Analysis of thermoviscoelastic behavior in cartilage

软骨热粘弹性行为分析

基本信息

批准号：
6941681
负责人：
Brian WONG
金额：
$ 7.63万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-09-01 至 2009-08-31
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): In Laser Cartilage Reshaping (LCR), shape change is accomplished by first mechanically deforming the tissue and then heating it rapidly using a laser to approximately 60-70 degrees C. Using LCR, cartilages in the head and neck may be reshaped into new stable geometries without the need for cutting or suturing to relieve and/or balance the intrinsic forces that resist deformation. The specific objectives of this proposal include: 1) determining both the acute and long-term mechanical stability of laser irradiated cartilage grafts, 2) characterizing the critical relationship between mechanical stress behavior in response to heat generation in cartilage, 3) developing a finite element model (FEM) to simulate thermoviscoelasticity in cartilage in order to perform parametric analysis, and 4) correlating shape change with viability and laser dosimetry. These aims complement and extend the objectives outlined in the P.l.'s existing K-08 MCSDA. Cell/tissue culture techniques and an in vivo rabbit model will be used to evaluate the acute and long-term response of cartilage to laser irradiation. Thermal analysis (as used in materials science) will be performed to characterize cartilage temperature dependent thermal and mechanical properties, and these results will be incorporated into the FEM coupling heat transfer and viscoelastic behavior. Parametric analysis of the stress/strain field and temperature distribution to key variables and processes will be performed and used to optimize LCR in parallel with measurements of tissue viability in laser reshaped specimens. The range of laser parameters that produce effective shape change while preserving tissue viability will be determined, and estimates of phase transformation energy requirements will be calculated using the FEM. Since shape change in cartilage corresponds to stress relaxation, knowing the energy required to accelerate this process (phase transformation energy) will be a key factor in optimization since this energy deposition is largely determine by dosimetry and tissue thermal and optical properties. This proposal will focus on developing a more cogent understanding of the shape change process, and facilitate the safe transfer of LCR from the laboratory to the clinic in the U.S. Inasmuch as thermal tissue reshaping and modification is a growing topic of research, this proposal focuses on establishing the long-term mechanical behavior and fundamental physical mechanisms governing these processes in living tissues.

描述（由申请人提供）：在激光软骨重塑（LCR）中，形状的变化是通过机械机械变形的组织来完成的，然后使用激光迅速将其加热至大约60-70度C。使用LCR，使用LCR，头部和颈部的软骨可以将其重塑为新的稳定稳定的几何形状，而无需切割到不需要的静脉固定范围，即可将其切换到或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/或/nive。该提案的具体目标包括：1）确定激光照射的软骨移植物的急性和长期机械稳定性，2）表征机械压力行为对响应热量产生的机械压力行为之间的临界关系，3）开发有限元模型（FEM），以使软骨中的热量弹性在适合于commetrry和4的shorpry andry和4）中，并逐渐变化。这些目标补充并扩展了P.L.现有的K-08 MCSDA中概述的目标。细胞/组织培养技术和体内兔模型将用于评估软骨对激光照射的急性和长期反应。热分析（如材料科学中使用）将进行表征依赖软骨温度的热和机械性能，这些结果将纳入FEM耦合热传递和粘弹性行为中。将执行应力/应变场和温度分布到关键变量和过程的参数分析，并用于优化LCR与激光重塑样品中组织生存力的测量并行的LCR。将确定在保留组织生存力的同时确定产生有效形状的激光参数的范围，并将使用FEM计算相变能需求的估计值。由于软骨的形状变化对应于应力松弛，因此知道加速此过程所需的能量（相变能）将是优化的关键因素，因为该能量沉积在很大程度上通过剂量和组织热和光学特性确定。该提案将着重于对形状变化过程的更加有力理解，并促进LCR从实验室到美国的诊所的安全转移，因为热组织重塑和修改是一个越来越多的研究主题，这项建议着重于建立长期的机械行为行为和基本的物理机制，以这些过程在生活组织中。