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Reflected shear wave computed tomography for elasticity imaging of 3D cell cultures using a single-element transducer

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Applied Physics Letters 2024年第23期124卷

作者： Chen, Ting-Wei Chen, You-Chuan Li, Pai-Chi Graduate Institute of Biomedical Electronics and Bioinformatics National Taiwan University Taipei Taiwan Department of Electrical Engineering National Taiwan University Taipei Taiwan

Shear wave elasticity imaging (SWEI) has long been used to quantify tissue stiffness in clinical diagnoses. In comparison with conventional bulk-based measurement methods, SWEI offers the distinct advantage of nondestructive sampling, thereby enabling the spatiotemporal monitoring of stiffness variations. However, applying SWEI to assessing millimeter-scale three-dimensional (3D) cell environments has faced limitations despite its potential in mechanobiology, and the existing techniques are insufficient for imaging inhomogeneous media environments. In this study, we investigated a computed tomography technique specifically designed for reflected SWEI (called R-SWCT) by rotational scanning in a sample using a 20-MHz ultrasound single-element transducer. We focused on samples containing a single inclusion with higher stiffness than the surrounding medium, mimicking the situation of a tumor sphere embedded in a 3D gel. Our method reconstructs the stiffness distribution using a curve-fitting method, wherein coefficients of Gaussian curves are fitted to the wavefronts of simulated signals. This reconstruction method yielded coefficients that closely approximated the wavefronts obtained experimentally, with a maximum difference between the measured and predicted shear wave speeds of only 0.1 m/s for phantom samples and 0.2 m/s for cell samples. The system and methodologies proposed in this research have demonstrated the feasibility of employing R-SWCT to study the remodeling dynamics of a cell group within its surrounding matrix in an in vitro setting. This noninvasive method also facilitates an exploration of how irradiation dosage used in radiation therapy can induce temporal alterations in the shear wave speed in 3D cancer cell cultures. © 2024 Author(s).

关键词： Shear waves

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Conditional Convolution of Clinical Data Embeddings for Multimodal Prostate Cancer Classification

Conditional Convolution of Clinical Data Embeddings for Mult...

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IEEE International Symposium on biomedical Imaging

作者： Jiayang Zhong Fuyao Chen Lihui Chen Dennis Shung John A. Onofrey Department of Biomedical Engineering Medical Scientist Training Program Department of Biotatistics Yale School of Public Health CT USA Yale School of Medicine CT USA Radiology & Biomedical Imaging Urology

ISBN: (数字)9798331520526

ISBN: (纸本)9798331520533

Accurate risk prediction for prostate cancer (PCa) in multiparametric magnetic resonance imaging (mpMRI) is essential for non-invasive diagnosis. Current deep learning approaches, such as convolutional neural networks (CNNs), show promise in predicting Gleason scores (GS) directly from imaging data, yet often overlook valuable clinical data in other data modalities. In this study, we introduce EmbedCondConv a novel multimodal GS prediction model that incorporates clinical information by conditioning CNN kernels on principal components derived from patient clinical data. We tested our models on a public dataset of 921 selected MRI scans and corresponding structured data and compared the prediction performance to baseline models. Our results demonstrate that incorporating clinical information into the model improves GS prediction accuracy with AUROC of 0.90 compared to 0.69 using imaging alone. All code used in this study is publicly available at https://***/jiayangz/EmbedCondConv.

关键词： Dimensionality reduction Convolution Magnetic resonance imaging Predictive models Data models Convolutional neural networks Clinical diagnosis Prostate cancer Kernel Principal component analysis

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Study of Cell Encapsulation System in Using Thai Silk Fibroin-Based Hydrogel

Study of Cell Encapsulation System in Using Thai Silk Fibroi...

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biomedical engineering International Conference (BMEiCON)

作者： Nitchaya Suksomthong Sasitorn Aueviriyavit Juthamas Ratanavaraporn Interdisciplinary Program of Biomedical Engineering Faculty of Engineering Chulalongkorn University Bangkok Thailand Nano Safety and Bioactivity Research Team National Nanotechnology Center National Science and Technology Development Agency (NSTDA) Pathum Thani Thailand Biomedical Engineering Program Biomedical Engineering Research Center Biomaterial Engineering for Medical and Health Research Unit Faculty of Engineering Chulalongkorn University Bangkok Thailand

Designing biomimetic tissue models and developing scaffolds under cell-compatible protocols are a challenge in the field of tissue engineering. Cell encapsulation technique was selected with hydrogel fabrication due to its similarity to the condition within the human body. This study proposed SF-based hydrogels with the aim of application as cell encapsulation matrix. The vital properties, including gelation, diffusion, and cell viability were evaluated. SF/DMPG hydrogels exhibited rapid gelation and sufficient diffusion. L929 cells encapsulated in SF/DMPG survived after the fabrication process, with proliferation occurred at day 1 of culture which was done in static condition. The developed hydrogels showed potential application as a cell encapsulation matrix using tissue engineering, especially bioink.

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Enhancing the Performance of E-Mode AlGaN/GaN HEMTs With Recessed Gates Through Low-Damage Neutral Beam Etching and Post-Metallization Annealing

IEEE Open Journal of Nanotechnology

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IEEE Open Journal of Nanotechnology 2023年 4卷 150-155页

作者： Chen, Yi-Ho Ohori, Daisuke Aslam, Muhammad Lee, Yao-Jen Li, Yiming Samukawa, Seiji National Yang Ming Chiao Tung University Parallel and Scientific Computing Laboratory Graduate Degree Program of College of Electrical and Computer Engineering Hsinchu300093 Taiwan Tohoku University Institute of Fluid Science Sendai980-8577 Japan National Yang Ming Chiao Tung University Parallel and Scientific Computing Laboratory Electrical Engineering and Computer Science International Graduate Program Hsinchu300093 Taiwan National Yang Ming Chiao Tung University Institute of Pioneer Semiconductor Innovation Hsinchu300093 Taiwan National Yang Ming Chiao Tung University Parallel and Scientific Computing Laboratory Institute of Communications Engineering Institute of Biomedical Engineering Hsinchu300093 Taiwan National Yang Ming Chiao Tung University Department of Electronics and Electrical Engineering Hsinchu300093 Taiwan National Yang Ming Chiao Tung University Institute of Communications Engineering Hsinchu300093 Taiwan

This study investigated the electrical properties of AlGaN/GaN high-electron-mobility transistors (HEMTs) with varied recess depths under the gate electrode. We demonstrated a recess depth of approximately 6 nm, which was achieved through neutral beam etching (NBE) technique with a low etch rate of 1.8 nm/min, resulting in device enhancement-mode (E-mode) behavior with threshold voltage (Vth) of 0.49 V. The effects of post-metallization annealing (PMA) on the device performance were also examined. The results revealed that PMA treatment improves the DC characteristics of the devices, including maximum drain current (IDMAX), transconductance (gm), subthreshold swing (SS), on-off ratio, and off-state leakage current, with maximum enhancement percentage of 18.3% for IDMAX, 3758% for on-off ratio, and 54.3% for SS. Moreover, this study compared the recess depths of metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMTs) with the SiN dielectric layer. The results showed that MIS-HEMTs exhibit more negative Vth values, which can be attributed to the controlled surface states achieved through passivation. © 2020 IEEE.

关键词： Etching

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The protective role of cognitive reserve on sleeping disorders on an aging population. A cross-sectional study

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Translational Medicine of Aging 2023年第1期7卷 75-79页

作者： Colombo, Barbara Caravita, Simona C.S. Hayes, Marie Behavioral Neuroscience Lab Champlain College United States Norwegian Centre for Learning Environment and Behavioural Research in Education University of Stavanger Stavanger Norway Psychology and Graduate School of Biomedical Science and Engineering University of Maine United States

Sleep disorders and depression have been identified as risk factors for aging-related problems. This cross-sectional studiy explored the protective role of the cognitive reserve on a sample of 377 healthy aging adults. After assessing participants’ cognitive reserve (CR) in an extensive and comprehensive way, participants also filled out self-report scales aimed at measuring their sleep quality (PSQI - Pittsburgh Sleep Quality Index) and depressive symptoms. A series of regression models and path analyses showed that higher CR levels predicted lower PSQI scores overall, even after controlling for depressive symptoms, age, and gender. Depressive symptoms had significant role as a moderators of the effect of CR on sleep disorders. The possible effects of interventions aimed at increasing the CR in preventing the incidence of sleep disorders, cognitive decline, and other aging-related disorders are discussed. © 2023 The Authors

关键词： Cognitive decline Cognitive reserve Depression Sleep disorders

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Efficient Electrode Arrangement for Presenting Phosphenes in Both Upper and Lower Visual Fields

Efficient Electrode Arrangement for Presenting Phosphenes in...

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IEEE Region 10 Humanitarian Technology Conference (R10-HTC)

作者： Manami Kanamaru Keita Tanaka Eiji Kamioka Devision of Electronic Information and Biomedical Engineering Tokyo Denki University Saitama Japan Graduate School of Engineering and Science Shibaura Institute of Technology Tokyo Japan

ISBN: (数字)9798350340204

ISBN: (纸本)9798350340211

Methods of presenting visual information, known as phosphenes, to visually impaired people have been researched. Phosphenes are perceived by applying electrical stimulation to the visual pathway, and the position of the electrodes can control the presentation position. However, presenting one phosphenes requires two electrodes, and presenting multiple phosphenes requires placing many electrodes on the face. Therefore, this study discusses a method that reduces the number of electrodes placed in the limited space on the human face and presents multiple phosphenes.

关键词： Electrodes Visualization Forehead Interference Electrical stimulation Aerospace electronics Faces IEEE Regions

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Efficient Nearly Piecewise Continuous Signal Basis Expansion by Precision Calculation

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IEEE Access 2025年 13卷 95963-95976页

作者： Lee, Hsin-Jung Lee, Cheng-Che Chen, Kuei-Chen Luo, Shao-Yun Chang, Shu-Ping Ding, Jian-Jiun National Taiwan University Graduate Institute of Electronics Engineering Taipei 10617 Taiwan National Taiwan University Graduate School of Advanced Technology Taipei 10617 Taiwan National Taiwan University Graduate Institute of Biomedical Electronics and Bioinformatics Taipei 10617 Taiwan National Taiwan University Graduate Institute of Communication Engineering Taipei 10617 Taiwan

Many one-dimensional (1D) signals, including ECG signals, economic data, particle distributions, seismic waveforms, image rows, and traffic statistics, are nearly piecewise continuous. These signals vary gradually in most regions but vary rapidly in certain narrow regions. Due to the non-uniform distribution of gradients, it is very challenging to well expand these nearly piecewise continuous signals. In this paper, we propose a novel algorithm, called “precise calculation,” to adaptively expand such signals. It categorizes signals into three types and then segments each type into smooth and large-gradient parts by using gradient-based analysis, adaptive thresholding, and morphology refinement. After decomposition, adaptive expansion is applied in each segment. Experiments on 1D ECG signals, electron-density distributions, seismic waveforms, image-row data, and economic time-series demonstrate that the proposed methods accurately expand nearly piecewise continuous signals. Under a fixed number of basis functions, our approach achieves significantly lower approximation errors than existing methods, highlighting its effectiveness for high-fidelity signal reconstruction. While applying only 5% of the expansion functions, experiments show that, for ECG signals, the expansion errors obtained by the proposed method range from 0.0003 to 0.0094—significantly lower than those achieved using only the DCT (0.0023–0.1506) and the Legendre method (0.00318–0.1677). © 2013 IEEE.

关键词： ECG signal expansion efficient one-dimensional basis expansion large-gradient part nearly piecewise continuous signal Signal expansion

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Prototyping a Flowmeter for a Continuous Positive Airway Pressure Device 9th

Prototyping a Flowmeter for a Continuous Positive Airway ...

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9th Latin American Congress on biomedical engineering, CLAIB 2022 and 28th Brazilian Congress on biomedical engineering, CBEB 2022

作者： Motta-Ribeiro, Gabriel C. Giannella-Neto, Antonio Programa Doutor Empreendedor Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro Rio de Janeiro Brazil Biomedical Engineering Program Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil

ISBN: (纸本)9783031494062

Continuous positive airway pressure (CPAP) is an effective therapy for obstructive sleep apnea. Although the controlled variable in CPAP devices is pressure, flow measurement can supplement monitoring of therapy effectiveness. Here, we describe desired sensor characteristics, application constraints and a theoretical framework for designing a differential pressure flowmeter for a CPAP device. Our aim is to validate this framework through experimental verification of the permanent pressure loss and flow-pressure curve of a 3D-printed prototype. Pressure at patient interface was less than 5% lower than that measured before the restrictive element, despite pressure drop in such element being always above that threshold. The predicted quadratic flow-pressure relationship was achieved with a 97% approximation. These findings indicate that the type of restrictive element chosen for the prototype, a Venturi tube, is suitable for the application, and the used framework is adequate for sensor design. However, refinements to the current geometry are needed to adjust flow sensibility and the fitting to other CPAP device’s components. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Flowmeters

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Microvolt T-Wave and Ventricular Repolarization Duration Alternans 9th

Microvolt T-Wave and Ventricular Repolarization Duration Alt...

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9th Latin American Congress on biomedical engineering, CLAIB 2022 and 28th Brazilian Congress on biomedical engineering, CBEB 2022

作者： Winkert, Thaís Nadal, Jurandir Benchimol-Barbosa, Paulo Roberto Biomedical Engineering Program COPPE Institute Universidade Federal do Rio de Janeiro Rio de Janeiro Brazil Hospital Universitário Pedro Ernesto Universidade do Estado do Rio de Janeiro Rio de Janeiro Brazil

ISBN: (纸本)9783031494031

The ventricular tachyarrhythmia is an important cause of sudden cardiac death, impacting economic, social, and health systems. Microvolt T-wave alternans (MTWA) represent transmural gradient alternation in phase-3 ventricular action potential duration, leading to T-wave amplitude shortening in every other beat. The T-peak T-end interval (TpTe) represents the terminal ventricular repolarization duration and is explained by differences in phase-3 repolarization times from ventricular epicardial to endocardial fibers. Whether TpTe alternation occurs in patients with MTWA is unknown. This work investigated whether terminal ventricular repolarization duration alternation is present in MTWA patients. Seven 12-lead ECG records from Physionet T-wave Alternans Database were analyzed. The TpTe alternans was assessed in even and odds beats, in a series of 128 consecutive beats. In even and odd beats, TpTe intervals were ensembled and averaged, and the magnitude of TpTe alternans was defined as the difference between averages (ΔTpTe). The MTWA was quantified by the difference between the average peak of the T-wave in even and odd beats. ΔTpTe and MTWA were compared by Pearson’s coefficient. Even and odd beats on TpTe alternans and MTWA were compared with non-paired Student t-tests. ΔTpTe positively correlated with MTWA (r = 0.5;p © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Electrocardiograms

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Recent advances in electronic devices for monitoring and modulation of brain

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Nano Research 2021年第9期14卷 3070-3095页

作者： Yong Won Kwon Yoon Sun Jun Young-Geun Park Jiuk Jang Jang-Ung Park Nano Science Technology Institute Department of Materials Science and EngineeringYonsei UniversitySeoul 03722Republic of Korea Center for Nanomedicine Institute for Basic Science(IBS)Seoul 03722Republic of Korea Graduate Program of Nano Biomedical Engineering(NanoBME) Advanced Science InstituteYonsei UniversitySeoul 03722Republic of Korea

The brain is actuated by billions of neurons with trillions of interconnections that regulate human *** the mechanisms of these systems that induce sensory reactions and respond to disease remains one of the greatest challenges in science,engineering,and *** advances in nanomaterials and nanotechnologies have led to the extensive research of electronic devices for brain interfaces to better understand the neural activities of the brains complex nervous *** development of sensor devices for monitoring the physiological signals of the brain related to traumatic injury status has accompanied by the progress of electronic neural probes in *** addition,these neurological and stereotactic surgical revolutions hold immense potential for clinical analysis of pharmacological systems within cerebral ***,we review the progress of electronic devices interfacing with brain in terms of the materials,fabrication technologies,and device *** activity can be measured and modulated by brain probes based on newly developed nanofabrication ***,in vivo pathological monitoring of the brain and pharmacological assessment has been developed in miniaturized and wireless *** also consider the key challenges and prospects for further development,and explore the future directions emerging in the latest research.

关键词： neural interfaces neural recording neuromodulation intracranial pressure monitoring microfluidic drug delivery

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