Quick response electronic thermometer based on infrared detection

Abstract

The invention relates to a quick response electronic thermometer based on infrared detection, which is characterized in that a thin-wall hollow probe is made of a low-thermal-resistance and low-specific-heat-capacity material, and an internal high-emissivity processing surface and an infrared temperature sensor are combined, so that the contradiction that the speed and the precision of a traditional clamping type thermometer cannot be obtained at the same time is thoroughly solved; the thermometer probe can rapidly achieve heat balance with the armpit skin within 1-3 seconds, the internal infrared sensor synchronously and accurately captures signals, the total measurement time is shortened to be within 10 seconds from several minutes, the precision is comparable to that of an actual measurement type, errors of a prediction algorithm are avoided, the requirement for clamping tightness of the thermometer is low, fault tolerance is high, the measurement failure rate is greatly reduced, and the measurement accuracy is improved. The temperature measuring device provides the temperature measuring experience which is almost quick, accurate and reliable and can obtain the temperature by touching, is particularly suitable for infants, patients and other people who are difficult to cooperate, and is a major breakthrough of the armpit temperature measuring technology.

Description

Technical Field

[0001] This invention relates to a fast-response electronic thermometer based on infrared detection, belonging to the field of medical electronic equipment technology. Background Technology

[0002] Axillary temperature measurement is one of the most widely used and accepted methods of human body temperature measurement worldwide due to its non-invasiveness, hygiene, and ease of use. Both traditional glass mercury thermometers and modern electronic thermometers support this method. However, this "clamping" measurement characteristic brings inherent technical challenges and user experience issues.

[0003] Real-world electronic thermometers operate on the principle of thermal equilibrium. Their temperature sensor (usually a thermistor) needs to make full contact with the skin under the armpit and reach thermal equilibrium before a stable reading can be obtained. Because the armpit is a relatively open space, it's difficult to create a perfectly sealed environment when the thermometer is held in place, leading to air heat exchange. Furthermore, the force with which the user's arm is held, the contact area and tightness between the probe and the skin all affect heat conduction efficiency. These factors result in a long time to reach thermal equilibrium, typically requiring 5 minutes or even longer. For infants, post-operative patients, or restless individuals, maintaining a still and tightly held position for extended periods is very difficult, often leading to measurement failures, inaccurate readings, or the need for remeasurement, significantly impacting measurement efficiency and user experience.

[0004] Predictive electronic thermometers use algorithmic models to predict the final equilibrium temperature based on the initial temperature rise curve, reducing measurement time to approximately 30 seconds. This alleviates the waiting time issue to some extent. However, their prediction accuracy heavily relies on the algorithmic model and the initial thermal contact between the probe and the skin. When measuring under the armpit, the initial thermal contact conditions are often imperfect, unstable, and vary from person to person, leading to biases in the prediction algorithm's underlying assumptions. Consequently, the accuracy and consistency (i.e., repeatability) of the measurement results are often inferior to those of practical thermometers, especially when dealing with different body types and varying clamping tightness, where reliability decreases.

[0005] In summary, the core contradiction faced by existing clip-on electronic thermometers lies in the fact that pursuing measurement accuracy requires enduring long waiting times and cooperation, while pursuing measurement speed may sacrifice the reliability and consistency of the results. This contradiction stems from the bottlenecks in their technical principles: 1) High probe thermal inertia: Traditional metal probes (such as stainless steel) have high specific heat capacity and high thermal resistance, requiring a long time to heat up to the axillary temperature; 2) Sensor response delay: Contact sensors (such as NTC) inherently have thermal response delays; 3) The unique characteristics of the axillary measurement environment: The complex heat exchange in the microenvironment created by clipping further prolongs the process of reaching equilibrium.

[0006] Therefore, there is an urgent need in this field for an electronic thermometer specifically designed for clamping measurement scenarios such as under the armpit. It must be able to achieve extremely fast (within seconds), high accuracy and stable measurement at the same time, fundamentally solving the above-mentioned long-standing contradictions and improving the user experience. Summary of the Invention

[0007] The purpose of this invention is to provide a fast-response electronic thermometer based on infrared detection to solve the above-mentioned problems.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a rapid-response electronic thermometer based on infrared detection, the rapid-response electronic thermometer comprising: The probe assembly includes a thin-walled hollow probe housing made of a material with low thermal resistance and low specific heat capacity, wherein the inner wall of the probe housing has a high emissivity surface in the far-infrared band. An infrared temperature sensor is disposed in the internal cavity of the probe housing, with the optical receiving window of the infrared temperature sensor facing the high emissivity surface of the inner wall. The infrared temperature sensor is used to measure the infrared radiation temperature of the inner wall. A signal processing unit, electrically connected to the infrared temperature sensor, is used to process the electrical signal output by the infrared temperature sensor. The main control unit, connected to the signal processing unit, is used to receive the processed signal and calculate the body temperature value. The display unit, connected to the main control unit, is used to display the body temperature value; The power supply unit is used to supply power to the infrared temperature sensor, signal processing unit, main control unit and display unit.

[0009] Furthermore, the material of the probe housing satisfies the formula for calculating thermal diffusivity, which is as follows: ,in, , k is the thermal conductivity of the probe housing material, ρ is the density of the probe housing material, and c is the specific heat capacity of the probe housing material.

[0010] Furthermore, the wall thickness of the probe housing is 0.2 mm to 1.0 mm.

[0011] Furthermore, the high emissivity surface of the inner wall of the probe housing is a high infrared emissivity layer formed by a surface treatment process, and the emissivity of the high infrared emissivity layer in the 5-14μm far-infrared band is not less than 90%.

[0012] Furthermore, the high infrared emissivity layer is a coating layer formed by a coating process.

[0013] Furthermore, the high infrared emissivity layer is a porous metal oxide layer formed through an oxidation process.

[0014] Furthermore, the high infrared emissivity layer is a micro-rough surface formed by sandblasting.

[0015] Furthermore, the high infrared emissivity layer is a coating formed by applying and curing a high emissivity paint.

[0016] Furthermore, the infrared temperature sensor measures at a frequency of 1 Hz to 50 Hz.

[0017] Furthermore, the main control unit is configured to: continuously receive temperature data from the infrared temperature sensor after temperature measurement is initiated, and output the final body temperature value after determining that the temperature data is stable or when a preset sampling time is reached, wherein the preset sampling time is no more than 10 seconds.

[0018] The beneficial effects of this invention are as follows: By using a thin-walled hollow probe made of a low thermal resistance and low specific heat capacity material, and combining it with an internal high emissivity surface and an infrared temperature sensor, this invention completely solves the contradiction between speed and accuracy in traditional clip-on thermometers. This allows the thermometer probe to rapidly reach thermal equilibrium with the axillary skin within 1-3 seconds, while the internal infrared sensor synchronously and accurately captures the signal. This reduces the total measurement time from several minutes to within 10 seconds, achieving accuracy comparable to real-world measurements. It avoids errors from predictive algorithms, has low requirements for clamping tightness, and high fault tolerance, greatly reducing the measurement failure rate. It provides users with a near-instantaneous, extremely fast, accurate, and reliable temperature measurement experience, making it particularly suitable for infants, patients, and other individuals with difficulty cooperating. This represents a major breakthrough in axillary temperature measurement technology.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a fast-response electronic thermometer based on infrared detection, according to an embodiment of this application. Figure 2 for Figure 1 This is a schematic diagram of the internal structure of the probe assembly. Detailed Implementation

[0021] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] Please refer to Figures 1 to 2 An embodiment of this application shows a rapid response electronic thermometer 100 based on infrared detection. The rapid response electronic thermometer 100 includes a probe assembly, an infrared temperature sensor 20, a signal processing unit, a main control unit, a display unit 30, and a power supply unit.

[0025] The probe assembly includes a thin-walled hollow probe housing 10 made of a material with low thermal resistance and low specific heat capacity, and the inner wall of the probe housing 10 has a high emissivity surface 11 in the far-infrared band. An infrared temperature sensor 20 is disposed within the internal cavity of the probe housing 10. The optical receiving window 21 of the infrared temperature sensor 20 faces the high emissivity surface 11 of the inner wall. The infrared temperature sensor 20 is used to measure the far-infrared radiation temperature of the inner wall. In this embodiment, the infrared temperature sensor 20 is a digital output sensor such as the ZT9800 or ZT9799, which is compact in size. The probe of the infrared temperature sensor 20 is fixedly installed in the cavity inside the probe, ensuring that its optical receiving window 21 faces and focuses on the central area of ​​the inner wall of the probe. The measurement frequency of the infrared temperature sensor 20 is set to 10Hz through MCU programming, that is, temperature sampling is performed once every 100 milliseconds. Of course, in other embodiments, the infrared temperature sensor 20 can also use other models of analog output sensors, equipped with a corresponding analog signal conversion unit to achieve temperature measurement.

[0026] The signal processing unit is electrically connected to the infrared temperature sensor 20 and is used to process the electrical signal output by the infrared temperature sensor 20. The signal processing unit is an analog front-end chip that integrates an operational amplifier and an ADC. It amplifies and filters the analog voltage signal output by the infrared temperature sensor 20 and converts it into a 16-bit digital signal.

[0027] The main control unit is connected to the signal processing unit, which receives the processed signal and calculates the body temperature value. The main control unit receives the digital signal from the signal processing unit and runs the temperature measurement algorithm. The algorithm continuously monitors 10 consecutive sampling points (i.e., data within 1 second). If the difference between the maximum and minimum values ​​among these 10 points is less than 0.05℃, the temperature is considered to have stabilized, and the average value of these 10 points is taken as the final body temperature.

[0028] The display unit 30 is connected to the main control unit. The display unit 30 is used to display body temperature values. The display unit 30 is a small segment LCD screen used to display temperature values.

[0029] The power supply unit provides power to the infrared temperature sensor 20, the signal processing unit, the main control unit, and the display unit 30. A switch button 40 is electrically connected between the power supply unit and the main control unit to start the thermometer 100.

[0030] It should be noted that the application scenarios of this rapid response electronic temperature measurement technology 100 are not limited to measuring users' body temperature. It can also be used to test the temperature of other objects, such as the rapid detection of food temperature in the kitchen, similar to testing the temperature of steak, etc., or other forms including but not limited to underarm thermometers, watches, wristbands, headphones, rings, smart glasses and other smart wearable devices.

[0031] In one embodiment, the probe housing 10 is made of a material that satisfies the formula for calculating thermal diffusivity, which is: ,in, Where k is the thermal conductivity of the probe housing material, ρ is the density of the probe housing material, and c is the specific heat capacity of the probe housing material. Materials that meet the above requirements include silver, copper, gold, aluminum, or alloy materials. Taking aluminum as an example, aluminum has a thermal conductivity k of 237 W / (m·K) and a density ρ of 2,700 kg / m³. 3 Its specific heat capacity c is 897 J / (kg·K), and its thermal diffusivity α is... It meets the above requirements, while also being an engineering material that is low in thermal resistance, low in heat capacity, easy to process into thin-walled complex shapes, and has controllable costs, thus achieving rapid thermal response while reducing production costs.

[0032] In one embodiment, the wall thickness of the probe housing 10 is 0.2 mm to 1.0 mm.

[0033] In one embodiment, the high emissivity surface 11 of the inner wall of the probe housing 10 is a high infrared emissivity layer formed by a surface treatment process, and the emissivity of the high infrared emissivity layer in the 5-14μm far-infrared band is not less than 90%.

[0034] In one embodiment, the high infrared emissivity layer is a coating layer formed by a coating process, and the coating layer is any one of titanium nitride film, diamond-like carbon film or metal oxide film.

[0035] In one embodiment, the high infrared emissivity layer is a porous metal oxide layer formed by an oxidation process.

[0036] In one embodiment, the high infrared emissivity layer is a micro-roughened surface formed by sandblasting.

[0037] In one embodiment, the high infrared emissivity layer is a coating formed by coating and curing a high emissivity coating, wherein the coating is any one of ceramic-based coating, carbon nanotube dispersion, or high emissivity polymer material.

[0038] In one embodiment, the infrared temperature sensor 20 measures at a frequency of 1 Hz to 50 Hz.

[0039] In one embodiment, the main control unit is configured to: continuously receive temperature data from the infrared temperature sensor 20 after the temperature measurement is started, and output the final body temperature value after determining that the temperature data is stable or when a preset sampling time is reached, wherein the preset sampling time is no more than 10 seconds.

[0040] This application also provides a rapid body temperature measurement method based on infrared detection, the temperature measurement method comprising: S1: Start temperature measurement, so that the probe housing 10 comes into contact with the surface of the human body part being measured; S2: The infrared temperature sensor 20 measures the temperature of the inner wall of the probe housing 10 at a preset frequency and outputs a corresponding electrical signal; S3: The signal processing unit processes the electrical signal and then transmits it to the main control unit; S4: The main control unit processes the received temperature data and calculates the final body temperature value when the output conditions are met; S5: The display unit 30 displays the final body temperature value.

[0041] In one embodiment, the output condition in step S4 is: the temperature change rate of N consecutive sampling points is lower than a preset threshold since the start of temperature measurement, and / or the duration experienced since the start of temperature measurement reaches a preset sampling time T, where T≤10 seconds.

[0042] In one embodiment, the probe housing 10 is made of aluminum alloy or copper alloy. The user presses the switch button 40 to start the temperature measurement and places the probe under the armpit or tongue. The probe assembly rapidly absorbs heat, and its temperature reaches the same level as the human body surface temperature within 1.5 seconds. Its highly emissive inner wall radiates infrared energy outward, which is captured in real time by the internal infrared temperature sensor 20. The sensor outputs a signal every 0.1 seconds, which is processed and read by the main control unit. The main control unit collects 25 data points within 2.5 seconds. Finding that the fluctuations between the 15th and 25th data points (i.e., between the 1.5th and 2.5th seconds) are minimal, it immediately calculates the average value and drives the LCD screen to display it. Once the temperature stabilizes and remains stable for 2 seconds, it alerts the user that the temperature measurement is complete via vibration or voice announcement. The entire process takes only about 6 seconds.

[0043] This application completely solves the contradiction between speed and accuracy in traditional clip-on thermometers by using a thin-walled hollow probe made of low thermal resistance and low specific heat capacity material, combined with an internal high emissivity surface and an infrared temperature sensor. This allows the thermometer probe to reach thermal equilibrium with the axillary skin rapidly within 1-3 seconds, while the internal infrared sensor synchronously and accurately captures the signal, reducing the total measurement time from several minutes to within 10 seconds. It achieves accuracy comparable to actual measurement models, avoids errors from prediction algorithms, and has low requirements for clamping tightness and high fault tolerance, greatly reducing the measurement failure rate. It provides users with a near "one-touch" ultra-fast, accurate, and reliable temperature measurement experience, and is especially suitable for infants, patients, and other people who have difficulty cooperating. It represents a major breakthrough in axillary temperature measurement technology.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A fast-response electronic thermometer based on infrared detection, characterized in that, The rapid-response electronic thermometer includes: The probe assembly includes a thin-walled hollow probe housing made of a material with low thermal resistance and low specific heat capacity, wherein the inner wall of the probe housing has a high emissivity surface in the far-infrared band. An infrared temperature sensor is disposed in the internal cavity of the probe housing, with the optical receiving window of the infrared temperature sensor facing the high emissivity surface of the inner wall, and the infrared temperature sensor is used to measure the infrared radiation temperature of the inner wall. A signal processing unit, electrically connected to the infrared temperature sensor, is used to process the electrical signal output by the infrared temperature sensor. The main control unit, connected to the signal processing unit, is used to receive the processed signal and calculate the body temperature value. The display unit, connected to the main control unit, is used to display the body temperature value; The power supply unit is used to supply power to the infrared temperature sensor, signal processing unit, main control unit and display unit.

2. The rapid-response electronic thermometer based on infrared detection as described in claim 1, characterized in that, The material of the probe shell satisfies the formula for calculating thermal diffusivity, which is as follows: ,in, , k is the thermal conductivity of the probe housing material, ρ is the density of the probe housing material, and c is the specific heat capacity of the probe housing material.

3. The rapid-response electronic thermometer based on infrared detection as described in claim 1, characterized in that, The wall thickness of the probe housing is 0.2 mm to 1.0 mm.

4. The rapid-response electronic thermometer based on infrared detection as described in claim 2, characterized in that, The high-emissivity surface of the inner wall of the probe housing is formed by a surface treatment process to create a high infrared emissivity layer, and the emissivity of the high infrared emissivity layer in the 5-14μm far-infrared band is not less than 90%.

5. The rapid-response electronic thermometer based on infrared detection as described in claim 4, characterized in that, The high infrared emissivity layer is a coating layer formed by a coating process.

6. The rapid-response electronic thermometer based on infrared detection as described in claim 4, characterized in that, The high infrared emissivity layer is a porous metal oxide layer formed through an oxidation process.

7. The rapid-response electronic thermometer based on infrared detection as described in claim 4, characterized in that, The high infrared emissivity layer is a micro-rough surface formed by sandblasting.

8. The rapid-response electronic thermometer based on infrared detection as described in claim 4, characterized in that, The high infrared emissivity layer is a coating formed by applying and curing a high emissivity paint.

9. The rapid-response electronic thermometer based on infrared detection as described in claim 1, characterized in that, The infrared temperature sensor measures at a frequency of 1 Hz to 50 Hz.

10. The rapid-response electronic thermometer based on infrared detection as described in claim 1, characterized in that, The main control unit is configured to continuously receive temperature data from the infrared temperature sensor after the temperature measurement is started, and output the final body temperature value after determining that the temperature data is stable or when a preset sampling time is reached, wherein the preset sampling time is no more than 10 seconds.

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