Separable skin parameter measurement module

Abstract

The present invention relates to a separable skin parameter measurement module, comprising a handheld wireless detection module and a base. The base separably bears the detection module. The detection module is provided with a first measurement electrode, a second measurement electrode, a CDC, a memory, a first interface and an energy storage module; the measurement electrodes are configured to come into contact with the skin by means of insulating layers to obtain capacitance data reflecting the human skin health state; the base is provided with a second interface, a controller and a base processing module; and the base processing module processes the capacitance data from the memory. According to the present invention, skin parameter measurement is carried out in a capacitive mode to obtain the advantages of arrangement, structural cost, direct measurement and the like, and in addition, the generation of a human body-to-ground distributed capacitance Cw is reduced or even eliminated, thereby achieving the objective of further improving the measurement accuracy.

Description

A split skin parameter detection module Technical Field

[0001] The present invention relates to the field of skin detection, and in particular to a split skin parameter detection module. Background Art

[0002] The detection of human skin health status, such as the detection of skin parameters such as moisture content, oil content, elasticity, etc., is of great significance to dermatology or cosmetology.

[0003] Capacitive measurement solutions are increasingly popular for skin testing due to their ease of electrode placement, cost-effective structure, and ability to directly measure skin parameters without the interference of indirect measurement errors. For example, the CK corneal measurement device uses the mutual capacitance electric field formed by two measuring electrodes to penetrate human skin. The addition of water causes the dielectric constant in the sensing area to change. The mutual capacitance value of the two measuring electrodes can be used to reflect the moisture content of the skin. This measurement method can also be applied to oil and fat measurement.

[0004] Regarding the method of measuring skin parameters using capacitance, we found that the circuit volume and power supply wires on the detection module (such as the probe) have a negative impact on the detection accuracy. For example, in a scenario where person A holds the detection module to detect person B, assuming that person A and person B are separated and not close together, since the power supply wire needs to be connected to the ground, and the detection module needs to be held by the person for detection, person A will form a loop through the electrode-power supply line-ground-A. Since the circuit is built into the detection module, the circuit is large, so when person B holds the circuit, it will also be coupled with the circuit. B will generate another loop through the circuit-power supply line-ground-B, causing person A and person B to form two distributed capacitances C between the human body and the ground. w In patent 2023104839645, we introduced the distributed capacitance C formed by the human body to the ground. w Adverse effects on skin detection due to C w The presence of will reduce the detection accuracy of the skin. Although we proposed in 2023104839645 that the series capacitance C between the electrode and the skin can be measured a To improve / eliminate C w However, if there is another way to reduce or even eliminate the disadvantages of C w The above describes the negative impact of the circuit volume and power supply wires when A is measuring B. For the scenario where A holds the detection module and measures himself, for example, when A presses the probe on the skin of his face for detection, the two parts of the body will also form a circuit, and C will also be generated. w ; For the scenario where A holds the detection module to detect B but the two come into physical contact, C will also be generated w, which is detrimental to the accuracy of detection.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to use capacitive skin parameter detection to obtain advantages such as layout, structural cost and direct measurement, while reducing or even eliminating the distributed capacitance C between the human body and the ground. w The generation of , in order to further improve the measurement accuracy.

[0007] To this end, a split skin component detection module is proposed, including:

[0008] A handheld wireless detection module is configured to include a first measuring electrode, a second measuring electrode, a capacitance-to-digital conversion circuit (CDC), a memory, a first interface, and an energy storage module. The measuring electrodes are configured to contact the skin through an insulating layer to obtain capacitance data reflecting the health status of human skin. The capacitance-to-digital conversion circuit couples to each measuring electrode and obtains capacitance and transmits it to the memory. The memory is coupled to the first interface. The energy storage module is configured to provide the handheld wireless detection module with electrical energy required for capacitance detection.

[0009] The base is configured to detachably carry the handheld wireless detection module and has a second interface, a controller, and a base processing module. The second interface is used to dock with the first interface when the handheld wireless detection module is carried on the base. The controller is coupled to the base processing module and the second interface respectively. The base processing module is used to process the capacitance data from the memory. The processing configuration includes but is not limited to external communication and / or data display.

[0010] In the above skin detection scheme, the handheld detection module is briefly powered by the built-in energy storage module, which can meet the short-term low-power supply requirements of the detection, and at the same time remove the connection between the detection module and the ground. By allocating the display and / or communication circuits to the base, the circuit in the detection module is slimmed down, and the circuit volume including the size of the circuit board can be reduced, thereby enhancing the impedance between the human body and the internal circuit when held by the hand, reducing or even disconnecting the coupling between the human body and the internal circuit when held by the hand. In the scenario where human body A holds the detection module to detect human body B and AB are in contact, the connection with the ground is disconnected, and no loop can be formed between A and the ground, B and the ground, and AB. Similarly, in the scenario where A holds the detection module to detect itself, and the scenario where A holds the detection module to detect B but the two are in physical contact, the generation of the loop is reduced or prevented, and ultimately, the distributed capacitance C of the human body to the ground is reduced or even eliminated. w , achieving improved accuracy.

[0011] After the handheld detection module detects, the data is temporarily stored in the memory, which can be a type that retains data when power is off, such as flash. After the detection module finishes the detection and is placed back on the base, it is processed by the controller and the base processing module through the interface.

[0012] In the above solution, the capacitance data reflecting the health status of human skin can be capacitance data including moisture, grease and / or elasticity, etc. For versatility, the moisture detection module, grease detection module and elasticity detection module can all share the same base.

[0013] In the present invention, the handheld wireless detection module can be configured to retain only the capacitance detection function, thereby achieving optimal decoupling.

[0014] As an improved solution, the sidewall of the housing of the handheld wireless detection module features a grip for guiding the user's hand-holding position. The minimum distance between the grip and the measuring electrodes is configured to be at least 40 mm. The grip can be used to provide guidance through factors such as shape and / or color, ensuring a safe distance between the fingers and the electrodes when held by the user, isolating the coupling between the two. The minimum distance of at least 40 mm is intended to account for the effects of the power and area of ​​the electrodes when detecting corresponding skin parameters, as well as the human body's electric field, on coupling.

[0015] On this basis, as a further improvement of the improved solution, the capacitance-to-digital conversion circuit (CDC) is arranged on the first PCB board. Considering the layout, the first PCB board is implemented using an FPC. The FPC is arranged adjacent to the measuring electrode, where adjacent should be understood as making the length of the connection line between the measuring electrode and the CDC less than 20 mm. On this section of the line from the measuring electrode to the CDC, an analog signal is transmitted. By controlling the length of this section of the line by setting the FPC adjacent to the measuring electrode, the parasitic capacitance of the line can be effectively controlled, further improving the accuracy. More preferably, a second PCB board is also provided, which is a hard board for carrying. The memory and / or energy storage module is arranged on the second PCB board (if the controller is placed in the detection module, the controller and / or energy storage module is arranged on the board). After the first PCB board is separated from the second PCB board, they are coupled through a transmission line. In this section of the transmission line from the first PCB board to the second PCB board, a digital signal is transmitted without affecting the parasitic capacitance. Therefore, the layout and position of this section of the transmission line can have greater freedom and restrictions. As for the arrangement of the transmission line between the second PCB board and the first interface, it can be arranged along the inner wall of the detection module housing. In order to avoid coupling with human hands, a suspended central structural member can be built into the housing of the detection module. The central structural member is suspended away from the side wall, and this section of the transmission line is arranged on the central structural member to ensure that it is away from human hands on the gripping part.

[0016] In the present invention, in order to fully isolate the coupling between the fingers or palms and the second PCB board, the shortest distance between the second PCB board and the gripping part is configured to be at least 1 mm. On this basis, it is preferably set so that the second PCB board and the gripping part are offset in the horizontal direction. In this way, there is no intersection between the projections of the two in the horizontal direction, and the coupling area between the hand grip and the PCB is reduced, which can minimize the influence of parasitic capacitance and ensure accuracy. Preferably, the measuring electrodes and / or the first interface are distributed in the Z-axis direction of the handheld wireless detection module; the gripping part is distributed in the X-axis direction of the handheld wireless detection module, and is offset with the second PCB board in the Z-axis direction, forming a relatively vertical distribution method to minimize the coupling effect.

[0017] As another further improvement to this improved solution, a switch is provided on the grip portion, that is, a switch that needs to be pressed further strengthens the guiding role of the hand-held position. When in use, the switch can be used to trigger the execution of the detection action, such as when the electrodes of the detection module are pressed against the skin through the insulating layer, the user uses the switch to manually control the detection. In the present invention, since power is supplied by an energy storage module instead of a wired power supply, the amount of electricity stored in the energy storage module cannot be set too large (proportional to the volume) to avoid enhanced coupling. Therefore, it is not appropriate to use automatic / all-weather detection. Manual control by the user when ready and temporary power consumption are beneficial for achieving the function while ensuring coupling.

[0018] As another improvement, the energy storage module can be a battery or a capacitor. Considering that batteries are more prone to failure than capacitors, and given the low power requirements of the detection module under the above design, capacitors are preferred for powering the detection module. Furthermore, the base is equipped with a charging circuit to charge the energy storage module when the handheld detection module is mounted on the base.

[0019] As another improvement, the base processing module is provided with a wireless communication module and / or a wired interface for external communication and coupled to the second interface; and / or the base processing module is provided with a display module coupled to the second interface.

[0020] As another improvement solution, the detection module and the base are configured to be fixed to each other through magnetic attraction, so as to achieve convenient mutual fixation and separation.

[0021] As another improvement, the structure is set so that the series capacitance C between the first measuring electrode and the human body is a1 and the series capacitance C between the second measuring electrode and the human body a2The ratio is configured to set a known proportional coefficient k. The proportional coefficient k can be configured to be equal to 1 or different from 1. The solution where k is equal to 1 can be achieved by setting the normal projection area of ​​the first measuring electrode and the second measuring electrode corresponding to the human body to be the same, and the spacing between the first measuring electrode and the human body to be the same as that of the second measuring electrode. This solution is more conducive to reducing computing power and improving detection speed, and is a preferred solution. For the solution where k is not equal to 1, it can be achieved by setting different areas and / or spacings, for example, setting the area of ​​the first measuring electrode to half the area of ​​the second measuring electrode, or setting the spacing between the first measuring electrode and the human body to 1 / 3 of the spacing between the second measuring electrode and the human body, etc.

[0022] Furthermore, in CDC, the first measuring electrode and the second measuring electrode are in contact with the skin through the insulating layer, and based on the known proportionality coefficient k, the series capacitor C a To calculate the component information in the skin, in conjunction with the above scheme, to achieve higher performance accuracy and reliability. Specifically, a capacitance-to-digital conversion circuit can be configured to couple each measuring electrode and obtain a first capacitance and a second capacitance. The first capacitance is configured as one of the first self-capacitance measurement value obtained by the first measuring electrode, the second self-capacitance measurement value obtained by the second measuring electrode, the third self-capacitance measurement value obtained by connecting the first measuring electrode and the second measuring electrode in parallel, and the first mutual capacitance measurement value obtained by the first measuring electrode and the second measuring electrode. The second capacitance is configured as one of the other three. A processing module is used to construct a distributed capacitance C of the human body to the ground based on the first capacitance. w , the first equation with the corresponding series capacitance as the variable, and the second capacitance to construct the human body to ground distribution C w , the second equation with the corresponding series capacitance as the variable, and the series capacitance C is calculated using the equation system consisting of the first and second equations and the proportional coefficient k. a1 or series capacitor C a2 To output the component information in the skin. In actual scenarios, during detection, the first and second measuring electrodes are closely attached to the skin through the insulating layer, and the distance between the electrodes and the skin is fixed. In this way, as long as the area ratio of the first and second measuring electrodes is set after manufacturing, the proportional coefficient k can be determined by structural settings (the series capacitance of one is C a , the other series capacitance is k*C a ), on this basis, by measuring the self-capacitance or mutual capacitance of the electrodes twice, since the self-capacitance or mutual capacitance is determined by C w with C a Composition, so each measurement can construct a C w with C a Function equation of C using the system of two equations wPerform elimination to construct C a The monotonic function of the first capacitance and the second capacitance is used to solve C using the first capacitance and the second capacitance obtained by the two measurements. a Since C w is eliminated, so C can be eliminated w The measurement error caused by this is then used to accurately measure and calculate C a To reflect the content of skin components, such as moisture and oil content. Furthermore, using a capacitance-to-digital converter (CDC), such as the ADI7142 or ADI7147, a Δ-Σ modulation method is used to directly convert the measured capacitance value into a digital value by repeatedly charging and discharging the measured capacitance and comparing it with a reference capacitance (see: US Patent Number: 5,134,401). This can increase the capacitance measurement sensitivity to 1ff, easily meeting the capacitance measurement sensitivity requirements of the measurement system. In particular, the design of these chips with multiple channels makes the circuit design simple and convenient, thereby effectively reducing costs and installation difficulty.

[0023] In the above solution, the controller is placed on the base, that is, all processing logic is placed on the base. In a secondary solution, the controller can be configured on the detection module. To this end, another split skin component detection module is provided, including:

[0024] A handheld wireless detection module is configured to include a first measuring electrode, a second measuring electrode, a capacitance-to-digital conversion circuit, a controller, a first interface, and an energy storage module. The measuring electrodes are configured to contact the skin through an insulating layer to obtain capacitance data reflecting the health status of human skin. The capacitance-to-digital conversion circuit couples to each measuring electrode and obtains capacitance and transmits it to the controller. The controller is coupled to the first interface. The energy storage module is configured to provide the handheld wireless detection module with electrical energy required for capacitance detection.

[0025] The base is configured to detachably carry the handheld wireless detection module and has a second interface and a base processing module. The second interface is used to dock with the first interface when the handheld wireless detection module is carried on the base. The base processing module is coupled to the second interface and is used to process capacitance data from the controller. The processing configuration includes but is not limited to external communication and / or data display.

[0026] In this solution, other improvement schemes, such as the distance configuration between the grip and the measuring electrode, the structural configuration of the first and second PCB boards, the central structural member, and the transmission line, the distribution of the electrodes, the grip, and the interface, the coefficient setting between the electrodes, etc., can all be borrowed from the solution of placing the controller on the base and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG1 shows a schematic structural diagram of a split-type skin component detection module;

[0028] FIG2 shows a schematic structural diagram of a handheld wireless detection module;

[0029] FIG3 shows a schematic structural diagram of a detection electrode assembly;

[0030] FIG4 shows a schematic structural diagram of the transmission line assembly and the second PCB;

[0031] FIG5 shows a schematic diagram of the distribution of hand gripping positions;

[0032] FIG6 shows a schematic diagram of the base structure;

[0033] FIG7 shows a schematic diagram of the distribution structure of detection electrodes;

[0034] FIG8 is a schematic diagram showing the distributed capacitance of the human body to the ground generated by the first detection electrode and the second detection electrode; DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0036] As shown in Figure 1, the split skin component detection module mainly includes two parts, a handheld wireless detection module 100 and a base 200. The base 200 is used to detachably carry the handheld wireless detection module 100 and perform data transmission through a fixed interface.

[0037] As shown in Figure 2, the handheld wireless detection module 100 primarily comprises a detection electrode assembly 110, a second PCB 120, a transmission line assembly 130, a first interface 140, and a hand grip 150. The detection electrode assembly 110 includes detection electrodes that contact the skin of the person being tested via an insulating layer to acquire skin parameter information. After signal processing, the signals are transmitted via a detection electrode transmission line 114 to the second PCB 120, which contains an energy storage module and memory.

[0038] As shown in Figure 3, the detection electrode assembly 110 mainly includes a first detection electrode 111, a second detection electrode 112, a capacitance information processing module 113, a detection electrode transmission line 114, and a first PCB 115. The first detection electrode 111 and the second detection electrode 112 are in contact with human skin via an insulating layer. The insulating layer includes but is not limited to an insulating film or an insulating coating. The capacitance information processing module 113 mainly includes a capacitance-to-digital conversion circuit to obtain capacitance change information of the first detection electrode 111 and the second detection electrode 112, and then derive the skin characteristic parameters of the tester. The first PCB 115 is configured as an FPC. The capacitance information processing module 113 is arranged close to the first detection electrode 111 and the second detection electrode 112 to reduce interference. The capacitance change information of the first detection electrode 111 and the second detection electrode 112 is processed by the capacitance information processing module 113, converted into a digital signal, and transmitted to the second PCB 120 via the detection electrode transmission line.

[0039] As shown in Figure 4, the second PCB 120 mainly includes a transfer PCB 121, an energy storage module 122, and the transmission line assembly 130 mainly includes a transmission data line 131 and a central suspension structure 132. The second PCB 120 includes an energy storage module 122, which can be configured with a small battery or a capacitor device, such as a farad capacitor, which can provide short-term test energy. The central suspension component 132 of the transmission line assembly 130 is fixed to the outer shell, and the transmission data line 131 is placed inside the central suspension component 132, away from the hand holding part 150, to reduce the impact of the human body on the data of the measurement results. When human body A holds the handheld wireless detection module 100 to detect human body B, the power supply wire needs to be connected to the ground, and A holds the handheld wireless detection module 100, so human body A forms a loop through the electrode-power supply line-ground-A, and B forms another loop through the electrode-power supply line-ground-B, causing A and B to form distributed capacitance C to the ground respectively. w By using capacitor devices for power supply and misaligning the hand gripping part 150 with the internal PCB, the connection between the hand gripping part and the ground is disconnected. No loop can be formed between A and the ground, B and the ground, or AB. Similarly, in the scenario where A holds the detection module to measure itself, or when A holds the wireless detection module to measure B but the two have physical contact, the generation of loops is reduced or prevented, and the distributed capacitance C of the human body to the ground is reduced or even eliminated. w , achieving improved accuracy.

[0040] As shown in FIG5 , the hand-holding portion 150 and the transmission line assembly 130 do not contact in the X direction, and a gap needs to be retained. The shortest distance between the detection electrode of the detection electrode assembly 110 and the hand-holding portion 150 is at least 40 mm, as shown by the distance DA in FIG5 , and the distance between the second PCB 120 and the hand-holding portion 150 is at least 1 mm, as shown by the distance DB in FIG5 .

[0041] As shown in Figure 6, the base 200 primarily comprises a second interface 210, a base processing module 220, an external interface 230, and a display device 240. The second interface 210 interfaces with the first interface 140 of the handheld wireless detection module 100 and is then connected to the second PCB via the transmission line assembly 130, enabling data transmission between the handheld wireless detection module 100 and the base 200. This also allows for charging the energy storage module 122 to meet short-term measurement needs. The second interface 210 and the first interface 140 can be configured to be magnetically attached, relying on mechanical fixation and mutual magnetic force to ensure contact and avoid signal disturbances caused by poor contact. The base processing module 220 includes a communication module that transmits data to a terminal device or server through the communication module and also enables wired data transmission via the external interface 230. The display device 240 displays information such as detection results in real time to the operator, providing information such as operation progress and prompts. The base processing module 220 of the base 200 transfers some functions to the base 200, reducing the size of the handheld wireless detection module 100 and making it easier to use.

[0042] As shown in FIG7 , the first detection electrode 111 and the second detection electrode 112 form a series capacitance C with the human body. a1 with C a2 , C a1 with C a2 The ratio of is configured as K, and the proportional coefficient K can be configured to be 1 or not equal to 1. The configuration of the proportional coefficient K value depends on the change of the projection area of ​​the detection electrode and the human body. The change of the projection area is affected by the selection of the detection electrode design process. As shown in Figure 8, C a1 with C a2 The ratio is configured as K, that is, the series capacitance of one electrode is C a , the other is KC a During the test, the self-capacitance measurement value C of the first detection electrode 111 is obtained. s1 , the self-capacitance measurement value C of the second detection electrode 112 s2 , the third self-capacitance measurement value C of the first detection electrode 111 and the second detection electrode 112 in parallel s3 , choose any two of the measured values ​​to establish the equations, and perform elimination C w Operation can eliminate the influence of the human body's distributed capacitance to the ground, and thus accurately measure the tester's skin characteristic information value.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A split skin parameter detection module, characterized in that: include: A handheld wireless detection module is configured to have a first measuring electrode, a second measuring electrode, a capacitance-to-digital conversion circuit, a memory, a first interface, and an energy storage module, wherein the measuring electrode is used to contact the skin via an insulating layer to obtain capacitance data reflecting the health status of human skin, the capacitance-to-digital conversion circuit couples each measuring electrode and obtains capacitance and transmits it to the memory, the memory is coupled to the first interface, and the energy storage module is used to provide the handheld wireless detection module with electrical energy required for capacitance detection; The base is configured to detachably carry the handheld wireless detection module and has a second interface, a controller and a base processing module. The second interface is used to dock with the first interface when the handheld wireless detection module is carried on the base. The controller is coupled to the base processing module and the second interface respectively. The base processing module is used to process the capacitance data from the memory. The processing configuration includes but is not limited to external communication and / or data display.

2. The split skin parameter detection module according to claim 1, characterized in that: The housing side wall of the handheld wireless detection module has a gripping portion for guiding the user's holding position, and the shortest distance between the gripping portion and the measuring electrode is configured to be at least 40 mm.

3. The split skin parameter detection module according to claim 2, characterized in that: The capacitance-to-digital conversion circuit is arranged on a first PCB board, and the first PCB board is arranged adjacent to the measuring electrode.

4. The split skin parameter detection module according to claim 3, characterized in that: The memory and / or energy storage module is arranged on a second PCB board, and the first PCB board is separated from the second PCB board and coupled through a transmission line.

5. The split skin parameter detection module according to claim 4, characterized in that: The housing of the handheld wireless detection module is internally provided with a suspended central structure, and the transmission line between the second PCB board and the first interface is arranged on the central structure so as to be away from the holding portion.

6. The split skin parameter detection module according to claim 4, characterized in that: The shortest distance between the second PCB board and the gripping portion is configured to be at least 1 mm.

7. The split skin parameter detection module according to claim 6, characterized in that: The second PCB board and the holding portion are offset in a horizontal direction.

8. The split skin parameter detection module according to claim 7, characterized in that: The measuring electrodes and / or the first interface are distributed in the Z-axis direction of the handheld wireless detection module; The gripping part is arranged in the X-axis direction of the handheld wireless detection module and is offset from the second PCB board in the Z-axis direction.

9. The split skin parameter detection module according to claim 2, characterized in that: The gripping portion is provided with a switch.

10. The split skin parameter detection module according to claim 1, characterized in that: The energy storage module is configured as a capacitor.

11. The split skin parameter detection module according to claim 1, characterized in that: The series capacitance C between the first measuring electrode and the human body a1 and the series capacitance C between the second measuring electrode and the human body a2 The ratio is configured to set a known proportionality factor k.

12. A split skin parameter detection module, characterized in that: include: A handheld wireless detection module is configured to have a first measuring electrode, a second measuring electrode, a capacitance-to-digital conversion circuit, a controller, a first interface, and an energy storage module, wherein the measuring electrode is used to contact the skin through an insulating layer to obtain capacitance data reflecting the health status of human skin, the capacitance-to-digital conversion circuit couples each measuring electrode and obtains capacitance and transmits it to the controller, the controller is coupled to the first interface, and the energy storage module is used to provide the handheld wireless detection module with electrical energy required for capacitance detection; The base is configured to detachably carry the handheld wireless detection module and has a second interface and a base processing module, wherein the second interface is used to dock with the first interface when the handheld wireless detection module is carried on the base, and the base processing module is coupled to the second interface and is used to process the capacitance data from the controller, wherein the processing is configured to include but is not limited to external communication and / or data display.

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