Automatic detection device and detection method for mechanical pain threshold value of animal

Abstract

The invention relates to the technical field of animal experiment devices, in particular to an automatic animal mechanical pain threshold value detection device and method.The automatic animal mechanical pain threshold value detection device comprises a box body, an iron gauze and a needling mechanism are arranged in the box body, the iron gauze is horizontally arranged on the side wall of the box body, and the needling mechanism is located under the iron gauze and used for applying pressure to stimulate the pelma of an experimental animal; a translation mechanism is further arranged in the box body, the needling mechanism is installed on the translation mechanism, and the translation mechanism is used for driving the needling mechanism to move along the horizontal plane of the box body. The needling mechanism comprises a guide cylinder with two open ends, a pressure sensing device and a driving device; the translation mechanism is sleeved with the guide cylinder, the pressure sensing device is installed in the guide cylinder, and the pressure sensing device is used for fixing the cellosilk and can sense the change of the pressure value between the foot bottom of an animal and the cellosilk. The device not only can automatically detect the mechanical pain threshold value of the animal, but also can quickly replace the cellosilk and reliably fix the cellosilk, so that the pain threshold value detection efficiency is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of animal experiment devices, in particular to an animal mechanical pain threshold automatic detection device and a detection method. BACKGROUND

[0002] In the field of neuroscience, pharmacology and pain research, the determination of mechanical pain threshold is one of the core experimental methods for evaluating neuropathic pain or the effect of analgesic drugs in animals (such as rats and mice). At present, the most widely used classical method is manual Von Frey filament test. This method completely relies on the experimental personnel to hold different calibrated force values of Von Frey monofilament, and manually applies pressure stimulation to the plantar of the experimental animal (such as rats) from the specific opening of the cage bottom grid or test box at a nearly vertical angle. The experimenter needs to closely observe the animal's withdrawal, licking and other escape reactions with the naked eye to subjectively judge whether the pain threshold is reached, and record the Von Frey filament number corresponding to the minimum force value that triggers the reaction. However, this traditional manual operation method has significant defects: first, the angle, speed and contact point with the foot bottom of each stimulation cannot be guaranteed to be consistent, introducing human operation errors and affecting the repeatability and objectivity of the results; second, the experimenter needs to maintain a specific posture (such as bending over and tilting head to observe the foot bottom reaction) for a long time, which easily leads to neck and back fatigue, poor operation comfort and low efficiency; third, the judgment of animal reaction depends on the subjective experience and immediate attention of the experimenter, which has a certain risk of subjective bias.

[0003] After searching, it is found that some new animal mechanical pain threshold automatic detection devices have appeared, mainly improving in two aspects: one is to solve the problem of neck and back fatigue caused by bending over and tilting head, such as the animal mechanical pain threshold detection device disclosed in Chinese patent (CN217525100U), which sets an observation mirror between the pain measurement rack bottom and the ground glass, and the observation mirror is placed behind the pain measurement rack, and the observation mirror and the bottom surface of the pain measurement rack form a certain angle, the angle is 30°-45°, and the full view of the bottom of the detection cage can be observed on the observation mirror, that is, the lifting of the animal's foot in the detection cage can be clearly observed in the observation mirror, so that the experimenter can observe the observation mirror to conduct the experiment; the other is to change the detection principle, such as the inclined plate type mechanical pain sensitivity determination device disclosed in Chinese invention patent (CN105167753B), which adjusts the angle of the inclined plate to grade the degree of pain by angle; the stimulation force of the probe on the rat's measured palm surface increases with the decrease of the angle of the inclined plate, and the greater the measured angle, the more sensitive the animal is to pain, and the effect can meet the experimental requirements and can replace the existing detection method.

[0004] The above two methods solve the corresponding problems, but cannot achieve automatic detection, still have human operation errors and are highly dependent on subjective experience of experimenters. Therefore, the applicant has invented an animal mechanical pain threshold automatic detection device and detection method. SUMMARY

[0005] The animal mechanical pain threshold automatic detection device and detection method can not only automatically detect the mechanical pain threshold of animals, but also quickly replace the fiber filaments and reliably fix the fiber filaments, greatly improving the pain threshold detection efficiency.

[0006] The animal mechanical pain threshold automatic detection device comprises a box body, characterized in that an iron wire mesh and a needle pricking mechanism are arranged in the box body, the iron wire mesh is horizontally arranged on the side wall of the box body, the needle pricking mechanism is located directly below the iron wire mesh, and the needle pricking mechanism is used for applying pressure stimulation to the foot bottom of the experimental animal; a horizontal moving mechanism is further arranged in the box body, the needle pricking mechanism is installed on the horizontal moving mechanism, and the horizontal moving mechanism is used for driving the needle pricking mechanism to move along the horizontal plane of the box body.

[0007] Further, the needle pricking mechanism comprises a guide cylinder with openings at both ends, a pressure sensing device, and a driving device; the guide cylinder is sleeved on the horizontal moving mechanism, the pressure sensing device is installed in the guide cylinder, and the pressure sensing device is used for fixing the fiber filament and can sense the pressure value change between the foot bottom of the animal and the fiber filament; the driving device can make the fiber filament fixed on the pressure sensing device contact the foot bottom of the animal and generate pressure.

[0008] Further, the pressure sensing device comprises a pressure sensor, a spring, a pad, and silicone rubber; the pressure sensor is embedded in the guide cylinder, one end of the spring is connected with the sensing end of the pressure sensor, and the other end of the spring is fixedly connected with the bottom of the pad; the silicone rubber is attached to the top surface of the pad, the pad is an annular pad, and the side wall is slidably connected with the inner wall of the guide cylinder; the silicone rubber is sleeved on the surface of the fiber filament after the fiber filament passes through.

[0009] Further, the driving device comprises a step motor three and a threaded rod three; one end of the threaded rod three is fixedly connected with the output end of the step motor three.

[0010] Further, the guide cylinder is composed of two separable cylinder bodies; one of the two cylinder bodies of the guide cylinder is sleeved on the horizontal moving mechanism, the step motor three is embedded in the cylinder body, and the other cylinder body of the guide cylinder is sleeved on the outer side wall of the threaded rod three.

[0011] Further, the step motor three is installed on the inner side wall of the box body, the threaded rod three is vertically arranged, and the iron wire mesh is sleeved on the threaded rod three.

[0012] Furthermore, the translation mechanism includes a first stepper motor, a first threaded rod, a second stepper motor, a second threaded rod, and a slider; the first stepper motor is embedded in the slider, and one end of the first threaded rod is fixedly connected to the output end of the first stepper motor; the second stepper motor is installed on the side wall of the housing, the second threaded rod is horizontally arranged, and one end of the second threaded rod is fixedly connected to the output end of the second stepper motor; the slider is sleeved on the second threaded rod.

[0013] Furthermore, a camera is installed on the top of the needle-punching mechanism, and a display screen and operating table are installed on the outer wall of the housing. A controller is installed on the operating table, and the display screen, controller, camera, and translation mechanism are electrically connected.

[0014] This invention also provides an automatic method for detecting the mechanical pain threshold in animals, which is applied to the detection device according to any one of claims 1-8; the specific steps are as follows:

[0015] S1: The translation mechanism drives the needle-punching mechanism to move along a two-dimensional plane, so that the tip of the fiber fixed by the needle-punching mechanism moves to the sole of the animal's foot.

[0016] S2: The drive device applies the tip of the fiber to the animal's foot area, while the pressure sensor monitors and reads the pressure of the spring.

[0017] S3: When the change characteristics of the real-time pressure value F(t) meet the preset withdrawal reflex judgment conditions, it is determined that the currently applied stimulus has reached the pain threshold, and the calibration force value of the fiber and the peak pressure value recorded by the pressure sensor at this time are recorded as the pain threshold.

[0018] S4: Control the needle puncture mechanism to return to the initial position.

[0019] Furthermore, the preset conditions for determining foot retraction reflection in S3 include one or a combination of the following conditions:

[0020] Condition A: The real-time pressure value F(t) is within the preset judgment time window T. detect Inside, from the peak F peak The drop exceeds the preset absolute threshold ΔF threshold That is, F(t)≤F peak -ΔF threshold ;

[0021] Condition B: Real-time pressure change rate Or the real-time pressure change ΔF(t) within the preset judgment time window T detect Within, below the preset negative rate of change threshold Right now

[0022] Condition C: The real-time pressure value F(t) is within the preset judgment time window T. detectThe pressure values of the N continuous sampling points are all lower than the pressure value of the previous sampling point, and the cumulative decrease exceeds the preset threshold value AF sum-threshold ;

[0023] Condition D: after detecting that the real-time pressure value F(t) reaches a relatively stable state, conditions A, B or C are satisfied.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] 1. The device can accurately control the movement and positioning of the fiber in the two-dimensional plane by driving the needling mechanism with a lead screw, and can monitor the dynamic changes of the pressure applied by the fiber tip to the animal foot bottom in real time in combination with a pressure sensor. When the pressure suddenly decreases due to the animal's withdrawal reflex, the system automatically determines and records the critical force value reaching the pain threshold. This process does not require the experimenter to hold the fiber for operation or to observe the animal's reaction at close range with the naked eye, thereby fundamentally eliminating the forced posture of the experimenter needing to bend over, tilt his head or even lie down to observe the animal's reaction on the cage bottom, greatly freeing the experimenter's hands and head, and effectively avoiding the muscle strain and discomfort of the neck and back caused thereby; in addition, the automatic determination logic based on the pressure sensor data completely replaces the naked eye judgment relying on the experimenter's subjective experience and immediate attention, significantly improving the objectivity, repeatability and data reliability of the pain threshold detection results, and reducing human errors and individual differences;

[0026] 2. The device designs the guide cylinder as a through cylinder with openings at the top and bottom, and fills the cylinder with silicone rubber with excellent self-healing ability. When replacing the fiber with different force values, it is extremely simple to operate, only need to gently pierce the new fiber from the lower part of the guide cylinder to the upper part, and the silicone rubber layer can be penetrated. The punctured silicone rubber can instantly self-heal, tightly wrap and firmly clamp the fiber, without any additional screws, clamps or adhesives for complicated physical fixation, and significantly shorten the time for replacing consumables, avoid damage to the fiber (such as bending and indentation), and ensure the accuracy of the test force;

[0027] 3. The device provides two equivalent automatic driving schemes for the stimulation application method, scheme one adopts a two-section guide cylinder design, and precisely drives the upper section of the guide cylinder containing silicone rubber to move upward by a lead screw, actively applying the fiber tip to the animal foot bottom; scheme two adopts a whole guide cylinder, and drives the wire mesh platform carrying the experimental animal to move downward by a lead screw, passively contacting the animal foot bottom with the fixed fiber tip. These two designs achieve the same goal, and both can realize the automation and precise control of stimulation application;

[0028] 4. The scheme provided by the application can not only stimulate the foot bottom of animals, but also adapt to the size of animals, and conveniently change the actual size of the upper accommodation space of the test box. The experimenter can set the most suitable activity space height according to the size difference of animals (such as rats or mice), which can provide sufficient activity space for large animals, reduce the feeling of oppression and stress reaction, and limit the excessive activity range of small animals to ensure that the foot bottom is stably located in the touchable area of the fiber wire. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a side sectional view of an animal mechanical pain threshold automatic detection device provided by embodiment 1 of the application;

[0030] Figure 2 is a plan view of the animal mechanical pain threshold automatic detection device provided by embodiment 1 of the application located in the plane of the translation mechanism;

[0031] Figure 3 is a structural schematic view of a needle puncture mechanism provided by embodiment 1 of the application;

[0032] Figure 4 is Figure 3 is an enlarged view of A in

[0033] Figure 5 is a side sectional view of an animal mechanical pain threshold automatic detection device provided by embodiment 2 of the application;

[0034] Figure 6 is a structural schematic view of a needle puncture mechanism provided by embodiment 2 of the application;

[0035] Figure 7 is Figure 6 is an enlarged view of A in

[0036] The reference signs involved in the above drawings are as follows:

[0037] 1, box; 2, wire mesh; 3, shock pad; 4, sliding block; 5, threaded rod two; 6, threaded rod one; 7, guide cylinder; 8, fiber wire; 9, stepper motor one; 10, operation table; 11, controller; 12, display screen; 13, guide rod two; 14, guide rod one; 15, stepper motor two; 16, camera; 17, threaded rod three; 18, silicone rubber; 19, pad; 20, spring; 21, pressure sensor; 22, stepper motor three. DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0039] The implementation of the present application will be described in detail below with reference to specific embodiments.

[0040] In the drawings of the present embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation of the present patent, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0041] Referring to Figures 1-7 , a preferred embodiment provided by the present application is shown.

[0042] Embodiment 1: An animal mechanical pain threshold automatic detection device, as shown in Figures 1-4 , comprising a box body 1, a wire mesh 2 is horizontally fixedly installed on the inner side wall of the box body 1, in this embodiment, rats are taken as an example, before the experiment, the rats need to be placed on the wire mesh 2 to adapt for a period of time. A needle pricking mechanism and a translation mechanism are installed below the wire mesh 2 in the box body 1, the translation mechanism is used to drive the needle pricking mechanism to move along the X-Y two-dimensional plane. The needle pricking mechanism is used to fix fiber filaments 8 with different weight values.

[0043] Specifically, as shown in Figure 1 and Figure 2As shown, the translation mechanism mainly consists of stepper motor 9, threaded rod 6, stepper motor 15, threaded rod 5, guide rod 14, guide rod 13, and two sliders 4. Two horizontal grooves (not labeled in the figure) are opened on the inner wall of the housing 1. Threaded rod 5 and guide rod 13 are located in the two grooves respectively. Stepper motor 15 is embedded in the side wall of housing 1. One end of threaded rod 5 is fixedly connected to the output end of stepper motor 15, and the other end is connected to the side wall of the groove via a bearing. Both ends of guide rod 13 are fixedly connected to the ends of the groove respectively. The two sliders 4 are respectively sleeved on threaded rod 5 and guide rod 13. The two sliders 4 are fixedly connected by guide rod 14, which is parallel to threaded rod 6. One end of threaded rod 6 is fixedly connected to the power output end of stepper motor 9, and the other end is connected to slider 4 via a bearing. Stepper motor 9 is embedded in the other slider 4. The needle-punching mechanism is simultaneously fitted onto the threaded rod 6 and the guide rod 14.

[0044] The translation mechanism drives the threaded rod 6 to rotate via stepper motor 9, thereby controlling the needle-punching mechanism to move along the X-axis. Since the two sliders 4 are respectively sleeved on the threaded rod 5 and the guide rod 13, the stepper motor 15 drives the threaded rod 5 to rotate, thereby controlling the needle-punching mechanism to move along the Y-axis.

[0045] To avoid the motor drive affecting the rat's activity, in this embodiment, a ring-shaped shock-absorbing pad 3 is installed in the box 1 below the wire mesh 2.

[0046] In this embodiment, the needle-piercing mechanism is as follows: Figure 3 and Figure 4 As shown, it mainly consists of a guide cylinder 7, a spring 20, a pad 19, silicone rubber 18, and a pressure sensor 21. The guide cylinder 7 is mainly composed of upper and lower sections, which are separable. The outer wall of the lower guide cylinder 7 is simultaneously fitted onto the threaded rod 6 and the guide rod 14, and both its top and bottom are open. The spring 20, pad 19, silicone rubber 18, and pressure sensor 21 are all located within the upper guide cylinder 7; specifically as shown... Figure 4 As shown, pressure sensor 21 is embedded in the bottom of guide cylinder 7, and the pressure sensor 21 is arranged around the through hole at the bottom of guide cylinder 7. One end of spring 20 is fixedly connected to the sensing end of pressure sensor 21, and the other end of spring 20 is fixedly connected to the bottom of pad 19. Pad 19 slides along the length of guide cylinder 7. Pad 19 is an annular pad 19, and silicone rubber 18 is attached to the top surface of pad 19. In order to make it easier for fiber filament 8 to pass through silicone rubber 18, silicone rubber 18 can be made of a relatively soft silicone rubber 18. In this embodiment, the self-recovering ability of silicone rubber 18 is utilized, so that when fiber filament 8 passes through, it can be sleeved on its surface through the self-recovering ability.

[0047] In order to make the fiber filament 8 accurately pass through the silicone rubber 18, the bottom of the lower guide cylinder 7 is designed as a conical shape, and the inner top of the guide cylinder 7 is also designed as a conical shape, so that the fiber filament 8 can pass through the through hole of the pad 19 and the silicone rubber 18 under the guidance of the conical section after being inserted into the guide cylinder 7.

[0048] In order to make the upper guide cylinder 7 drive the fiber filament 8 to move upwards and stimulate the rat's foot bottom, the driving device is arranged on the guide cylinder 7, as shown in Figure 4 The driving device mainly consists of a step motor three 22 and a threaded rod three 17. The step motor three 22 is embedded in the side wall of the guide cylinder 7, one end of the threaded rod three 17 is fixedly connected with the output end of the step motor three 22, and the outer side wall of the upper guide cylinder 7 is sleeved on the threaded rod three 17. Thus, when the step motor three 22 drives the threaded rod three 17 to rotate, the guide cylinder 7 and the fiber filament 8 can be driven to move upwards, so as to stimulate the rat's foot bottom.

[0049] In order to facilitate the experimenter to observe the position of the rat's foot bottom, the top of the upper guide cylinder 7 is provided with a camera 16, and the display screen 12 and the operation table 10 are arranged on the outer side wall of the box body 1. The operation table 10 is provided with a controller 11, and the controller 11 can be remotely controlled. The camera 16, the display screen 12, the controller 11 and the rest of the electrical elements are electrically connected. The camera 16 transmits the picture to the display screen 12 in real time, and the experimenter can judge whether the guide cylinder 7 has reached the rat's foot bottom by watching the display screen 12. When it reaches the rat's foot bottom, the experimenter presses the button, and the threaded rod three 17 drives the guide cylinder 7 and the fiber filament 8 to move upwards to stimulate the rat's foot bottom.

[0050] Working principle: the mouse is placed in the wire mesh 2 of the box 1, the experimenter first inserts the fiber filament 8 from the guide cylinder 7 upward through the silicone rubber 18, and makes the end of the fiber filament 8 slightly higher than the top of the guide cylinder 7. The silicone rubber 18 is sleeved on the fiber filament 8. Then the experimenter moves the guide cylinder 7 to the position directly below the mouse's foot bottom by shaking the rocker of the controller 11 and combining the picture presented by the display screen 12. Then press the button, at this time the step motor three 22 drives the threaded rod three 17 to rotate, so that the upper end guide cylinder 7 moves upward, thereby driving the fiber filament 8 to move upward, when the fiber filament 8 generates a positive pressure on the mouse's foot bottom, at this time the silicone rubber 18 will compress the pad 19, the pad 19 makes the spring 20 have a certain compression amount, so that the pressure sensor 21 senses that the pressure gradually rises. When the rat does not shrink the foot, the step motor three 22 drives the threaded rod three 17 to rotate in the opposite direction, so that the guide cylinder 7 returns to the initial position. Then repeat the above operation 6 times, the system can automatically identify and record whether the foot is shrunk. And adopt the up and down way to determine whether the weight of the fiber filament 8 reaches the pain threshold. If the system determines that it does not reach, prompt the experimenter, and the experimenter replaces the fiber filament 8 with a larger weight in turn. Repeat the above operation, and finally obtain the mechanical pain threshold of the rat.

[0051] Since the device is automatically detecting and automatically identifying whether the mouse has a foot shrinkage reaction, the embodiment also provides an automatic detection method of animal mechanical pain threshold. The main way is:

[0052] The tip of the fiber filament is applied to the foot bottom area of the animal through the driving device, and the pressure sensor monitors and reads the pressure of the spring; when the change characteristics of the real-time pressure value F(t) meet the preset foot withdrawal reflex judgment condition, it is judged that the current applied stimulation reaches the pain threshold, and the calibrated force value of the fiber filament at this time and the peak pressure value recorded by the pressure sensor are recorded as the pain threshold;

[0053] The preset foot withdrawal reflex conditions of the system mainly have four kinds, as long as one of them is met, the system will determine that the mouse has a foot shrinkage reaction.

[0054] Condition A: the real-time pressure value F(t) in the preset judgment time window T detect drops from the peak F peak by more than a preset absolute threshold ΔF threshold , that is, F(t)≤F peak -ΔF theshold ; wherein T detect can be set to any value between 1ms-200ms, and ΔF threshold can be set to any value between 5-10mN.

[0055] Condition B: the real-time pressure change rate or the real-time pressure change amount ΔF(t) is below the preset determination time window T detect , below the preset negative change rate threshold That is Wherein, Can be set to any value between -100-200 mN / s.

[0056] Condition C: the real-time pressure value F(t) is below the preset determination time window T detect , the pressure value of the N sampling points is below the pressure value of the previous sampling point, and the cumulative drop exceeds the preset threshold ΔF sum-threshold ; wherein ΔF sum-threshold Can be set to any value between 7-14 mN.

[0057] Condition D: after detecting that the real-time pressure value F(t) reaches a relatively stable state, conditions A, B or C are met.

[0058] Embodiment 2: an animal mechanical pain threshold automatic detection device, the difference between this embodiment and embodiment 1 is that the installation position of the driving device is different, the guide cylinder 7 of the needle mechanism in this embodiment is integrally formed, the driving mechanism is as shown in Figure 5 The step motor three 22 is embedded in the side wall of the box body 1, the output end of the step motor three 22 is fixedly connected with one end of the threaded rod three 17, and the wire mesh 2 is sleeved on the threaded rod three 17. In this way, when the guide cylinder 7 moves to the bottom of the rat foot, the step motor three 22 drives the threaded rod three 17 to rotate, so that the wire mesh 2 translates downward, so that the bottom of the rat foot and the fiber wire 8 are in contact and generate pressure.

[0059] The structure of this embodiment not only has the same technical effect as embodiment 1, but also can adjust the size of the space above the wire mesh 2 in the box body 1 according to the size of the animal.

[0060] The automatic control logic and the condition of determining whether the rat withdraws the foot in this embodiment are the same as those in embodiment 1, which will not be described here.

[0061] It should be noted that whether the fiber wire is controlled to move or the wire mesh (animal) is controlled to move, as long as the fiber wire can contact the bottom of the animal's foot and generate pressure, such a structure is within the scope of protection of the present application.

[0062] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An animal mechanical pain threshold automatic detection device comprising a box (1), characterized in that, The box (1) is provided with a wire mesh (2) and a needling mechanism, the wire mesh (2) is horizontally arranged on the side wall of the box (1), the needling mechanism is located directly below the wire mesh (2), and the needling mechanism is used for applying pressure stimulation to the foot bottom of the experimental animal; the box (1) is also provided with a horizontal moving mechanism, the needling mechanism is installed on the horizontal moving mechanism, and the horizontal moving mechanism is used for driving the needling mechanism to move along the horizontal plane of the box (1).

2. The animal mechanical pain threshold automatic detection device according to claim 1, wherein The needling mechanism comprises a guide cylinder (7) with openings at both ends, a pressure sensing device and a driving device; the guide cylinder (7) is sleeved on the horizontal moving mechanism, the pressure sensing device is installed in the guide cylinder (7), and the pressure sensing device is used for fixing the fiber wire (8) and can sense the pressure value change between the foot bottom of the animal and the fiber wire (8); the driving device can make the fiber wire (8) fixed on the pressure sensing device contact the foot bottom of the animal and generate pressure.

3. The animal mechanical pain threshold automatic detection device according to claim 2, wherein The pressure sensing device comprises a pressure sensor (21), a spring (20), a backing plate (19) and a silicone rubber (18); the pressure sensor (21) is embedded in the guide cylinder (7), one end of the spring (20) is connected with the sensing end of the pressure sensor (21), and the other end of the spring (20) is fixedly connected with the bottom of the backing plate (19); the silicone rubber (18) is attached to the top surface of the backing plate (19), the backing plate (19) is an annular backing plate (19), and the side wall is slidably connected with the inner wall of the guide cylinder (7); the silicone rubber (18) is sleeved on the surface of the fiber wire (8) after the fiber wire (8) passes through.

4. The animal mechanical pain threshold automatic detection device according to claim 3, wherein The driving device comprises a stepping motor three (22) and a threaded rod three (17); one end of the threaded rod three (17) is fixedly connected with the output end of the stepping motor three (22).

5. The animal mechanical pain threshold automatic detection device according to claim 4, wherein The guide cylinder (7) is composed of two separable cylinder bodies; one of the guide cylinder (7) is sleeved on the horizontal moving mechanism, the stepping motor three (22) is embedded in the guide cylinder (7), and the other side wall of the guide cylinder (7) is sleeved on the threaded rod three (17).

6. The animal mechanical pain threshold automatic detection device according to claim 4, wherein The stepping motor three (22) is installed on the inner side wall of the box (1), the threaded rod three (17) is vertically arranged, and the wire mesh (2) is sleeved on the threaded rod three (17).

7. The apparatus according to any one of claims 1 to 6, wherein The horizontal moving mechanism comprises a stepping motor one (9), a threaded rod one (6), a stepping motor two (15), a threaded rod two (5) and a sliding block (4); the stepping motor one (9) is embedded in the sliding block (4), one end of the threaded rod one (6) is fixedly connected with the output end of the stepping motor one (9); the stepping motor two (15) is installed on the side wall of the box (1), the threaded rod two (5) is horizontally arranged, and one end of the threaded rod two (5) is fixedly connected with the output end of the stepping motor two (15); the sliding block (4) is sleeved on the threaded rod two (5).

8. The apparatus for automatic detection of mechanical pain threshold of animals according to any one of claims 1 to 6, wherein The top of the needling mechanism is provided with a camera (16), the outer side wall of the box (1) is provided with a display screen (12) and an operation table (10), the operation table (10) is provided with a controller (11), and the display screen (12), the controller (11), the camera (16) and the horizontal moving mechanism are electrically connected.

9. An automatic detection method of a mechanical pain threshold of an animal, characterized by, The method is applied to the detection device of any one of claims 1-8; the specific steps are: S1: The translation mechanism drives the needling mechanism to move along a two-dimensional plane, so that the tip of the fiber filament fixed by the needling mechanism moves to the animal's foot bottom; S2: The fiber filament tip is applied to the animal's foot bottom area by driving the device, while the pressure sensor monitors and reads the spring pressure; S3: When the change characteristics of the real-time pressure value F(t) meet the preset withdrawal reflex judgment condition, it is determined that the current applied stimulus reaches the pain threshold, and the calibrated force value of the fiber filament at this time and the peak pressure value recorded by the pressure sensor are recorded as the pain threshold; S4: Control the needling mechanism to return to the initial position.

10. The animal mechanical pain threshold automatic detection device according to claim 9, wherein The preset withdrawal reflex judgment condition in S3 includes one of the following conditions or a combination thereof: Condition A: the real-time pressure value F(t) falls below a pre-set absolute threshold value AF detect from the peak value F peak by more than a pre-set absolute threshold value AF threshold i.e. F(t) < F peak - AF threshold ; Condition B: real-time pressure change rate or the real-time pressure change amount ΔF(t) is lower than the preset negative change rate threshold within a preset determination time window T detect ​​ Condition C: the real-time pressure value F(t) is lower than the pressure value of the previous sampling point within the preset determination time window T detect , and the cumulative decrease exceeds the preset threshold value AF sum-threshold ; Condition D: After detecting that the real-time pressure value F(t) reaches a relatively stable state, conditions A, B or C are met.

Images