Measurement device for bio-diffused substances

Abstract

The present invention relates to a measuring device for bio-diffused substances, the measuring device comprising a measuring chamber, a sensor, and an evaluation device, wherein the measuring chamber has at least one top opening for discharge and a bottom opening for direct or indirect contact with a living body, the area of ​​the top opening being smaller than that of the bottom opening, the measuring chamber further comprising at least one third opening for forming a bottom-open structure in the measuring chamber during measurement, the sensor located in the peripheral wall of the measuring chamber and used to measure the concentration of a substance diffused from a living body, and the evaluation device being coupled to the sensor.

Description

Technical Field

[0001] The present invention relates to the measurement of biological diffusing substances, and particularly to the detection of water evaporation from the skin.

Background Art

[0002] In the detection of skin moisture, currently, the most widely used in the market for beauty or medical applications is the skin transepidermal water loss (TEWL) measurement device manufactured by CK in Germany. As shown in the related patent technology CN202080026313.8, two open cylindrical measurement chambers of the same size are used vertically, and sensors for measuring the concentration, temperature, humidity, etc. of diffusing substances (such as water vapor) are arranged on the inner wall of the measurement chamber to obtain the temperature distribution and water vapor flow distribution at each location in the measurement chamber. The evaluation device uses the measured values of the sensors to measure water vapor based on the substance or energy diffusion theory.

[0003] The diffusion theory employed by the CK Corporation's measuring device, namely Fick's law of diffusion, is based on a theoretical model that assumes a stable environment and stable airflow (diffusion includes both diffusion in still air and diffusion in convective airflow). In the CK Corporation's skin water loss (TEWL) measuring device, the bottom and top opening areas of the cylindrical measuring chamber are the same. The bottom opening is sealed when it comes into contact with the skin, creating a structure where the bottom is sealed but the top is open. Since the skin temperature of the human body is approximately 36 degrees Celsius, while the ambient temperature at the top opening is approximately 20 degrees Celsius, the temperature difference between the top and bottom creates vertical convection of air. Hot air flows out from the top opening and then flows back in, resulting in unstable airflow within the measuring chamber. To mitigate the effects of this contradiction, CK's measuring devices are required to have at least three sensors placed within the measurement chamber to measure the densely packed objects under test. These sensors are positioned at different distances from the object being measured during the measurement. In actual product development, CK uses five layers of sensors, six per layer (30 in total), within the measurement chamber to detect temperature and humidity gradient changes at different heights within the chamber. They then indirectly calculate the amount of water evaporation using averaging and diffusion theory. However, the detection results ignore the effects of convection, resulting in a significant error between the calculated amount and the actual amount of water evaporation. On the other hand, multilayer sensors have a complex structure and are relatively expensive. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] To improve upon the shortcomings of conventional technology, the present invention provides a device for measuring bio-diffused substances. [Means for solving the problem]

[0005] The measuring device of the present invention comprises a measuring chamber, a sensor, and an evaluation device, wherein the measuring chamber has at least one top opening for discharge and a bottom opening for direct or indirect contact with a living body, the area of ​​which is set to be smaller than that of the bottom opening, the measuring chamber is further provided with at least one third opening for forming a bottom-open structure in the measuring chamber during measurement, the sensor is located in the peripheral wall of the measuring chamber and is used to measure the concentration of a substance diffused from a living body, and the evaluation device is coupled to the sensor.

[0006] This invention improves measurement accuracy by setting the area of ​​the top opening of the measurement chamber to be smaller than the bottom opening, and by providing a third opening at the bottom of the measurement chamber to form a bottom-open structure, thereby ensuring that the airflow inside the measurement chamber is stable and directed upward, avoiding vertical convection, fundamentally resolving contradictions and conflicts with the theoretical basis of the law of diffusion, and improving measurement accuracy.

[0007] In this invention, the peripheral wall may include the outer wall and / or interior of the measurement chamber, and a pre-selected sensor is placed on the inner wall to enhance sensitivity.

[0008] The measuring device of the present invention can be applied to the detection of concentrations of various diffusive substances, and is particularly applicable to the detection of skin moisture evaporation. Taking the detection of moisture evaporation as an example, an improved version is proposed in which, since the flow of evaporated water vapor concentrates and flows out from a small opening at the top, sensors can be placed around the top opening of the measuring chamber to facilitate measurement at the cross-section of the top opening. Furthermore, since a stable airflow is formed in the measuring chamber, the number of sensors can be set to form a single-layer sensor structure arranged around the top opening, thereby achieving the objective of simplifying the structure and saving costs. Alternatively, the number of sensors can be set to at least two, each sensor having a different distance from the body during measurement, and a multi-layer sensor structure with different heights can be formed around the top opening to further improve measurement accuracy.

[0009] As a further improvement to the proposed improvement, the present invention can be configured to measure diffusing substances using a capacitive method. Specifically, the sensor is configured to include at least two electrodes, and the evaluation device is provided with a capacitive-to-digital conversion circuit (CDC) and a processing module. The capacitive-to-digital conversion circuit is coupled to each electrode and used to acquire mutual capacitance. With respect to the processing module, water vapor changes the dielectric constant in the field as it passes through the mutual capacitance field, and further changes the mutual capacitance. Therefore, the processing module can reflect the amount of water vapor that has passed through the mutual capacitance field based on the fluctuations in mutual capacitance, and can also output concentration information of substances diffused from the living body. The present invention provides a sensor composed of at least two electrodes. On the one hand, by combining the capacitance method with CDC, for example ADI7142 or ADI7147, and employing a Δ-Σ modulation method, the capacitance under test is charged and discharged multiple times and compared with a reference capacitance (see U.S. Patent No. 5,134,401), thereby directly converting the capacitance value under test into a digital value and increasing the capacitance measurement sensitivity to 1ff level. On the other hand, because the top opening is narrowed, the spacing between each electrode placed around the top opening becomes narrower, bringing the electrodes closer together. According to the principle of capacitance, this can improve the sensitivity and detection accuracy of mutual capacitance.Based on this, the sensor may be configured to include at least three electrodes, and a capacitive-to-digital conversion circuit is coupled to each electrode via a switch array, and each electrode in the sensor is sequentially used as an excitation to obtain the mutual capacitance with other electrodes in the layer. For example, in a solution where the sensor has three electrodes A, B, and C, when measuring for the first time, electrode A is excited and the mutual capacitance between electrodes A and B and between electrodes A and C is obtained; when measuring for the second time, electrode B is excited and the mutual capacitance between electrodes B and C is obtained; further, for example, in a solution where the sensor has four electrodes A, B, C, and D, when measuring for the first time, electrode A is excited and the mutual capacitance between electrodes A and B, between electrodes A and C and between electrodes A and D is obtained; when measuring for the second time, electrode B is excited and the mutual capacitance between electrodes B and C and between electrodes B and D is obtained; when measuring for the third time, electrode C is excited and the mutual capacitance between electrodes C and D is obtained. By analogy, the accuracy and sensitivity of detection can be further improved by dynamically and synchronously detecting the mutual capacitance of multiple pairs in this way.

[0010] Furthermore, the smaller the ratio of the area of ​​the top opening to the area of ​​the bottom opening, the greater the water vapor flow velocity at the top opening. This increases the requirements for the sensor's detection sensitivity and affects the accuracy of the detection results. Through numerous experiments, it was found that setting the area ratio of the top opening to the bottom opening to less than 0.6 allows for a balance between sensitivity, accuracy, and flow velocity.

[0011] Furthermore, the top opening is configured as a flat hole, and each electrode is distributed on the flat edges on both sides of the flat hole. In such a solution, the top opening area does not change, but the spacing between electrodes can be further reduced, thereby greatly optimizing the accuracy and sensitivity of detection. And / or, the top opening may be configured to include at least two, and a processing module is used to calculate and weight-average corresponding concentration information based on the sensor data collected from each top opening. By providing multiple openings, the total top opening area does not change, but the spacing between electrodes in each opening is reduced, and further accuracy is improved by weight-averaging.

[0012] The temperature difference between the ambient temperature at the top opening and the body temperature (the human skin temperature in the experimental environment is approximately 36 degrees Celsius, but the ambient temperature at the top opening is approximately 20 degrees Celsius, resulting in a temperature difference of 10 degrees Celsius or more) affects the flow velocity (in the volume sensing scheme, temperature and humidity also affect the mutual volume), and the body temperature of different organisms (e.g., humans) differs slightly. Therefore, as an alternative improvement, the measurement chamber may be equipped with a top temperature sensor to collect the ambient temperature at the top opening and a bottom temperature sensor to collect the body temperature during measurement. The evaluation device is coupled to the top temperature sensor and the bottom temperature sensor, respectively, and is used to correct the concentration of substances diffused from the body based on the temperature difference collected by both, thereby eliminating the influence of temperature difference fluctuations during measurement. Furthermore, since temperature and humidity differ in different environments, differences arise in environmental measurement standards, introducing measurement errors. For this reason, the bio-diffused substance measuring device is further equipped with an ambient temperature sensor and / or ambient humidity sensor located outside the measurement chamber. The evaluation device is coupled to the ambient temperature sensor and / or ambient humidity sensor and is used to correct the concentration of substances diffused from the body based on the data collected by the ambient temperature sensor and / or ambient humidity sensor, thereby eliminating interference due to fluctuations in temperature and humidity in the environment.

[0013] As another improvement, in this invention, the top opening is located on the top surface of the measurement chamber, the bottom opening is located on the bottom surface of the measurement chamber, the projection of the top opening is within the projection area of ​​the bottom opening, and by vertically aligning the top and bottom openings, the stability of the airflow is improved and the effect of preventing turbulence in the airflow is achieved. Furthermore, the measurement chamber has a conical structure that gradually narrows from the bottom to the top.

[0014] In the present invention, there are various methods for utilizing the third opening to form an open bottom structure in the measurement chamber during measurement. For example, if the bottom of the third opening communicates with the bottom opening and the third opening is set to be sufficiently large, when the bottom opening is pressed against a living body, such as a human body, the elastic skin of the living body cannot completely block the third opening, thereby achieving the objective of keeping the bottom open. In such a solution, since the elasticity of each living body's skin differs, the degree of occlusion of the third opening also differs, which causes differences in the air velocity flowing in from the third opening and affects the measurement. Therefore, it is desirable to keep the open area of ​​the bottom as consistent as possible each time a measurement is taken. Accordingly, it is preferable to set a gap between the lower edge of the third opening and the bottom opening, further eliminating the possibility of the living body's skin sinking into the third opening and maintaining the stability of the bottom opening area measured each time. In the present invention, there is at least 1 mm from the lower edge of the third opening to the bottom opening.

[0015] In this invention, the height of the measurement chamber is set to be greater than 1 cm, thereby allowing water vapor released from the living body to rise steadily. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic diagram showing the structure of a device for measuring bio-diffused substances. [Figure 2] This is a structural cross-sectional view showing a device for measuring bio-diffused substances. [Figure 3] This is a schematic diagram showing the arrangement of sensors in a single layer. [Figure 4] This is a schematic diagram showing a two-layer arrangement of sensors. [Figure 5] This is a schematic diagram showing the configuration when two sensors are placed. [Figure 6] This is a schematic diagram showing the arrangement of eight sensors. [Figure 6-1] This is a time chart showing the T1 cycle. [Figure 6-2] This is a time chart showing one detection cycle T1 to T7. [Figure 7]Schematic diagram when the top opening is configured as a flat hole. [Figure 8] Schematic diagram when two top openings are arranged. [Figure 9] Schematic diagram when a temperature and humidity sensor is added to the biological diffusion substance measurement device. [Figure 10] Schematic diagram when the projection of the top opening is within the projection area of the bottom opening. [Figure 11] Schematic diagram when the bottom of the third opening communicates with the bottom opening.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, referring to the drawings of the embodiments of the present invention, the technical solution means of the embodiments of the present invention will be clearly and completely described.

[0018] As shown in FIG. 1, a biological diffusion substance measurement device includes a measurement chamber 100, a sensor 200, and an evaluation device 300. The measurement chamber 100 has at least one top opening 110 for discharge and a bottom opening 120 for directly or indirectly contacting the living body. The area of the top opening 110 is set to be smaller than that of the bottom opening 120. The measurement chamber 100 is further provided with at least one third opening 130 for forming a bottom open structure in the measurement chamber 100 during measurement.

[0019] As shown in FIG. 2, the sensor 200 is located on the peripheral wall of the measurement chamber 100 and is used to measure the concentration of the substance diffused from the living body. The evaluation device 300 is coupled to the sensor 200. The peripheral wall may include the outer wall and / or the interior of the measurement chamber 100. The pre-selected sensor 200 is arranged on the inner wall to enhance sensitivity.

[0020] As shown in Figure 1, the present invention sets the area of ​​the top opening 110 of the measurement chamber 100 to be smaller than the bottom opening 120, and provides a third opening 130 at the bottom of the measurement chamber 100 to form a bottom-open structure, thereby ensuring that the airflow inside the measurement chamber 100 is stably directed upward, avoiding vertical convection, fundamentally resolving contradictions and conflicts with the theoretical basis of the diffusion law, and improving measurement accuracy.

[0021] As shown in Figure 3, taking the detection of water evaporation as an example, the evaporated water vapor flow 400 concentrates and flows out from the small opening 110 at the top. Therefore, by arranging the sensors 200 around the top opening 110 of the measurement chamber 100, measurement at the cross-section of the top opening 110 can be facilitated. Furthermore, since a stable airflow is formed within the measurement chamber 100, the number of sensors 200 can be set to form a single-layer sensor structure arranged around the top opening 110, thereby achieving the objective of simplifying the structure and saving costs. Alternatively, as shown in Figure 4, the number of sensors 200 can be set to at least two, with each sensor 210, 220 being at a different distance from the body during measurement. Furthermore, a multi-layer sensor structure with different heights can be formed around the top opening 110, achieving the objective of further improving measurement accuracy.

[0022] As shown in Figure 5, the sensor is configured to include two electrodes 201 and 202, and the evaluation device 300 is equipped with a capacitive-to-digital converter (CDC) 500 and a processing module 600. The capacitive-to-digital converter 500 is coupled to electrodes 201 and 202 and is used to acquire mutual capacitance. With respect to the processing module 600, as water vapor 400 passes through the electric field of the mutual capacitance, the dielectric constant in the electric field changes, and further changes the mutual capacitance. Based on the fluctuation of mutual capacitance, the processing module 600 can reflect the content of water vapor 400 that has passed through the electric field of the mutual capacitance and can also output concentration information of substances diffused from the living body. As shown in Figure 6, the sensor is configured to include eight electrodes 201, 202, 203, 204, 205, 206, 207, and 208, and a capacitive-to-digital conversion circuit 500 is coupled to each electrode via a switch array 700 and is used to sequentially use each electrode in the sensor as an excitation to obtain the mutual capacitance with the other electrodes in the layer, for example, as shown in Figure 6-2, with a total of seven detection times T1 to T7 within one detection cycle. In the T1 cycle, electrode 201 is excited to acquire the mutual capacitance between electrode 201 and other electrodes in the layer. The specific detection method is shown in Figure 6-1. By closing analog switches K1 and K2, the mutual capacitance between electrodes 201 and 202 is detected. By closing analog switches K1 and K3, the mutual capacitance between electrodes 201 and 203 is detected. By closing analog switches K1 and K4, the mutual capacitance between electrodes 201 and 204 is detected. By closing analog switches K1 and K5, the mutual capacitance between electrodes 201 and 205 is detected. By closing analog switches K1 and K6, the mutual capacitance between electrodes 201 and 206 is detected. By closing analog switches K1 and K7, the mutual capacitance between electrodes 201 and 207 is detected. By closing analog switches K1 and K8, the mutual capacitance between electrodes 201 and 208 is detected. As shown in Figure 6-2, the electrode detection method during T2 to T7 is the same as the electrode detection method during T1, and the number of detected mutual capacitances decreases. By dynamically and synchronously detecting the mutual capacitance of multiple pairs in this way, the accuracy and sensitivity of the detection can be further improved.

[0023] As shown in Figure 7, the top opening 110 is configured as a flat hole, and the electrodes 200 are distributed on the flat edges on both sides of the flat hole. In this solution, the top opening area does not change, but the spacing between the electrodes can be further reduced, thereby greatly optimizing the accuracy and sensitivity of the detection. And / or, as shown in Figures 5 and 8, there may be two top openings (i.e., 111, 112), and the processing module 600 is used to calculate and weight-average the corresponding concentration information based on the sensor data collected from each top opening. By providing multiple openings, the total top opening area does not change, but the spacing between the electrodes in each opening is reduced, and further accuracy is improved by weight-averaging.

[0024] As shown in Figure 1, the temperature difference between the ambient temperature at the top opening and the body temperature (the human skin temperature in the experimental environment is approximately 36 degrees Celsius, but the ambient temperature at the top opening is approximately 20 degrees Celsius, so the temperature difference between the two is 10 degrees Celsius or more) affects the flow velocity (in the volume sensing scheme, temperature and humidity also affect the mutual volume), and the body temperature of different organisms (e.g., humans) differs slightly. Therefore, as shown in Figure 9, the measurement chamber 100 may be equipped with a top temperature sensor 810 for collecting the ambient temperature at the top opening 110 and a bottom temperature sensor 820 for collecting the body temperature during measurement. The evaluation device 300 is coupled to the top temperature sensor 810 and the bottom temperature sensor 820, respectively, and is used to correct the concentration of substances diffused from the body based on the temperature difference collected by the two, thereby eliminating the effect of fluctuations in the temperature difference during measurement. Furthermore, since temperature and humidity differ in different environments, differences arise in environmental measurement standards, introducing measurement errors. For this reason, the bio-diffused substance measuring device is further equipped with an environmental temperature sensor 830 and / or environmental humidity sensor 840 located outside the measurement chamber. The evaluation device 300 is coupled to the environmental temperature sensor 830 and / or environmental humidity sensor 840 and is used to correct the concentration of substances diffused from living organisms based on the data collected by the environmental temperature sensor 830 and / or environmental humidity sensor 840, thereby eliminating interference due to fluctuations in temperature and humidity in the environment.

[0025] As shown in Figure 10, the top opening 110 is located on the top surface of the measurement chamber, the bottom opening 120 is located on the bottom surface of the measurement chamber, the projection of the top opening 110 is within the projection area of ​​the bottom opening 120, and by aligning the top opening 110 and the bottom opening 120 vertically, the stability of the airflow is improved and the effect of preventing turbulence in the airflow is achieved. The measurement chamber 100 has a conical structure that gradually narrows from the bottom to the top.

[0026] As shown in Figure 10, there are various ways in which the third opening 130 can be used to form an open bottom structure in the measurement chamber 100 during measurement. For example, as shown in Figure 11, the bottom of the third opening 130 communicates with the bottom opening 120, and the third opening 130 is set to be sufficiently large. This way, when the bottom opening is pressed against a living body, such as a human body, the elastic skin of the living body cannot completely block the third opening 130, thus achieving the purpose of keeping the bottom open. In such a solution, since the elasticity of each living body's skin differs, the degree of occlusion of the third opening 130 also differs. This causes differences in the air velocity flowing in from the third opening 130, which affects the measurement. Therefore, it is desirable to keep the open area of ​​the bottom as consistent as possible each time a measurement is taken. Accordingly, a gap can be set between the lower edge of the third opening 130 and the bottom opening 120. Furthermore, the possibility of the living body's skin sinking into the third opening 130 is eliminated, and the stability of the area of ​​the bottom opening measured each time is maintained. In this invention, there is a gap of at least 1 mm between the lower edge of the third opening 130 and the bottom opening.

[0027] Finally, it should be noted that the above embodiments are merely for illustrating the technical solutions of the present invention and do not limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A device for measuring bio-diffused substances, A measuring chamber having at least one top opening for discharge and a bottom opening for direct or indirect contact with a living body, A sensor located on the periphery wall of the aforementioned measurement chamber is used to measure the concentration of substances diffused from living organisms. The device comprises an evaluation device coupled to the sensor, The area of ​​the top opening is set to be smaller than that of the bottom opening. A measuring device for bio-diffused substances, characterized in that the measuring chamber is further provided with at least one third opening for forming an open bottom structure in the measuring chamber during measurement.

2. The apparatus for measuring bio-diffused substances according to claim 1, characterized in that the sensor is arranged around the top opening of the measurement chamber.

3. The number of sensors is set to one, thereby forming a single-layer sensor structure, or The bio-diffused substance measuring device according to claim 2, characterized in that the number of sensors is set to at least two, and each sensor is at a different distance from the living body during measurement, thereby forming a multilayer sensor structure.

4. The sensor is configured to include at least two electrodes, The evaluation device is equipped with a capacitance-to-digital conversion circuit and a processing module. The capacitance-to-digital conversion circuit is coupled to each electrode and is used to obtain mutual capacitance. The bio-diffused substance measuring device according to claim 3, characterized in that the processing module is used to output concentration information of a substance diffused from a living body based on the mutual capacitance.

5. The sensor is configured to include at least three electrodes, The apparatus for measuring bio-diffused substances according to claim 4, characterized in that the capacitance-to-digital conversion circuit is coupled to each electrode via a switch array and is used to sequentially use each electrode in the sensor as an excitation to obtain the mutual capacitance with other electrodes in the layer.

6. The bio-diffused substance measuring device according to claim 4, characterized in that the area ratio of the top opening to the bottom opening is set to be less than 0.

6.

7. The apparatus for measuring bio-diffused substances according to claim 4, 5, or 6, characterized in that the top opening is configured as a flat hole, and each electrode is dispersed on the flat edges on both sides of the flat hole.

8. The aforementioned top opening is configured to include at least two, The bio-diffused substance measuring device according to claim 4, 5, or 6, characterized in that the processing module is used to calculate and weight average the corresponding concentration information based on the data collected by the sensors of each of the top openings.

9. The measurement chamber is equipped with a top temperature sensor for collecting ambient temperature at the top opening and a bottom temperature sensor for collecting biological temperature during measurement. The bio-diffused substance measuring device according to claim 1 or 4, characterized in that the evaluation device is coupled to the top temperature sensor and the bottom temperature sensor, respectively, and is used to correct the concentration of a substance diffused from a living body based on the temperature difference collected by the two.

10. The bio-diffused substance measuring device is further provided with an ambient temperature sensor and / or ambient humidity sensor located outside the measuring chamber. The bio-diffused substance measuring device according to claim 9, characterized in that the evaluation device is coupled to the ambient temperature sensor and / or ambient humidity sensor and is used to correct the concentration of a substance diffused from a living body based on the data collected by the ambient temperature sensor and / or ambient humidity sensor.

11. The apparatus for measuring bio-diffused substances according to claim 1, characterized in that the top opening is located on the top surface of the measurement chamber, the bottom opening is located on the bottom surface of the measurement chamber, and the projection of the top opening is within the projection area of ​​the bottom opening.

12. The measuring device for bio-diffused substances according to claim 11, characterized in that the measuring chamber has a conical structure that gradually narrows from the bottom to the top.

13. The bio-diffused substance measuring device according to claim 11, characterized in that there is a gap from the lower edge of the third opening to the bottom opening.

14. The measuring device for bio-diffused substances according to claim 1, characterized in that the diffused substance is set as diffused water vapor.

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