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Asilomar Conference on Signals, Systems & Computers

作者： Fatima Ahsan Aravind C. Govindaraju Robert M. Raphael Taiyun Chi Sameer A. Sheth Wayne Goodman Behnaam Aazhang Department of Electrical and Computer Engineering Rice University Houston TX USA Applied Physics Graduate Program Smalley-Curly Institute Rice University Houston TX Department of Bioengineering Rice University Houston TX USA Department of Neurosurgery Baylor College of Medicine Houston TX USA Menninger Department of Psychiatry and Behavioral Sciences Baylor College of Medicine Houston TX USA

This paper presents the biophysical modeling for neuronal stimulation caused by amplitude-modulated giga-hertz (GHz) electromagnetic (EM) waves. We model a 1D cable equation for electrical signal propagation in a vestibular ganglion neuronal fiber and use Hodgkin-Huxley formalism to model voltage-dependent channel conductances. We find out that for a given stimulation signal strength, the GHz waveform amplitude-modulated at a low frequency of Δf causes neuronal firing with the frequency of Δf whereas the continuous wave GHz did not elicit any neuronal firing. Moreover, the voltage-dependent channel gating dynamics of the Δf amplitude-modulated GHz stimulation matches that of a simple low frequency stimulation at Δf. Additionally, we find that the modulation depth controls the firing rate of the neurons. The significance of this property is that the amplitude modulation caused by the interference of two similar high frequency signals could be leveraged to focally excite neurons at depth without stimulating overlying cortical regions. These theoretical predictions based on the Hodgkin-Huxley model can later be tested experimentally.

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Multimaterial 3D Nanoprinting of a 2 Fr Soft Robotic Microcatheter for Transarterial Chemoembolization of Liver Cancer

Multimaterial 3D Nanoprinting of a 2 Fr Soft Robotic Microca...

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IEEE International Conference on Soft Robotics (RoboSoft)

作者： Bailey M. Felix Jordi T. Andreou Sarah McHugh Jack E. McCann Olivia M. Young Molly A. Carton Dheeraj Gandhi Miroslaw Janowski Mark Fuge Axel Kreiger Clifford R. Weiss Christopher R. Bailey Ryan D. Sochol Fischell Department of Bioengineering University of Maryland College Park MD USA Department of Mechanical Engineering University of Maryland College Park MD USA Department of Diagnostic Radiology and Nuclear Medicine Program in Image Guided Neurointerventions University of Maryland School of Medicine Baltimore MD USA Department of Mechanical Engineering ETH Zurich Zurich Switzerland Department of Mechanical Engineering Johns Hopkins University Baltimore MD USA The Russell H. Morgan Department of Radiology and Radiological Science Division of Vascular and Interventional Radiology Johns Hopkins University School of Medicine Baltimore MD USA Maryland Robotics Center University of Maryland College Park MD USA Robert E. Fischell Institute for Biomedical Devices University of Maryland College Park MD USA

ISBN: (数字)9798331520205

ISBN: (纸本)9798331520212

Transarterial chemoembolization (TACE)—i.e., the delivery of chemotherapeutics directly into the vasculature of liver tumors—necessitates the use of guidewire-microcatheter systems to navigate tortuous vascular networks. These guide-wires and microcatheters typically lack effective steering controls, making successful navigation through geometrically complex anatomy challenging. Recent advancements in the area of soft microrobotics could offer a pathway to remotely steerable microcatheters at size scales relevant to TACE procedures; however, the difficulties associated with fabricating such systems have represented a critical hurdle. To overcome this barrier, here we present a multimaterial additive nanomanufacturing— or "three-dimensional (3D) nanoprinting"—strategy to achieve steerable soft robotic microcatheters that not only facilitate on-demand regulation of catheter tip deflection, but also comprise 2 French (Fr) outer dimensions (i.e., ⌀ = 666 μm) that are suitable for clinical chemoembolization of liver cancers. Specifically, we use "Two-Photon Direct Laser Writing (DLW)" to 3D nanoprint 1.5 mm-tall microcatheters capable of unidirectional tip bending of approximately 140° as well as mediating delivery of a fluidic payload. Experimental results for navigating the soft robotic microcatheter through a vascular phantom to deliver fluid payloads to target sites suggest the presented strategy holds promise for TACE as well as additional endovascular interventions and minimally invasive surgeries.

关键词： Liver cancer Actuators Navigation Deformation Phantoms Liver Soft robotics Bending Three-dimensional printing Payloads

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Perturbation-induced electromyographic activity is predictive of flexion synergy expression and a sensitive measure of post-stroke motor impairment

Perturbation-induced electromyographic activity is predictiv...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Nirvik Sinha Julius P.A. Dewald Yuan Yang Interdepartmental Neuroscience Program Northwestern University Chicago Illinois USA Edmond and Lily Safra Center for Brain Sciences Hebrew University Jerusalem Israel Department of Physical Therapy and Human Movement Sciences Feinberg School of Medicine Northwestern University Chicago Illinois USA Department of Biomedical Engineering McCormick School of Engineering and Applied Sciences Northwestern University Chicago Illinois USA Department of Bioengineering Grainger College of Engineering University of Illinois Urbana-Champaign Urbana Illinois USA Carle Foundation Hospital Urbana Illinois USA

ISBN: (数字)9798350371499

ISBN: (纸本)9798350371505

The goal of this study was to explore whether the stretch reflex-induced muscle activity is correlated with the expression of the flexion synergy and, therefore, can serve as a quantitative indicator of post-stroke motor impairment. Eleven stroke participants stroke were recruited for this study. Their forearm was connected to a robotic device that applied continuous position perturbations to the paretic elbow joint. The magnitude of EMG activity of the spastic biceps brachii was measured. The expression of the flexion synergy was determined using the increase of synergistic elbow flexion torque when subjects were gradually lifting their paretic arm with two derived measures: normalized flexion synergy area (NFSA) and the mean slope of the expression of flexion synergy (ΔFS). Significant positive correlations were found between spastic biceps EMG (predictor variable) and the flexion synergy expression (response variables), i.e., NFSA (ρ = 0.89, p < 0.001) and ΔFS (ρ = 0.73, p = 0.01). This result indicates that the perturbation-induced EMG activity can serve as a sensitive indicator of post-stroke motor impairments related to the expression of spasticity and flexion synergy and demonstrates that these motor impairments may be mechanistically linked.

关键词： Torque Perturbation methods Muscles Motors Particle measurements Electromyography Torque measurement Elbow engineering in medicine and biology Robots

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Electrochemical measurement of serotonin by Au-CNT electrodes fabricated on microporous cell culture membranes

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Microsystems & Nanoengineering 2020年第1期6卷 494-506页

作者： Ashley A.Chapin Pradeep R.Rajasekaran David N.Quan Liangbing Hu Jens Herberholz William E.Bentley Reza Ghodssi Fischell Department of Bioengineering College ParkMD 20742USA Institute for Systems Research College ParkMD 20740USA Department of Materials Science and Engineering College ParkMD 20740USA Department of Psychology and Neuroscience and Cognitive Science Program College ParkMD 20740USA Institute for Bioscience and Biotechnology Research RockvilleMD 20850USA Robert E.Fischell Institute for Biomedical Devices RockvilleMD 20850USA Department of Electrical and Computer Engineering College ParkMD 20742USA

Gut–brain axis(GBA)communication relies on serotonin(5-HT)signaling between the gut epithelium and the peripheral nervous system,where 5-HT release patterns from the basolateral(i.e.,bottom)side of the epithelium activate nerve *** have been few quantitative studies of this gut-neuron signaling due to a lack of real-time measurement tools that can access the basolateral gut *** vitro platforms allow quantitative studies of cultured gut tissue,but they mainly employ offline and endpoint assays that cannot resolve dynamic molecular-release ***,we present the modification of a microporous cell culture membrane with carbon nanotube-coated gold(Au-CNT)electrodes capable of continuous,label-free,and direct detection of 5-HT at physiological *** characterization of single-walled carbon nanotube(SWCNT)-coated Au electrodes shows increased electroactive surface area,5-HT specificity,sensitivity,and saturation time,which are correlated with the CNT film drop-cast *** microliters of CNT films,with a 10-min saturation time,0.6μA/μM 5-HT sensitivity,and reliable detection within a linear range of 500 nM–10μM 5-HT,can be targeted for high-concentration,high-time-resolution 5-HT *** films(12.5μL)with a 2-h saturation time,4.5μA/μM 5-HT sensitivity,and quantitative detection in the linear range of 100 nM–1μM can target low concentrations with low time *** electrodes achieved continuous detection of dynamic diffusion across the porous membrane,mimicking basolateral 5-HT release from cells,and detection of cell-released 5-HT from separately cultured RIN14B cell ***-integrated cell culture systems such as this can improve in vitro molecular detection mechanisms and aid in quantitative GBA signaling studies.

关键词： release saturation dynamic

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3D-Printed electrochemical sensor-integrated transwell systems

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Microsystems & Nanoengineering 2020年第1期6卷 357-368页

作者： Pradeep Ramiah Rajasekaran Ashley Augustiny Chapin David N.Quan Jens Herberholz William E.Bentley Reza Ghodssi Institute for Systems Research University of MarylandCollege ParkMDUSA Fischell Department of Bioengineering University of MarylandCollege ParkMDUSA Department of Psychology and Neuroscience and Cognitive Science Program University of MarylandCollege ParkMDUSA Institute for Bioscience and Biotechnology Research University of MarylandCollege ParkMDUSA Robert E.Fischell Institute for Biomedical Devices University of MarylandCollege ParkMDUSA Department of Electrical and Computer Engineering University of MarylandCollege ParkMDUSA

This work presents a 3D-printed,modular,electrochemical sensor-integrated transwell system for monitoring cellular and molecular events in situ without sample extraction or microfluidics-assisted downstream *** additive manufacturing techniques such as 3D printing,shadow masking,and molding are used to fabricate this modular system,which is autoclavable,biocompatible,and designed to operate following standard operating protocols(SOPs)of cellular *** to the platform is a flexible porous membrane,which is used as a cell culture substrate similarly to a commercial transwell *** electrochemical sensors fabricated on the membrane allow direct access to cells and their products.A pair of gold electrodes on the top side of the membrane measures impedance over the course of cell attachment and growth,characterized by an exponential decrease(~160%at 10Hz)due to an increase in the double layer capacitance from secreted extracellular matrix(ECM)*** voltammetry(CV)sensor electrodes,fabricated on the bottom side of the membrane,enable sensing of molecular release at the site of cell culture without the need for downstream ***-time detection of ferrocene dimethanol injection across the membrane showed a three order-of-magnitude higher signal at the membrane than in the bulk media after reaching *** modular sensor-integrated transwell system allows unprecedented direct,real-time,and noninvasive access to physical and biochemical information,which cannot be obtained in a conventional transwell system.

关键词： transwell electrochemical culture

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Next-generation Antimicrobial Peptides (AMPs) incorporated nanofibre wound dressings

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Medical Devices and Sensors 2021年第1期4卷

作者： Afshar, Ayda Yuca, Esra Wisdom, Cate Alenezi, Hussain Ahmed, Jubair Tamerler, Candan Edirisinghe, Mohan Department of Mechanical Engineering University College London London United Kingdom Institute for Bioengineering Research University of Kansas [KU LawrenceKS United States Department of Mechanical Engineering and Bioengineering Program University of Kansas [KU LawrenceKS United States Department of Manufacturing Engineering College of Technological Studies PAAT Kuwait City Kuwait

Antimicrobial peptides (AMPs) containing polymer-based nanodelivery systems offer to overcome many challenges in wound care. While preventing the contact of the external agents on the wound, it also addresses a rising concern on the drug resistance. AMPs as the host defence peptides have been increasingly recognized for therapeutic potential owning to their critical role in innate immunity. Here we investigated a nanofibre mesh approach using AMPs incorporated polyethylene oxide (PEO) for wound healing applications. PEO was prepared to carry GH12-COOH-M2 (type 1 AMP) and AMP2 (type 2 AMP), and their antibacterial activity was assessed against Staphylococcus epidermidis (S. epidermidis). PEO-AMP nanofibre meshes were successfully formed by using pressurized gyration (PG), which allows rapid mass production. Bacterial viability of the nanofibre meshes was investigated using the AlamarBlue assay. Fibre morphology, size distribution and AMP incorporation in the nanofibres were characterized by scanning electron microscopy (SEM), fluorescence microscopy (polarization contrast images) and Fourier transform infrared spectroscopy (FTIR). While both PEO-AMP1 and PEO-AMP2 nanofibres indicate promising bacterial inhibition at 105 µg/ml, PEO-AMP2 fibres showed the highest S. epidermidis reduction. The results demonstrated that increase in the AMP content reduced the bacterial growth. Another important implementation of the PEO-AMP nanofibres is that they can be tuned to rapidly releasing the peptides. Antimicrobial peptide-loaded nanofibres represent a viable biologically active solution to next-generation wound dressings. © 2020 The Authors. Medical Devices & Sensors published by Wiley Periodicals LLC.

关键词： Polyethylene oxides

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Mechanistic Modeling of Copper Corrosions in Datacenter Environments

SSRN

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SSRN 2023年

作者： Zhang, Rui Zhang, Jianshun Schmidt, Roger Gilbert, Jeremy L. Department of Mechanical and Aerospace Engineering College of Engineering and Computer Science Syracuse University 263 Link Hall SyracuseNY13244 United States Buildings and Transportation Science Division Oak Ridge National Laboratory Oak RidgeTN37830 United States SyracuseCoE New York Center of Excellence in Environmental and Energy Systems Syracuse University 727 E. Washington Street SyracuseNY13244 United States Department of Mechanical and Aerospace Engineering College of Engineering and Computer Science Syracuse University 212 Link Hall SyracuseNY13244 United States Department of Bioengineering Clemson University Clemson United States Medical University of South Carolina Bioengineering Program CharlestonSC29425 United States

To evaluate the reliability of information technology equipment under various thermal and air-pollution conditions, a mechanistic model based on multi-ion transport and chemical reactions was developed. The model was used to predict Cu corrosion caused by Cl2-containing pollutant mixtures. It also accounted for the effects of temperature (25°C and 28°C), relative humidity (50%, 75%, and 95%), and synergism. It also identified higher air temperature as a corrosion barrier and higher relative humidity as a corrosion accelerator, which agreed well with the experimental results. The average root mean square error of the prediction was 13.7 Å. © 2023, The Authors. All rights reserved.

关键词： Copper corrosion

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An Approach for 3D Microprinting Soft Robotic Surgical Tools at 1.5 French Length Scales for Endovascular Interventions

An Approach for 3D Microprinting Soft Robotic Surgical Tools...

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IEEE International Conference on Soft Robotics (RoboSoft)

作者： Bailey M. Felix Olivia M. Young Jordi T. Andreou Nicholas Portwood Kieran J. Barvenik Noah Barnes Clifford R. Weiss Christopher R. Bailey Dheeraj Gandhi Miroslaw Janowski Jeremy D. Brown Eleonora Tubaldi Mark Fuge Axel Krieger Ryan D. Sochol Department of Bioengineering University of Maryland College Park MD USA Department of Mechanical Engineering University of Maryland College Park MD USA Department of Mechanical Engineering Johns Hopkins University Baltimore MD USA The Russell H. Morgan Department of Radiology and Radiological Science Division of Vascular and Interventional Radiology Johns Hopkins University School of Medicine Baltimore MD USA Department of Diagnostic Radiology and Nuclear Medicine Program in Image Guided Neurointerventions University of Maryland School of Medicine Baltimore MD USA Maryland Robotics Center University of Maryland College Park MD USA Robert E. Fischell Institute for Biomedical Devices University of Maryland College Park MD USA

A wide range of endovascular interventions rely on surgical tools such as guidewire-catheter systems for navigating through blood vessels to, for example, deliver embolic materials, stents, and/or therapeutic agents to target sites as well as biopsy tools (e.g., forceps and punch needles) for medical diagnostics. In response to the difficulties in maneuvering such endovascular instruments safely and effectively to access intended sites in the body, researchers have developed an array of soft robotic surgical tools that harness fluidic (e.g., pneumatic or hydraulic) actuation schemes to support on-demand steering and control. Despite considerable progress, scaling these tools down to the sizes required for medical procedures such as cerebral aneurysm treatment and liver chemoembolization have been hindered by manufacturing-induced constraints. To provide a pathway to overcome these miniaturization challenges, this work presents a novel additive manufacturing strategy for 3D microprinting integrated soft actuators directly atop multilumen microfluidic tubing via “Two-Photon Direct Laser Writing (DLW)”. As an exemplar, a two-actuator tip was 3D printed onto custom dual-lumen tubing-resulting in a system akin to a 1.5 French (Fr) guidewire with a steerable tip. Experimental results revealed independent actuator control via the discretized lumens, with tip bending of approximately 60° under input pressures of 130 kPa via hydraulic actuation. These results suggest that the presented strategy could be extended to achieve new classes of fluidically actuated soft robotic surgical tools at unprecedented length scales for emerging applications in minimally invasive surgery.

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Multimodal Spatial Attention Network for Automatic Head and Neck Tumor Segmentation in FDG-PET and CT Images 1

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2nd 3D Head and Neck Tumor Segmentation in PET/CT Challenge, HECKTOR 2021, held in conjunction with 24th International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2021

作者： Cho, Minjeong Choi, Yujin Hwang, Donghwi Yie, Si Young Kim, Hanvit Lee, Jae Sung School of Electrical and Electronics Engineering Chung-Ang University Seoul06974 Korea Republic of Department of Biomedical Engineering Kyunghee University College of Electronics and Information 1732 Deogyeong-daero Giheung-gu Gyeonggi-do Yongin-si Korea Republic of Department of Nuclear Medicine Seoul National University College of Medicine Seoul03080 Korea Republic of Department of Biomedical Sciences Seoul National University College of Medicine Seoul03080 Korea Republic of Interdisciplinary Program in Bioengineering Seoul National University Graduate School Seoul Korea Republic of Integrated Major in Innovative Medical Science Seoul National University Graduate School Seoul Korea Republic of Ulsan Korea Republic of Artificial Intelligence Institute Seoul National University Seoul08826 Korea Republic of Brightonix Imaging Inc. Seoul04782 Korea Republic of

ISBN: (数字)9783030982539

ISBN: (纸本)9783030982522

Quantitative positron emission tomography/computed tomography (PET/CT), owing to the functional metabolic information and anatomical information of the human body that it presents, is useful to achieve accurate tumor delineation. However, manual annotation of a Volume Of Interest (VOI) is a labor-intensive and time-consuming task. In this study, we automatically segmented the Head and Neck (H&N) primary tumor in combined PET/CT images. Herein, we propose a convolutional neural network named Multimodal Spatial Attention Network (MSA-Net), supplemented with a Spatial Attention Module (SAM), which uses a PET image as an input. We evaluated this model on the MICCAI 2021 HEad and neCK TumOR (HECKTOR) segmentation challenge dataset. Our method delivered a competitive cross-validation efficiency, with Dice Similarity Coefficient (DSC) 0.757, precision 0.788, and recall 0.785. When we tested out method on test dataset, we achieved an average DSC and Hausdorff Distance at 95% (HD95) of 0.766 and 3.155 respectively. Our team name is ‘Heck_Uihak’. © 2022, Springer Nature Switzerland AG.

关键词： Tumors

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Alerting Network Alteration in Idiopathic Rapid Eye Movement Sleep Behavior Disorder Patients with Mild Cognitive Impairment

Alerting Network Alteration in Idiopathic Rapid Eye Movement...

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亚洲睡眠医学会2021年学术大会暨第十三届中国睡眠研究会年会

作者： Jeong,El Cha,Kwang Su Sunwoo,Jun-Sang Jung,Ki-Young El Jeong Interdisciplinary Program in Bioengineering College of EngineeringSeoul National University Department of Neurology Seoul National University HospitalNeuroscience Research InstituteSeoul National University College of Medicine Department of Neurosurgery Seoul National University Hospital

Objective: It is reported that idiopathic REM sleep behavior disorder (iRBD) is associated with alteration of attention,executive functions,and visuospatial abilities. In addition,it is known that about half of the iRBD patients have mild cognitive impairment (MCI). The aim of this study was to explore the differences between iRBD patients with MCI and ones without MCI. Methods: 14 healthy controls (HC),24 iRBD patients without MCI (iRBD-nMCI),and 24 iRBD patients with MCI (iRBD-MCI) were recruited.

关键词： Alerting Network Alteration in Idiopathic Rapid Eye Movement Sleep Behavior Disorder Patients with Mild Cognitive Impairment

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