Thermal Properties in Biomaterials: The Need for Microscale Measurement in Thin Tissue Systems.

CBET 1236760PI：Bischof在组织中的热传输测量和建模在心血管生物医学中越来越重要，例如局部治疗或生物保存，其中受控和可重复使用的热过程可以保存或破坏具有毫米级特征尺寸的组织。遗憾的是，目前文献中缺乏对控制薄壁(毫米及以下)和各向异性(即多层和定向)心血管组织内热传递的热性质的精确知识。从根本上说，这是因为目前测量生物组织热特性的标准技术涉及毫米级探针和厘米级组织样本。该项目将通过为这些测量采用3欧米伽技术来解决这一限制。它将产生一些重要的新的智力贡献，包括：(1)一个经修改的3欧米伽测试配置，可容纳用于测量的生物软组织，具有精确的温度和光学通道；(2)一套新的属性测量方法，其特征尺寸从1毫米到10s微米；(3)评估心血管组织热属性各向异性的重要性(即组织结构中各层和方向性的影响)；(4)量化界面效应，包括在靶组织和邻近组织(即热疗对食道、肺和神经的影响)热处理过程中的接触电阻。此外，尽管最初的重点将放在心血管应用上，但这项研究将为其他重要的保存或治疗奠定基础，这些组织包括筋膜、神经、胃肠和其他薄的多层组织。本项目将测量小规模生物组织的热属性。它将利用一种测量方法来确定薄型无机材料的性质，并对其进行适当的修改，以应用于生物组织。这项研究的测量数据将极大地有助于建立许多目前未知的生物组织的热性质数据库，并有助于开发更可靠的热预测模型。该项目将影响未来利用热能治疗疾病的生物医学设备的改进发展，并有助于确定更有效地保存药品和食品的新战略。

CBET 1236760PI: BischofThermal transport measurement and modeling in tissues is of increasing importance in cardiovascular biomedicine such as focal therapy or biopreservation where the controlled and reproducible use of a thermal process can either preserve or destroy tissues with characteristic dimensions at the millimeter scale. Unfortunately, precise knowledge of the thermal properties that govern heat transfer within thin (mm scale and below) and anisotropic (i.e. multi-layered and directionally oriented) cardiovascular tissues is currently lacking in the literature. Fundamentally this is because the current standard techniques for measuring thermal properties of biological tissues involve mm-scale probes and cm-scale tissue samples. This project will address this limitation through adaptation of the 3 omega technique for these measurements. It will yield a number of important new intellectual contributions including: (1) A modified 3 omega test configuration which accommodates biological soft tissue for measurement with precise temperature and optical access; (2) A new set of property measurements in tissues with characteristic sizes from 1 mm to 10s of microns; (3) An assessment of the importance of anisotropy in cardiovascular tissue thermal properties (i.e. impact of layers and directionality in the tissue structure); and (4) A quantification of interfacial effects including contact resistance during thermal treatments in target and adjacent tissues (i.e. esophagus, lung and nerve impact of heart thermal treatments). In addition, although the initial focus will be on cardiovascular applications, this study will lay the groundwork for thermal property characterization necessary for other important preservation or therapy treatments in as yet uncharacterized biological tissues including fascia, neural, gastro-intestinal and other thin multi-layered tissues.This project will measure the thermal properties of biological tissue with small-scale dimensions. It will utilize a measurement method used to determine properties of thin inorganic materials with suitable modifications to be applied for biological tissue. The measured data from this research will greatly contribute to the formalization of a thermal property database for many types of biological tissue not currently known, and to the development of more reliable thermal prediction models. This project will influence the development of future enhancements to biomedical devices utilizing thermal energy for disease treatment, and it could help identify new strategies for more effective preservation of pharmaceutical and food products.