Thermal Diffusion Measurement via Heating Control
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Solution Overview
Problem
Existing deep-body temperature measurement techniques face challenges in accuracy due to thermal resistance components at the body surface and internal tissues, leading to errors in measuring deep-body temperature, especially in thermal nonequilibrium states, and are limited by the separation of temperature and heat flux sensors which assume thermal equilibrium.
Innovation Solution
A thermal diffusion coefficient measuring device with a biological information sensor comprising an extremely thin temperature sensor and heat flux sensor, combined with a heating/cooling control means to measure the temperature diffusion coefficient of thermal resistance components from the skin surface to internal body parts, using a thin thermoelectric converter element for reduced heat resistance and improved accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If temperature sensor and heat flux sensor are disposed adjacent to each other with space left between them, then the device structure is simplified, but measurement precision deteriorates due to assumption of thermal equilibrium
Solution Approach 1:
The patent extracts the thermal resistance component from the measurement system by introducing a separate heating/cooling control means that can independently control heat flow through the thermal resistance component. This allows the temperature sensor and heat flux sensor to remain adjacent while eliminating the assumption of thermal equilibrium, as the thermal resistance is now a controlled variable rather than an unknown factor.
2Measurement precision
If zero flux method is used with thermally insulating material layer, then deep temperature measurement accuracy is improved, but device complexity and size increase
Solution Approach 1:
The patent introduces a heating/cooling control means as an intermediary component that mediates the heat flow through the thermal resistance component. This intermediary allows precise control of thermal conditions without requiring complex multi-layer insulating structures, thereby maintaining measurement accuracy while simplifying the overall device structure.
3Ease of manufacture
If heat flux sensor and temperature sensor are separated with space, then thermal equilibrium assumption is made simplifying calculations, but measurement reliability deteriorates in thermal nonequilibrium states
Solution Approach 1:
The patent applies dynamics by making the heating/cooling control means capable of dynamically adjusting heat flow to create controlled thermal nonequilibrium states. This allows the system to operate reliably in nonequilibrium conditions while maintaining measurement accuracy, as the thermal resistance component becomes a controlled parameter rather than an source of error.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables more accurate measurement of deep-body temperature by accounting for thermophysical properties at the skin surface and internal body, reducing errors associated with thermal resistance components and allowing estimation of deep-body temperature in thermal nonequilibrium states.
Implementation Method 1
an extremely thin temperature sensor for measuring skin temperature
Implementation Method 2
a similarly extremely thin heat flux sensor for measuring heat flux generated in a normal direction to a skin surface
Implementation Method 3
enables measurement of a temperature diffusion coefficient of a thermal resistance component
Implementation Method 4
using a thin thermoelectric converter element for reduced heat resistance and improved accuracy
Data Source
AI summary
In order to enable the measurement of thermal property information about a subject, this thermal diffusion coefficient measuring device, which is used by contacting the surface of a living body, is provided with: a biological information sensor comprising a temperature sensor and a heat flux sensor; and a heating/cooling control means. The temperature sensor is provided at a position contacting the surface of the living body, and operates so as to detect skin temperature. The heat flux sensor is provided at a position contacting the surface of the living body, while being adjacent to the temperature sensor, and operates so as to detect heat flux on the surface of the living body. The heating/cooling control means enables the measurement of the temperature diffusion coefficient of a thermal resistance component that is present between the biological information sensor and a deep inner portion of the living body.