Biorheology最新文献_第2页

The effects of non-Newtonian blood modeling and pulsatility on hemodynamics in the food and drug administration's benchmark nozzle model. 非牛顿血液模型和脉动对食品和药物管理局基准喷嘴模型中血液动力学的影响。

IF 1.1 4区医学

Biorheology Pub Date : 2023-01-01 DOI: 10.3233/BIR-201019

Bryan C Good

{"title":"The effects of non-Newtonian blood modeling and pulsatility on hemodynamics in the food and drug administration's benchmark nozzle model.","authors":"Bryan C Good","doi":"10.3233/BIR-201019","DOIUrl":"https://doi.org/10.3233/BIR-201019","url":null,"abstract":"Background: Computational fluid dynamics (CFD) is an important tool for predicting cardiovascular device performance. The FDA developed a benchmark nozzle model in which experimental and CFD data were compared, however, the studies were limited by steady flows and Newtonian models.Objective: Newtonian and non-Newtonian blood models will be compared under steady and pulsatile flows to evaluate their influence on hemodynamics in the FDA nozzle.Methods: CFD simulations were validated against the FDA data for steady flow with a Newtonian model. Further simulations were performed using Newtonian and non-Newtonian models under both steady and pulsatile flows.Results: CFD results were within the experimental standard deviations at nearly all locations and Reynolds numbers. The model differences were most evident at Re = 500, in the recirculation regions, and during diastole. The non-Newtonian model predicted blunter upstream velocity profiles, higher velocities in the throat, and differences in the recirculation flow patterns. The non-Newtonian model also predicted a greater pressure drop at Re = 500 with minimal differences observed at higher Reynolds numbers.Conclusions: An improved modeling framework and validation procedure were used to further investigate hemodynamics in geometries relevant to cardiovascular devices and found that accounting for blood's non-Newtonian and pulsatile behavior can lead to large differences in predictions in hemodynamic parameters.","PeriodicalId":9167,"journal":{"name":"Biorheology","volume":"59 1-2","pages":"1-18"},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9655879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A broad and variable lumbosacral myotome map uncovered by foraminal nerve root stimulation. 韧带神经根刺激法揭示了一个广泛而多变的腰骶部肌图。

IF 2.8 4区医学

Biorheology Pub Date : 2022-05-13 Print Date: 2022-11-01 DOI: 10.3171/2022.3.SPINE2212

Dennis London, Ben Birkenfeld, Joel Thomas, Marat Avshalumov, Alon Y Mogilner, Steven Falowski, Antonios Mammis

{"title":"A broad and variable lumbosacral myotome map uncovered by foraminal nerve root stimulation.","authors":"Dennis London, Ben Birkenfeld, Joel Thomas, Marat Avshalumov, Alon Y Mogilner, Steven Falowski, Antonios Mammis","doi":"10.3171/2022.3.SPINE2212","DOIUrl":"10.3171/2022.3.SPINE2212","url":null,"abstract":"Objective: The human myotome is fundamental to the diagnosis and treatment of neurological disorders. However, this map was largely constructed decades ago, and its breadth, variability, and reliability remain poorly described, limiting its practical use.Methods: The authors used a novel method to reconstruct the myotome map in patients (n = 42) undergoing placement of dorsal root ganglion electrodes for the treatment of chronic pain. They electrically stimulated nerve roots (n = 79) in the intervertebral foramina at T12-S1 and measured triggered electromyography responses.Results: L4 and L5 stimulation resulted in quadriceps muscle (62% and 33% of stimulations, respectively) and tibialis anterior (TA) muscle (25% and 67%, respectively) activation, while S1 stimulation resulted in gastrocnemius muscle activation (46%). However, L5 and S1 both resulted in abductor hallucis (AH) muscle activation (17% and 31%), L5 stimulation resulted in gastrocnemius muscle stimulation (42%), and S1 stimulation in TA muscle activation (38%). The authors also mapped the breadth of the myotome in individual patients, finding coactivation of adductor and quadriceps, quadriceps and TA, and TA and gastrocnemius muscles under L3, L4, and both L5 and S1 stimulation, respectively. While the AH muscle was commonly activated by S1 stimulation, this rarely occurred together with TA or gastrocnemius muscle activation. Other less common coactivations were also observed throughout T12-S1 stimulation.Conclusions: The muscular innervation of the lumbosacral nerve roots varies significantly from the classic myotome map and between patients. Furthermore, in individual patients, each nerve root may innervate a broader range of muscles than is commonly assumed. This finding is important to prevent misdiagnosis of radicular pathologies.","PeriodicalId":9167,"journal":{"name":"Biorheology","volume":"32 1","pages":"680-686"},"PeriodicalIF":2.8,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74876560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rising Star Awards. 新星奖。

IF 1.1 4区医学

Biorheology Pub Date : 2021-01-01 DOI: 10.3233/BIR-219902

引用次数: 0

Hemodynamic effects of the human aorta arch with different inflow rate waveforms from the ascending aorta inlet: A numerical study. 升主动脉入口不同流速波形对人主动脉弓血流动力学影响的数值研究。

IF 1.1 4区医学

Biorheology Pub Date : 2021-01-01 DOI: 10.3233/BIR-201009

Ying Chen, Yunmei Yang, Wenchang Tan, Liqin Fu, Xiaoyan Deng, Yubin Xing

{"title":"Hemodynamic effects of the human aorta arch with different inflow rate waveforms from the ascending aorta inlet: A numerical study.","authors":"Ying Chen, Yunmei Yang, Wenchang Tan, Liqin Fu, Xiaoyan Deng, Yubin Xing","doi":"10.3233/BIR-201009","DOIUrl":"https://doi.org/10.3233/BIR-201009","url":null,"abstract":"Background: Heart failure (HF) is a common disease globally. Ventricular assist devices (VADs) are widely used to treat HF. In contrast to the natural heart, different VADs generate different blood flow waves in the aorta.Objective: To explore whether the different inflow rate waveforms from the ascending aorta generate far-reaching hemodynamic influences on the human aortic arch.Methods: An aortic geometric model was reconstructed based on computed tomography data of a patient with HF. A total of five numerical simulations were conducted, including a case with the inflow rate waveforms from the ascending aorta with normal physiological conditions, two HF, and two with typical VAD support. The hemodynamic parameters, wall shear stress (WSS), oscillatory shear index (OSI), relative residence time (RRT), and the strength of the helical flow, were calculated.Results: In contrast to the natural heart, numerical simulations showed that HF decreased WSS and induced higher OSI and RRT. Moreover, HF weakened helical flow strength. Pulsatile flow VADs that elevated the WSS, induced some helical flow, while continuous flow VADs could not.Conclusions: HF leads to an adverse hemodynamic environment by decreasing WSS and reducing the helical flow strength. Based upon hemodynamic effects, pulsatile flow VADs may be more advantageous than continuous flow VADs. Thus, pulsatile flow VADs may be a better option for patients with HF.","PeriodicalId":9167,"journal":{"name":"Biorheology","volume":"58 1-2","pages":"27-38"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BIR-201009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25447090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Visualizing and exploring nonlinear behavior, timescales, and mechanical signatures of human blood. 可视化和探索非线性行为，时间尺度，和人类血液的机械特征。

IF 1.1 4区医学

Biorheology Pub Date : 2021-01-01 DOI: 10.3233/BIR-201007

Matthew Armstrong, Erin Milner, Chi Nguyen, Trevor Corrigan, Yu-Fan Lee

{"title":"Visualizing and exploring nonlinear behavior, timescales, and mechanical signatures of human blood.","authors":"Matthew Armstrong, Erin Milner, Chi Nguyen, Trevor Corrigan, Yu-Fan Lee","doi":"10.3233/BIR-201007","DOIUrl":"https://doi.org/10.3233/BIR-201007","url":null,"abstract":"Background: Human blood is a thixo-elasto-visco-plastic (TEVP) material that exhibits unique fluctuations in mechanical properties based on physiology, and shear rate. We demonstrate new visual tools to help visualize and characterize these varied mechanical properties.Objective: Our objective is to demonstrate contemporary visual and numerical tools to help visualize and characterize the varied mechanical properties of human blood.Methods: Using the ARESG2 strain-controlled rheometer with double wall couette geometry and eight human blood donors, with lab test results, elastic and viscous properties are investigated using Series of Physical Processes (SPP) and MITLaos to both analyze and visualize the mechanical signatures of the blood.Results: Variations of mechanical properties are shown via SPP generated Cole-Cole plots and MITLaos analysis. These variations are a function of physiological properties of blood on the day of the blood draw based on hematocrit, fibrinogen, cholesterol, triglycerides, and a host of other proteins and constituents. Each rheological experiment with blood is replicated with an analogous experiments with 0.04 wt% xanthan in glycerol, and water to demonstrate that the mechanical properties of the human blood, and its rheological signatures are unique to human blood.Conclusions: Human blood is proven to be a TEVP material, as shown on a series of Cole-Cole plots for eight different donors, at two different frequency and strain amplitude combinations. Variations in Cole-Cole plots for each donor are shown. MITLaos average mechanical properties are calculated and shown. Aggregated elastic and viscous projections and a Cole-Cole plot is shown for Donors 1-8, along with 95% confidence interval.","PeriodicalId":9167,"journal":{"name":"Biorheology","volume":"58 1-2","pages":"1-26"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BIR-201007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38817314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Spectral analysis of blood flow oscillations to assess the plantar skin blood flow regulation in response to preconditioning local vibrations. 血流振荡的频谱分析，以评估足底皮肤血流调节响应于预处理局部振动。

IF 1.1 4区医学

Biorheology Pub Date : 2021-01-01 DOI: 10.3233/BIR-201011

Xiaotong Zhu, Keying Zhang, Li He, Fuyuan Liao, Yuanchun Ren, Yih-Kuen Jan

{"title":"Spectral analysis of blood flow oscillations to assess the plantar skin blood flow regulation in response to preconditioning local vibrations.","authors":"Xiaotong Zhu, Keying Zhang, Li He, Fuyuan Liao, Yuanchun Ren, Yih-Kuen Jan","doi":"10.3233/BIR-201011","DOIUrl":"https://doi.org/10.3233/BIR-201011","url":null,"abstract":"Background: Local vibration has shown promise in improving skin blood flow and wound healing. However, the underlying mechanism of local vibration as a preconditioning intervention to alter plantar skin blood flow after walking is unclear.Objective: The objective was to use wavelet analysis of skin blood flow oscillations to investigate the effect of preconditioning local vibration on plantar tissues after walking.Methods: A double-blind, repeated measures design was tested in 10 healthy participants. The protocol included 10-min baseline, 10-min local vibrations (100 Hz or sham), 10-min walking, and 10-min recovery periods. Skin blood flow was measured over the first metatarsal head of the right foot during the baseline and recovery periods. Wavelet amplitudes after walking were expressed as the ratio of the wavelet amplitude before walking.Results: The results showed the significant difference in the metabolic (vibration 10.06 ± 1.97, sham 5.78 ± 1.53, p < 0.01) and neurogenic (vibration 7.45 ± 1.54, sham 4.78 ± 1.22, p < 0.01) controls. There were no significant differences in the myogenic, respiratory and cardiac controls between the preconditioning local vibration and sham conditions.Conclusions: Our results showed that preconditioning local vibration altered the normalization rates of plantar skin blood flow after walking by stimulating the metabolic and neurogenic controls.","PeriodicalId":9167,"journal":{"name":"Biorheology","volume":"58 1-2","pages":"39-49"},"PeriodicalIF":1.1,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.3233/BIR-201011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38906381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Preface. 前言。

IF 1.1 4区医学

Biorheology Pub Date : 2021-01-01 DOI: 10.3233/BIR-219900

引用次数: 0

Keynote Lectures. 主题讲座。

IF 1.1 4区医学

Biorheology Pub Date : 2021-01-01 DOI: 10.3233/BIR-219904

引用次数: 0

Free Communications. 自由通信。

IF 1.1 4区医学

Biorheology Pub Date : 2021-01-01 DOI: 10.3233/BIR-219906