OPTIMAL DESIGN OF THERMAL DEVICE FOR SKIN PERFUSION

生物医学研究中最重要的衡量标准之一是 血流量和组织灌注量的测定。尽管一个 很少有非侵入性方法被广泛研究，这些方法是 在应用和准确性方面受到限制。随着……的发展 用于加热和传感的复杂固态设备 温度，现在可以最优地设计一种测量 用于估计给定流量的系统和实验协议 组织。传感器可以以小个体阵列的形式制造 元素，每个元素都可以产生指定的时变 温度。为了使这样的传感器被优化设计成 评价血流灌注量，有必要建立数学模型 结合了足够的细节的热传递 被测组织的结构和性质以及 设备本身。潜在的假设是，通过产生一个 组织表面的温度变化以及随后的动态变化 在同一表面上测量的热传递速率将取决于 对下面组织的血液流动的影响。因此，它 应该可以解释传感器对灌流的反应 在不同的深度，因此，为了估计血液流量 不同的层次。为了建立多元素的规范， 多温度热流传感器用于估计血流灌注量 应使用数学模型来模拟动态响应 对系统的影响。此外，我们可以在以下条件下确定 这些反应对血液流动最为敏感和特异。 有了这些信息，我们可以开发简化的模型来获得 一种实用的信号处理方法。最初的目标是 评价真皮毛细血管环血流灌注。测量的方法 皮肤的血流和血流是了解正常的重要因素 皮肤生理学、热调节、皮肤病理和状况 与连续监测的经皮氧分压(a 重症监护医学中广泛使用的仪器)具有中央 动脉价值。尽管皮肤灌流本身很重要 对，它也是评估经皮吸氧的关键 表面电极的张力。此外，如果这一基本方法 是可行的，那么它就可以应用于其他医学应用 用于非侵入性评估组织中更深层次的血液流动。

One of the most important measurements in biomedical research is the determination of blood flow and tissue perfusion. Although a few noninvasive methods have been studied extensively, these are limited in application and accuracy. With the development of sophisticated solid-state devices for heating and sensing temperature, it is now possible to optimally design a measurement system and experimental protocol to estimate flow in a given tissue. Sensors can be fabricated in arrays of small individual elements that can each produce a specified time-varying temperature. For such a sensor to be optimally designed to evaluate perfusion, it is necessary to develop a mathematical model of heat transfer that incorporates sufficient detail of the structure and properties of the tissue being measured and of the device itself. The underlying hypothesis is that by producing a temperature change at the tissue surface the subsequent dynamics of the heat transfer rate measured at the same surface will depend on the blood flow of the underlying tissue. Consequently, it should be possible to interpret the sensor response to perfusion at different depths and, thus, to estimate the blood flow in different layers. To establish specifications of a multi-element, multi-temperature heat flux sensor for estimating perfusion, we shall use a mathematical model to simulate the dynamic responses of the system. Furthermore, we can determine conditions under which the responses are most sensitive and specific to blood flow. With this information, we can develop simplified models to obtain a practical method of signal processing. The initial goal is to evaluate the dermal capillary-loop perfusion. The measurement of skin perfusion and blood flow is important in understanding normal skin physiology, thermal regulation, skin pathology and conditions relating continuously monitored transcutaneous oxygen tension (a widely applied instrument in critical care medicine) with central arterial values. Although skin perfusion is important in its own right, it is also essential for evaluating transcutaneous oxygen tension by surface electrodes. Furthermore, if this basic approach is feasible, then it can be applied to other medical applications for the noninvasive evaluation of blood flow deeper in tissues.