Injection device and control method

Abstract

This invention relates to the field of syringe technology, and discloses an injection device and control method. A linear vibration motor is mounted on a needle assembly. The movement direction of the mover of the linear vibration motor is the same as the direction of the excitation force generated by the motor, and the movement direction of the mover of the linear vibration motor is set to be non-perpendicular to the liquid discharge direction of the needle assembly. This allows the excitation force generated by the linear vibration motor to output a force parallel to the injection direction and a force perpendicular to the injection direction to the needle assembly. By adjusting the angle between the movement direction of the linear vibration motor mover and the liquid discharge direction and the vibration frequency of the vibration source, the excitation force drives the needle of the needle assembly to oscillate during injection, thereby intermittently forming a gap between the needle tip and the skin tissue. Simultaneously, the excitation force is transmitted to the skin surface through the needle assembly. The injection device of this invention solves the problem that existing vibrating syringes cannot simultaneously achieve analgesia and anti-clogging effects.

Description

Technical Field

[0001] This invention relates to the field of syringe technology, and more specifically, to an injection device and control method. Background Technology

[0002] Skin aspiration therapy (such as intradermal injection and subcutaneous injection) is widely used in the field of medical aesthetics for wrinkle treatment, scar repair, and transdermal drug delivery. However, this therapy always faces two technical problems: First, because the dermis is rich in nerve endings, the injection process can cause significant pain, affecting patient experience and treatment compliance; second, when injecting preparations containing microspheres, liposomes, or other particles, or high-viscosity drugs, they are prone to aggregation at the needle tip or tissue interface, leading to needle blockage and affecting the smoothness of injection and the accuracy of drug delivery.

[0003] To address these challenges, existing technologies have incorporated vibration into the injection process. The theoretical basis for this approach primarily includes two aspects: first, based on the neuroscience's "gating theory," peripheral vibration stimulation applied to the skin activates coarse sensory nerve fibers, thereby inhibiting the transmission of pain signals to the central nervous system, achieving pain reduction or analgesia; second, it is believed that mechanical vibration acting on the needle or medication helps to agitate fluids and particles, reducing their adhesion and aggregation tendencies, thus possessing potential anti-clogging capabilities. However, existing syringe vibration technologies generally suffer from a limited range of vibration modes. Whether integrated into the handle with a vibration motor or an external vibration accessory, they often only provide fixed frequencies, amplitudes, and waveforms, or only a very limited adjustment range. This single vibration mode makes it difficult to simultaneously and effectively meet the different vibration parameter requirements for "anti-clogging" and "anesthesia." For example, achieving optimal analgesia may require a specific frequency range and an appropriate amplitude acting on the skin surface; while effectively preventing clogging by high-viscosity or particulate formulations may require a different set of vibration parameters. Fixed, single vibration patterns cannot be dynamically adapted to different drug physicochemical properties, anatomical differences in injection sites, and individual patient sensitivity, resulting in unstable and unreliable vibration effects in both anti-blocking and anesthesia.

[0004] In summary, existing vibrating syringes struggle to achieve both analgesia and anti-blockage effects, a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide an injection device and control method that can solve the problems of injection pain and easy blockage in the prior art, and achieve the effects of pain reduction and blockage prevention through controllable linear vibration.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An injection device includes a main unit and a handle, the handle being used in conjunction with a syringe and a needle assembly; the main unit is equipped with a vibration source, and the vibration frequency of the vibration source is controlled by the main unit.

[0008] The vibration source is a linear vibration motor, which is mounted on the needle assembly. The movement direction of the moving part of the linear vibration motor is the same as the direction of the excitation force generated by the motor, and the movement direction of the moving part of the linear vibration motor is set to be non-perpendicular to the liquid discharge direction of the needle assembly. This allows the excitation force generated by the linear vibration motor to output a force parallel to the injection direction and a force perpendicular to the injection direction to the needle assembly.

[0009] In this process, by adjusting the angle between the movement direction of the linear vibration motor and the liquid discharge direction and the vibration frequency of the vibration source, the excitation force drives the needle of the needle assembly to swing during the injection, thereby intermittently forming a gap between the needle tip and the skin tissue. At the same time, the excitation force is transmitted to the skin surface through the needle assembly, providing mechanical stimulation to the skin surface.

[0010] Preferably, the needle assembly includes:

[0011] A mounting housing is provided, wherein a receiving cavity is provided within the mounting housing; a mounting surface for mounting the vibration source is provided on the mounting housing; the mounting surface is located on the side of the mounting housing away from the receiving cavity; a vacuum tube communicating with the receiving cavity is provided on the mounting housing. At least one needle is provided; at least one of the needles is disposed within the receiving cavity.

[0012] Preferably, a fixing part is provided in the receiving cavity; the fixing part divides the receiving cavity into an inner cavity and an outer cavity; an injection protrusion is provided on the fixing part; the injection protrusion is located in the outer cavity; a contact surface is provided at the end of the injection protrusion away from the fixing part; the needle passes through the contact surface.

[0013] Preferably, the needle assembly includes a needle seat; the needle seat is disposed within the inner cavity; the needle is disposed within the needle seat; and the needle seat abuts against the side wall of the inner cavity.

[0014] Preferably, the needle holder is provided with an installation channel; the needle passes through the receiving cavity through the installation channel; the installation channel includes a first installation channel and a second installation channel; the first installation channel communicates with the second installation channel; the first installation channel is located on the side of the second installation channel closer to the outer cavity; along the direction of the outer cavity away from the inner cavity, the cross-sectional area of ​​the first installation channel is larger than the cross-sectional area of ​​the second installation channel.

[0015] Preferably, the needle holder includes a first flange and a second flange connected to each other; the first flange is located on the side of the second flange closer to the outer cavity; the first flange is slidably connected to the inner wall surface of the inner cavity; a guide groove is provided on the second flange; the guide groove extends along the moving direction of the needle; and a guide protrusion that cooperates with the guide groove is provided on the inner wall surface of the inner cavity.

[0016] Preferably, the needle assembly further includes an infusion tubing and a connector; the infusion tubing is connected to the syringe; the connector is sleeved on the infusion tubing; and the connector is engaged with the mounting housing.

[0017] Preferably, the outer surface of the needle assembly is provided with a mounting protrusion; the mounting protrusion protrudes from the mounting surface and forms a fixing groove for accommodating the vibration source; the mounting protrusion is provided with a connecting groove communicating with the fixing groove; the connecting groove passes through the mounting protrusion and communicates with the fixing groove.

[0018] A control method applicable to the above-mentioned injection device, the control method comprising:

[0019] Set the injection parameters for the injection device;

[0020] The injection device is activated, generating negative pressure inside the needle assembly;

[0021] When the negative pressure reaches the preset value, the vibration source is activated, and the push rod pushes the syringe to inject.

[0022] After injection, the push rod retracts.

[0023] The vibration source has stopped working.

[0024] Preferably, the method for starting the vibration source includes:

[0025] Set the preset vibration frequency of the vibration source and start the vibration source;

[0026] The real-time vibration frequency of the vibration source is detected and compared with the preset vibration frequency.

[0027] When the real-time vibration frequency does not reach the preset vibration frequency, the vibration frequency of the vibration source is adjusted using the vibration source controller.

[0028] By using the injection device provided by this invention, specific technical effects are achieved by adjusting the angle between the movement direction of the linear vibration motor and the liquid discharge direction, as well as the vibration frequency of the vibration source, through the main unit: On the one hand, the excitation force drives the needle of the needle assembly to oscillate during injection. This oscillation allows the needle tip to intermittently form tiny gaps during contact with skin tissue, which is beneficial for the diffusion and absorption of the drug solution and prevents tissue debris from clogging the needle tip. On the other hand, the excitation force is also transmitted to the skin surface through the needle assembly, producing continuous mechanical stimulation to the skin surface. According to the "gating theory" of neuroscience, this vibration stimulation can activate the coarse sensory nerve fibers of the skin, thereby inhibiting the transmission of pain signals to the central nervous system, resulting in a significant analgesic or anesthetic effect. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0030] Figure 1 A schematic diagram of the injection device provided by the present invention from one perspective;

[0031] Figure 2 A schematic diagram of the injection device provided by the present invention from another perspective;

[0032] Figure 3 This is a side view of the injection device provided by the present invention;

[0033] Figure 4 for Figure 3 A cross-sectional view along the AA direction;

[0034] Figure 5 This is a schematic diagram of the needle assembly of the injection device provided by the present invention.

[0035] Figure 6 This is a schematic diagram of the structure of the vibration source of the injection device provided by the present invention;

[0036] Figure 7 A flowchart of an embodiment of the control method provided by the present invention;

[0037] Figure 8 A flowchart of another embodiment of the control method provided by the present invention.

[0038] The above figures include the following reference numerals:

[0039] 2. Handle; 21. Mounting part; 22. Mounting slot; 3. Syringe; 322. Vacuum tubing; 4. Needle assembly; 14. Vibration source; 15. Push rod; 42. Mounting shell; 43. Needle; 421. Receiving cavity; 422. Mounting surface; 423. Mounting protrusion; 425. Connecting groove; 426. Fixing part; 427. Inner cavity; 428. Outer cavity; 429. Injection protrusion; 430. Contact surface; 431. Needle seat; 434. First mounting channel; 435. Second mounting channel; 432. First flange; 433. Second flange; 44. Connecting seat; 45. Infusion tubing. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The core of this invention is to provide an injection device and its control method, which aims to solve the problems of injection pain and easy blockage in the prior art. Through controllable linear vibration, it can simultaneously achieve the effects of pain reduction and blockage prevention.

[0042] Please refer to Figures 1 to 6 In one specific embodiment, the injection device provided by the present invention includes a main unit (not shown in the figure) and a handle 2. The handle 2 is used in conjunction with a syringe 3 and a needle assembly 4. A vibration source 14 is provided on the main unit, and the vibration frequency of the vibration source 14 is controlled by the main unit.

[0043] The key improvement in this embodiment is that the vibration source 14 is a linear vibration motor, and this linear vibration motor is directly mounted on the needle assembly 4. Combined with... Figure 6 As shown, the movement direction of the mover of the linear vibration motor is the same as the direction of the excitation force generated by the motor, which is a basic characteristic of the linear vibration motor. More importantly, the movement direction of the mover of the linear vibration motor is set to be non-perpendicular to the liquid discharge direction of the needle assembly 4. The direct result of this setting is that the excitation force generated by the linear vibration motor can output two components to the needle assembly 4: one is a force parallel to the injection direction, and the other is a force perpendicular to the injection direction.

[0044] With this setup, the operator can adjust the angle (i.e., installation angle) between the direction of motion of the linear vibration motor and the direction of liquid dispensing, as well as the vibration frequency of the vibration source 14, via the main unit to achieve specific technical effects: On the one hand, the excitation force drives the needle 43 of the needle assembly 4 to oscillate during injection. This oscillation allows the needle tip to intermittently form tiny gaps during contact with skin tissue, which is beneficial for the diffusion and absorption of the medication and prevents tissue debris from clogging the needle tip. On the other hand, the excitation force is also transmitted to the skin surface through the needle assembly 4, producing continuous mechanical stimulation to the skin surface. According to the "gating theory" of neuroscience, this vibration stimulation can activate the coarse sensory nerve fibers of the skin, thereby inhibiting the transmission of pain signals to the central nervous system, resulting in a significant pain reduction or anesthetic effect.

[0045] Therefore, the solution in this embodiment achieves both anti-clogging and pain reduction functions simultaneously through a linear vibration motor, solving the technical problem that a single vibration mode in the prior art cannot simultaneously address both issues. By adjusting the vibration frequency and the motor mounting angle, it can flexibly adapt to different viscosities of medications and different patients' pain sensitivities, greatly improving the applicability of the injection device and the user experience.

[0046] Furthermore, in order to firmly integrate the vibration source 14 onto the needle assembly 4 and achieve the negative pressure adsorption function, such as... Figures 1-4 As shown, the needle assembly 4 includes a mounting housing 42 and at least one needle 43. The mounting housing 42 has a receiving cavity 421, and the side of the mounting housing 42 away from the receiving cavity 421 is a mounting surface 422, which is in close contact with the skin during injection. Specifically, the mounting housing 42 is provided with a vacuum line 322 communicating with the receiving cavity 421. At least one needle 43 is disposed within the receiving cavity 421 and extends from the mounting housing 42. This structure integrates the needle 43 into a separate mounting housing 42, forming a modular unit that can be assembled independently. When the vibration source 14 is mounted on the mounting housing 42, the excitation force it generates can be directly and efficiently transmitted to the mounting housing 42 and the internal needle 43, ensuring that the vibration energy is accurately applied to the needle tip and the skin. At the same time, by evacuating the receiving cavity 421 through the vacuum tube 322, a negative pressure can be formed between the mounting surface 422 and the skin, drawing the target skin tissue into the receiving cavity 421, making the contact surface between the skin and the needle 43 fit more closely, facilitating needle insertion, and helping to form a more precise injection wheal.

[0047] To ensure the stability of the needle 43 within the mounting housing 42 and the accuracy of the injection, such as Figure 4As shown, a fixing part 426 is provided within the receiving cavity 421. The fixing part 426 divides the receiving cavity 421 into an inner cavity 427 and an outer cavity 428. An injection protrusion 429 is provided on the fixing part 426, and the injection protrusion 429 is located within the outer cavity 428. A contact surface 430 is provided at the end of the injection protrusion 429 away from the fixing part 426, through which the needle 43 passes. This design allows the needle 43 to be effectively supported and guided during injection. The injection protrusion 429 and its end contact surface 430 provide a stable support platform when the needle 43 pierces the skin, preventing the needle 43 from excessively bending or deviating during vibration and insertion, thus ensuring the accuracy of the injection depth.

[0048] To further stabilize needle 43 and enable it to respond better to vibration, such as Figure 4 and Figure 5 As shown, the needle assembly 4 also includes a needle holder 431. The needle holder 431 is disposed within the inner cavity 427, and the needle 43 is disposed within the needle holder 431. The needle holder 431 abuts against the side wall of the inner cavity 427. As the "base" of the needle 43, the needle holder 431 not only provides a longer fixed length for the needle 43, increasing its stability, but also, due to the tight abutment between the needle holder 431 and the side wall of the inner cavity 427, can evenly transmit the resistance (such as insertion resistance) experienced by the needle 43 during injection to the mounting shell 42, and can also more evenly transmit the vibration on the mounting shell 42 to the needle 43.

[0049] To facilitate the installation of needle 43 and the smooth flow of the medication, such as Figure 5 As shown, the needle holder 431 has an installation channel, through which the needle 43 passes through the receiving cavity 421. Specifically, the installation channel includes a first installation channel 434 and a second installation channel 435, which are connected. The first installation channel 434 is located on the side of the second installation channel 435 closer to the outer cavity 428. Along the direction of the outer cavity 428 away from the inner cavity 427 (i.e., towards the needle tip), the cross-sectional area of ​​the first installation channel 434 is larger than that of the second installation channel 435. The function of the first installation channel 434 is that when the needle 43 vibrates slightly due to vibration, the wider inner wall can provide some clearance for the needle 43, avoiding rigid collision or excessive friction between the root of the needle 43 and the needle holder 431, thereby protecting the needle 43 and maintaining smooth vibration. The second installation channel 435 is filled with glue to fix the needle 43. The bottom of the second mounting channel 435 forms a flared or conical structure to facilitate fixing the needle 43 before filling with glue.

[0050] To ensure that the needle 43 can move stably in a predetermined direction during vibration, such as Figure 4 and Figure 5 As shown, the needle holder 431 includes a first flange 432 and a second flange 433 connected to each other. The first flange 432 is located on the side of the second flange 433 closer to the outer cavity 428. The first flange 432 is slidably connected to the inner wall surface of the inner cavity 427. This sliding fit can guide the needle holder 431 and the needle 43 on it to move axially, while also allowing a slight radial oscillation. A guide groove (not shown in the figure) is provided on the second flange 433, which extends along the moving direction of the needle. Correspondingly, a guide protrusion (not shown in the figure) is provided on the inner wall surface of the inner cavity 427 to cooperate with the guide groove. Through the cooperation of the guide groove and the guide protrusion, the rotational degree of freedom of the needle holder 431 can be precisely restricted, ensuring that the needle 43 will not undergo unexpected torsion during vibration, thereby ensuring that its oscillation direction is consistent with the preset direction, making the vibration effect more precise and controllable.

[0051] To achieve flexible transfer of the medication from syringe 3 to needle assembly 4 and avoid rigid connections hindering vibration, such as... Figure 1 , Figure 2 and Figure 4 As shown, the needle assembly 4 also includes an infusion tube 45 and a connecting seat 44. One end of the infusion tube 45 is connected to the syringe 3, and the other end communicates with the interior of the needle assembly 4. The connecting seat 44 is sleeved on the infusion tube 45 and snaps into the mounting housing 42. Using the infusion tube 45 for connection effectively isolates the syringe 3 from the needle assembly 4, preventing vibrations of the needle assembly 4 from being directly transmitted to the syringe 3 and the handle 2, thus ensuring the stability of the injection process. The snap-fit ​​connection between the connecting seat 44 and the mounting housing 42 provides a quick and reliable connection structure, facilitating the replacement and installation of the needle assembly 4.

[0052] In order to securely integrate the vibration source 14 onto the needle assembly 4, such as Figures 1-4 As shown, a mounting protrusion 423 is provided on the outer surface of the needle assembly 4. The mounting protrusion 423 protrudes from the mounting surface 422 and forms a fixing groove for accommodating the vibration source 14. A connecting groove 425 communicating with the fixing groove is also provided on the mounting protrusion 423, penetrating the mounting protrusion 423 and communicating with the fixing groove. The fixing groove formed by the mounting protrusion 423 provides precise physical positioning and a stable mounting space for the vibration source 14, ensuring that the vibration source 14 can fit tightly against the needle assembly 4, achieving efficient energy transfer. The design of the connecting groove 425 provides a routing channel for the wires of the vibration source 14, resulting in a neat wiring layout and preventing the wires from being pulled or interfered with during operation.

[0053] In some embodiments, the handle 2 includes a mounting portion 21, on which a mounting groove 22 is provided; the syringe 3 is engaged in the mounting groove 22; the needle assembly 4 is located outside the mounting groove 22; and the needle assembly 4 is connected to the syringe.

[0054] By providing a mounting part 21 with a mounting groove 22 on the handle 2, the standard syringe 3 can be easily and securely locked in place. This locking structure simplifies the loading and replacement process of the syringe 3, improves operational efficiency, and ensures the positional stability of the syringe 3 on the handle 2, providing a foundation for subsequent precise injection. The needle assembly 4 is located outside the mounting groove 22, facilitating its independent installation, replacement, and integration with the vibration source 14.

[0055] Furthermore, the present invention also provides a control method applicable to any of the above-described injection devices. In one specific embodiment, such as... Figure 7 As shown, the control method includes the following steps:

[0056] S1: Set the injection parameters of the injection device, such as injection volume and injection speed;

[0057] S2: Start the injection device. First, negative pressure is generated inside the needle assembly 4 through the vacuum line 322. The purpose of this step is to draw the target skin tissue into the needle assembly 4 through negative pressure, so that the contact surface between the skin and the needle 43 is more closely aligned, making it easier for the needle to penetrate and helping to form a more precise injection wheal;

[0058] S3: When the negative pressure reaches the preset value, the vibration source 14 is activated, and simultaneously the push rod 15 pushes the piston of the syringe 3 to begin injecting the medication. During the injection process, the vibration source 14 continues to operate, playing a role in pain reduction and preventing blockage;

[0059] S4: After the preset drug solution is injected, the push rod 15 retracts to stop the injection;

[0060] S5: Finally, vibration source 14 stops working, completing the entire injection cycle. This control method organically combines negative pressure suction, vibration stimulation, and injection action to form a standardized, automatically executed injection process, greatly improving the convenience of operation and the repeatability of injection effects.

[0061] To ensure that vibration source 14 always operates at its optimal state to achieve stable pain reduction and anti-blockage effects, such as Figure 8 As shown, step S3 of activating the vibration source 14 may further include:

[0062] S31: Set the preset vibration frequency of vibration source 14 (for example, set it to 50Hz or 100Hz according to the viscosity of the drug solution or the patient's needs), and then start vibration source 14;

[0063] S32: The real-time vibration frequency of the vibration source 14 is detected by the sensor and compared with the preset vibration frequency.

[0064] S33: When the real-time vibration frequency is detected to be below the preset vibration frequency, the vibration source controller automatically adjusts the input current or voltage of the vibration source 14 to accurately adjust the vibration frequency back to the preset value.

[0065] The above settings ensure that the vibration source 14 can still stably output vibration at a preset frequency even when the load changes (such as changes in needle resistance or drug viscosity), thus guaranteeing the continuity and reliability of the pain relief and anti-blockage effects.

[0066] In summary, the injection device and control method provided by this invention, by directly mounting a linear vibration motor onto the needle assembly and carefully designing its vibration direction, allows a single vibration source to simultaneously generate the needle oscillation required for anti-clogging and the mechanical stimulation of the skin surface required for pain reduction. Combined with the ingenious internal structural design of the needle assembly, needle stability and effective vibration transmission are ensured, and negative pressure adsorption is achieved through a vacuum tubing. Finally, a complete closed-loop control method automates the injection process and precisely controls the vibration frequency. This technical solution effectively addresses the two major pain points of existing injection techniques: pain and clogging, and has high practical value and clinical significance.

[0067] In addition, it should be noted that the orientation or positional relationship indicated by "horizontal", "vertical", etc. in this application is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the purpose of simplifying the description and making it easier to understand, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0068] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. Any combination of all embodiments provided by this invention is within the scope of protection of this invention and will not be elaborated upon here.

[0069] The injection device and control method provided by this invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. An injection device, comprising a main unit and a handle (2), the handle (2) being used in conjunction with a syringe (3) and a needle assembly (4); the main unit is provided with a vibration source (14), the vibration frequency of the vibration source (14) being controlled by the main unit, characterized in that: The vibration source (14) is a linear vibration motor, which is mounted on the needle assembly (4). The movement direction of the moving part of the linear vibration motor is the same as the direction of the excitation force generated by the motor. The movement direction of the moving part of the linear vibration motor is set to be non-perpendicular to the liquid discharge direction of the needle assembly (4). This causes the excitation force generated by the linear vibration motor to output a force parallel to the injection direction and a force perpendicular to the injection direction to the needle assembly (4). In this process, by adjusting the angle between the direction of motion of the linear vibration motor mover and the direction of liquid discharge and the vibration frequency of the vibration source (14), the excitation force drives the needle (43) of the needle assembly (4) to swing during the injection, thereby intermittently forming a gap between the needle tip and the skin tissue. At the same time, the excitation force is transmitted to the skin surface through the needle assembly (4) to mechanically stimulate the skin surface.

2. The injection device according to claim 1, characterized in that, The needle assembly (4) includes: Mounting housing (42), wherein a receiving cavity (421) is provided inside the mounting housing (42); a mounting surface (422) for mounting the vibration source (14) is provided on the mounting housing (42); the mounting surface (422) is located on the side of the mounting housing (42) away from the receiving cavity (421); a vacuum pipe (322) communicating with the receiving cavity (421) is provided on the mounting housing (42). At least one needle (43); at least one of the needles (43) is disposed within the receiving cavity (421).

3. The injection device according to claim 2, characterized in that, The receiving cavity (421) is provided with a fixing part (426); the fixing part (426) divides the receiving cavity (421) into an inner cavity (427) and an outer cavity (428); the fixing part (426) is provided with an injection protrusion (429); the injection protrusion (429) is located in the outer cavity (428); the end of the injection protrusion (429) away from the fixing part (426) is provided with a contact surface (430); the needle (43) passes through the contact surface (430).

4. The injection device according to claim 3, characterized in that, The needle assembly (4) includes a needle seat (431); the needle seat (431) is disposed within the inner cavity (427); the needle (43) is disposed within the needle seat (431); the needle seat (431) abuts against the side wall of the inner cavity (427).

5. The injection device according to claim 4, characterized in that, The needle holder (431) is provided with an installation channel; the needle (43) passes through the receiving cavity (421) through the installation channel; the installation channel includes a first installation channel (434) and a second installation channel (435); the first installation channel (434) communicates with the second installation channel (435); the first installation channel (434) is located on the side of the second installation channel (435) closer to the outer cavity (428); along the direction of the outer cavity (428) away from the inner cavity (427), the cross-sectional area of ​​the first installation channel (434) is larger than the cross-sectional area of ​​the second installation channel (435).

6. The injection device according to claim 4, characterized in that, The needle holder (431) includes a first flange (432) and a second flange (433) connected to each other; the first flange (432) is located on the side of the second flange (433) near the outer cavity (428); the first flange (432) is slidably connected to the inner wall surface of the inner cavity (427); a guide groove is provided on the second flange (433); the guide groove extends along the moving direction of the needle; a guide protrusion that cooperates with the guide groove is provided on the inner wall surface of the inner cavity (427).

7. The injection device according to claim 2, characterized in that, The needle assembly (4) also includes an infusion tube (45) and a connector (44); the infusion tube (45) is connected to the syringe (3); the connector (44) is sleeved on the infusion tube (45); the connector (44) is engaged with the mounting shell (42).

8. The injection device according to claim 2, characterized in that, The outer surface of the needle assembly (4) is provided with a mounting protrusion (423); the mounting protrusion (423) protrudes from the mounting surface (422) and forms a fixing groove for accommodating the vibration source (14); the mounting protrusion (423) is provided with a connecting groove (425) communicating with the fixing groove; the connecting groove (425) passes through the mounting protrusion (423) and communicates with the fixing groove.

9. A control method applicable to the injection device according to any one of claims 1 to 8, characterized in that, The control method includes: Set the injection parameters for the injection device; Start the injection device to generate negative pressure inside the needle assembly (4); When the negative pressure reaches the preset value, the vibration source (14) is activated, and the push rod (15) pushes the syringe (3) to inject; After injection is completed, the push rod (15) retracts; The vibration source (14) stops working.

10. The control method according to claim 9, characterized in that, Methods for starting the vibration source (14) include: Set the preset vibration frequency of the vibration source (14) and start the vibration source (14). The real-time vibration frequency of the vibration source is detected and compared with the preset vibration frequency. When the real-time vibration frequency does not reach the preset vibration frequency, the vibration frequency of the vibration source (14) is adjusted by the vibration source controller.

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