{"title":"A Multi-Technique Reconfigurable Electrochemical Biosensor: Enabling Personal Health Monitoring in Mobile Devices","authors":"Alexander Sun, A. Venkatesh, D. Hall","doi":"10.1109/TBCAS.2016.2586504","DOIUrl":"https://doi.org/10.1109/TBCAS.2016.2586504","url":null,"abstract":"This paper describes the design and characterization of a reconfigurable, multi-technique electrochemical biosensor designed for direct integration into smartphone and wearable technologies to enable remote and accurate personal health monitoring. By repurposing components from one mode to the next, the biosensor's potentiostat is able reconfigure itself into three different measurements modes to perform amperometric, potentiometric, and impedance spectroscopic tests all with minimal redundant devices. A 3.9 × 1.65 cm2 PCB prototype of the module was developed with discrete components and tested using Google's Project Ara modular smartphone. The amperometric mode has a ±1 nA to ±200 μA measurement range. When used to detect pH, the potentiometric mode achieves a resolution of <; 0.08 pH units. In impedance measurement mode, the device can measure 50 Ω-10 MΩ and has been shown to have <; 6° of phase error. This prototype was used to perform several point-of-care health tracking assays suitable for use with mobile devices: 1) Blood glucose tests were conducted and shown to cover the diagnostic range for Diabetic patients (~200 mg/dL). 2) Lactoferrin, a biomarker for urinary tract infections, was detected with a limit of detection of approximately 1 ng/mL. 3) pH tests of sweat were conducted to track dehydration during exercise. 4) EIS was used to determine the concentration of NeutrAvidin via a label-free assay.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"945-954"},"PeriodicalIF":5.1,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2016.2586504","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S Abdollah Mirbozorgi, Yaoyao Jia, Daniel Canales, Maysam Ghovanloo
{"title":"A Wirelessly-Powered Homecage With Segmented Copper Foils and Closed-Loop Power Control.","authors":"S Abdollah Mirbozorgi, Yaoyao Jia, Daniel Canales, Maysam Ghovanloo","doi":"10.1109/TBCAS.2016.2577705","DOIUrl":"10.1109/TBCAS.2016.2577705","url":null,"abstract":"<p><p>A new wireless electrophysiology data acquisition system, built around a standard homecage, is presented in this paper, which can power up and communicate with sensors and actuators/stimulators attached to or implanted in small freely behaving animal subjects, such as rodents. Key abilities of the energized homecage (EnerCage) system is enabling longitudinal experiments with minimal operator involvement or interruption, while providing test subjects with an enriched environment closer to their natural habitat, without the burden of being tethered or carrying bulky batteries. The magnetic resonant multi-coil design used in the new EnerCage-HC2 automatically localizes the transmitted electromagnetic power from a single transmitter (Tx) coil at the bottom of the cage toward the receiver coil (Rx), carried on/in the animal body, obviating the need for tracking the animal or switching the coils. In order to increase the resonators' quality factor (Q > 166) at the desired operating frequency of 13.56 MHz, while maintaining a high self-resonance frequency [Formula: see text], they are made of wide copper foils and optimally segmented based on a set of design rules that can be adopted for experimental arenas with different shapes and dimensions. The Rx rectified voltage is regulated at a user-defined window [Formula: see text] by a Tx-Rx closed-loop power control (CLPC) mechanism that creates a volume inside the homecage with 42 mW of power delivered to the load (PDL), and a homogeneous power transfer efficiency (PTE) plane of 14% on average at ∼7 cm height, plus stability against angular mis-alignments of up to 80°.</p>","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"979-989"},"PeriodicalIF":5.1,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5258855/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62966015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deep Neural Networks for Identifying Cough Sounds","authors":"Justice Amoh, K. Odame","doi":"10.1109/TBCAS.2016.2598794","DOIUrl":"https://doi.org/10.1109/TBCAS.2016.2598794","url":null,"abstract":"In this paper, we consider two different approaches of using deep neural networks for cough detection. The cough detection task is cast as a visual recognition problem and as a sequence-to-sequence labeling problem. A convolutional neural network and a recurrent neural network are implemented to address these problems, respectively. We evaluate the performance of the two networks and compare them to other conventional approaches for identifying cough sounds. In addition, we also explore the effect of the network size parameters and the impact of long-term signal dependencies in cough classifier performance. Experimental results show both network architectures outperform traditional methods. Between the two, our convolutional network yields a higher specificity 92.7% whereas the recurrent attains a higher sensitivity of 87.7%.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"1003-1011"},"PeriodicalIF":5.1,"publicationDate":"2016-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2016.2598794","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62966464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Soltani, M. Aliroteh, M. T. Salam, J. P. Pérez Velázquez, R. Genov
{"title":"Low-Radiation Cellular Inductive Powering of Rodent Wireless Brain Interfaces: Methodology and Design Guide.","authors":"N. Soltani, M. Aliroteh, M. T. Salam, J. P. Pérez Velázquez, R. Genov","doi":"10.1109/TBCAS.2015.2502840","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2502840","url":null,"abstract":"This paper presents a general methodology of inductive power delivery in wireless chronic rodent electrophysiology applications. The focus is on such systems design considerations under the following key constraints: maximum power delivery under the allowable specific absorption rate (SAR), low cost and spatial scalability. The methodology includes inductive coil design considerations within a low-frequency ferrite-core-free power transfer link which includes a scalable coil-array power transmitter floor and a single-coil implanted or worn power receiver. A specific design example is presented that includes the concept of low-SAR cellular single-transmitter-coil powering through dynamic tracking of a magnet-less receiver spatial location. The transmitter coil instantaneous supply current is monitored using a small number of low-cost electronic components. A drop in its value indicates the proximity of the receiver due to the reflected impedance of the latter. Only the transmitter coil nearest to the receiver is activated. Operating at the low frequency of 1.5 MHz, the inductive powering floor delivers a maximum of 15.9 W below the IEEE C95 SAR limit, which is over three times greater than that in other recently reported designs. The power transfer efficiency of 39% and 13% at the nominal and maximum distances of 8 cm and 11 cm, respectively, is maintained.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 4 1","pages":"920-32"},"PeriodicalIF":5.1,"publicationDate":"2016-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2502840","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62965608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Lecoutere, A. Thielens, S. Agneessens, H. Rogier, W. Joseph, R. Puers
{"title":"Wireless Fidelity Electromagnetic Field Exposure Monitoring With Wearable Body Sensor Networks","authors":"J. Lecoutere, A. Thielens, S. Agneessens, H. Rogier, W. Joseph, R. Puers","doi":"10.1109/TBCAS.2015.2487264","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2487264","url":null,"abstract":"With the breakthrough of the Internet of Things and the steady increase of wireless applications in the daily environment, the assessment of radio frequency electromagnetic field (RF-EMF) exposure is key in determining possible health effects of exposure to certain levels of RF-EMF. This paper presents the first experimental validation of a novel personal exposimeter system based on a distributed measurement approach to achieve higher measurement quality and lower measurement variability than the commonly used single point measurement approach of existing exposimeters. An important feature of the system is the integration of inertial sensors in order to determine activity and posture during exposure measurements. The system is designed to assess exposure to frequencies within the 389 to 464, 779 to 928 and 2400 to 2483.5 MHz bands using only two transceivers per node. In this study, the 2400 to 2483.5 MHz band is validated. Every node provides antenna diversity for the different bands in order to achieve higher sensitivity at these frequencies. Two AAA batteries power each standalone node and as such determine the node hardware size of this proof of concept (53 mm×25 mm×15 mm), making it smaller than any other commercially available exposimeter.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"779-786"},"PeriodicalIF":5.1,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2487264","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62964826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fully Parallel Electrical Impedance Tomography Using Code Division Multiplexing","authors":"M. Tsoeu, M. Inggs","doi":"10.1109/TBCAS.2015.2487321","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2487321","url":null,"abstract":"Electrical Impedance Tomography (EIT) has been dominated by the use of Time Division Multiplexing (TDM) and Frequency Division Multiplexing (FDM) as methods of achieving orthogonal injection of excitation signals. Code Division Multiplexing (CDM), presented in this paper is an alternative that eliminates temporal data inconsistencies of TDM for fast changing systems. Furthermore, this approach eliminates data inconsistencies that arise in FDM when frequency bands of current injecting electrodes are chosen over frequencies that have large changes in the imaged object's impedance. To the authors knowledge no fully functional wideband system or simulation platform using simultaneous injection of Gold codes currents has been reported. In this paper, we formulate, simulate and develop a fully functional pseudo-random (Gold) code driven EIT system with 15 excitation currents and 16 separate voltage measurement electrodes. In the work we verify the use of CDM as a multiplexing modality in simultaneous injection EIT, using a prototype system with an overall bandwidth of 15 kHz, and attainable speed of 462 frames/s using codes with a period of 31 chips. Simulations and experiments are performed using the Electrical Impedance and Diffuse Optics Reconstruction Software (EIDORS). We also propose the use of image processing on reconstructed images to establish their quality quantitatively without access to raw reconstruction data. The results of this study show that CDM can be successfully used in EIT, and gives results of similar visual quality to TDM and FDM. Achieved performance shows average position error of 3.5% and size error of 6.2%.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"556-566"},"PeriodicalIF":5.1,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2487321","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62964922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Libin George, G. Gargiulo, T. Lehmann, T. J. Hamilton
{"title":"A 0.04 mm$^2$ Buck-Boost DC-DC Converter for Biomedical Implants Using Adaptive Gain and Discrete Frequency Scaling Control","authors":"Libin George, G. Gargiulo, T. Lehmann, T. J. Hamilton","doi":"10.1109/TBCAS.2015.2480035","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2480035","url":null,"abstract":"This paper presents the design of a reconfigurable buck-boost switched-capacitor DC-DC converter suitable for use in a wide range of biomedical implants. The proposed converter has an extremely small footprint and uses a novel control method that allows coarse and fine control of the output voltage. The converter uses adaptive gain control, discrete frequency scaling and pulse-skipping schemes to regulate the power delivered to a range of output voltages and loads. Adaptive gain control is used to implement variable switching gain ratios from a reconfigurable power stage and thereby make coarse steps in output voltage. A discrete frequency scaling controller makes discrete changes in switching frequency to vary the power delivered to the load and perform fine tuning when the output voltage is within 10% of the target output voltage. The control architecture is predominately digital and it has been implemented as part of a fully-integrated switched-capacitor converter design using a standard bulk CMOS 0.18 μm process. Measured results show that the converter has an output voltage range of 1.0 to 2.2 V, can deliver up to 7.5 mW of load power and efficiency up to 75% using an active area of only 0.04 mm2, which is significantly smaller than that of other designs. This low-area, low-complexity reconfigurable power converter can support low-power circuits in biomedical implant applications.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"668-678"},"PeriodicalIF":5.1,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2480035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62964649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A 200-Channel Area-Power-Efficient Chemical and Electrical Dual-Mode Acquisition IC for the Study of Neurodegenerative Diseases","authors":"G. Guo, Waichiu Ng, Jie Yuan, Suwen Li, M. Chan","doi":"10.1109/TBCAS.2015.2468052","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2468052","url":null,"abstract":"Microelectrode array (MEA) can be used in the study of neurodegenerative diseases by monitoring the chemical neurotransmitter release and the electrical potential simultaneously at the cellular level. Currently, the MEA technology is migrating to more electrodes and higher electrode density, which raises power and area constraints on the design of acquisition IC. In this paper, we report the design of a 200-channel dual-mode acquisition IC with highly efficient usage of power and area. Under the constraints of target noise and fast settling, the current channel design saves power by including a novel current buffer biased in discrete time (DT) before the TIA (transimpedance amplifier). The 200 channels are sampled at 20 kS/s and quantized by column-wise SAR ADCs. The prototype IC was fabricated in a 0.18 μm CMOS process. Silicon measurements show the current channel has 21.6 pArms noise with cyclic voltammetry (CV) and 0.48 pArms noise with constant amperometry (CA) while consuming 12.1 μW. The voltage channel has 4.07 μVrms noise in the bandwidth of 100 kHz and 0.2% nonlinearity while consuming 9.1 μW. Each channel occupies 0.03 mm2 area, which is among the smallest.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"567-578"},"PeriodicalIF":5.1,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2468052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62964323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Low-Complexity Seizure Prediction From iEEG/sEEG Using Spectral Power and Ratios of Spectral Power","authors":"Zisheng Zhang, K. Parhi","doi":"10.1109/TBCAS.2015.2477264","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2477264","url":null,"abstract":"Prediction of seizures is a difficult problem as the EEG patterns are not wide-sense stationary and change from seizure to seizure, electrode to electrode, and from patient to patient. This paper presents a novel patient-specific algorithm for prediction of seizures in epileptic patients from either one or two single-channel or bipolar channel intra-cranial or scalp electroencephalogram (EEG) recordings with low hardware complexity. Spectral power features are extracted and their ratios are computed. For each channel, a total of 44 features including 8 absolute spectral powers, 8 relative spectral powers and 28 spectral power ratios are extracted every two seconds using a 4-second window with a 50% overlap. These features are then ranked and selected in a patient-specific manner using a two-step feature selection. Selected features are further processed by a second-order Kalman filter and then input to a linear support vector machine (SVM) classifier. The algorithm is tested on the intra-cranial EEG (iEEG) from the Freiburg database and scalp EEG (sEEG) from the MIT Physionet database. The Freiburg database contains 80 seizures among 18 patients in 427 hours of recordings. The MIT EEG database contains 78 seizures from 17 children in 647 hours of recordings. It is shown that the proposed algorithm can achieve a sensitivity of 100% and an average false positive rate (FPR) of 0.0324 per hour for the iEEG (Freiburg) database and a sensitivity of 98.68% and an average FPR of 0.0465 per hour for the sEEG (MIT) database. These results are obtained with leave-one-out cross-validation where the seizure being tested is always left out from the training set. The proposed algorithm also has a low complexity as the spectral powers can be computed using FFT. The area and power consumption of the proposed linear SVM are 2 to 3 orders of magnitude less than a radial basis function kernel SVM (RBF-SVM) classifier. Furthermore, the total energy consumption of a system using linear SVM is reduced by 8% to 23% compared to system using RBF-SVM.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"693-706"},"PeriodicalIF":5.1,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2477264","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62964682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Robust System for Longitudinal Knee Joint Edema and Blood Flow Assessment Based on Vector Bioimpedance Measurements","authors":"Sinan Hersek, H. Toreyin, O. Inan","doi":"10.1109/TBCAS.2015.2487300","DOIUrl":"https://doi.org/10.1109/TBCAS.2015.2487300","url":null,"abstract":"We present a robust vector bioimpedance measurement system for longitudinal knee joint health assessment, capable of acquiring high resolution static (slowly varying over the course of hours to days) and dynamic (rapidly varying on the order of milli-seconds) bioresistance and bioreactance signals. Occupying an area of 78×90 mm2 and consuming 0.25 W when supplied with ±5 V, the front-end achieves a dynamic range of 345 Ω and noise floor of 0.018 mΩrms (resistive) and 0.055 mΩrms (reactive) within a bandwidth of 0.1-20 Hz. A microcontroller allows real-time calibration to minimize errors due to environmental variability (e.g., temperature) that can be experienced outside of lab environments, and enables data storage on a micro secure digital card. The acquired signals are then processed using customized physiology-driven algorithms to extract musculoskeletal (edema) and cardiovascular (local blood volume pulse) features from the knee joint. In a feasibility study, we found statistically significant differences between the injured and contralateral static knee impedance measures for two subjects with recent unilateral knee injury compared to seven controls. Specifically, the impedance was lower for the injured knees, supporting the physiological expectations for increased edema and damaged cell membranes. In a second feasibility study, we demonstrate the sensitivity of the dynamic impedance measures with a cold-pressor test, with a 20 mΩ decrease in the pulsatile resistance associated with increased downstream peripheral vascular resistance. The proposed system will serve as a foundation for future efforts aimed at quantifying joint health status continuously during normal daily life.","PeriodicalId":13151,"journal":{"name":"IEEE Transactions on Biomedical Circuits and Systems","volume":"10 1","pages":"545-555"},"PeriodicalIF":5.1,"publicationDate":"2016-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/TBCAS.2015.2487300","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62964914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}