Purpose

This study aims to at numerically retrieve five constant dimensional thermo-physical properties of a biological tissue from dimensionless boundary temperature measurements.

Design/methodology/approach

The thermal-wave model of bio-heat transfer is used as an appropriate model because of its realism in situations in which the heat flux is extremely high or low and imposed over a short duration of time. For the numerical discretization, an unconditionally stable finite difference scheme used as a direct solver is developed. The sensitivity coefficients of the dimensionless boundary temperature measurements with respect to five constant dimensionless parameters appearing in a non-dimensionalised version of the governing hyperbolic model are computed. The retrieval of those dimensionless parameters, from both exact and noisy measurements, is successfully achieved by using a minimization procedure based on the MATLAB optimization toolbox routine lsqnonlin. The values of the five-dimensional parameters are recovered by inverting a nonlinear system of algebraic equations connecting those parameters to the dimensionless parameters whose values have already been recovered.

Findings

Accurate and stable numerical solutions for the unknown thermo-physical properties of a biological tissue from dimensionless boundary temperature measurements are obtained using the proposed numerical procedure.

Research limitations/implications

The current investigation is limited to the retrieval of constant physical properties, but future work will investigate the reconstruction of the space-dependent blood perfusion coefficient.

Practical implications

As noise inherently present in practical measurements is inverted, the paper is of practical significance and models a real-world situation.

Social implications

The findings of the present paper are of considerable significance and interest to practitioners in the biomedical engineering and medical physics sectors.

Originality/value

In comparison to Alkhwaji et al. (2012), the novelty and contribution of this work are as follows: considering the more general and realistic thermal-wave model of bio-heat transfer, accounting for a relaxation time; allowing for the tissue to have a finite size; and reconstructing five thermally significant dimensional parameters.

中文翻译：

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在生物传热的波型模型中重建热性质

目的

这项研究旨在从无量纲边界温度测量值中数字检索生物组织的五个恒定维度的热物理性质。

设计/方法/方法

由于生物热传递的热波模型在热通量极高或极低并且在短时间内施加的情况下是现实的，因此将其用作合适的模型。为了进行数值离散，开发了一种无条件稳定的有限差分方案作为直接求解器。计算相对于控制双曲线模型的无量纲形式中出现的五个恒定无量纲参数的无量纲边界温度测量的灵敏度系数。通过使用基于MATLAB优化工具箱例程lsqnonlin的最小化过程，可以成功地从精确测量和噪声测量中检索这些无量纲参数。

发现

使用提出的数值程序，可以从无因次边界温度测量中获得生物组织未知热物理性质的准确和稳定的数值解。

研究局限/意义

当前的研究仅限于恢复恒定的物理性质，但是未来的工作将研究与空间有关的血液灌注系数的重建。

实际影响

由于实际测量中固有存在的噪声被反转，因此本文具有实际意义，并可以模拟现实情况。

社会影响

本文的发现对生物医学工程和医学物理学领域的从业者具有重要意义和兴趣。

创意/价值

与Alkhwaji等人相比。（2012年），这项工作的新颖性和贡献如下：考虑更一般和现实的生物热传递的热波模型，考虑了弛豫时间。使组织具有有限的大小；并重建五个热有效尺寸参数。