Development of a device to impose myocardial mechanical stress for the quant itative reproduction of volume and pressure overload in vivo

开发一种施加心肌机械应力的装置，用于定量再现体内容量和压力超负荷

• 批准号: 12670716
• 负责人: SUGIMACHI Masaru
• 金额: $ 1.98万
• 依托单位: National Cardiovascular Center Research Institute
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12670716/
• 关键词: volume overload; pressure overlooad; finite element analysis; the law of Laplace; myocardial strain; myocardial stress; real-time loading; transmural distributiion; 異方性

We have developed a framework to translate ventricular load into myocardial load in this study. By finite element analysis using nonlinear homogenous isotropic material and thick-walled sphere geometry, we obtained transmural stress and strain distribution. While the law Laplace does not give stress distribution, finite element analysis requires a large computational cost and was unsuited for real-time application. To circumvent these problems, we developed a new method to calculate stress distribution by applying the law of Laplace to each layer of a multi-layer myocardial model. This method enabled us to calculate stress distribution without too much computational cost, but taking nonlinear material property and finite geometric deformation into consideration. This method is, however, only applicable to spheric ventricular model with homogenous isotropic material. Analogous to finite element analysis, subendocardial stress is larger than subepicardial stress. In volume overload such as aortic regurgitation, myocardial stress became pronounced during late diastole and early ejection phase, while (in press)ure overload such as aortic stenosis, stress and strain became pronounced during ejection phase. With this method, one can calculate myocardial strain distribution in quantitative manners in real-time. We have also custom made circuitry and software to impose mechanical strain, thus calculated by computers.

在这项研究中，我们已经建立了一个将心室负荷转化为心肌负荷的框架。采用非线性均质各向同性材料和厚壁球几何模型进行有限元分析，得到了跨壁应力应变分布。虽然拉普拉斯定律没有给出应力分布，但有限元分析需要很大的计算成本，并且不适合实时应用。为了克服这些问题，我们开发了一种新的方法来计算应力分布的应用拉普拉斯定律的多层心肌模型的每一层。该方法考虑了材料的非线性和有限的几何变形，在不增加计算量的情况下计算应力分布。然而，该方法仅适用于具有均匀各向同性材料的球心室模型。与有限元分析类似，心内膜下应力大于心外膜下应力。在容量超负荷如主动脉瓣反流中，心肌应力在舒张晚期和射血早期变得明显，而在压力超负荷如主动脉瓣狭窄中，应力和应变在射血期变得明显。利用该方法，可以实时定量地计算心肌应变分布。我们还定制了电路和软件来施加机械应变，从而由计算机计算。

项目成果

Toshiaki Shishido: "Single-Beat Estimation of End-Systolic Elastance Using Bilinearly Approximated Time-Varying Elastance Curve"Circulation. 102. 1983-1989 (2000)

Toshiaki Shishido：“使用双线性近似时变弹性曲线对收缩末期弹性进行单次估计”循环。

Masaru Sugimachi: "A new model-based method of reconstructing central aortic pressure from peripheral arterial pressure"Jpn J Physioi. 51. 217-222 (2001)

Masaru Sugimachi：“一种基于模型的从外周动脉压重建中心主动脉压的新方法”Jpn J Physioi。

Masaru Sugimachi: "Lower compliance rather than high reflection of arterial system decreases stroke volume in arteriosclerosis : A simulation"Jpn J Physiol 2001;51:43-51. 51. 43-51 (2001)

Masaru Sugimachi：“动脉系统的低顺应性而不是高反射会降低动脉硬化中的每搏输出量：模拟”Jpn J Physiol 2001；51：43-51。

Hayashi K: "Single-beat estimation of Ees/Ea as an index of ventricular mechano-energrtic performance."Anesthesiology. 92. 1769-1776 (2000)

Hayashi K：“Ees/Ea 的单搏估计作为心室机械能量性能的指标。”麻醉学。

Sugimachi M et al: "A new model-based method of reconstructing central aortic pressure from peripheral arterial pressure"Jpn J Physiol. 51. 217-222 (2001)

Sugimachi M 等人：“一种基于模型的从外周动脉压重建中心主动脉压的新方法”Jpn J Physiol。