Zero-heat-flux core body temperature measuring device

Abstract

The invention provides a zero-heat-flux core body temperature measuring device, which relates to the technical field of temperature measurement and comprises a middle heat insulation layer, a heating temperature measuring layer arranged above the middle heat insulation layer, a bottom temperature measuring layer arranged below the middle heat insulation layer and a top heat insulation layer arranged above the heating temperature measuring layer, wherein the bottom temperature measurement layer, the heating temperature measurement layer and the top heat insulation layer are attached to the middle heat insulation layer through adhesives, the heating temperature measurement layer comprises a flexible circuit formed by integrating a heating film and a film temperature sensor, and the bottom temperature measurement layer comprises a flexible film temperature sensor. Grooves are formed in the upper surface and the lower surface of the middle heat insulation layer according to the contour of the heating temperature measurement layer and the contour of the bottom temperature measurement layer respectively, and the heating temperature measurement layer and the bottom temperature measurement layer are embedded into the grooves of the middle heat insulation layer. The problem that the core body temperature is difficult to measure accurately is solved.

Description

Technical Field

[0001] The present invention relates to the field of temperature measurement technology, and in particular to a zero heat flux core body temperature measurement device. Background Art

[0002] Core body temperature refers to the temperature deep inside the chest, abdomen, and cranial cavity of a human or animal. Core body temperature has physiological fluctuations, but is less affected by the patient's psychological or emotional state. It is generally stable, with fluctuations generally not exceeding 1°C. It is an important medical vital sign. Abnormal fluctuations in core body temperature have a great impact on the health of humans or animals. For example, when the core body temperature of a person is lower than 36°C during the perioperative period, it will increase many adverse conditions such as cardiovascular adverse events, coagulation / fibrinolysis dysfunction, and increased blood transfusion requirements. In severe cases, it may even lead to death. Therefore, core body temperature plays an important role in disease monitoring, diagnosis, and treatment.

[0003] The measurement of core body temperature is divided into invasive measurement and non-invasive measurement. In medicine, pulmonary artery temperature is regarded as the gold standard of core body temperature, but invasive measurement methods cause great damage to the patient's body, increase the risk of cross infection, and increase the difficulty of operation. Therefore, non-invasive measurement of core body temperature is more beneficial to the safety and comfort of patients, as well as the convenience of clinical operation.

[0004] The basic idea of ​​the zero heat flux method is to set an insulating layer on the skin surface. Due to heat conduction, the heat inside the tissue is continuously transferred to the body surface, and the existence of the insulating layer prevents the heat from being transferred to the outside. More and more heat accumulates on the skin surface, forming an isothermal channel, which eventually makes the skin surface temperature consistent with the temperature of the subcutaneous tissue. When the heat flux is zero, the skin temperature is considered to be equal to the core body temperature. In reality, absolutely insulating materials do not exist, and the heat loss caused by the insulating layer cannot be avoided, so a heating plate needs to be introduced for heat compensation. The temperature of the isothermal channel is higher than the temperature of the surrounding tissue, and the heat is transferred to the surrounding tissue, causing lateral heat loss, which affects the measurement accuracy of the core body temperature.

[0005] The design and manufacture of the zero heat flux core body temperature measurement device can affect the formation of the isothermal channel and can also realize the monitoring and compensation of lateral heat loss, which mainly involves the size of the measurement device, the structure of the heater and the layout of the temperature sensor. When the zero heat flux core body temperature measurement device is in contact with the tissue, the heat loss caused by the lateral temperature gradient of the tissue makes it impossible for the heater with uniform power density to achieve uniform heat compensation at the contact end of the measurement device and the skin. The insulation layer is compensated with power of the same power density, so that the temperature at the outer edge of the contact end is lower than that at the center, which reduces the cross-sectional area of ​​the isothermal channel and affects the effective measurement of the core body temperature. According to the temperature distribution of the contact end, the power density of different areas of the heater is adjusted to construct an isothermal channel with a large enough cross-sectional area, which is crucial for the accurate measurement of the core body temperature. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides a zero heat flux core body temperature measurement device that solves the problem that core body temperature is difficult to measure accurately.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a zero heat flux core body temperature measurement device, comprising: a middle thermal insulation layer, a heating temperature measuring layer arranged above the middle thermal insulation layer, a bottom temperature measuring layer arranged below the middle thermal insulation layer, and a top thermal insulation layer arranged above the heating temperature measuring layer; wherein the bottom temperature measuring layer, the heating temperature measuring layer and the top thermal insulation layer are bonded to the middle thermal insulation layer by an adhesive, the heating temperature measuring layer includes a flexible circuit integrated with a heating film and a thin film temperature sensor, the bottom temperature measuring layer includes a flexible thin film temperature sensor, the upper surface and the lower surface of the middle thermal insulation layer are respectively provided with grooves according to the contours of the heating temperature measuring layer and the bottom temperature measuring layer, and the heating temperature measuring layer and the bottom temperature measuring layer are embedded in the grooves of the middle thermal insulation layer.

[0008] Furthermore, the middle heat insulation layer and the top heat insulation layer are foam materials with low thermal conductivity, including polytetrafluoroethylene foam, polyethylene foam and polyurethane foam.

[0009] Furthermore, the flexible film temperature sensor included in the bottom temperature measurement layer is composed of a positive temperature coefficient resistive metal material and a polyimide insulating film; wherein the flexible film temperature sensor is a circular temperature sensor with four different radii.

[0010] Furthermore, the lower surface of the heating temperature measuring layer is a thin film temperature sensor with polyimide as an outer insulator, and four circular temperature sensors are used, whose radii correspond one to one with the radii of the circular temperature sensors of the bottom temperature measuring layer.

[0011] Furthermore, the upper surface of the heating and temperature measuring layer is a heating film with polyimide as the outer insulator. The heating film is unevenly distributed, the radial spacing of the heating films gradually decreases along the heating and temperature measuring layer, and the corresponding heating power gradually increases, forming a basically uniform temperature distribution from the center to the periphery of the heating and temperature measuring layer.

[0012] Furthermore, the bottom temperature measuring layer is provided with an adhesive material, and the measuring device is attached to the skin surface during measurement to sense the temperature distribution of different areas on the skin surface. When the temperature corresponding to the heating temperature measuring layer is lower than the temperature sensed by the bottom temperature measuring layer, the heater is controlled by the temperature controller to increase the temperature of the heating temperature measuring layer and reduce the heat flux through the skin surface and the middle insulation layer.

[0013] Furthermore, when the temperature difference between the four circular temperature sensors of the bottom temperature measuring layer and the corresponding circular temperature sensors of the heating temperature measuring layer is less than 0.05°C, and the temperature difference between the four temperature sensors of the bottom temperature measuring layer is also less than 0.05°C, the core body temperature is obtained:

[0014]

[0015] Among them, T core represents core body temperature, T k Indicates the temperature of the kth circular temperature sensor, where k represents the serial number of the circular temperature sensor.

[0016] The beneficial effects of the present invention are as follows: by providing a groove according to the contour of the bottom temperature measuring layer under the middle thermal insulation layer, the thin film temperature sensor can better contact with the middle thermal insulation layer, avoiding the gap caused by the welding of traditional sensor elements, and reducing the lateral heat loss of the bottom temperature measuring layer; the integrated structure of the thin film heater and the temperature sensor enables the heating temperature measuring layer to be in good contact with the middle thermal insulation layer, thereby better performing heat compensation and temperature measurement; the top thermal insulation layer covers the upper surface of the heating temperature measuring layer to form a partially closed thermal insulation environment, reducing the heat loss of the heating film in the vertical direction, reducing the time required for thermal equilibrium, and improving the measurement rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0018] Figure 1 is an exploded perspective schematic diagram of a zero heat flux core body temperature measurement device according to some embodiments of the present specification;

[0019] Figure 2 is a schematic cross-sectional diagram of a bottom temperature measurement layer of a zero heat flux core body temperature measurement device according to some embodiments of this specification;

[0020] Figure 3A It is a schematic cross-sectional diagram of a heating portion of a heating temperature measuring layer of a zero heat flux core body temperature measurement device according to some embodiments of this specification;

[0021] Figure 3B It is a schematic cross-sectional diagram of a temperature measuring portion of a heating temperature measuring layer of a zero heat flux core body temperature measuring device according to some embodiments of this specification;

[0022] Figure 4 is a temperature measurement system block diagram of a zero heat flux core body temperature measurement device according to some embodiments of this specification;

[0023] Figure 5 It is a flow chart of a method for measuring body temperature using a novel zero heat flux core body temperature measurement device according to some embodiments of this specification. DETAILED DESCRIPTION

[0024] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0025] Example

[0026] Figure 1 It is a schematic exploded perspective view of a zero heat flux core body temperature measurement device according to some embodiments of the present specification.

[0027] In some embodiments, Figure 1 As shown, the zero heat flux core body temperature measurement device includes: a middle thermal insulation layer, a heating temperature measuring layer arranged above the middle thermal insulation layer, a bottom temperature measuring layer arranged below the middle thermal insulation layer, and a top thermal insulation layer arranged above the heating temperature measuring layer; wherein the bottom temperature measuring layer, the heating temperature measuring layer and the top thermal insulation layer are bonded to the middle thermal insulation layer, the heating temperature measuring layer includes a flexible circuit integrated with a heating film and a thin film temperature sensor, the bottom temperature measuring layer includes a flexible thin film temperature sensor, the upper surface and the lower surface of the middle thermal insulation layer are respectively provided with grooves according to the contours of the heating temperature measuring layer and the bottom temperature measuring layer, and the heating temperature measuring layer and the bottom temperature measuring layer are embedded in the grooves of the middle thermal insulation layer.

[0028] In some embodiments, the bottom thermometric layer can be used to sense the temperature distribution on the skin surface.

[0029] In some embodiments, the intermediate insulating layer can be used to form a local insulating environment to promote the formation of an isothermal channel between the skin and tissue.

[0030] In some embodiments, the heated temperature measuring layer can be used to sense the upper surface temperature of the middle insulation layer and control the heater to heat and compensate for the heat flow loss of the middle insulation layer.

[0031] In some embodiments, the top insulation layer can be used to form a local insulation environment with the middle insulation layer to reduce heat flow loss when the heating and temperature measuring layer is heated.

[0032] In some embodiments, the heating temperature measuring layer and the top thermal insulation layer are bonded to the middle thermal insulation layer by an adhesive; wherein the middle thermal insulation layer and the top thermal insulation layer are foam materials with low thermal conductivity, including polytetrafluoroethylene foam, polyethylene foam and polyurethane foam.

[0033] In some embodiments, the flexible film temperature sensor included in the bottom temperature measurement layer is composed of a positive temperature coefficient resistive metal material and a polyimide insulating film; wherein the flexible film temperature sensor is a plurality of circular temperature sensors with different radii.

[0034] In some embodiments, the bottom temperature measurement layer can be wound at different distances from the center to form multiple groups of temperature sensors to monitor the temperature at different positions of the measurement end surface.

[0035] In some embodiments, Figure 2 As shown, the bottom temperature measurement layer can use a flexible thin film temperature sensor constructed with four circular temperature sensors with different radii to measure the average temperature of the skin surface within this range.

[0036] In some embodiments, the shape of the thin film temperature sensor may include, but is not limited to, circular, rectangular, elliptical, and diamond.

[0037] In some embodiments, the winding shape of the thin film temperature sensor may include a circle, a rectangle, a semicircle, an ellipse, a petal shape, etc.

[0038] In some embodiments, Figure 3B As shown, the lower surface of the heating temperature measuring layer is a thin film temperature sensor with polyimide as the outer insulator, and 4 circular temperature sensors with radii corresponding to the radii of the circular temperature sensors of the bottom temperature measuring layer are used.

[0039] In some embodiments, a thin film temperature sensor on the lower surface of the heated temperature measuring layer can cooperate with a bottom temperature measuring layer sensor to monitor whether a zero heat flux condition is formed.

[0040] In some embodiments, the heating and temperature measuring layer may include a flexible circuit integrated with a thin film temperature sensor and a non-uniform heating film, wherein the thin film temperature sensor and the non-uniform heating film are distributed on both sides of the insulating film; wherein the winding of the thin film temperature sensor is consistent with the winding of the thin film temperature sensor in the bottom temperature measuring layer; the density of the metal foil in the non-uniform heating film gradually increases from the center to the periphery, and the increase pattern may be linear or non-linear.

[0041] In some embodiments, the upper surface of the heating and temperature measuring layer is a heating film with polyimide as the outer insulator. The heating film is unevenly distributed, and the radial spacing of the heating films along the heating and temperature measuring layer gradually decreases. The corresponding heating power gradually increases, forming a basically uniform temperature distribution from the center to the periphery of the heating and temperature measuring layer.

[0042] In some embodiments, Figure 3A As shown, the interior of the heating film can be composed of metal foil, which is unevenly distributed. The radial distance between the metal foils along the heating and temperature measuring layer gradually decreases, and the corresponding heating power density gradually increases to compensate for the heat loss in different areas of the intermediate insulation layer, forming a basically uniform temperature distribution from the center to the periphery of the heating and temperature measuring layer.

[0043] In some embodiments, Figure 4 As shown, the bottom temperature measuring layer is provided with an adhesive material. During measurement, the measuring device is attached to the skin surface to sense the temperature distribution of different areas on the skin surface. When the temperature corresponding to the heating temperature measuring layer is lower than the sensed temperature of the bottom temperature measuring layer, the heater is controlled by the temperature controller to increase the temperature of the heating temperature measuring layer and reduce the heat flux through the skin surface and the middle insulation layer. The temperature controller belongs to the temperature measurement and control system, and adjusts the heating power of the heater according to the temperature difference between the heating temperature measuring layer and the bottom temperature measuring layer until the temperature approaches 0.

[0044] In some embodiments, when the temperature difference between the four circular temperature sensors of the bottom temperature measuring layer and the corresponding circular temperature sensors of the heating temperature measuring layer is less than 0.05°C, and the temperature difference between the four temperature sensors of the bottom temperature measuring layer is also less than 0.05°C, it is considered that the heat flux through the middle insulation layer is zero, and an isothermal area is formed in the bottom temperature measuring layer to obtain the core body temperature.

[0045] In some embodiments, the expression for core body temperature may be:

[0046]

[0047] Among them, T core represents core body temperature, T k Indicates the temperature of the kth circular temperature sensor, where k represents the serial number of the circular temperature sensor.

[0048] In some embodiments, Figure 5As shown, the zero heat flux core body temperature measurement device uses a thin film temperature sensor to collect temperature information; when it is detected that the temperature corresponding to the heating temperature measuring layer is lower than the sensed temperature of the bottom temperature measuring layer, the heater is controlled by the temperature controller to heat the heating film and increase the temperature of the heating temperature measuring layer; when the temperature of the device reaches thermal equilibrium, calculations are performed based on the zero heat flux model to obtain core body temperature data; wherein, the zero heat flux model is a mathematical model used to calculate core body temperature.

[0049] In some embodiments of the present specification, by providing a groove according to the contour of the bottom temperature measuring layer under the middle thermal insulation layer, the thin film temperature sensor can better contact the middle thermal insulation layer, avoid the gap caused by the welding of traditional sensor elements, and reduce the lateral heat loss of the bottom temperature measuring layer; the integrated structure of the thin film heater and the temperature sensor enables the heating temperature measuring layer to be in good contact with the middle thermal insulation layer, thereby better performing heat compensation and temperature measurement; the top thermal insulation layer covers the upper surface of the heating temperature measuring layer to form a partially closed thermal insulation environment, reducing the heat loss of the heating film in the vertical direction, reducing the time required for thermal equilibrium, and improving the measurement rate.

Claims

1. A zero heat flux core body temperature measurement device, characterized in that: include: A middle thermal insulation layer, a heating and temperature measuring layer arranged above the middle thermal insulation layer, a bottom temperature measuring layer arranged below the middle thermal insulation layer, and a top thermal insulation layer arranged above the heating and temperature measuring layer; wherein the bottom temperature measuring layer, the heating and temperature measuring layer and the top thermal insulation layer are bonded to the middle thermal insulation layer, the heating and temperature measuring layer includes a flexible circuit integrated with a heating film and a thin film temperature sensor, the bottom temperature measuring layer includes a flexible thin film temperature sensor, the upper surface and the lower surface of the middle thermal insulation layer are respectively provided with grooves according to the contours of the heating and temperature measuring layer and the bottom temperature measuring layer, and the heating and temperature measuring layer and the bottom temperature measuring layer are embedded in the grooves of the middle thermal insulation layer.

2. The zero heat flux core temperature measurement device according to claim 1, characterized in that: The heating and temperature measuring layer and the top heat-insulating layer are bonded to the middle heat-insulating layer by an adhesive; wherein the middle heat-insulating layer and the top heat-insulating layer are foam materials with low thermal conductivity, including polytetrafluoroethylene foam, polyethylene foam and polyurethane foam.

3. The zero heat flux core temperature measurement device according to claim 1, characterized in that: The flexible film temperature sensor included in the bottom temperature measurement layer is composed of a positive temperature coefficient resistive metal material and a polyimide insulating film; wherein the flexible film temperature sensor is a circular temperature sensor with a plurality of different radii.

4. The zero heat flux core temperature measurement device according to claim 3, characterized in that: The lower surface of the heating temperature measuring layer is a thin film temperature sensor with polyimide as the outer insulator, and multiple circular temperature sensors with radii corresponding to the radii of the circular temperature sensors of the bottom temperature measuring layer are used.

5. The zero heat flux core temperature measurement device according to claim 1, characterized in that: The upper surface of the heating and temperature measuring layer is a heating film with polyimide as the outer insulator. The heating film is unevenly distributed, and the radial spacing of the heating films gradually decreases along the heating and temperature measuring layer. The corresponding heating power gradually increases, forming a basically uniform temperature distribution from the center to the periphery of the heating and temperature measuring layer.

6. The zero heat flux core temperature measurement device according to claim 1, characterized in that: The bottom temperature measuring layer is provided with an adhesive material. During measurement, the measuring device is attached to the skin surface to sense the temperature distribution of different areas on the skin surface. When the temperature corresponding to the heating temperature measuring layer is lower than the temperature sensed by the bottom temperature measuring layer, the heater is controlled by the temperature controller to increase the temperature of the heating temperature measuring layer and reduce the heat flux through the skin surface and the middle insulation layer.

7. The zero heat flux core body temperature measurement device according to any one of claims 1 to 6, characterized in that: When the temperature difference between the four circular temperature sensors of the bottom temperature measuring layer and the corresponding circular temperature sensors of the heating temperature measuring layer is less than 0.05°C, and the temperature difference between the four temperature sensors of the bottom temperature measuring layer is less than 0.05°C, the core body temperature is obtained: Among them, T core represents core body temperature, T k Indicates the temperature of the kth circular temperature sensor, where k represents the serial number of the circular temperature sensor.

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