A magnetic resonance compatible small animal mechanical nociceptive stimulation device

Abstract

The utility model discloses a kind of small animal mechanical pain sensation stimulating devices compatible with magnetic resonance, including fixed subassembly and stimulating subassembly, it is characterized by: the fixed subassembly includes fixed box, oxygen supply mechanism is arranged at the front end of fixed box, bite lever mechanism is installed at the front end of oxygen supply mechanism;The stimulating subassembly includes fixed plate slidingly installed in fixed box interior, locking mechanism is arranged at the both sides of fixed plate, stimulating plate is detachably installed at the front end of fixed plate, a plurality of conical protrusions are arranged on the surface of stimulating plate, restraint belt is hinged in one side of stimulating plate, tensioning hole is arranged in the other side of stimulating plate, guide hole is communicated with tensioning hole and is penetrated through fixed plate, power mechanism is detachably installed at the distal end of fixed box, pull rope is connected between power mechanism and restraint belt, distal controller is installed on power mechanism.The utility model is convenient to operate, stimulate accurate, low in cost and compatible with magnetic resonance environment.

Description

Technical Field

[0001] This utility model relates to the field of magnetic resonance assistive devices for small animals, specifically to a magnetic resonance compatible mechanical pain stimulation device for small animals. Background Technology

[0002] In neuroscience research, functional magnetic resonance imaging (fMRI) is an important tool for observing brain activation patterns in animals under specific stimuli, and for studying pain mechanisms, drug targets, and neural circuits. Small animal fMRI (such as the 9.4T system) has the advantages of high resolution and non-invasiveness, making it the preferred tool for studying brain function in live mice.

[0003] Pain is one of the core topics in neuroscience research; mechanical pain stimulation is the standard method for assessing pain threshold and pain sensitivity in animals; however, combining mechanical pain stimulation with magnetic resonance imaging (MRI) technology requires overcoming the special limitations of the MRI environment, including strong magnetic fields, radio frequency interference, and space constraints.

[0004] Currently, using fiber optic or pneumatic systems to transmit stimuli presents some problems:

[0005] 1. Poor magnetic resonance compatibility: Traditional mechanical pain stimulation devices (such as Von Frey wires) contain metal parts, which cannot be used under strong magnetic fields or produce serious artifacts;

[0006] 2. Insufficient precision and controllability of stimulation: Existing magnetic resonance-compatible stimulation methods (such as pneumatic or fiber optic) are difficult to simulate the fine mechanical properties of classic mechano-pain stimuli such as Von Frey wire, resulting in poor controllability and repeatability of stimulation.

[0007] 3. High operational complexity: Remote operation of existing stimulation devices is very difficult within the narrow aperture of a magnetic resonance scanner, affecting experimental efficiency and the reliability of results;

[0008] 4. High cost: Fiber optic or pneumatic stimulation systems designed specifically for magnetic resonance environments are typically expensive.

[0009] Therefore, in order to solve the above-mentioned technical problems, this utility model provides a magnetic resonance compatible mechanical pain stimulation device for small animals. Utility Model Content

[0010] The purpose of this invention is to provide a magnetic resonance-compatible mechanical pain stimulation device for small animals that is easy to operate, provides precise stimulation, is low in cost, and is compatible with the magnetic resonance environment, so as to serve the reliable development of cutting-edge neuroscience research on pain mechanisms, drug targets, and neural circuits.

[0011] To achieve the above-mentioned technical effects, this utility model is implemented through the following technical solution: a magnetic resonance compatible small animal mechanical pain stimulation device, comprising a fixing component and a stimulation component, characterized in that: the fixing component includes a fixing box, an oxygen supply mechanism disposed at the front end of the fixing box, and a bite bar mechanism installed at the front end of the oxygen supply mechanism; the stimulation component includes a fixing plate slidably installed inside the fixing box, a locking mechanism disposed on both sides of the fixing plate, a detachable stimulation plate installed at the front end of the fixing plate, several conical protrusions disposed on the surface of the stimulation plate, a restraint strap hinged to one side of the stimulation plate, a tension hole disposed on the other side of the stimulation plate, a guide hole penetrating the fixing plate and communicating with the tension hole, a detachable power mechanism installed at the far end of the fixing box, a traction rope connecting the power mechanism and the restraint strap, and a remote controller installed on the power mechanism;

[0012] Furthermore, the locking mechanism includes stabilizing plates disposed on both sides of the bottom end of the fixing plate, and first fixing clips disposed on both sides of the top end of the positioning plate; the first fixing clips are detachably mounted on the side wall of the fixing box.

[0013] Furthermore, the power mechanism includes a second fixing clamp that is detachably mounted on the far side wall of the fixing box, a power box located at the side end of the second fixing clamp, a battery and a power motor installed inside the power box, and a winch located on the output shaft of the power motor; one end of the pull rope is fixedly connected to the winch.

[0014] Furthermore, the remote controller includes a control line located at the side of the power box and a PLC controller installed at the end of the control line; the control line is electrically connected to the battery, the power motor and the PLC controller.

[0015] Furthermore, the dimensions of the fixing box are compatible with the delivery slots of existing small animal magnetic resonance imaging instruments.

[0016] Furthermore, the fixing box, oxygen supply mechanism, biting rod mechanism, fixing plate, stimulation plate, locking mechanism, restraint strap and traction rope are all made of non-metallic materials; the restraint strap and traction rope are both made of non-elastic rope.

[0017] Furthermore, the fixing box, oxygen supply mechanism, bite bar mechanism, fixing plate, stimulation plate and locking mechanism are all made of medical-grade hard plastic; the restraint strap is made of cloth; the traction rope is made of nylon rope.

[0018] Furthermore, the oxygen supply mechanism includes a rubber mounting clip located at the front end of the fixed box, a breathing mask that is snapped into the mounting clip, and a breathing tube connected to the end of the breathing mask.

[0019] Furthermore, the biting rod mechanism includes fixing holes on both sides of the fixing box, a biting rod inserted into the fixing holes, and a pinch handle at one end of the biting rod; the fixing holes are located on the front side of the rubber mounting clip.

[0020] Furthermore, the PLC controller is equipped with forward rotation control buttons and reverse rotation control buttons for controlling the operation of the power motor.

[0021] Furthermore, during MRI, the power mechanism at the distal end of the fixation box does not enter the MRI machine.

[0022] The beneficial effects of this utility model are:

[0023] This invention is made entirely of non-metallic materials, effectively avoiding artifact interference and equipment safety issues caused by traditional metal components in strong magnetic field environments. It ensures clear image quality and reliable data during fMRI scanning, providing technical support for precise research on brain functional area activation. Precise control of the power motor via a remote controller, combined with the traction rope and stimulation plate structure, enables stable control of the intensity and duration of mechanical pain stimulation, effectively simulating the mechanical properties of classic stimuli such as Von Frey wire, thus improving the standardization and repeatability of the experiment. The bite bar mechanism and restraint strap work synergistically, combined with an adjustable traction structure, to effectively fix the experimental animal during scanning, reducing experimental errors caused by animal movement and ensuring the accuracy of stimulus application and the reliability of experimental results.

[0024] The design of this utility model fully considers the internal space limitations of the magnetic resonance scanner. The size of the fixing box matches the existing small animal magnetic resonance delivery tank. The stimulation component can be operated remotely from the outside, effectively reducing the complexity of the experimental setup and improving experimental efficiency and operational safety. At the same time, the device uses a mechanical traction method to replace the expensive fiber optic or pneumatic stimulation system, which greatly reduces the manufacturing cost while ensuring the realization of functions. It is easy to promote and apply in most scientific research environments and has good versatility and economy. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0027] Figure 2 This is a schematic diagram of the overall structure of this utility model from another perspective;

[0028] Figure 3 This is a utility model Figure 2 Enlarged structural diagram at point A in the middle;

[0029] Figure 4 This is a front view of the present invention;

[0030] Figure 5 This is an axonometric view of the present invention.

[0031] The attached diagram lists the components represented by each number as follows:

[0032] 1. Fixing box; 2. Oxygen supply mechanism; 21. Breathing mask; 3. Biting bar mechanism; 31. Biting bar; 4. Fixing plate; 5. Locking mechanism; 51. Stabilizing plate; 52. First fixing clamp; 6. Stimulating plate; 61. Conical protrusion; 62. Tensioning hole; 63. Guide hole; 7. Restraint strap; 8. Power mechanism; 81. Second fixing clamp; 82. Power box; 83. Winch; 9. Pull rope; 10. Remote controller; 101. Control line; 102. PLC controller. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0034] Example 1

[0035] See Figures 1 to 5 As shown, a magnetic resonance compatible small animal mechanical pain stimulation device includes a fixation component and a stimulation component. The fixation component includes a fixation box 1, an oxygen supply mechanism 2 located at the front end of the fixation box 1, and a bite bar mechanism 3 installed at the front end of the oxygen supply mechanism 2. The stimulation component includes a fixation plate 4 slidably installed inside the fixation box 1, locking mechanisms 5 located on both sides of the fixation plate 4, a detachable stimulation plate 6 installed at the front end of the fixation plate 4, several conical protrusions 61 on the surface of the stimulation plate 6, a restraint strap 7 hinged to one side of the stimulation plate 6, a tension hole 62 located on the other side of the stimulation plate 6, a guide hole 63 penetrating the fixation plate 4 and communicating with the tension hole 62, a detachable power mechanism 8 installed at the far end of the fixation box 1, a traction rope 9 connecting the power mechanism 8 and the restraint strap 7, and a remote controller 10 installed on the power mechanism 8.

[0036] The locking mechanism 5 includes stabilizing plates 51 on both sides of the bottom end of the fixing plate 4 and first fixing clips 52 on both sides of the top end of the positioning plate 4. The first fixing clips 52 are detachably installed on the side wall of the fixing box 1 to achieve precise positioning and stable fixation of the stimulation component. Through the cooperation of the "stabilizing plates 51" and the "first fixing clips 52", it is ensured that the stimulation plate will not shift or shake when stimulation is applied, thereby ensuring the accuracy and consistency of the stimulation application position each time.

[0037] The power mechanism 8 includes a second fixing clip 81 detachably mounted on the far side wall of the fixing box 1, a power box 82 located at the side end of the second fixing clip 81, a battery and a power motor installed inside the power box 82, and a winch 83 located on the output shaft of the power motor; one end of the traction rope 7 is fixedly connected to the winch 83; it provides a remotely controllable, non-magnetically interfered power source; the power part is connected and fixed to the main body through the "second fixing clip 81", clearly defining the "power motor" and "winch 83" as core driving elements, realizing the conversion of electrical control signals into mechanical traction actions; it provides a foundation for precise and programmable stimulation control, and is the core to solving the problems of "operational complexity" and "magnetic resonance compatibility".

[0038] The remote controller 10 includes a control line 101 located on the side of the power box 82, and a PLC controller 102 installed at the end of the control line 101; the control line 101 is electrically connected to the battery, the power motor, and the PLC controller 102. This achieves both convenient operation and precise control. Through the PLC controller and independent control circuitry, researchers can remotely and precisely control the start, stop, intensity, and duration of stimulation outside the magnetic resonance imaging room.

[0039] The dimensions of the fixing box 1 are compatible with the delivery slots of existing small animal magnetic resonance imaging (MRI) instruments. By matching the dimensions of existing standard equipment (delivery slots), this device can be seamlessly integrated into the vast majority of small animal MRI platforms without requiring any modifications to existing core equipment, greatly improving the ease of promotion and application value of the device.

[0040] The fixation box 1, oxygen supply mechanism 2, bite bar mechanism 3, fixation plate 4, stimulation plate 6, and locking mechanism 5 are all made of medical-grade rigid plastic; the restraint strap 7 is made of cloth; and the traction rope 9 is made of nylon rope. By using non-metallic materials throughout, the risks of magnetic artifacts and equipment flying under the force of a magnetic field are fundamentally eliminated, ensuring the quality of fMRI image data and experimental safety.

[0041] The oxygen supply mechanism 2 includes a rubber mounting clip at the front end of the fixed box 1, a breathing mask 21 that is clipped into the mounting clip, and a breathing tube connected to the end of the breathing mask; thus, while administering stimulation, it ensures the life support and physiological stability of the experimental animal.

[0042] Stable oxygen supply is a necessary condition for long-term in vivo experiments (such as fMRI scans). The design of the oxygen supply mechanism 2 mentioned above ensures the physiological homeostasis of the animal during fixation and stimulation, thereby making the obtained brain function data more realistically reflect the influence of the stimulation itself, eliminating interference factors such as hypoxia, and improving the reliability of experimental results.

[0043] The bite bar mechanism 3 includes fixing holes on both sides of the fixing box, a bite bar 31 inserted into the fixing holes, and a handle at one end of the bite bar 31; the fixing holes are located on the front side of the rubber mounting clip. This provides an effective and user-friendly animal head fixation solution; by having the animal bite the bite bar 31, its head position can be stabilized, greatly reducing image blurring caused by head movement during scanning. The "handle" design facilitates quick installation and removal of the bite bar 31 by experimental personnel, improving the efficiency of experimental operations.

[0044] The PLC controller 102 is equipped with forward and reverse control buttons for controlling the motor's operation. This enables intuitive and bidirectional control of the stimulation process. The forward control button applies stimulation (tightens the restraint strap 7), and the reverse control button releases stimulation (loosens the restraint strap 7). This simple and direct control logic makes operation very easy to master, while ensuring the timeliness and accuracy of stimulation application and release, further enhancing the device's operability and the controllability of the stimulation.

[0045] During MRI, the power mechanism 8 at the distal end of the fixation box 1 does not enter the interior of the MRI machine. This completely isolates potential sources of interference from the physical space; explicitly placing the power mechanism, including the motor and battery, outside the high field strength area of ​​the MRI machine is the most direct and effective way to ensure absolute MRI compatibility and operational safety, avoiding any risks that may arise from electronic components being too close to the magnet.

[0046] The first fixing clamp 52 and the second fixing clamp 81 have the same structure, both including an L-shaped plate, a threaded sleeve disposed in the middle of the L-shaped plate, a screw threadedly connected inside the threaded sleeve, and locking plates and adjusting handles disposed at both ends of the screw. Clamping can be achieved by rotating the screw.

[0047] The fixing plate 4 has positioning protrusions on both sides of its surface, and the stimulation plate 6 has positioning grooves on both sides of its back that are adapted to the positioning protrusions, so that the stimulation plate 6 can be disassembled and installed (slot connection) on the fixing plate 4.

[0048] Example 2

[0049] A method of using a magnetic resonance compatible small animal mechanical pain stimulation device includes the following steps:

[0050] Step 1: Experimental Preparation and Apparatus Installation

[0051] 1. Device inspection: Confirm that all components, including the fixing box 1, stimulation plate 6, and traction rope 7, are made of non-metallic materials and are undamaged; check whether the battery power of the power mechanism 8 is sufficient and whether the traction rope 7 moves smoothly in the guide hole 63.

[0052] 2. Fixed platform integration: The fixed box 1 of the device is placed steadily into the special delivery slot of the small animal magnetic resonance imaging system to ensure that it is placed stably and is compatible with the scanning platform;

[0053] 3. Power Mechanism Positioning: The power mechanism 8 is mounted at the far end of the mounting box 1 (i.e., the end furthest from the scanner inlet) via its second fixing clip 81, ensuring that the power mechanism 8 is completely outside the main magnetic field range of the magnetic resonance scanner during scanning to avoid interference. The mounting box 1 is long enough to meet the above requirements.

[0054] Step 2: Fixation of experimental animals

[0055] 1. Animal anesthesia and placement: The experimental animals (such as C57 mice) are moderately anesthetized and placed in a prone position in the fixation box 1;

[0056] 2. Head fixation and life support connection: Take a suitable bite bar 31, hold the handle end, and insert the other end of the bite bar 31 into the fixing hole on the side of the fixing box 1. Then, guide the animal to bite the bite bar to effectively fix its head and prevent movement during scanning. Then, gently cover the animal's mouth and nose with the breathing mask and connect the breathing tube to the anesthesia machine and oxygen supply system to ensure that the animal breathes steadily during the scanning process.

[0057] 3. Body restraint: Place the animal stimulation site (C57 mouse foot) steadily on the surface of the stimulation plate 6 and within the coverage area of ​​the restraint strap 7. Wrap the restraint strap 7 around the stimulation site and pass the free end through the tension hole 62 on the other side of the stimulation plate 6. Adjust it to a suitable tightness initially.

[0058] 4. Connecting the traction system: After passing the restraint strap 7 through the guide hole 63, its end is reliably connected to the traction rope 9 led out from the power mechanism 8 (using conventional rope connection methods such as binding or snapping).

[0059] Step 3: Magnetic Resonance Scan and Remote Stimulation Application

[0060] 1. Insert into the scanning position: Smoothly push the entire structure of the animal, which has been fixed, to the designated imaging center position of the magnetic resonance scanner;

[0061] 2. Start Scan: Initiate the magnetic resonance imaging (MRI) scan sequence to begin acquiring basic brain function images.

[0062] 3. Applying stimulation remotely:

[0063] • When mechanical pain stimulation needs to be applied, the operator presses the forward control button outside the scanning room via the remote controller (PLC controller 102);

[0064] • The power motor inside the power mechanism 8 starts, driving the winch 83 to rotate and tighten the pulling rope 9;

[0065] • The traction rope 9 pulls the restraint strap 7 through the guide hole 63, causing it to press on the animal's stimulation site, thereby making the animal's stimulation site come into contact with the conical protrusion 61 on the surface of the stimulation plate 6 and generating pressure, simulating precise and controllable mechanical pain stimulation.

[0066] The intensity and duration of the stimulus can be actively controlled by the controller.

[0067] 4. Stimulation release: After a single stimulation, press the reverse control button on the controller, the power motor reverses, the winch releases the traction rope 9, the restraint belt 7 loosens, and the stimulation pressure is released.

[0068] Step 4: Post-experiment processing

[0069] 1. Animal removal: After all scanning and stimulation experiments are completed, remove the device from the magnetic resonance scanner; reverse the above fixation steps, loosen the restraint strap 7, remove the bite bar 31 and breathing mask 21, and safely remove the animal;

[0070] 2. Device cleaning: Thoroughly clean and disinfect or replace all parts that come into contact with the animal (such as the stimulation plate 6, bite bar 31, and restraint straps) for the next use.

[0071] Finally, it should be noted that the above are merely preferred embodiments of this utility model and are not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A magnetic resonance-compatible small animal mechanical pain stimulation device, comprising a fixation component and a stimulation component, characterized in that: The fixing component includes a fixing box, an oxygen supply mechanism located at the front end of the fixing box, and a bite bar mechanism installed at the front end of the oxygen supply mechanism; the stimulation component includes a fixing plate slidably installed inside the fixing box, a locking mechanism located on both sides of the fixing plate, a detachable stimulation plate installed at the front end of the fixing plate, several conical protrusions on the surface of the stimulation plate, a restraint strap hinged to one side of the stimulation plate, a tension hole located on the other side of the stimulation plate, a guide hole penetrating the fixing plate and communicating with the tension hole, a detachable power mechanism installed at the far end of the fixing box, a traction rope connecting the power mechanism and the restraint strap, and a remote controller installed on the power mechanism; The locking mechanism includes stabilizing plates disposed on both sides of the bottom end of the fixing plate and first fixing clips disposed on both sides of the top end of the positioning plate; the first fixing clips are detachably installed on the side wall of the fixing box. The power mechanism includes a second fixing clamp that is detachably installed on the far side wall of the fixing box, a power box located at the side end of the second fixing clamp, a battery and a power motor installed inside the power box, and a winch located on the output shaft of the power motor; one end of the pull rope is fixedly connected to the winch. The remote controller includes a control line located on the side of the power box and a PLC controller installed at the end of the control line; the control line is electrically connected to the battery, the power motor and the PLC controller.

2. The magnetic resonance-compatible small animal mechanical pain stimulation device according to claim 1, characterized in that, The dimensions of the fixation box are compatible with the delivery slot of existing small animal magnetic resonance imaging equipment.

3. The magnetic resonance-compatible small animal mechanical pain stimulation device according to claim 1, characterized in that, The fixing box, oxygen supply mechanism, bite bar mechanism, fixing plate, stimulation plate, locking mechanism, restraint strap and traction rope are all made of non-metallic materials; the restraint strap and traction rope are all made of non-elastic rope.

4. A magnetic resonance-compatible small animal mechanical pain stimulation device according to claim 3, characterized in that, The fixing box, oxygen supply mechanism, bite bar mechanism, fixing plate, stimulation plate and locking mechanism are all made of medical hard plastic; the restraint strap is made of cloth strap; the traction rope is made of nylon rope.

5. A magnetic resonance-compatible small animal mechanical pain stimulation device according to claim 1, characterized in that, The oxygen supply mechanism includes a rubber mounting clip located at the front end of the fixed box, a breathing mask that is snapped into the mounting clip, and a breathing tube connected to the end of the breathing mask. The biting rod mechanism includes fixing holes on both sides of the fixing box, a biting rod inserted into the fixing holes, and a pinch handle at one end of the biting rod; the fixing holes are located on the front side of the rubber mounting clip.

6. A magnetic resonance-compatible small animal mechanical pain stimulation device according to claim 1, characterized in that, The PLC controller is equipped with forward and reverse control buttons for controlling the operation of the power motor.

7. A magnetic resonance-compatible small animal mechanical pain stimulation device according to claim 1, characterized in that, During MRI, the power mechanism at the distal end of the fixation box does not enter the MRI machine.

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