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Assessing Hemodynamic Changes in Cerebral Aneurysms Post Coil Embolization: A Preliminary Investigation

Journal of engineering and Science in Medical Diagnostics and Therapy 2025年第3期8卷 031014页

作者： Monfared, Mohammadali Hollingsworth, Luke Gamage, Peshala Thibbotuwawa Taebi, Amirtaha Biomedical Engineering Program Mississippi State University Mississippi StateMS39762 United States Department of Biomedical Engineering and Science Florida Institute of Technology MelbourneFL32901 United States

A cerebral aneurysm is a weakened area in the wall of a blood vessel within the brain that causes the vessel to bulge outwards. The choice of treatment depends on various factors including the size and location of the aneurysm and the risk of rupture, and should be tailored to individual situations rather than following a universal approach due to their variability among individuals. This approach provides the possibility of choosing precise treatment plans that are proper for each patient's circumstances. The utilization of computational fluid dynamics (CFD) allows for the prediction of after-surgery hemodynamic changes before any surgical approach. The goal of this research was to investigate the flow characteristics and hemodynamic parameters in cerebral arteries before and after endovascular embolization treatments using CFD in three patient-specific geometries with at least one aneurysm at the middle cerebral artery's bifurcation. To model the coiling, the computational domain was divided into two fluid domains, a general fluid domain consisting of the parent arteries and a porous domain inside the aneurysm. CFD modeling was conducted to simulate blood flow in pre- and postcoiling scenarios. Results showed that the coiling model with different porosity values led to a redirection of blood flow away from the aneurysm sac. Additionally, changes in shear stress indicated potential alterations in susceptibility to vascular remodeling. In conclusion, these findings indicated that utilizing CFD modeling for simulating blood flow in patient-specific cerebral arteries could be utilized to predict hemodynamic parameters before any treatment. Copyright © 2025 by ASME.

关键词： Computational fluid dynamics

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Probing mechanisms of cryopreservation damage to natural killer cells

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Cytotherapy 2025年第5期27卷 649-660页

作者： Joules, Adam Mallya, Akshat S. Louwagie, Troy Yu, Guanglin Hubel, Allison Department of Biomedical Engineering University of Minnesota Minneapolis MN United States Department of Mechanical Engineering University of Minnesota Minneapolis MN United States

Background aims: Natural killer (NK) cells show significant potential in targeting hard to treat cancers, but these cells need effective preservation methods to maintain viability and efficacy after cryopreservation. Traditional methods of preserving NK cells result in low post-thaw recovery and function. Dimethyl sulfoxide (DMSO) is a very common cryoprotectant for preserving NK cells, but its infusion into patients post-thaw can cause dose-dependent adverse effects, including nausea, discomfort and cardiac arrest. The aim of this work was to evaluate low DMSO- and osmolyte-based cryopreservation solutions across multiple steps in the cryopreservation process for NK cells. Methods: This study investigated NK cell membrane responses to cryoprotectants, dependence of cell survival on cooling rate and nucleation temperature and influence of osmotic shock and pH changes with regard to freezing NK cells using the NK cell line NK-92 as a model system. Results: Exposure to cryoprotectants reduced the membrane fluidity and NK cell-induced cytotoxicity of the cells before freezing, but combinations of osmolytes mitigated this loss. The introduction of cryoprotectants did not reduce perforin or granzyme content, and slow or rapid dilution after thawing did not reduce viability, recovery or proliferation. Controlled rate freezing and Raman cryomicroscopy studies revealed that NK cells tolerated fast cooling rates, and the optimal cooling rate for NK cells was 4–5°C/min. Raman cryomicroscopy mapped the distribution of cryoprotectants and ice of frozen NK cells at –50°C, showing a reduction in cytotoxic granule signal. Conclusions: The large, osmotically inactive volume of NK cells demonstrates cell sensitivity to cryoprotectants and freezing. Exposure to cryoprotectants can reduce NK cell-induced cytotoxicity and membrane fluidity. We hypothesize that cell dehydration and freezing disrupt cytolytic granules, causing NK intracellular damage. These data emphasize the importance

关键词： cell therapy controlled rate freezing cryopreservation DMSO-free natural killer Raman spectroscopy

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Engine Performance Using Blended Fuels of Biodiesel and Eco Diesel

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Energy engineering 2023年第1期120卷 107-123页

作者： Muhammad Idris IHusin Indra Hermawan Uun Novalia RDBatubara Nugroho Agung Pambudi Alfan Sarifudin Study Program of Mechanical Engineering Universitas Medan AreaMedan20156Indonesia Study Program of Mechanical Engineering Politeknik Negeri MedanMedan20156Indonesia Study Program of Industrial Engineering Universitas Harapan MedanMedan20156Indonesia Department of Mechanical Engineering Education Universitas Sebelas MaretSurakarta57126Indonesia

Diesel engines is an internal combustion engine with high thermal efficiency,which also uses biodiesel fuel,an environmentally friendly,non-toxic,and low sulfur *** has been around for a long time due to its similar characteristics to diesel fuels which has limited ***,several disadvantages are associated with biodiesel,such as poor volatility and high viscosity,which reduces engine ***,this study was carried out to improve the diesel engine performance by mixing biodiesel with ecodiesel(ED),an additive produced from natural ingredients that is dissolvable in *** biodiesel fuel properties used are density 860 kg/m3,dynamic viscosity 4.50E-06 m2/s,cetane number 45,and flashpoint 52°*** results showed that biodiesel-ED mixture could improve engine performance and the optimum performance was at a speed of 3000 rpm on 43.30(kW),124.93(N.m)of the engine torque,and 2.45E–5(kg/kW.s)of the specific fuel *** to paired sample t-test,the difference in the engine performance is only experienced in the torque,which has a significant increase in the composition of the biodiesel+ED by 0.07 gr mixture.

关键词： Car vehicle experiment combustion ED renewable energy

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Development of a Multilayer Iliac Crest Numerical Model for Simulating Honeybee Stinger-Inspired Hollow Needle Insertion

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Journal of engineering and Science in Medical Diagnostics and Therapy 2024年第1期71卷 011201页

作者： Nadda, Rahul Repaka, Ramjee Sahani, Ashish Kumar Department of Biomedical Engineering Indian Institute of Technology Ropar Punjab 140001 India Department of Mechanical Engineering Indian Institute of Technology Ropar Punjab 140001 India

Minimally invasive biopsy needles are frequently inserted into the desired body regions while performing the bone marrow biopsy (BMB) procedure. The key problem with needle insertion in tissues is that the insertion force damages the tissue and deviates the needle path, leading the needle to miss the desired target and reducing biopsy sample integrity. To address these shortcomings, the present work developed a unique bio-inspired barbed biopsy needle design that reduces insertion/extraction forces and needle deflection. This study established several design parameters, including barb geometry and shape (viz., the height of barb, barbed front angle, barbed back angle, and length of portion containing barbs), and examined the impact of these factors on insertion/extraction force and deflection. A Lagrangian surface-based nonlinear finite element (FE) approach has been used to numerically simulate the BMB procedure on a three-dimensional (3D) multilayered heterogeneous model of the human iliac crest. The proposed honeybee stinger-inspired needle design has been found to reduce both insertion and extraction forces because of the decreased frictional surface of the biopsy needle. Copyright © 2023 by ASME.

关键词： Needles

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programmable magnetic hydrogel robots with drug delivery and physiological sensing capabilities

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Materials Today 2025年 87卷 66-76页

作者： Li, Hegeng Jiang, Shaojun Deng, Qiyu Li, Wei Zhang, Weixin Zhu, Hengjia Zhao, Zhipeng Zhang, Yiyuan Wang, Liqiu Xu, Lizhi School of Mechanical and Electronic Engineering Wuhan University of Technology Wuhan China Department of Mechanical Engineering The University of Hong Kong Hong Kong Department of Mechanical Engineering The Hong Kong Polytechnic University Hong Kong Advanced Biomedical Instrumentation Centre Limited Hong Kong Shenzhen518057 China

Magnetic hydrogels are promising materials for the construction of magnetic soft robots applied in robotic systems and implantable devices. However, programming geometric shapes and magnetization profiles of magnetic hydrogel robots (MHRs), as well as integrating functional modules into robotic systems, remain challenging. Here, we report an assembly strategy for MHRs with programmable magnetization profiles and geometries, constructed from discrete integration of magnetized hydrogels and a patterned elastomer membrane based on covalent crosslinking. The resulting robots exhibit sophisticated deformations under varying magnetic fields, enabling effective carrying and delivery of solid drugs. Moreover, the proposed fabrication method preserves the highly porous and hydrophilic microstructures of the hydrogels, facilitating loading, adhesion, and transport of liquid drugs in combination with magnetic properties. Besides, integrating ultrathin and multifunctional microfabricated electronics into the MHRs is also achieved for physiological sensing and simulation, which has negligible effects on their intrinsic mechanics and deformability. The introduction of these magnetic materials and fabrication methods can shed new insights for the development of advanced biomedical tools and robotic systems. © 2025 The Author(s)

关键词： programmable robots

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Aerosol jet printing of surface acoustic wave microfluidic devices

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Microsystems & Nanoengineering 2024年第1期10卷 231-242页

作者： Joseph Rich Brian Cole Teng Li Brandon Lu Hanyu Fu Brittany N.Smith Jianping Xia Shujie Yang Ruoyu Zhong James L.Doherty Kanji Kaneko Hiroaki Suzuki Zhenhua Tian Aaron D.Franklin Tony Jun Huang Department of Biomedical Engineering Duke UniversityDurhamNC 27708USA Department of Electrical and Computer Engineering Duke UniversityDurhamNC 27708USA Department of Mechanical Engineering Virginia Polytechnic Institute and State UniversityBlacksburgVA 24061USA Thomas Lord Department of Mechanical Engineering and Materials Science Duke UniversityDurhamNC 27708USA Deptartment of Precision Mechanics Faculty of Science and EngineeringChuo UniversityTokyo 112-8551Japan Department of Chemistry Duke UniversityDurhamNC 27708USA

The addition of surface acoustic wave(SAW)technologies to microfluidics has greatly advanced lab-on-a-chip applications due to their unique and powerful attributes,including high-precision manipulation,versatility,integrability,biocompatibility,contactless nature,and rapid ***,the development of SAW microfluidic devices is limited by complex and time-consuming micro/nanofabrication techniques and access to cleanroom facilities for multistep photolithography and vacuum-based *** simplify the fabrication of SAW microfluidic devices with customizable dimensions and functions,we utilized the additive manufacturing technique of aerosol jet *** successfully fabricated customized SAW microfluidic devices of varying materials,including silver nanowires,graphene,and poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS).To characterize and compare the acoustic actuation performance of these aerosol jet printed SAW microfluidic devices with their cleanroom-fabricated counterparts,the wave displacements and resonant frequencies of the different fabricated devices were directly measured through scanning laser Doppler ***,to exhibit the capability of the aerosol jet printed devices for lab-on-a-chip applications,we successfully conducted acoustic streaming and particle concentration ***,we demonstrated a novel solution-based,direct-write,single-step,cleanroom-free additive manufacturing technique to rapidly develop SAW microfluidic devices that shows viability for applications in the fields of biology,chemistry,engineering,and medicine.

关键词： printing wave fluid

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Taguchi and ANN approaches for predicting the FSW parameters to analyse the mechanical properties

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Interactions 2024年第1期245卷 1-12页

作者： Manickam, Selvaraj Kavitha, N. Rao, N. Srinivasa Indira, K.P. Pydi, Hari Prasadarao Cheepurupalli, N. Rao Department of Automation and Robotics IMPACT College of Engineering and Applied Sciences Bangalore India Department of Physics NPR College of Engineering and Technology Tamilnadu Natham Dindigul624 401 India Department of Mechanical Engineering Shri Vishnu Engineering College for Women Bhimavaram India Department of Biomedical Engineering Saveetha School of Engineering SIMATS Chennai Kuthambakkam India Department of Mechanical Engineering College of Engineering and Technology Bule Hora University Bule Hora Ethiopia Department of Mineral Processing and Metallurgical Engineering Faculty of Mines Aksum University Aksum Ethiopia

Taguchi design utilized to execute mathematical analysis to assess friction stir welding factors on the mechanical properties like ultimate tensile strength (UTS) and Hardness (BHN). Tool rotational speed (TO), pin depth of tool (PI) and welding speed (WE) were selected. The collected experimental data were used to train ANN model using the LM backpropagation algorithm, aiming to achieve accurate predictions of the maximize the mechanical properties. The optimized ANN was structured as a multilayer perceptron with a feed-forward architecture, consisting of 3 input nodes, 10 neurons in the hidden layer, and 2 output node (3-10-3 structure). The developed model accurately which predicted UTS and BHN values, with an overall R of 0.99335 which indicates a high level of accuracy. The optimal settings for UTS at the highest and lowest levels in Exp. No 8 and Exp. No 3 are identified as TO3-WE2-PI1(1600 rpm, 200 mm/min, and 0.3 mm) and TO1-WE3-PI3 (1200 rpm, 250 mm/min, and 0.9 mm). © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.

关键词： Aluminum alloys

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Vortex dynamics in healthy and pro-atherogenic carotid artery bifurcation models

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Physical Review Fluids 2024年第8期9卷 083102页

作者： Nora Caroline Wild Kartik V. Bulusu Michael W. Plesniak Department of Mechanical and Aerospace Engineering The Department of Mechanical and Aerospace Engineering and Department of Biomedical Engineering The

Carotid artery atherosclerosis is a significant contributor to mortality in the United States. While it is recognized that low wall-shear stresses trigger plaque formation, there is a limited comprehension of the internal vortical structures that impact these stresses and how they differ between a healthy and a disease-prone, high-risk patient cohort. Our objective is to determine which driving factors, such as anatomical features (artery geometry) and mass-flow split, govern vortex behavior. Physiological pulsatile flow computational fluid dynamics simulations were performed on a “healthy” and a “disease-prone” carotid artery bifurcation model. Geometry and flow effects are investigated separately by simulating a third hybrid model having a healthy geometry with outlet boundary conditions imposing disease-prone flow conditions. This “unhealthy ΔP” model recreated disease-prone mass-flow split and internal carotid artery sinus axial pressure gradient conditions in a healthy carotid artery bifurcation geometry. The results of our study revealed that the main vortex's time of formation is primarily dictated by carotid artery bifurcation geometry, whereas its lifespan is determined by the flow conditions. The main vortex's spatial expansion, as well as its circulation decay rate, are dictated by the geometry, not the flow conditions. We conclude that a high internal carotid artery mass flow rate and a higher favorable pressure gradient maximum magnitude occurring near peak systole are strong indicators of a high predisposition towards atherogenesis.

关键词： Biological fluid dynamics Haemodynamics

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Computational Simulation of Adolescent Idiopathic Scoliosis in the Spine 31

Computational Simulation of Adolescent Idiopathic Scoliosis ...

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31st National and 9th International Iranian Conference on biomedical engineering, ICBME 2024

作者： Zadeh-Posti, Mohammad Hosein Kamal, Zeinab Rajaeirad, Mohadese Einafshar, Mohammadjavad Matin Jamshidi, Nima University of Guilan Faculty of Mechanical Engineering Rasht Iran Amirkabir University of Technology Department of Biomedical Engineering Tehran Iran University of Isfahan Faculty of Engineering Department of Biomedical Engineering Isfahan Iran

ISBN: (纸本)9798331529710

Adolescent Idiopathic Scoliosis (AIS) is a condition marked by an abnormal curvature of the spine. This study aims to model AIS using computational techniques to analyze varying bone densities within vertebrae under different muscle paralysis conditions. The aim is to investigate how unilateral muscle paralysis affects bone density and to model conditions similar to AIS. A three-dimensional model of the L2 vertebra was created using Mimics and 3-matic software for segmentation and meshing. The model was imported into ABAQUS for further integration and assignment of properties. The bone remodeling algorithm was applied over 12 months, simulating the intact scoliosis (IS) condition. Loading conditions specific to IS were applied, and three scenarios of muscle paralysis were modeled: longissimus pars thoracic (LGPT) muscle paralysis, multifidus lumborum (MFL) muscle paralysis, and both muscles' paralysis. The current study found variable bone density and Young's modulus distributions for cancellous and cortical bones in the AIS model. Trabecular bone density varied between 0.297 and 0.317g/cm3, with Young's modulus ranging from 99.61 to 115.83 MPa. Cortical bone density ranged from 1.466 to 1.665 g/cm3, while Young's modulus was between 11,794 and 16,110 MPa. The highest von Mises stress was observed in the cortical bone, particularly in the concave region, which is under higher compression in AIS patients than healthy spines. The results of this study support Frost's mechanostat theory, suggesting that uneven loading leads to higher bone density on the concave side of scoliotic vertebrae. The study demonstrates the feasibility of using computational models to simulate AIS and highlights the significance of muscle conditions on bone remodeling and stress distribution in vertebrae. © 2024 IEEE.

关键词： ABAQUS

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Impact of elastin-collagen fiber connections on failure positions in aortic tissues: Experimental and simulation analysis

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Journal of Biorheology 2024年第2期38卷 47-54页

作者： Sugita, Shukei Okada, Seisuke Department of Electrical and Mechanical Engineering Graduate School of Engineering Nagoya Institute of Technology Nagoya Japan Center of Biomedical Physics and Information Technology Nagoya Institute of Technology Nagoya Japan

Aortic aneurysms, characterized by local dilation of the aorta, often lead to catastrophic ruptures. Although aneurysm size is a well-established risk factor, smaller aneurysms can also rupture, indicating unclear rupture mecha-nisms. This study aims to elucidate the role of elastin-collagen fiber connections in failure positions within the aortic wall. Using porcine thoracic aorta samples, uniaxial tensile tests under a multiphoton microscope were conducted to capture images of elastin and collagen fibers. Potential connection points were identified by tracking fiber displacements. Simulation models—unconnected, connected, and partially connected fibers—were developed to analyze the impact of these connections on stress and failure positions. Results showed that up to 10% of crossing points were possibly connected;however, these connections had minimal effects on deformation, stress, and failure positions in collagen fibers, although they influenced stress in elastin fibers. This study confirms that elastin and collagen fiber connections do not significantly affect the initiation sites of aortic rupture. This work advances the understanding of aortic rupture mechanisms, highlighting the complexity of fiber interactions within the arterial wall. © Japanese Society of Biorheology 2024.

关键词： Tensile testing

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