Device for transmitting electroencephalogram signals and electromyographic signals on two sides of freely-moving rat

Abstract

The utility model belongs to the field of experimental devices, and relates to a 360-degree rotating device capable of continuously transmitting bilateral electroencephalogram and myoelectricity of a freely moving rat for a long time. The device is mainly composed of a small conductive slip ring, a slip ring stator end wire protection cover, a slip ring rotor end wire fixing clamping box, a double-row pin header and an acrylic fixing shelf. A wire at a stator end of the small conductive slip ring is welded with the two double-row contact pins and is a bilateral electroencephalogram and electromyographic signal transmitting end; a wire at the rotor end of the slip ring is welded with the double-row pin header and is a bilateral electroencephalogram and electromyographic signal input end; and the main body of the slip ring is fixed on the acrylic shelf through a flange. The novel experimental device is small and light, stable in signal transmission, low in cost and capable of respectively recording electroencephalograms of brains on the left side and the right side of the rat for a long time and providing powerful help for basic experimental researches such as evaluation of brain function states and prognosis of injuries such as cerebral ischemia, evaluation of treatment effects and screening of new intervention measures.

Description

Technical Field

[0001] The utility model belongs to the field of experimental devices, in particular to a device for transmitting bilateral electroencephalogram and electromyographic signals of freely moving rats. Background Art

[0002] According to historical records, stroke is one of the leading causes of death worldwide and a significant contributor to adult disability, making it a major public health issue today. Conducting basic experimental research to elucidate the pathological mechanisms of cerebral ischemia, assess brain function and treatment efficacy, predict prognosis, and develop new treatment strategies is crucial. Electroencephalography (EEG), as a biomarker, is a key experimental tool for real-time monitoring and assessment of brain function after stroke. Studies have shown significant differences in EEG activity between the injured and uninjured sides of the brain. However, current experimental animal studies primarily record unilateral EEG, which cannot accurately reflect and compare changes in brain function between the injured and uninjured sides.

[0003] To address the experimental need for stable bilateral EEG and EMG recording in rats, while ensuring unrestricted free movement and understanding the functional status of different cerebral hemispheres, the inventors of this application developed a device for long-term bilateral EEG and EMG recording using a small conductive slip ring that can smoothly rotate 360 degrees in any direction. This device prevents twisting of the EEG / EMG electrode leads during free movement, ensuring stable bioelectrical transmission and reliable experimental results, while also enabling the acquisition of bilateral EEG activity information. This device provides a simple method for achieving reliable, long-term, continuous recording of bilateral EEG and EMG data in studies of brain injuries such as cerebral ischemia. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the present invention provides a 360-degree rotating device capable of long-term continuous transmission of bilateral EEG and EMG signals from freely moving rats. The device is compact and lightweight, offers stable signal transmission, is simple to manufacture, and is inexpensive. The signal input and output wiring for both EEG and EMG signals are transparent and intuitive, making it easy for researchers to detect and repair signal transmission failures. Furthermore, the device can simultaneously monitor changes in electrical activity in both hemispheres in real time, providing valuable insights into experimental research investigating brain function and prognosis after unilateral brain injury, such as cerebral ischemia, as well as evaluating treatment efficacy and screening interventions.

[0005] This utility model aims to meet the experimental requirements of stable bilateral EEG and EMG signals while not restricting the rat's free movement. Utilizing a small conductive slip ring that can smoothly rotate 360 degrees in any direction, this device prevents twisting of the EEG and EMG electrode leads during free movement, which could affect the rat's movement and stable bioelectrical transmission. This device provides a simple method for achieving long-term, continuous, and reliable bilateral EEG and EMG data recording in studies of brain injuries such as cerebral ischemia.

[0006] This utility model is a 360-degree rotating device for long-term continuous transmission of bilateral EEG and EMG signals from freely moving rats. It features a small conductive slip ring and double-row pin headers, which transmit bilateral EEG and EMG signals via electrode cables connected to the rat's head to a preamplifier. The rotor end of the small conductive slip ring is connected to the electrode cables connected to the rat's head. Because minimal torque is required to drive the rotor of the small conductive slip ring, the electrode cables can easily rotate the rotor when the rat is freely moving. This prevents twisting of the electrode cables, which could damage them and restrict the rat's movement, ensuring the reliability of experimental data. Long-term continuous recording of bilateral EEG and EMG signals in rats is a key experimental tool for studying brain function after brain injury, such as cerebral ischemia. The device is compact and lightweight, offers stable signal transmission, is simple to manufacture, and is low-cost. Its transparent circuitry facilitates inspection and maintenance, providing significant practical value for monitoring the course of disease, evaluating treatment efficacy, and screening neuroprotective strategies in research on brain injuries such as stroke.

[0007] This device, which utilizes a small conductive slip ring to transmit bilateral EEG and EMG signals in freely moving rats, consists of a small conductive slip ring 1, a protective cover for the stator-side wires 2, a fixing card box 3 for the rotor-side wires, a first double-row pin header 4, a second double-row pin header 5, and a third double-row pin header 6, and an acrylic fixing shelf 7. The small conductive slip ring 1 is fixed to the acrylic fixing shelf 7 via a flange. The rotor-side wires connect to the rat's bilateral EEG and EMG electrodes, while the stator-side wires connect to a signal preamplifier.

[0008] In this utility model, the small conductive slip ring 1 is the core component of the invention. Its rotor can smoothly rotate 360 degrees in any direction. It contains twelve conductors, ten of which are used in this device: two for left-side EEG transmission, two for right-side EEG transmission, four for EMG transmission (two each on the left and right sides), and two for reference electrode wires (one each on the left and right sides). The rotor-end conductors serve as the input for bilateral EEG and EMG signals. These wires are soldered to the first double-row pin header 4, corresponding to the rat's bilateral EEG, EMG, and reference electrode wires. The stator-end conductors serve as the output for bilateral EEG and EMG signals. Based on the order of EEG, EMG, and reference electrode signals input from the preamplifier input female pin header, the right-side EEG, EMG, and reference electrode wires are soldered to the second double-row pin header 5, corresponding to the left-side EEG, EMG, and reference electrode wires.

[0009] In the present invention, the slip ring stator end wire protection cover 2 is a small plastic square box, which plays the role of protecting the slip ring stator and the stator end wires and making the device look neat. The bottom ends of the two sides are each provided with a small slot for the wires to pass through.

[0010] In this utility model, the slip-ring rotor-end wire fixing card box 3 has a circular hole at one end, which is inserted and fixed to the slip-ring rotor through this circular hole. The other end is a slot for fixing the slip-ring rotor-end wire and the first double-row pin header 4. After the rat's bilateral EEG and EMG electrode wires are connected to the first double-row pin header 4, the fixing card box drives the rotation of the slip-ring rotor.

[0011] In the present invention, the first double-row pin header 4 is a 2*5P (2.54mm) pin header, the short ends of which are respectively welded to the ten wires at the end of the slip ring rotor (see welding sequence for details). Figure 4 The soldered wires are isolated from each other by transparent insulating glue and fixed to the card slot of the fixed card box 3.

[0012] In the present invention, the second double-row pin header 5 and the third double-row pin header 6 are 2*5P (2.54mm) pin headers, which are welded one by one with the stator end wires of the slip ring (see welding sequence for details). Figure 5 Use transparent insulating glue to seal and insulate each welding point to avoid signal crosstalk between wires and facilitate the plugging and unplugging of the double-row pin header and the signal preamplifier input port.

[0013] In the present invention, the acrylic fixed shelf 7 has a hole at one end corresponding to the diameter of the slip ring stator. The slip ring stator passes through the hole and is suspended and fixed to the acrylic fixed shelf 7 via the slip ring flange. The shelf is fixed to the crossbeam support above the rat recording cage through the rectangular hole at the other end, with the slip ring rotor end facing downward.

[0014] Preferably, a device for transmitting bilateral EEG and EMG signals of freely moving rats comprises a small conductive slip ring (1), a slip ring stator end wire protection box (2), a slip ring rotor end wire fixing card box (3), a first double-row pin header (4), a second double-row pin header (5), a third double-row pin header (6), and an acrylic fixed shelf (7); the wires at the stator end of the small conductive slip ring (1) are welded to the second double-row pin header (5) and the third double-row pin header (6), which are the outgoing ends of the right EEG / EMG and the left EEG / EMG signals, respectively, and are connected to a signal preamplifier; the wires at the rotor end of the small conductive slip ring (1) are welded to the first double-row pin header (4), which are the incoming ends of the left and right EEG and EMG signals, and are connected to the left and right EEG and EMG electrode wires of the rat; the main body of the small conductive slip ring (1) is fixed to the acrylic fixed shelf (7) by means of a flange. The small conductive slip ring (1) is a 360-degree smoothly rotating slip ring containing twelve wires. This device uses ten wires; two of them are used as left-side EEG transmission wires, two are used as right-side EEG transmission wires, and four are used as electromyography transmission wires, two on each side. Two are used as reference electrode wires, one on each side. The rotor end wires are the input ends of bilateral EEG and electromyography signals, and the stator end wires are the output ends of bilateral EEG and electromyography signals. The ten wires at the rotor end of the small conductive slip ring (1) are welded to the first double-row pin header (4) to connect to the pin header female sockets of the bilateral EEG, electromyography and reference electrode wires of the experimental rat. The first double-row pin header (4) welded to the ten wires at the rotor end of the small conductive slip ring (1) is fixed to one end of the fixed card box (3) using insulating glue. The fixing card box (3) of the first double-row pin header (4) welded with the ten wires at the rotor end is fixed to the rotor of the small conductive slip ring (1) through the circular hole at the other end. After the electrode wire pin headers connected to the bilateral EEG and EMG electrodes of the experimental rat's head are docked with the first double-row pin header (4), the slip ring rotor is driven to rotate 360 degrees by the fixing card box (3), which is conducive to preventing the wires at the rotor end of the small conductive slip ring (1) from being damaged by the pulling of the electrode wires when the rat moves freely. The ten wires at the stator end of the small conductive slip ring (1) are welded to the second double-row pin header (5) one by one according to the EEG, EMG and reference electrode signal input sequence of the pin header at the input end of the preamplifier, and the wires of the left EEG, EMG and reference electrode are welded to the third double-row pin header (6) one by one. The protective box (2) of the wires at the stator end of the small conductive slip ring (1) is used to protect and store the stator end of the slip ring and the wires. An acrylic fixed shelf (7) is provided with a corresponding hole at one end of the acrylic fixed shelf (7) according to the diameter of the stator of the small conductive slip ring (1) and the position of the fixing hole on the slip ring flange. The stator of the slip ring passes through the shelf and is fixed to the acrylic fixed shelf (7) with screws through the small hole on the flange.An acrylic fixed shelf (7) is used as a hanging fixed support plate for a small conductive slip ring (1), with the slip ring rotor end facing downward, and is fixed to a beam above a circular transparent recording cage for rats. The bilateral EEG and EMG electrode wires of the rats in the recording cage are connected to the first double-row pin headers (4) welded to the wires at the end of the slip ring rotor, and the slip ring rotor is smoothly driven to rotate when the rat moves, thereby realizing long-term recording of the bilateral EEG and EMG signals of the rats without restricting the free movement of the rats.

[0015] The advantages of this device include: compactness and lightness (the device's main component is a small conductive slip ring, with a stator diameter of only 22 mm and an even smaller rotor of only 7.8 mm); extremely smooth rotor rotation with almost no resistance; transparent wiring connections; stable signal transmission; simple production; and low cost. This device has high practical value in bilateral brain function research. Comparative experiments have confirmed that the bilateral EEG and EMG signals recorded using this device are no different from those recorded using expensive foreign components that transmit unilateral EEG (see [1]). Figure 7 As shown in the figure, on the one hand, it solves the problem of recording line twisting during long-term acquisition and recording of bioelectric signals such as EEG and EMG in freely moving rats at a low cost; on the other hand, it can synchronously obtain EEG activity information of both cerebral hemispheres, providing an easy method to achieve long-term continuous recording of reliable bilateral EEG and EMG data in basic research on brain damage such as cerebral ischemia.

[0016] In addition, the main component of the small conductive slip ring in the utility model can be replaced with a through-hole small conductive slip ring, and the optical fiber or drug delivery catheter can pass through the central hole of the small conductive slip ring to reach the mouse brain, realizing experiments such as optogenetics or brain nucleus drug delivery.

[0017] During the operation, the rats' bilateral EEG and EMG activities were recorded synchronously.

[0018] For ease of understanding, the present invention will be described in detail below with reference to specific drawings and embodiments. It should be noted that the specific examples and drawings are for illustrative purposes only, and researchers in this field may, based on the description herein, make various modifications and changes to the present invention within the scope of the present invention, and such modifications and changes are also included within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of a device for transmitting bilateral EEG and EMG signals from freely moving rats using a small conductive slip ring. 1 is a small conductive slip ring, 2 is a protective cover on the stator end of the small conductive slip ring, 3 is a wire securing card box on the rotor end of the small conductive slip ring, 4 is a first double-row pin header, 5 is a second double-row pin header, and 6 is a third double-row pin header. 7 is an acrylic mounting plate.

[0020] Figure 2 is a cross-sectional view of the core component of the device, the small conductive slip ring 1. In it, 1.1 is the conductor at the stator end of the slip ring, 1.2 is the stator, 1.3 is the slip ring flange, 1.4 is the slip ring rotor, and 1.5 is the conductor at the rotor end of the slip ring. Figure 2 The right side is a cross-sectional view of the slip ring flange, where 1.3.1 is the fixing hole of the slip ring flange.

[0021] Figure 3 is a schematic diagram of the mounting bracket 3 for the conductors at the rotor end of the small conductive slip-ring in this device. Modified from a USB housing, the diagram shows, from left to right, the inner view of the USB housing's upper shell, the outer view of the USB housing's lower shell, and the right side view of the USB housing. Reference numeral 3.1 denotes the 8mm diameter opening at the rear end of the USB housing's upper shell, through which the USB housing is inserted and secured to the slip-ring rotor. The right side view shows the slots securing the first double-row pin header 4.

[0022] Figure 4 shows the first double-row pin header 4 of this device, soldered to the wires at the small conductive slip ring rotor end. The double-row pin header is 2x5P (2.54 mm). Pin 4.1 is soldered to the two reference electrode wires at the slip ring rotor end, pins 4.2 and 4.4 are soldered to the two right EEG transmission wires at the slip ring rotor end, pins 4.3 and 4.5 are soldered to the two left EEG transmission wires at the slip ring rotor end, and pins 4.6 and 4.7 are soldered to the four EMG transmission wires at the slip ring rotor end.

[0023] Figure 5 shows the second and third double-row pin headers 5 and 6, soldered to the stator-side wires of the small conductive slip ring. From left to right, the front, side, and top views of the double-row pin headers are shown. The double-row pin headers are 2x5P (2.54 mm). Pins 5.1 and 5.2 are soldered to the two myoelectric transmission wires on the stator side of the slip ring, respectively. Pins 5.3 and 5.4 are soldered to the two right-side EEG transmission wires (pin header 5) or the two left-side EEG transmission wires (pin header 6), respectively. Pin 5.5 is soldered to the single reference electrode transmission wire on the stator side of the slip ring.

[0024] Figure 6 shows a schematic diagram of the acrylic mounting bracket 7 used to suspend and secure a small conductive slip ring in this device. Reference numeral 6.1 is a 2.5 cm diameter circular hole at one end of the shelf; reference numeral 6.2 is a 0.5 cm diameter circular hole corresponding to the slip ring flange; and reference numeral 6.3 is a 5 cm long x 0.8 cm wide rectangular hole at the other end of the shelf, used to secure the acrylic mounting bracket to the horizontal beam above the rat recording cage.

[0025] Figure 7 is a schematic diagram of recording bilateral EEG and EMG signals in a rat using the device of the present invention, combined with an amplifier, data acquisition card, and computer. Item 7.1 represents the device of the present invention; items 7.2 and 7.3 are preamplifiers, which initially amplify and transmit the rat's right and left EEG / EMG signals, respectively; item 7.4 is a secondary amplifier, which further amplifies the bilateral EEG and EMG signals; and item 7.5 is the computer screen displaying the actual bilateral EEG and EMG recordings. Note: The EEG and EMG data of one rat are shown. The first and third rows represent the EEG waves of the right and left brain, respectively; the second and fourth rows represent the EMG waves. EEG-R: Electroencephalogram-Right, EEG-L: Electroencephalogram-Left, EMG: Electromyography. DETAILED DESCRIPTION

[0026] The following is a further description of the utility model patent with reference to the accompanying drawings and specific examples.

[0027] It is intended to explain the present invention and should not be understood as limiting the present invention. Example

[0028] As shown in Figure 1, this device, which uses a small conductive slip ring to transmit bilateral EEG and EMG signals in freely moving rats, consists of a small conductive slip ring 1, a protective cover for the wires on the stator end of the slip ring 2, a fixing card box for the wires on the rotor end of the slip ring 3, a first double-row pin header 4, a second double-row pin header 5, and a third double-row pin header 6, and an acrylic fixing shelf 7. The small conductive slip ring 1 is fixed to the acrylic fixing shelf 7 via a flange. The wires on the rotor end of the slip ring are connected to the rat's bilateral EEG and EMG electrodes; the wires on the stator end of the slip ring are connected to two signal preamplifiers.

[0029] The small conductive slip ring 1 is the core component of this utility model. Its rotor can smoothly rotate 360 degrees in any direction. It contains twelve wires: two for left-side EEG transmission, two for right-side EEG transmission, four for EMG transmission (two each on the left and right sides), and two for reference electrode wires (one each on the left and right sides). The rotor-end wires serve as the input terminals for bilateral EEG and EMG signals. These wires are soldered to the first double-row pin header 4, corresponding to the rat's bilateral EEG and EMG electrodes. The stator-end wires serve as the output terminals for bilateral EEG and EMG signals. Based on the order of EEG, EMG, and reference electrode signals input from the preamplifier's female pin headers, the right-side EEG, EMG, and reference electrode wires are soldered to the second double-row pin header 5, corresponding to the left-side EEG, EMG, and reference electrode wires.

[0030] The slip ring stator end wire protection cover 2 is a small plastic square box that protects the slip ring stator and the stator end wires and keeps the device neat in appearance. A small slot is opened at the bottom of both sides for the wires to pass through.

[0031] The slip-ring rotor-end wire fixing card box 3 is fixed to the slip-ring rotor through a circular hole at one end. The other end is a slot for securing the rotor-end wires and the first double-row pin header 4. After the rat's bilateral EEG and EMG electrode wires are connected to the first double-row pin header 4, the fixing card box drives the rotation of the slip-ring rotor.

[0032] The first double-row pin header 4 is a 2*4P (2.54mm) pin header, the short ends of which are respectively welded to the ten wires at the end of the slip ring rotor (see welding sequence for details). Figure 4 The soldered wires are isolated from each other by transparent insulating glue and fixed to the card slot of the fixed card box 3.

[0033] The second double-row pin header 5 and the third double-row pin header 6 are both 2*5P (2.54mm) pin headers, which are welded one by one to the stator end wires of the slip ring (see welding sequence for details). Figure 5 As shown in the accompanying drawings), use transparent insulating glue to seal and insulate each welding point to avoid signal short circuits between wires and facilitate the plugging and unplugging of the double-row pin header and the signal preamplifier input port.

[0034] The acrylic fixed shelf 7 has a hole at one end corresponding to the diameter of the slip ring stator. The slip ring stator passes through the hole and is suspended and fixed to the acrylic fixed shelf 7 via the slip ring flange. The shelf is placed with the slip ring rotor end facing downward through the rectangular hole at the other end and fixed to the beam support above the rat recording cage.

[0035] Connect the electrode cables connected to the rat's bilateral EEG, EMG, and reference electrodes to the double-row pin header 4. When the rat is freely moving, the slip ring rotor rotates via the electrode cables, the first double-row pin header 4, and the fixed card box 3. The rat's bilateral EEG and EMG signals are input via the conductive slip ring rotor-end wires and output via the conductive slip ring stator-end wires. These signals are then fed into the signal preamplifier via the second and third double-row pin headers 5 and 6. This device achieves long-term continuous transmission of bilateral EEG and EMG signals from freely moving rats, meeting the experimental requirements of obtaining stable and synchronous EEG activity signals from both cerebral hemispheres without restricting the rat's free movement.

Claims

1. A device for transmitting bilateral EEG and EMG signals of freely moving rats, characterized in that: It comprises a small conductive slip ring (1), a slip ring stator end wire protection box (2), a slip ring rotor end wire fixing card box (3), a first double row of pin headers (4), a second double row of pin headers (5), a third double row of pin headers (6), and an acrylic fixing shelf (7); The wire at the stator end of the small conductive slip ring (1) is welded to the second double-row pin header (5) and the third double-row pin header (6), which are the outgoing ends of the right EEG / EMG and left EEG / EMG signals, respectively, and are connected to the signal preamplifier; The wire at the rotor end of the small conductive slip ring (1) is welded to the first double-row pin header (4), serving as the left and right EEG and EMG signal input terminals, and is connected to the left and right EEG and EMG electrode wires of the rat; The main body of the small conductive slip ring (1) is fixed to an acrylic fixed shelf (7) by means of a flange.

2. The device according to claim 1, characterized in that The small conductive slip ring (1) is a 360-degree smoothly rotating slip ring containing twelve wires. This device uses ten wires; two of them are used as left-side EEG transmission wires, two are used as right-side EEG transmission wires, four are used as electromyography transmission wires, two on the left and two on the right sides, and two are used as reference electrode wires, one on the left and one on the right sides. The rotor end wires are bilateral EEG and electromyography signal input terminals, and the stator end wires are bilateral EEG and electromyography signal output terminals.

3. The device according to claim 2, characterized in that The ten wires at the rotor end of the small conductive slip ring (1) are welded to the first double-row pin header (4) to connect to the pin header female sockets of the experimental rat's bilateral EEG, EMG and reference electrode wires.

4. The device according to claim 3, characterized in that The first double-row pin header (4) welded to the ten wires at the rotor end of the small conductive slip ring (1) is fixed to one end of the fixed card box (3) using insulating glue.

5. The device according to claim 4, characterized in that The fixing card box (3) of the first double-row pin header (4) fixed to the ten wires welded to the rotor end is inserted and fixed to the rotor of the small conductive slip ring (1) through the circular hole at the other end thereof. After the electrode wire pin headers connected to the bilateral EEG and EMG electrodes on the head of the experimental rat are docked with the first double-row pin header (4), the slip ring rotor is driven to rotate 360 degrees at will through the fixing card box (3), which is beneficial to avoid the wires at the rotor end of the small conductive slip ring (1) being damaged by the pulling of the electrode wires when the rat is in free motion.

6. The device according to claim 2, characterized in that The ten wires at the stator end of the small conductive slip ring (1) are welded one by one to the second double-row pin header (5) for the right side of the EEG, EMG and reference electrode wires, and one by one to the third double-row pin header (6) for the left side of the EEG, EMG and reference electrode wires according to the order of EEG, EMG and reference electrode signal input of the pin header at the preamplifier input end.

7. The device according to claim 1, characterized in that The protective box (2) for the stator end wire of the small conductive slip ring (1) is used to protect and accommodate the stator end of the slip ring and the wire.

8. The device according to claim 1, characterized in that The acrylic fixed shelf (7) is provided with a corresponding hole at one end of the acrylic fixed shelf (7) according to the diameter of the stator of the small conductive slip ring (1) and the position of the fixing hole on the slip ring flange. The stator of the slip ring passes through the shelf and is fixed to the acrylic fixed shelf (7) with screws through the small hole on the flange.

9. The device according to claim 1, characterized in that The acrylic fixed shelf (7) serves as a hanging fixed support plate for the small conductive slip ring (1), with the slip ring rotor end facing downward, and is fixed to the beam above the circular transparent recording cage of the rat. The bilateral EEG and EMG electrode wires of the rat in the recording cage are connected through the first double row of pins (4) welded to the wires at the end of the slip ring rotor, and the slip ring rotor is smoothly driven to rotate when the rat moves, so that the bilateral EEG and EMG signals of the rat can be recorded for a long time without restricting the free movement of the rat.

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