Method and apparatus for measuring the surface viscoelasticity of biological tissues

Abstract

The present invention relates to a method and apparatus for measuring the surface viscoelasticity of biological tissue. The method includes: step S1, driving the surface of the biological tissue in the direction normal to the surface of the surface to move it to a certain displacement along the normal and then holding it; step S2, using a sensor to measure the time-dependent mechanical response of the surface of the biological tissue during the execution of step S1; and step S3, outputting viscoelastic characteristic data of the surface of the biological tissue by a processing module in accordance with the mechanical response acquired by the sensor. The measurement method of the present invention is intended to more scientifically and reliably detect the surface viscoelasticity of biological tissue, particularly human skin.

Description

Technical Field

[0001] The present invention relates to a method and an apparatus for measuring the surface viscoelasticity of biological tissues, particularly the human skin.

Background Art

[0002] Analyzing the physical properties of the surface of biological tissues such as the human skin or the epidermis of plant fruits has important significance. Taking the human skin as an example, the surface elasticity of the skin has measurement value in both the beauty field and the dermatology field.

[0003] In the measurement of skin elasticity, the commonly seen CK device in the current market adopts a negative pressure + optical measurement method as shown in the technology of US Patent No. 5054502A. Each time it detects, by pressing the front end surface of the outer wall of the probe module against the skin, the skin is deformed / displaced by a suction method using vacuum or a pressing method using a piston, and further measurement is carried out in combination with the attenuation of the light intensity transmitted from the optical transmitter to the optical receiver. In actual products, for example, in the related elasticity measurement products shown on the official website www.courage-khazaka.de, the adopted scheme is the vacuum negative pressure scheme. From the measurement principle described on the CK official website and the technical manual, the CK device sucks the skin with a certain suction force for 0.1 s, observes the changes and recoveries of the skin before and after about 0.1 s, obtains characteristic indexes such as R-Parameters, F-Parameters and Q-Parameters, and evaluates the viscoelastic characteristics of the skin. The CK scheme can also be understood as observing the tensile distance of the skin for 0.1 s with a certain suction force and the subsequent recovery. However, the setting of the 0.1 s time length experience value therein has become a major target of discussion in the industry. For example, scientists in the United States have conducted related research and believe that 0.04 s to 0.07 s is appropriate, but some people propose that the setting of this value varies from person to person and changes due to the difference in the subject samples. Currently, the recognized limitations of the CK device are that it is difficult to reproduce and interpret data, and the resolution due to negative pressure suction is insufficient.

[0004] On the other hand, skin itself has a specific elastic modulus, and according to the study "Stiffness and Elasticity of the Masticatory and Facial Expression Muscles in Patients with the Masticatory MusclePain" (Korean J Oral Med, Vol.34, No.3, 2009), the elasticity of human skin is approximately 0.70 ± 0.46 N. However, when the CK device is used for measurement, it presses against the skin with its tip surface to generate pressure. Since skin has an elastic modulus and the skin in each area is related, the pressure exerted by the tip surface on the skin it covers (here, the pressing force is called external pressure, and refers to the pressure between the tip surface and the skin) changes the elasticity of the skin within the hole of the tip surface. The degree of change is related to the degree of pressure, and if the external pressure used for each measurement is different, the pressure environment for each measurement changes, resulting in different standards for each measurement and causing interference. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The objective of this invention is to provide a novel measurement method intended to more scientifically and reliably detect the surface viscoelasticity of biological tissues, particularly human skin. [Means for solving the problem]

[0006] To this end, a method for measuring the surface viscoelasticity of biological tissue is provided, which includes: step S1 of driving the surface of the biological tissue in the direction normal to the surface of the biological tissue to move it to a certain displacement along the normal and then holding it; step S2 of using a sensor to measure the time-dependent mechanical response of the surface of the biological tissue during the execution of step S1; and step S3 of outputting viscoelastic characteristic data of the surface of the biological tissue by a processing module in accordance with the mechanical response acquired by the sensor.

[0007] The measurement method of the present invention does not adopt the idea of ​​CK measuring deformation with a constant force, but rather measures the mechanical response of the surface that changes over time (measures the force over a constant distance) by driving the surface of a biological tissue, such as human skin, and moving it by a certain distance, and further acquires relevant characteristics (e.g., the various characteristics mentioned above) based on the curve of the mechanical response and provides them to experts to evaluate the surface viscoelasticity of the biological tissue. Skin composition differs from person to person, and there are differences in the mechanical response that is fed back when a certain displacement is applied to the skin. The present invention, by measuring the force with a constant displacement, reflects these differences in the mechanical response, avoids the introduction of empirical judgment, better fits the measurement results to different subjects, makes the measurement results more accurate, and theoretically, the measurement method is more scientific.

[0008] The measurement method of the present invention is particularly suitable for measuring the viscoelasticity of human skin and can also be applied to measuring the surface viscoelasticity of other biological tissues such as plant fruits.

[0009] When measuring the viscoelasticity of human skin, an improved method involves, in step S1, using an actuator to drive the sensor to apply motion to the surface of the biological tissue, move the surface to a certain displacement, and then hold it there, with the motion being set to include at least mechanical pressing or mechanical tension. If the skin tensioning motion performed by the CK device relies on negative pressure, a sealed environment must be provided during the motion, which inevitably requires pressing the tip surface against the skin, thus disrupting the natural state. The present invention offers the possibility of detecting skin in a natural state without disruption, or with minimal disruption, by performing mechanical motion using the sensor.

[0010] As a model combining elastic elements obeying Hooke's Law and viscous elements obeying Newton's Law of Viscosity, the skin has specific requirements regarding the operating time of mechanical movements. Taking pressing as an example, it is desirable to minimize the diffusion of the skin caused by viscosity during pressing and release it as much as possible after pressing to achieve more accurate results. Therefore, this cannot be achieved if the pressing is too slow, and similar problems arise if the pressing is too fast. For example, since it is difficult to maintain precision in mechanical braking, the degree of deviation in the amount of skin displacement becomes excessive. In order to achieve both detection accuracy and control of the diffusion and displacement of the pressed skin, after numerous experiments, it is necessary to control the time from when the sensor starts to move in step S1 until the surface moves to a certain displacement along the normal to within 0.1 to 1 second.

[0011] As a further improvement to skin viscoelasticity measurement, the measurement method of the present invention is for cyclically repeating steps S1 to S3 and further includes step S4 to obtain the mechanical response of different layers of skin by controlling a constant displacement in which the surface moves along the normal to be different in each cycle. For example, when steps S1 to S3 are performed for the first time, the amount of skin displacement is controlled to be between 0 and 2 mm, and this displacement is used to measure the mechanical response of the epidermal tissue to pressing or tensile motion. When steps S1 to S3 are performed cyclically for the second time, the amount of skin displacement is controlled to be between 2 and 4.4 mm, and this displacement is used to measure the overall mechanical response of the epidermal and dermal tissues. Subcutaneous tissue (optional) is measured in a similar manner thereafter. By controlling a different moving distance each time, the characteristics of different layers of skin can be reflected. Furthermore, in order to avoid the previous pressing interfering with the next measurement, a recovery time is set from the end of each cycle to the start of the next cycle to allow the skin to return to its natural state.

[0012] As a further improvement, step S2 further includes forming a mechanical curve based on the mechanical response acquired by the sensor, the starting point of the mechanical curve being set to be at least the point corresponding to the maximum value or before the point corresponding to the maximum value, the maximum value being the value when the force fed back from the surface is at its maximum, and the ending point of the mechanical curve being set to be at least the point corresponding to the steady value or after the point corresponding to the steady value, the steady value being the value when the force gradually decreases and stabilizes after the maximum value, and the curve segment from the maximum value to the steady value can adequately reflect the viscoelastic characteristics of the surface of the biological tissue. The method for determining the steady value further includes setting the value corresponding to the first point on the mechanical curve after the maximum value where the slope becomes smaller than a set threshold as the steady value, or setting the value of the point on the mechanical curve after the maximum value where a set time has elapsed as the steady value. Preferably, when the sensor acquires the ending point, a presentation device may be installed that provides a presentation, for example by sound / light / vibration.

[0013] The present invention further provides a device for measuring the surface viscoelasticity of biological tissue, the device comprising: a sensor for measuring the mechanical response of the surface when an action is applied to the surface of the biological tissue; an actuator for driving the sensor to perform the action; a processing module coupled to the actuator and the sensor, respectively; and a memory configured to store computer executable instructions, the memory for causing the processing module to perform the method described above when the executable instructions are executed.

[0014] To avoid interference with the measurement due to the destruction of the natural state of the surface structure by pressing the tip surface during elastic measurement of the surface structure, an improved method is proposed in which the measuring device has a distance detection device and a reference surface that faces the surface during the measurement period, and the sensor is configured to protrude from the reference surface and contact the surface during the measurement period, thereby achieving non-contact between the reference surface and the surface, and the distance detection device is used to obtain the distance between the reference surface and the biological tissue surface. When detection is performed, by utilizing the distance between the reference surface and the surface structure to be measured obtained by the distance detection device, the distance from the external system, such as the manipulator movement module, to the reference surface distance surface structure will match the previous time, thereby ensuring the stability of the measurement standard / measurement environment each time. Furthermore, by utilizing the structure in which the sensor protrudes from the reference surface and contacts the surface during the measurement period, the surface structure is not pressed due to non-contact between the reference surface and the surface structure, and interference from external pressure is fundamentally eliminated, thereby allowing the sensor to measure the mechanical response by applying pressing or tensile motion to the surface in its natural state (a state not destroyed by pressing), resulting in more accurate measurement results. In this scheme, the reference surface should be understood to be the outer surface of the module casing containing the sensor.

[0015] Furthermore, the distance detection device is configured to include at least two distance sensing electrodes provided on the reference surface, the distance sensing electrodes being provided on the front or back surface of the reference surface, the non-contact measurement module is equipped with a capacitive-to-digital conversion circuit (CDC) which is coupled to a processing module, the capacitive-to-digital conversion circuit acquires mutual capacitance by being coupled to each distance sensing electrode, the processing module outputs distance information based on mutual capacitance, specifically the mutual capacitance value formed by the distance sensing electrodes changes during the process of approaching a surface structure such as human skin, the distance between the human skin and the reference surface is acquired, the distance between the human skin and the reference surface is controlled to reach an initial value, and the distance is ensured to remain stable and not change. In the above scheme, only an approximate distance range can be calculated with a single pair of electrodes. To obtain more accurate distance information, the number of distance detection devices may be set to at least two and arranged around the sensor. By varying the area and / or spacing of the distance detection electrodes in each distance detection device, the intensity of the formed electric field lines may be varied, i.e., the height of the formed electric field lines may be varied. On the one hand, this expands the measurement range and provides a reference for the operating speed of the external actuator. More importantly, it allows for obtaining an accurate degree of approach by utilizing the difference in height formed by the electric field lines.

[0016] Alternatively, as a further improvement, the reference surface can be controlled to just touch the skin each time the surface structure is measured. Specifically, the measuring device includes a pressure detection device and a reference surface that directly or indirectly contacts the surface during the measurement period. The pressure detection device is configured to be used to sense the contact pressure between the reference surface and the surface when the reference surface directly or indirectly contacts the surface. During the detection process, the pressure detection device is used to feed back the contact pressure (external pressure) between the reference surface and the surface structure, such as human skin. An external system, such as a manipulator movement module, adjusts the contact pressure to match the previous measurement, for example, to a state of just contact where the contact force is 0.5N. On the one hand, since there is basically no pressing, the natural state of the skin is not fundamentally damaged. On the other hand, the sensor maintains a unified external pressure measurement environment in each measurement, avoiding the introduction of measurement errors. This allows the sensor to apply pressing or pulling motion on a stable measurement reference to measure the mechanical response of the surface structure, resulting in more accurate measurement results. Similarly, the pressure detection devices are set to be at least two in number and arranged around the sensor, thereby ensuring compatibility of each position in the circumferential direction and ensuring uniformity of detection. Preferably, the pressure detection devices are set to be at least three in number and arranged uniformly around the sensor.

[0017] In a scheme for pressing a surface structure using a sensor, the sensor is configured to include a pressure detection sensor, the pressure detection sensor is coupled to an actuator, the actuator may drive the pressure detection sensor to move along a normal to contact the surface structure during the measurement period. Furthermore, the pressure detection sensor is configured as a first sensor unit, the first sensor unit is provided with a flexible multifunctional layer, a curved elastic electrode electrically connected to the multifunctional layer is installed inside the flexible multifunctional layer as an upper electrode, a lower electrode is installed below the upper electrode, an insulating layer is installed between the upper electrode and the lower electrode, and the downward projection of the upper electrode covers at least a portion of the area of ​​the lower electrode, the flexible multifunctional layer is driven to deform under external force so that the upper electrode changes the contact area with the insulating layer, and the non-contact measurement module is provided with a capacitive-to-digital converter (CDC) coupled to a processing module, the CDC is coupled to each electrode via a switch array and is used for the capacitance formed between the upper electrode and the lower electrode in the first sensor unit. During compression, the deformation of the flexible multi-functional layer and the capacitance formed between the upper and lower electrodes reflect the force component in the normal direction. Furthermore, by collecting capacitance values ​​for each electrode in combination with CDC, a higher force resolution can be achieved, and since measurement is performed directly using a tactile method, the elastic force can be measured accurately.

[0018] On the other hand, in a scheme that uses a sensor to pull, the sensor is configured to include a tension detection sensor, and an adhesive layer, such as double-sided tape, is provided on the surface of the tension detection sensor for contact with the surface structure, and the tension detection sensor is coupled to an actuator, which may be used to drive the tension detection sensor during the measurement period to move it along the normal to contact the surface structure. When detection occurs, if the tension detection sensor comes into contact with the surface structure, such as human skin, the double-sided tape on the surface adheres to the human skin and provides a preliminary adhesive force, the actuator drives the tension detection sensor to move, the tension detection sensor is in a tensile state and generates a tensile force, and the actual contact stress between the human skin and the sensor can be obtained from the tensile force and the preliminary adhesive force. In this invention, after detection is complete, a protective cover can be attached, thereby preventing the double-sided tape from undergoing an oxidation reaction due to prolonged contact with air and changing its viscosity, or allowing the double-sided tape to be treated as a consumable item. When detection is required, the double-sided tape is placed in a groove in the device case, and once monitoring is complete, the double-sided tape is peeled off and the adhesive position is wiped clean, ensuring that the preliminary adhesive strength in each test remains more stable. [Brief explanation of the drawing]

[0019] [Figure 1] This is a schematic flowchart illustrating a method for measuring the surface viscoelasticity of biological tissues. [Figure 2] This is a schematic diagram showing the relative positional relationship between the device for measuring the surface viscoelasticity of biological tissue and the tissue surface. [Figure 3] This is a schematic diagram showing a device for measuring the surface viscoelasticity of biological tissues. [Figure 4] This is a schematic diagram illustrating the effect of the measuring device when the sensor is pressed to the depth of the skin. [Figure 5] This is a schematic diagram illustrating the effect of the measuring device when the sensor is pressed to the depth of the dermis. [Figure 6] This is a schematic diagram showing the structural distribution of distance detection devices. [Figure 7-1]It is a schematic diagram showing the electric field line distribution structure when the distance detection electrode is located on the skin side of the reference plane. [Figure 7-2] It is a schematic diagram showing the electric field line distribution structure when the distance detection electrode is located on the side facing away from the skin of the reference plane. [Figure 8] It is a structural schematic diagram showing the pressing scheme of the test device for the surface viscoelasticity of biological tissue. [Figure 9] It is a schematic diagram showing the distribution relationship between the flexible upper electrode and the lower electrode. [Figure 10-1] It is a schematic diagram showing the distribution relationship of the group composed of each of the flexible multifunctional layer and the lower electrode. [Figure 10-2] It is a schematic diagram showing the distribution relationship of the group composed of each of the flexible multifunctional layer and the lower electrode. [Figure 11] It is a structural schematic diagram showing the tensile scheme of the test device for the surface viscoelasticity of biological tissue. [Figure 12] It is a schematic diagram showing the mounting structure of the protective cover after the detection is completed.

Mode for Carrying Out the Invention

[0020] As shown in FIG. 1, the flowchart of the measurement method for the surface viscoelasticity of biological tissue mainly includes step S1 of driving the measurement device to move along the normal line of the biological tissue surface to a certain displacement and then holding it in the normal direction of the surface of the biological tissue; and simultaneously with S1, step S2 of using a sensor to measure the mechanical response that changes with time on the surface of the biological tissue during the implementation process of step S1; and step S3 of outputting the viscoelastic characteristic data of the surface of the biological tissue by a processing module according to the mechanical response acquired by the sensor.

[0021] As shown in FIG. 2, the surface tissue measured by the measurement device for the surface viscoelasticity of the biological tissue is configured as skin, and mainly consists of a stratum corneum 601, an epidermis 602, a dermis 603, and a subcutaneous tissue 604.

[0022] As shown in Figure 3, the measuring device for the surface viscoelasticity of the biological tissue mainly consists of a sensor 100, an actuator 200, a distance detection device 300, and a processing module 400. In step S1, the actuator 200 drives the sensor 100 to pull or press the surface structure to reach a predetermined position, and the processing module 400 analyzes the information fed back from the sensor 100 to obtain the contact stress between the sensor 100 and the skin surface, completing the mechanical response data required for step S2. The time required from when the sensor 100 starts moving in step S1 until it reaches a predetermined position on the normal may be set as a constant time. The measuring device may be controlled by an external manipulator, ensuring that the position is relatively constant in each measurement, and that the relative positional relationship between the reference plane and the epidermal structure is stable during the test process by feedback information from the distance detection device 300.

[0023] As shown in Figures 4 and 5, each measurement process of the measuring device must include steps S1 to S3, and further include step S4, in which step S4 cyclically executes steps S1 to S3. In the repeated cyclic process, the displacement of sensor 100 may vary according to the commands of processing module 400 by driving actuator 200, determining a predetermined displacement of sensor 100 according to the depth distance of the skin surface. The viscoelastic characteristic value of the deep skin can be characterized by the viscoelastic characteristic data of the skin components at that depth by removing previous test data from the mechanical response curve measured at that depth, thereby achieving the effect of detecting the viscoelasticity of components at different depths. After each measurement is completed, the cyclic measurement gap should be set to a sufficient time so that the biological tissue surface, such as skin, can return to its natural state and to avoid inconsistencies in the initial state during repeated measurements. Sensor 100 performs a tensile or compressive action on the epidermal tissue by driving actuator 200. The starting point of the mechanical response curve of the force-receiving state of the epidermal tissue is set to be at least the point corresponding to the maximum value of the contact force or before the point corresponding to the maximum value. The maximum value of the contact force is the value at which the force fed back from the surface tissue is at its maximum. The endpoint of the mechanical curve is set to be at least the point corresponding to the steady-state value or after the point corresponding to the steady-state value. The steady-state value is the value at which the force gradually decreases and stabilizes after the maximum value. The method for determining the steady-state value includes setting the value corresponding to the first point on the mechanical curve after the maximum value where the slope of the mechanical change becomes smaller than a set threshold as the steady-state value, or setting the value at the point on the mechanical curve after the maximum value where a set time has elapsed as the steady-state value. When the force response curve reaches the endpoint, i.e., when the epidermis recovers to its initial state, the detection device can provide a notification. This can be done by providing an audio notification via a buzzer in the processing module, providing an image notification via an external display of the measuring device, or providing a light notification via a device such as a light-emitting diode.

[0024] As shown in Figure 6, the distance detection device 300 mainly includes distance detection electrodes, which include at least two sets of electrode groups, and the sensor 100 protrudes from the distance detection device. When the test device approaches epidermal tissue, such as skin, the capacitance value formed by the distance detection electrodes changes, and the processing module 400 can obtain the distance between the test device and the skin. Furthermore, the position of the test device and the human skin is made more stable in each measurement, and because the sensor 100 protrudes from the distance detection device, the distance detection device 300 does not come into direct contact with the skin, thus avoiding skin damage and preventing interference from external forces during the testing process.

[0025] As shown in Figures 7-1 and 7-2, the distance detection electrodes may be positioned on the side of the reference plane closer to the human skin or on the side facing away from the human skin. At least two sets of electrode groups can be configured, and the distance electrodes may be configured as electrode groups with different areas and spacings. This creates different electric field distributions, further expanding the overall detection distance range, subdividing the detection distance, and accurately determining the relative positional relationship between the reference plane and the human skin.

[0026] As shown in Figure 8, in the measuring device for the surface viscoelasticity of biological tissue, the sensor 100 in the pressing structure mainly consists of a flexible upper electrode 101 (a flexible multifunctional layer at the bottom and an upper electrode located in the center of the multifunctional layer that protrudes upward and forms a curved hemisphere, integrally molded), an insulating layer 102, and a lower electrode 103 installed in the processing module 400. The lower electrode 103 is included in the processing module 400, or it may be installed separately. The sensor 100 can move along the normal to the epidermal structure by driving the actuator 200, thereby realizing a pressing operation on the epidermal structure. The distance detection device 300 limits the initial state between the detection module and the epidermal structure. The sensor 100 presses by the action of the actuator 200, and due to differences in the viscoelasticity of the epidermal structure, the amount of deformation of the flexible multifunctional layer of the upper electrode 101 differs even in the same displacement state. The processing module 400 determines the difference in viscoelasticity of the epidermal structure based on the change in the capacitance value of the sensor 100. By detecting in real time the change in capacitance value due to the deformation of the upper electrode 101 of the sensor 100, the force response curve of the epidermal tissue during the test process can be obtained. Viscoelastic characteristic parameter values ​​of the epidermal tissue are obtained via the processing module 400. Multiple sensors 100 may be installed, and measurement errors can be reduced by calculating the average value of multiple sets.

[0027] As shown in Figure 9, when the flexible upper electrode 101 is subjected to an external force, it comes into contact with the insulating layer 102 on the surface of the lower electrode 103 and is pressed, causing the flexible upper electrode 101 to deform. The mutual capacitance formed by the flexible upper electrode 101 and the lower electrode 103 changes, and the magnitude of the normal force received by the sensor 100 can be obtained from the change in capacitance value.

[0028] As shown in Figure 10-1, the lower electrode 103 may be installed as multiple distributed electrodes, either in a strip or as at least three detection electrodes in different directions depending on the deformation. When the flexible multifunctional layer of the upper electrode 101 is subjected to force and deformed, the change in the projected area with respect to the lower electrode section differs depending on the direction and magnitude of the force received, and the information on the change in the measured capacitance value also differs. The upper electrode 101 is coupled to different combinations of upper and lower electrodes via the switch array of the processing module 400, and further, information on the magnitude and direction of the force actually received by the upper electrode 101 can be obtained depending on the difference in contact area.

[0029] As shown in Figure 10-2, the upper electrode 101 may be divided into multiple parts, each part being integrally bonded by an insulating layer, and each part is not electrically conductive. The lower electrode 103 is a single unit and functions as a common electrode, and it is also possible to obtain force magnitude and direction information based on the change in capacitance composed of different electrodes.

[0030] As shown in Figure 11, when the measuring device detects surface viscoelasticity in a tensile state, the sensor 100 mainly consists of a tension detection sensor 105 and an adhesive layer 104. The tension detection sensor 105 is fixed to an actuator 200, and the actuator 200 drives the tension detection sensor 105 during measurement to generate relative normal movement with respect to the surface tissue. The tension detection sensor 105 is in contact with the surface tissue, such as human skin, and the adhesive layer 104, such as double-sided tape, are fixed together as a single unit. The adhesive layer 104 provides a preliminary adhesive force, and the actuator 200 drives the tension detection sensor 105 to move normally. The tension detection sensor 105 is in a tensile state and generates a tensile force. The actual contact stress between the human skin and the sensor 100 can be obtained by the tensile force and the preliminary adhesive force. Steps S1 to S2 allow for the acquisition of a mechanical response curve under tensile force action on the surface tissue, and surface tissue viscoelastic characteristic parameters are output via the processing module 400.

[0031] As shown in Figure 12, after detection is complete, the protective cover 500 can be attached, thereby preventing the double-sided tape from undergoing an oxidation reaction due to prolonged contact with air and changing its viscosity, or making the adhesive layer 104 a consumable item. If detection is required, the adhesive layer 104 is placed in the groove of the apparatus case, and once detection is complete, the adhesive layer 104 is peeled off and the adhesive position is wiped clean, ensuring that the preliminary adhesive strength in each test is maintained to be more stable.

[0032] 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 method for measuring the surface viscoelasticity of biological tissues, Step S1 involves driving the surface of the biological tissue in the direction normal to the surface of the biological tissue to move it to a certain displacement along the normal and then holding it; Step S2 involves using a sensor to measure the time-dependent mechanical response of the surface of the biological tissue during the execution of step S1, A method for measuring the surface viscoelasticity of a biological tissue, comprising step S3, in which a processing module outputs viscoelastic characteristic data of the surface of the biological tissue in accordance with the mechanical response acquired by the sensor.

2. The measurement method according to claim 1, characterized in that the biological tissue is composed of skin.

3. Step S1 is, The measurement method according to claim 2, further comprising using an actuator to drive a sensor to apply movement to the surface of the biological tissue, move the surface to a certain displacement, and then hold it there, wherein the movement includes at least mechanical pressing or mechanical tension.

4. The measurement method according to claim 3, characterized in that the time from when the sensor starts to perform the operation in step S1 until the surface moves to a certain displacement along the normal is set to within 0.1 to 1 s.

5. The measurement method according to claim 2, further comprising step S4, which is for cyclically repeating steps S1 to S3 and for obtaining the mechanical response of different layers of skin by controlling the constant displacement of the surface moving along the normal to be different in each cycle.

6. The measurement method according to claim 5, characterized in that a recovery period is provided between the end of each cycle and the start of the next cycle to allow the skin to return to its natural state.

7. The aforementioned step S2 is, Based on the mechanical response acquired by the sensor, a mechanical curve is formed. The starting point of the mechanical curve is set to be located at least at the point corresponding to the maximum value or before the point corresponding to the maximum value, and the maximum value is the value at which the force fed back from the surface is maximum. The measurement method according to claim 1, further comprising the following: the endpoint of the mechanical curve is set to be at least a point corresponding to a steady value or located after a point corresponding to a steady value, and the steady value is the value at which the force gradually decreases and stabilizes after the maximum value.

8. The method for determining the steady-state value is: The steady-state value is defined as the value corresponding to the first point on the dynamic curve after the maximum value where the slope becomes smaller than the set threshold, or, The measurement method according to claim 7, further comprising the step of defining the steady-state value as the value at a point corresponding to the time elapsed after the maximum value on the dynamic curve.

9. A device for measuring the surface viscoelasticity of biological tissues, A sensor for measuring the mechanical response of the surface when an action is applied to the surface of the biological tissue, An actuator for driving the sensor to perform the operation, Each of the following is a processing module coupled to the actuator and the sensor, A device for measuring the surface viscoelasticity of biological tissue, comprising: a memory configured to store computer executable instructions, wherein when the executable instructions are executed, the memory causes the processing module to execute the method according to any one of claims 1 to 8.

10. The measuring device has a distance detection device and a reference surface that faces the surface during the measurement period. The sensor is configured to protrude from the reference surface and come into contact with the surface during the measurement period, thereby achieving non-contact between the reference surface and the surface. The measuring device according to claim 9, characterized in that the distance detection device is used to obtain the distance between the reference plane and the surface of the biological tissue.

11. The distance detection device is configured to include at least two distance detection electrodes provided on the reference surface, The non-contact measurement module is equipped with a capacitive-to-digital conversion circuit which is coupled to the processing module, and the capacitive-to-digital conversion circuit acquires mutual capacitance by being coupled to each distance sensing electrode. The measuring device according to claim 10, characterized in that the processing module outputs distance information between the reference plane and the biological tissue surface based on the mutual capacitance.

12. The measuring device according to claim 11, characterized in that the number of distance detection devices is set to at least two and arranged around the sensor, and the area and / or spacing of the distance detection electrodes in each distance detection device are different.

13. The measuring device comprises a pressure detection device and a reference surface that comes into direct or indirect contact with the surface during the measurement period. The measuring device according to claim 9, characterized in that the pressure detection device is used to sense the contact pressure between the reference surface and the surface when the reference surface is in direct or indirect contact with the surface.

14. The sensor is configured to include a pressure detection sensor, The measuring apparatus according to claim 9, wherein the pressure detection sensor is coupled to the actuator, and the actuator is used to drive the first pressure detection sensor during the measurement period to move along a normal to the surface.

15. The pressure detection sensor is configured as a first sensor unit, the first sensor unit is provided with a flexible multi-functional layer, a curved elastic electrode electrically connected to the multi-functional layer is installed inside the flexible multi-functional layer as an upper electrode, a lower electrode is installed below the upper electrode, an insulating layer is installed between the upper electrode and the lower electrode, and the downward projection of the upper electrode covers at least a portion of the area of ​​the lower electrode, and the flexible multi-functional layer is driven to deform when subjected to an external force, thereby changing the contact area of ​​the upper electrode with the insulating layer. The non-contact measurement module is equipped with a capacitive-to-digital conversion circuit that is coupled to a processing module, and the capacitive-to-digital conversion circuit is coupled to each electrode via a switch array and is used for the capacitance formed between the upper electrode and the lower electrode in the first sensor unit, as described in claim 14.

16. The sensor is configured to include a tension detection sensor, and an adhesive layer is provided on the surface of the tension detection sensor that contacts the surface. The measuring apparatus according to claim 9, characterized in that the tension detection sensor is coupled to the actuator, and the actuator is used to drive the tension detection sensor during the measurement period to move along the normal to the surface in contact with it.

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