A rat skull four-channel parallel electrode and telescopic positioning electrode fixing base

Abstract

The present application relates to the field of electric stimulation device, especially to a four-channel parallel electrode for rat brain and a telescopic positioning electrode fixing base. The four-channel parallel electrode for rat brain comprises an insulating connecting socket and an electrode wire, the electrode wire is inserted into the insulating connecting socket, and the insulating connecting socket is connected with an integrated circuit board serving as a lower machine of electric stimulation control and a power supply through the electrode wire. The telescopic positioning electrode fixing base comprises a base body, a screw fixing part and a positioning reinforcing part. In the provided multi-channel optimized electrode for rat brain and the fixing base thereof, the stimulating electrode is inserted into the electrode insertion hole in a vertical manner, the length of the electrode is designed to be just suitable for the depth of the target brain area, and the electrode insertion depth does not need to be controlled intentionally. When the electrode wire passes through the rat skull and is completely inserted into the brain tissue, the terminal electrode wire reaches the position of the target brain area, and the success rate of the experiment is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of electrical stimulation devices, and more particularly to a four-channel parallel electrode for rat brain and a retractable positioning electrode fixing base. Background Technology

[0002] Brain-Computer Interface (BCI) technology is a novel communication and control technology that has emerged in recent years. "Computer" refers to any processing or computing device, ranging from simple circuits to silicon chips to external devices and wheelchairs. "Interface" means "a medium for information exchange." The definition of a brain-computer interface is a connection pathway created between the human or animal brain and an external device for information exchange. As one of the most active research directions in the field of neural engineering, BCI has significant research importance and enormous application potential in biomedicine, neurorehabilitation, and intelligent robotics. In the past decade, BCI technology has made significant progress and developed rapidly, and its application areas are gradually expanding.

[0003] Rats, belonging to the family Muridae in the order Rodentia of the class Mammalia, reproduce rapidly and are highly adaptable to the external environment. They are commonly used experimental animal models in biomedicine and occupy an important position in biomedical research.

[0004] Meanwhile, compared to traditional electromechanical robots, "brain-controlled animals" offer significant advantages in terms of smooth, flexible movement and high energy efficiency. They can obtain energy for movement through foraging behavior, exhibiting strong long-term working capacity. Furthermore, they possess a certain degree of autonomous judgment and learning ability, enabling them to respond well to unexpected situations and adapt to complex environments. In addition, "brain-controlled animals" have low maintenance costs, requiring only small-scale rearing, and the loss of individual animals does not incur excessive economic costs. Therefore, rats are currently the preferred choice for "brain-controlled animals" in the field of brain-computer interfaces.

[0005] To achieve brain control, specific stimulation must be applied to specific brain regions to produce the desired effect. The "moving forward" behavior utilizes the rat's reward mechanism. Electrical stimulation of the medial forebrain tract (MFB) effectively drives the rat to move forward, climb, or descend using virtual rewards. Turning, however, requires training. This process combines electrical stimulation of the turning circuit with electrical stimulation of the reward for the correct behavior. The rat needs to learn to associate these two elements through training. The reward stimulus acts on the aforementioned MFB reward circuit, while the turning cue is simulated by mimicking the rat's whisker tactile sensation. The tactile response to the rat's whiskers is first transmitted from peripheral nerve fibers to the brainstem, where it undergoes preliminary processing in the contralateral thalamus's whisker sensory nuclei before reaching the primary somatosensory cortex whisker area (S1BF). Therefore, electrical stimulation of the rat's whisker sensory cortex (S1BF) produces a virtual sensation similar to natural whisker stimulation, thus enabling the rat to turn.

[0006] However, in existing technologies, animal models that use electrical stimulation of specific brain regions in rats to achieve "brain control" face challenges due to the small size of the rat skull and the large number of stimulation sites. This makes it difficult to precisely implant each electrode. Furthermore, rats with implanted electrodes need to be kept for more than a week before further training can begin. During this week, rats often scratch or rub against their cages, causing the implanted electrodes to fall off. Even in a few animal models where the electrodes are successfully retained until training, there are still many drawbacks, such as the large number of stimulation points leading to electrode wire tangling.

[0007] Therefore, we urgently need a four-channel parallel electrode for the rat brain and a positioning electrode fixation base that can generate a virtual sensation similar to natural beard stimulation by electrically stimulating the beard area (S1BF) of the rat sensory cortex. Summary of the Invention

[0008] Therefore, there is a need for a rat cranial four-channel parallel electrode and a positioning electrode fixing base that can generate a virtual sensation similar to natural beard stimulation by electrically stimulating the beard area (S1BF) of the rat sensory cortex.

[0009] To achieve the above objectives, the present invention provides a four-channel parallel electrode for rat brain, comprising: an insulating connection bayonet and an electrode wire, wherein the electrode wire is inserted into the insulating connection bayonet, and the insulating connection bayonet is connected to an integrated circuit board serving as a lower-level device for electrical stimulation control and a power supply through the electrode wire.

[0010] As a further improvement of the present invention: each branch of the electrode wire is 2.0-2.5cm long, the exposed part of the electrode wire is attached to the skull and reaches the insertion hole of the target brain region, and the vertical length of the upper two branch electrode wires is 4.5-4.9mm, and the vertical length of the lower two branch electrode wires is 9.8-10.6mm.

[0011] As a further improvement of the present invention: the insulating connection bayonet shell is made of insulating material.

[0012] The present invention also provides a retractable positioning electrode fixing base, which is based on the above-mentioned four-channel parallel electrode for rat brain and includes a base body, a screw fixing part, and a positioning and reinforcing part. The base body is provided with an electrode insertion part, and the screw fixing part is threadedly connected to the base body and located on the periphery of the electrode insertion part. The positioning and reinforcing part is used to fix the electrode and includes a slide rail, a first screw, a nut, a telescopic rod, a sleeve, and a second screw. The slide rail is fixedly connected to the screw fixing part and extends from the screw fixing part to the electrode insertion part. The first screw passes through from bottom to top and is slidably installed in the slide rail. The nut is threadedly fixed to the top of the first screw. One end of the telescopic rod is fixedly connected to the first screw, and the other end of the telescopic rod is fixedly connected to the sleeve. The second screw is threadedly connected to the periphery of the sleeve.

[0013] As a further improvement of the present invention: the diameter of the screw fixing part is 1.1-1.3mm, and the quantity is four.

[0014] As a further improvement of the present invention: the electrode insertion part is an elliptical hollow area with a long axis perpendicular to the midline of the rat skull, a length of 11 mm, and a short axis length of 8 mm.

[0015] As a further improvement of the present invention: the first screw is M1.4, the slide rail is 5mm long, the telescopic rod is 5mm long, the nut is M1.0mm, the sleeve has an inner diameter of 1mm and a length of 2mm, and the second screw is M0.5.

[0016] Unlike existing technologies, the above technical solution:

[0017] 1. This invention innovatively designs the stimulation electrode as a four-channel parallel circuit with only one electrode interface, which greatly reduces the difficulty of electrode implantation and also provides convenience for subsequent stimulation of the corresponding brain regions of rats through electrodes.

[0018] 2. In the rat cranial multi-channel optimized electrode and its fixing base provided by the present invention, the stimulation electrode that passes through the electrode insertion hole in a vertical manner has its own length designed to match the depth of the target brain region. Therefore, it is not necessary to deliberately control the electrode insertion depth. When the electrode wire passes through the rat skull and is fully inserted into the brain tissue, the end electrode wire reaches the position of the target brain region, which greatly improves the success rate of the experiment.

[0019] 3. The retractable positioning electrode fixing base plate of the present invention is attached to the surface of the rat skull. The screw fixing part is positioned with the assistance of the screw limiting hole and then tightened to the rat skull. Since the screw fixing part and the screw limiting hole are strictly matched, it is easy to control the length of the part of the screw fixing part screwed into the skull and the part remaining on the skull. Compared with directly screwing the screw into the smooth skull surface and then sealing it with dental cement, the installation stability of the stimulation electrode will be higher after adding the overall fixing base plate.

[0020] 4. Each mouse in the experiment of this invention may have individual differences, and the size of the skull and the relative position of the corresponding brain region may not be completely consistent. If the electrode insertion point is fixed in advance, there may be problems with inaccurate stimulation of the brain region. Therefore, this invention innovatively expands the electrode insertion part into a hollowed-out oval area, which completely covers the target brain region of mice of different sizes. Before implanting the electrode, by calculating the length of the anterior and posterior fontanelles of the rat skull, the position of the corresponding brain region can be approximately calculated by proportion with a standard size intracranial atlas, which improves the accuracy of the stimulation site.

[0021] 5. This invention innovatively adopts a sliding rail and telescopic rod structure, which allows for sliding and rotation operations in any area of ​​the electrode insertion part, enabling the end of the telescopic rod to accurately correspond to the position of the target brain region stimulation point. At the same time, this invention innovatively adds a reinforceable sleeve to the end of the telescopic rod, so that the electrode wire passes through the sleeve before being implanted into the cranium, and is reinforced by a second screw on the periphery of the sleeve, preventing the electrode wire from moving again, thereby further improving the stability of the entire electrode stimulation structure. Attached Figure Description

[0022] Figure 1 A schematic diagram of a retractable positioning electrode fixing base;

[0023] Figure 2 This is a schematic diagram of the positioning and reinforcement part in a retractable positioning electrode fixing base;

[0024] Figure 3 A front view of a retractable positioning electrode fixing base connected to a four-channel parallel electrode;

[0025] Figure 4 A view showing the connection between a retractable positioning electrode fixing base and a four-channel parallel electrode;

[0026] Figure 5 A top view of a telescopic positioning electrode fixing base connected to a four-channel parallel electrode;

[0027] Figure 6 This is a schematic diagram of a four-channel parallel electrode for the rat brain;

[0028] Figure 7 A longitudinal cross-sectional view of a retractable positioning electrode fixing base fixed to the rat skull, with four-channel parallel electrodes implanted in the skull.

[0029] Figure 8 A side view of a retractable positioning electrode fixing base fixed to the rat skull, with four-channel parallel electrodes implanted in the cranium;

[0030] Figure 9 A top view of a retractable positioning electrode fixing base fixed to the rat skull, with four-channel parallel electrodes implanted in the skull;

[0031] Explanation of reference numerals in the attached drawings: Base body 10, Screw fixing part 11, Slide rail 12, Nut 13, Telescopic rod 14, Insulating connection bayonet 15, Electrode wire 16, Second screw 17, Sleeve 18, Electrode insertion part 19, Positioning and reinforcement part 20, First screw 21, Sensory cortex beard area 51, Medial anterior cerebral tract 52, Rat skull 53, Rat skull anterior fontanelle (bregma point) 71, Rat skull posterior fontanelle (lambda point) 72. Detailed Implementation

[0032] To explain in detail the technical content, structural features, objectives, and effects of the technical solution, the following description is provided in conjunction with specific embodiments and accompanying drawings.

[0033] Please see Figure 1-5This embodiment of a retractable positioning electrode fixing base includes a base body 10, screw fixing parts 11, electrode insertion parts 19, and positioning reinforcement parts 20. The base body 10 is elliptical, and the electrode insertion parts 19 are elliptical hollow parts located in the center of the base body 10. There are four screw fixing parts 11, arranged in a rectangle and located around the electrode insertion parts 19. The positioning reinforcement parts 20 are used to fix the electrode wire 16. The positioning reinforcement parts 20 include a slide rail 12, a first screw 21, a nut 13, a telescopic rod 14, a sleeve 18, and a second screw 17. The slide rail 12 is fixed to the screw. The part 11 is fixed and extends from the screw fixing part 11 to the electrode insertion part 19. The first screw 21 passes through from bottom to top and is slidably installed in the slide rail 12. The nut 13 is threadedly fixed to the top of the first screw 21. One end of the telescopic rod 14 is fixed to the first screw 21, and the other end of the telescopic rod 14 is fixed to the sleeve 18. The sleeve 18 extends vertically downward. The circumferential side of the sleeve 18 is threadedly connected to the second screw 17. The nut 13 is used to adjust and fix the relative position of the slide rail 12 and the telescopic rod 14. In use, the electrode wire 16 passes through the sleeve 18 and is reinforced by the second screw 17.

[0034] This invention innovatively employs a slide rail 12 and a telescopic rod 14 structure, allowing for sliding and rotation operations within any area of ​​the electrode insertion part 19. This enables the end of the telescopic rod 14 to accurately correspond to the position of the target brain region stimulation point. Simultaneously, this invention innovatively adds a reinforceable sleeve 18 to the end of the telescopic rod 14, allowing the electrode wire 16 to pass through the sleeve 18 before implantation into the cranium and be reinforced by a second screw 17 made of insulating material from the sleeve 18, preventing the electrode wire 16 from moving further and thus further improving the stability of the entire electrode stimulation structure.

[0035] In this embodiment, the base body 10 is an ellipse with a major axis of 13mm and a minor axis of 11mm. The screw fixing part 11 is typically 1.1-1.3mm in diameter, and there are four of them arranged in a rectangular shape. The electrode insertion part 19 is an elliptical hollow area with a major axis perpendicular to the midline of the rat skull, a length of 11mm, and a minor axis length of 8mm. The first screw 21 is typically M1.4mm in diameter, the slide rail 12 connected to it is typically 5mm in length, the telescopic rod 14 is 5mm in length, the nut 13 is typically M1.0mm in diameter, the sleeve 18 has an inner diameter of 1mm and a length of 2mm, and the second screw 17 is typically M0.5mm in diameter, but is not limited to this.

[0036] Please see Figure 6 The rat cranial four-channel parallel electrode provided in this embodiment of the invention includes:

[0037] The insulating connection bayonet 15 and the electrode wire 16 are connected. The insulating connection bayonet 15 can be connected to the integrated circuit board, which serves as the lower-level machine for electrical stimulation control, and the power supply through the electrode wire 16. In this embodiment, the total length of each branch of the electrode wire 16 is usually 2.0-2.5 cm. The length of the electrode wire 16 can be trimmed according to individual differences, so that the exposed part of the electrode wire 16 fits the skull and reaches the insertion hole of the target brain region. The vertical length of the two upper branches of the electrode wire 16 is usually 4.5-4.9 mm, and the vertical length of the two lower branches of the electrode wire 16 is usually 9.8-10.6 mm, but it is not limited to these.

[0038] This invention innovatively designs the stimulation electrode as a four-channel parallel circuit with only one electrode interface, which greatly reduces the difficulty of electrode implantation and also facilitates subsequent stimulation of the corresponding brain regions of rats via electrodes.

[0039] Please see Figure 7 The sensory cortex beard area 51 (S1BF) can generate a virtual sensation similar to natural beard stimulation through electrical stimulation. The medial forebrain tract 52 (MFB) can establish a reward mechanism through electrical stimulation to drive the rat to complete forward behavior. The skull 53 is located at the top of the rat's skull. The retractable positioning electrode fixing base of the present invention is fixed at the skull 53 of the rat.

[0040] Please see Figure 9 The anterior fontanelle point 71 and the posterior fontanelle point 72 of the rat skull are used to locate the mounting position of the base body 10.

[0041] Please see Figure 7-9 The vertical length of the electrode wire 16 of the four-channel parallel electrode is fixed. After passing through the sleeve 18 of the positioning and reinforcement part 20 of the retractable positioning electrode fixing base, it passes through the dura mater and is vertically inserted into the beard area 51 of the sensory cortex of the intracranial cavity to be stimulated and the medial forebrain bundle 52. The screw fixing part 11 passes through the rat skull 53 to fix the entire structure above the rat skull 53.

[0042] In this embodiment, the stimulation electrode inserted vertically into a specific brain region passes through the sleeve 18 of the positioning and reinforcement part 20 on the retractable positioning electrode fixing base. The main body 10 of the retractable positioning electrode fixing base with sleeve 18 is also firmly installed on the rat skull 53 by the screw fixing part 11, making it difficult to fall off. At the same time, since the vertical length of the four-channel parallel electrode is fixed and its position has been determined and reinforced by the positioning and reinforcement part 20, the conductive contact part can be strictly and accurately limited to contact the specific brain region required for rat electrical stimulation after passing through the rat skull. Therefore, the safety and reliability of the rat dura mater electrical stimulation experiment are effectively guaranteed, and the success rate of the experiment is greatly improved.

[0043] Meanwhile, due to the large operating range of the electrode insertion part, the location of brain regions of different sizes of rats can be obtained by calculating the length of the anterior and posterior fontanelles of the rat skull and then approximately by proportional calculation with a standard-sized intracranial atlas. This reduces the difficulty of localization surgery, minimizes surgical trauma, and improves the accuracy of stimulation points. Furthermore, since the screw fixing part 11 and the screw limiting hole of the base body 10 are strictly matched, it is easy to control the length of the part of the screw fixing part 11 screwed into the skull 53 and the part remaining on the skull 53. Therefore, it is possible to avoid unintentional damage to the rat's dura mater and blood sinuses while ensuring high stability of electrode installation.

[0044] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element. Additionally, in this document, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number.

[0045] Although the above embodiments have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the above descriptions are merely embodiments of the present invention and do not limit the scope of patent protection of the present invention. Any equivalent structural or procedural transformations made using the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A retractable positioning electrode fixing base, characterized in that: The device includes a base body, a screw fixing part, and a positioning and reinforcing part. The base body has an electrode insertion part, and the screw fixing part is threadedly connected to the base body and located around the electrode insertion part. The positioning and reinforcing part is used to fix the electrode and includes a slide rail, a first screw, a nut, a telescopic rod, a sleeve, and a second screw. The slide rail is fixedly connected to the screw fixing part and extends from the screw fixing part to the electrode insertion part. The first screw passes through from bottom to top and is slidably installed in the slide rail. The nut is threadedly fixed to the top of the first screw. One end of the telescopic rod is fixedly connected to the first screw, and the other end of the telescopic rod is fixedly connected to the sleeve. The second screw is threadedly connected to the periphery of the sleeve. The electrode insertion part is an elliptical hollow area with a major axis perpendicular to the midline of the rat skull, a length of 11 mm, and a minor axis length of 8 mm.

2. The retractable positioning electrode fixing base according to claim 1, characterized in that: The diameter of the screw fixing part is 1.1-1.3mm, and the quantity is four.

3. The retractable positioning electrode fixing base according to claim 1, characterized in that: The first screw is M1.4, the slide rail is 5mm long, the telescopic rod is 5mm long, the nut is M1.0, the sleeve has an inner diameter of 1mm and a length of 2mm, and the second screw is M0.

5.

4. A four-channel parallel electrode for rat cranial cavity, wherein the four-channel parallel electrode for rat cranial cavity is located on the retractable positioning electrode fixing base according to any one of claims 1-3, characterized in that: include: An insulated connection bayonet and an electrode wire are used. The electrode wire is inserted into the insulated connection bayonet, and the insulated connection bayonet is connected to the integrated circuit board, which serves as the lower-level machine for electrical stimulation control, and the power supply through the electrode wire.

5. The four-channel parallel electrode for rat brain as described in claim 4, characterized in that: Each branch of the electrode wire is 2.0-2.5cm long. The exposed part of the electrode wire is attached to the skull and reaches the insertion hole of the target brain region. The vertical length of the two upper branch electrode wires is 4.5-4.9mm, and the vertical length of the two lower branch electrode wires is 9.8-10.6mm.

6. The four-channel parallel electrode for rat brain as described in claim 4, characterized in that: The insulated connection bayonet housing is made of insulating material.

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