.35 μm CMOS process with the resulting topology achieving good differential pH sensitivity with a measured low power consumption of only 165 nW due to weak inversion operation. A tunable gain is demonstrated with results confirming 15.56 dB gain at 20 nA of ISFET bias current and drift reduction of up to 100 times compared to a single-ended measurement is also reported due to the differential current output, making it ideal for robust, low-power chemical measurement.
Murphy OH, Borghi A, Bahmanyar MR, et al., 2014, RF communication with implantable wireless device: effects of beating heart on performance of miniature antenna, Healthcare Technology Letters, Vol: 1, Pages: 51-55, ISSN: 2053-3713
The frequency response of an implantable antenna is key to the performance of a wireless implantable sensor. If the antenna detunes significantly, there are substantial power losses resulting in loss of accuracy. One reason for detuning is because of a change in the surrounding environment of an antenna. The pulsating anatomy of the human heart constitutes such a changing environment, so detuning is expected but this has not been quantified dynamically before. Four miniature implantable antennas are presented (two different geometries) along with which are placed within the heart of living swine the dynamic reflection coefficients. These antennas are designed to operate in the short range devices frequency band (863-870 MHz) and are compatible with a deeply implanted cardiovascular pressure sensor. The measurements recorded over 27 seconds capture the effects of the beating heart on the frequency tuning of the implantable antennas. When looked at in the time domain, these effects are clearly physiological and a combination of numerical study and posthumous autopsy proves this to be the case, while retrospective simulation confirms this hypothesis. The impact of pulsating anatomy on antenna design and the need for wideband implantable antennas is highlighted.
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