An oncotherapy device

Abstract

This invention belongs to the field of medical device technology, specifically disclosing an oncology drug delivery device, including a protective shell and a pressure cylinder fixed to one side of a mounting base and arranged from top to bottom. A second piston and a first piston are coaxially and slidably mounted inside the pressure cylinder from top to bottom. A piston shaft is coaxially fixed to the upper side of the first piston, and a piston sleeve is coaxially fixed to the upper side of the second piston. The piston shaft slides upwards through the second piston and the piston sleeve. An integrated pressure-flush-seal switching mechanism is provided inside the protective shell, and a liquid control module is connected to the pressure cylinder. This invention uses a motor-driven crankshaft assembly and a knob to switch the piston's linkage mode. Through the relative reciprocating motion of the two pistons in conjunction with a one-way valve, continuous pressurized drug delivery is achieved. Subsequently, locking a single piston allows only the other piston to move, achieving unidirectional intermittent pulse flushing. During the liquid-pressurizing stroke, the needle is withdrawn to compensate for the volume with positive pressure, thus integrating continuous drug delivery and pulse flushing, avoiding backflow during needle withdrawal, and facilitating operation.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically referring to an oncology drug delivery device. Background Technology

[0002] In the field of clinical oncology treatment, implantable venous access ports are commonly used to establish long-term vascular access for long-term intravenous chemotherapy, targeted drug delivery, and nutritional support. During routine drug administration, external pressure devices such as infusion pumps are typically required to maintain a continuous and stable infusion of medication. After each administration session, to maintain catheter patency and prevent drug residue crystallization or blood clotting, the access port and catheter must be flushed and sealed according to standard procedures. However, existing oncology drug administration and flushing / sealing devices and procedures still have shortcomings in practical clinical application: During drug administration, continuous pressurization is typically required to maintain a stable drug concentration. During flushing, to effectively remove drug residues or fibrin sheaths adhering to the catheter wall, a "pulsating" flushing technique (i.e., intermittent positive pressure injection) must be used to artificially create fluid turbulence within the catheter. Current pressurized drug delivery devices (such as electronic infusion pumps) can only provide continuous pressure and cannot directly accommodate the fluid output requirements of pulsed flushing. Therefore, a separate procedure is often required clinically: continuous drug administration is first performed using an infusion pump, then the pump is removed, and finally, healthcare professionals manually perform pulsed flushing using a syringe. This separate procedure increases the workload of healthcare professionals, and the peak pressure and frequency of manual pulsed flushing are highly dependent on the operator's experience, making standardization difficult.

[0003] During the sealing phase, heparinized saline or other sealing solutions are typically injected into the port cavity and venous catheter to create an isobaric or positive pressure environment for anticoagulation. However, the septum at the top of existing ports is usually made of high-molecular-weight elastic silicone. When the sealing procedure is completed and the atraumatic needle is withdrawn, the friction between the needle surface and the elastic septum causes it to bulge outwards. This results in a momentary increase in the volume of the port cavity, creating a transient negative pressure within the closed catheter system. This pressure draws blood from the distal vein back into the catheter tip, causing backflow. Although the elastic septum rebounds and provides some positive pressure compensation after needle withdrawal, the pressure gradient generated by the septum rebound is often insufficient to push all the aspirated blood back into the vessel due to the viscosity and diffusivity of blood. Residual blood remaining at the catheter tip is highly susceptible to coagulation, potentially leading to thrombotic blockage and increasing clinical risks. Summary of the Invention

[0004] To address the above issues, this invention provides an oncology drug delivery device. A crankshaft assembly is driven by a motor, and a knob switches the piston's linkage mode. Through the relative reciprocating motion of the two pistons in conjunction with a one-way valve, continuous pressurized drug delivery is achieved. Subsequently, locking one piston allows only the other piston to move, enabling unidirectional intermittent pulse flushing. During the liquid compression stroke, the needle is withdrawn to compensate for the volume with positive pressure, thus integrating continuous drug delivery with pulse flushing, avoiding backflow during needle withdrawal, and providing convenient operation.

[0005] The technical solution adopted by the present invention is as follows: The present invention proposes an oncology drug delivery device, including a fixed mounting base, a protective shell and a pressure cylinder fixed to one side of the mounting base and arranged from top to bottom. A second piston and a first piston are coaxially and slidably disposed inside the pressure cylinder from top to bottom. A piston shaft is coaxially fixed on the upper side of the first piston, and a piston sleeve is coaxially fixed on the upper side of the second piston. The piston shaft slides upwards and slidably through the second piston and the piston sleeve. A liquid supply pipe is laterally connected to the pressure cylinder at the position between the second piston and the first piston, and a liquid outlet pipe is connected to the bottom of the pressure cylinder.

[0006] Furthermore, the protective shell is equipped with an integrated pressure-sealing switching mechanism, and the pressure cylinder is connected to a liquid control module.

[0007] Furthermore, the integrated pressurized stamping and sealing switching mechanism includes two crankshaft assemblies symmetrically arranged within the protective housing, a switchable connection assembly connected to the piston sleeve and piston shaft, and a synchronous drive assembly for driving the crankshaft assemblies and the switchable connection assembly to move synchronously and symmetrically.

[0008] Furthermore, each crankshaft assembly includes a main shaft that is rotatably connected to the protective housing at both ends, and two cranks mounted on the main shaft, with the two cranks on the same main shaft arranged 180 degrees opposite each other.

[0009] Furthermore, the switchable connection assembly includes a first crossbar symmetrically arranged on both sides of the upper part of the piston sleeve, a sliding sleeve that slides and is sleeved on the upper part of the piston shaft, and a second crossbar symmetrically arranged on both sides of the sliding sleeve, with the second crossbar located above the first crossbar; in the two crankshaft assemblies, two cranks that are in the same position and symmetrically distributed are respectively rotatably connected to the two first crossbars through rotatably arranged connecting rods, and the other two symmetrically distributed cranks are respectively rotatably connected to the two second crossbars through rotatably arranged connecting rods.

[0010] Furthermore, the switchable connection assembly also includes a fixed sleeve fixed to the protective shell, the piston shaft extending upward through the fixed sleeve, a first knob threaded through the sliding sleeve that can abut against the piston shaft, and a second knob threaded through the fixed sleeve that can abut against the piston shaft.

[0011] Furthermore, the synchronous drive assembly includes two gears coaxially fixed on the two main shafts and meshing with each other, and a servo motor fixed on the protective shell and used to drive one of the main shafts to rotate, so as to drive the two main shafts to rotate symmetrically in opposite directions.

[0012] Furthermore, the liquid control module includes a first one-way valve, a second one-way valve, and a third one-way valve; the first one-way valve is located at the connection between the liquid supply pipe and the pressure cylinder, and its one-way flow direction is from the liquid supply pipe to the pressure cylinder; the second one-way valve is disposed through the first piston, and its one-way flow direction is from the second piston to the liquid outlet pipe; the third one-way valve is located at the connection between the liquid outlet pipe and the pressure cylinder, and its one-way flow direction is from the pressure cylinder to the liquid outlet pipe.

[0013] Furthermore, the control program of the servo motor is set so that each time the servo motor stops, it rotates an integer number of revolutions, so that the first piston and the second piston are in the initial limit symmetrical position each time it stops.

[0014] Furthermore, the end of the liquid outlet tube is connected to a puncture needle, and the protective shell has an operating port at the position directly opposite the moving range of the first knob.

[0015] The beneficial effects achieved by the present invention using the above structure are as follows: (1) The present invention drives two crankshaft assemblies to rotate symmetrically in opposite directions through a synchronous drive assembly. When the first knob is tightened and the second knob is loosened, the switchable connection assembly transmits power to the first piston and the second piston simultaneously, causing them to reciprocate relative to each other in the pressurizing cylinder. With the unidirectional conduction logic of the first one-way valve, the second one-way valve and the third one-way valve in the liquid control module, the two pistons can stably output the same amount of liquid to the outlet pipe in both the half-cycle when they are far apart and the half-cycle when they are close to each other. This transforms the eccentric motion of the crankshaft into uninterrupted fluid output, thus realizing continuous pressurized drug delivery.

[0016] (2) In view of the pain points of the existing technology, manual pulse flushing is difficult to standardize and blood backflow is easy to occur when the needle is removed. In the flushing stage, the present invention only needs to change the state of the knob to fix the first piston and only the second piston will reciprocate. With the cooperation of the one-way valve, the second piston only draws liquid and does not inject liquid when it moves away, and only pushes out the liquid instantly when it moves closer, which automatically forms a standardized intermittent pulse fluid. Strong fluid turbulence is generated in the catheter, which effectively removes drug residues. At the same time, in the final sealing and needle removal stage, the medical staff removes the puncture needle during the downward stroke of the second piston. At this time, the device actively injects positive pressure heparin saline into the infusion port. This positive pressure fluid perfectly compensates for the instantaneous increase in cavity volume due to the outward deformation of the puncture diaphragm, avoids blood backflow into the end of the catheter, and greatly reduces the clinical risk of thrombotic catheter blockage.

[0017] (3) The present invention ingeniously integrates the pressure-flushing switching mechanism into the protective shell, which completely breaks the traditional clinical operation barrier that requires first using an electronic infusion pump to administer the drug and then removing the equipment to switch to a manual syringe for flushing. Medical staff only need to simply turn the first knob and the second knob to instantly switch between the continuous pressure administration mode and the pulse flushing mode without disconnecting the tubing or replacing the equipment. This design not only realizes the mechanical standardization of flushing pressure and frequency, but also greatly simplifies the clinical operation process and has extremely high practical promotion value. Attached Figure Description

[0018] Figure 1 This is a front view of an oncology drug delivery device proposed in this invention.

[0019] Figure 2 This is a three-dimensional structural diagram of an oncology drug delivery device proposed in this invention.

[0020] Figure 3 This is a schematic diagram of the internal structure of the protective shell of an oncology drug delivery device proposed in this invention.

[0021] Figure 4 This is a schematic diagram of the internal structure of the pressurized cylinder of an oncology drug delivery device proposed in this invention.

[0022] Figure 5 This is a schematic diagram showing the positional relationship between the piston shaft and the sliding sleeve of an oncology drug delivery device proposed in this invention.

[0023] Figure 6 This is an exploded structural diagram showing the positional relationship between the main shaft and gears of an oncology drug delivery device proposed in this invention.

[0024] Figure 7 for Figure 3 Enlarged view of section A in the middle.

[0025] Figure 8 This is a diagram illustrating the working trajectory of an oncology drug delivery device proposed in this invention.

[0026] The components include: 1. Mounting base; 2. Protective shell; 21. Operating port; 3. Pressurizing cylinder; 31. Discharge pipe; 32. Puncture needle; 33. Supply pipe; 4. First piston; 41. Piston shaft; 5. Second piston; 51. Piston sleeve; 6. Pressurizing and sealing integrated switching mechanism; 61. Crankshaft assembly; 611. Main shaft; 612. Crank crank; 62. Switchable connection assembly; 621. First crossbar; 622. Sliding sleeve; 623. Second crossbar; 624. Connecting rod; 625. First knob; 626. Fixed sleeve; 627. Second knob; 63. Synchronous drive assembly; 631. Servo motor; 632. Gear; 7. Liquid control module; 71. First check valve; 72. Second check valve; 73. Third check valve.

[0027] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0030] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 As shown, the present invention proposes an oncology drug delivery device, including a mounting base 1 as a basic support. The mounting base 1 can be raised and lowered and fixed next to an infusion stand or hospital bed to provide a stable working reference. A protective shell 2 and a pressure cylinder 3 are fixedly arranged from top to bottom on one side of the mounting base 1. The protective shell 2 is used to seal and protect the internal precision transmission components to avoid external contamination and interference. The pressure cylinder 3 serves as a cavity for receiving and pumping drug solution or flushing fluid.

[0031] To achieve complex fluid pumping logic, a second piston 5 and a first piston 4 are coaxially and slidably mounted inside the pressurizing cylinder 3 from top to bottom. A piston shaft 41 extending upward is coaxially fixed on the upper side of the first piston 4, and a piston sleeve 51 extending upward is coaxially fixed on the upper side of the second piston 5. The piston shaft 41 slides upward through the second piston 5 and the piston sleeve 51. This nested sliding design allows the first piston 4 and the second piston 5 to maintain coaxiality and achieve relatively independent or linked displacement according to transmission requirements.

[0032] In terms of fluid pipeline layout, the pressure cylinder 3 is laterally connected to a liquid supply pipe 33 at the position between the second piston 5 and the first piston 4, for introducing liquid from an external drug bag or heparin saline bag; the bottom of the pressure cylinder 3 is connected to an outlet pipe 31, and the end of the outlet pipe 31 is connected to a puncture needle 32 for inserting into the infusion port in the patient's body.

[0033] The protective shell 2 is equipped with a core pressure-sealing integrated switching mechanism 6. This mechanism can change the movement mode of the second piston 5 and the first piston 4 according to clinical needs. The pressure-sealing integrated switching mechanism 6 includes two crankshaft assemblies 61 symmetrically arranged in the protective shell 2, a switchable connection assembly 62 connected to the piston sleeve 51 and the piston shaft 41, and a synchronous drive assembly 63 for driving the above-mentioned assemblies to move synchronously and symmetrically.

[0034] Specifically, each crankshaft assembly 61 includes a main shaft 611 rotatably connected to the protective housing 2 at both ends, and two cranks 612 disposed on the main shaft 611. The two cranks 612 on the same main shaft 611 are arranged 180 degrees opposite to each other, so that when the main shaft 611 rotates, the rotational motion can be converted into two sets of reciprocating motions with a phase difference of 180 degrees.

[0035] The synchronous drive assembly 63 includes a servo motor 631 fixed on the protective shell 2, and two gears 632 coaxially fixed on the two main shafts 611 and meshing with each other. When the servo motor 631 drives one of the main shafts 611 to rotate, the meshing transmission of the two gears 632 will inevitably drive the other main shaft 611 to rotate symmetrically in the opposite direction. This symmetrical reverse drive design can counteract the lateral shear force during the transmission process, ensure that all components move symmetrically, effectively avoid mechanical jamming, and extend the service life of the device.

[0036] To transmit the motion of the crankshaft 612 to the piston, the switchable connection assembly 62 is arranged as follows: first crossbars 621 are symmetrically arranged on both sides of the upper part of the piston sleeve 51; a sliding sleeve 622 is sleeved on the upper part of the piston shaft 41, and second crossbars 623 are symmetrically arranged on both sides of the sliding sleeve 622, with the second crossbars 623 located above the first crossbars 621. In the two crankshaft assemblies 61, two crankshafts 612 that are in the same position and symmetrically distributed are rotatably connected to the two first crossbars 621 through a rotatably arranged connecting rod 624; the other two symmetrically distributed crankshafts 612 are rotatably connected to the two second crossbars 623 through a rotatably arranged connecting rod 624.

[0037] To enable switching between pressurized drug delivery and flushing modes, the switchable connection assembly 62 also includes a fixed sleeve 626 fixed to the protective shell 2. The piston shaft 41 extends upward through the fixed sleeve 626. A first knob 625, which can abut against the piston shaft 41, is threaded through the sliding sleeve 622. A second knob 627, which can abut against the piston shaft 41, is threaded through the fixed sleeve 626. The protective shell 2 has an operating port 21 at the range of motion of the first knob 625 to facilitate the turning operation by medical personnel.

[0038] Meanwhile, a liquid control module 7 is connected to the pressure cylinder 3. This module is the key to achieving continuous or pulsed operation. The liquid control module 7 includes a first one-way valve 71, a second one-way valve 72, and a third one-way valve 73. The first one-way valve 71 is located at the connection between the liquid supply pipe 33 and the pressure cylinder 3, and its one-way flow direction is from the liquid supply pipe 33 to the pressure cylinder 3, which is used to prevent the liquid from flowing back to the liquid supply bag. The second one-way valve 72 is installed through the first piston 4, and its one-way flow direction is from the second piston 5 to the liquid outlet pipe 31 (i.e., downward flow), which is used to control the fluid transfer in the internal chamber when the piston moves. The third one-way valve 73 is located at the connection between the liquid outlet pipe 31 and the pressure cylinder 3, and its one-way flow direction is from the pressure cylinder 3 to the liquid outlet pipe 31, which is used to prevent backflow back to the pressure cylinder 3.

[0039] In addition, the control program of the servo motor 631 is set to rotate an integer number of revolutions each time the servo motor 631 is turned off, so that the first piston 4 and the second piston 5 are in the initial limit symmetrical position (i.e., the initial state position where the first piston 4 and the second piston 5 are farthest or closest) each time they stop. This design ensures that the tightening and loosening positions of the first knob 625 and the second knob 627 are the initial positions each time the mode is switched, avoiding transmission misalignment or locking caused by random piston position.

[0040] The specific work process is as follows: Continuous pressurized drug delivery stage: Connect the supply tube 33 to the drug bag. Medical staff ensure that the first knob 625 is tightened through the operating port 21, while simultaneously loosening the second knob 627. At this time, the sliding sleeve 622 is locked to the piston shaft 41, and the piston shaft 41 is released from its fixation to the fixed sleeve 626. Therefore, the piston shaft 41 and the first piston 4 can be driven by the connecting rod 624 in the mechanism to perform relative reciprocating motion with the second piston 5. The servo motor 631 is started, driving one of the main shafts 611 to rotate, which in turn drives the other main shaft 611 to rotate via the gear 632. The cranks 612 on each main shaft 611 rotate in opposite directions, performing eccentric circular motion. At a certain moment, two symmetrically moving cranks 612 indirectly drive the first piston 4 to move in one direction, while the other two cranks 612 drive the second piston 5 to move in the opposite direction. When the first piston 4 and the second piston 5 move away from each other, the second one-way valve 72 is closed, preventing the liquid below the first piston 4 from entering the upper part of the pressure cylinder 3. At this time, the first piston 4 moves towards the third one-way valve 73, allowing the liquid in the pressure cylinder 3 below it to enter the upper part of the pressure cylinder 3. The body is pressurized, and finally one unit of medicine is injected into the human body through the third one-way valve 73. At the same time, the negative pressure created by the first piston 4 and the second piston 5 moving away from each other draws two units of medicine (derived from the piston stroke volume) from the external supply pipe 33 through the first one-way valve 71 into the chamber. At this time, there is one unit of medicine left in the pressurizing cylinder 3 (minus the amount discharged). Subsequently, when the first piston 4 and the second piston 5 move closer to each other, the liquid in the outlet pipe 31 will not flow back due to the one-way shut-off effect of the third one-way valve 73. During the upward movement of the first piston 4, the second one-way valve 72 opens, and the second piston 5 moves downward toward the first piston 4, so that the medicine below the second piston 5 enters the human body through the second one-way valve 72 and the third one-way valve 73 (a total of one unit of medicine enters). Through the above cyclical movement, whether the first piston 4 and the second piston 5 are moving away from each other or moving closer to each other, within half a cycle (one revolution of the main shaft 611 is one cycle), one unit of medicine is injected into the human body, thus forming a stable and continuous pressurized drug delivery process.

[0041] Pulsating flushing stage: After drug administration, connect the infusion tubing 33 to the heparinized saline bag. Medical staff ensure that the second knob 627 is tightened and the first knob 625 is loosened. At this time, since the servo motor 631 has remained stationary after a full rotation since the previous stage, the first piston 4 and the second piston 5 are still in their initial symmetrical positions. After tightening the second knob 627, the piston shaft 41 and the first piston 4 are fixed to the protective shell 2 and remain stationary. Loosening the first knob 625 allows the sliding sleeve 622 to slide freely up and down relative to each other on the piston shaft 41. When the servo motor 631 is restarted, only the second piston 5 moves. As the device moves back and forth, when the second piston 5 moves upward away from the first piston 4, due to the state of each valve (the second one-way valve 72 is closed and the first one-way valve 71 is open), the device only draws a unit amount of heparinized saline from the supply tube 33 into the cavity. At this time, no liquid is injected into the body. When the second piston 5 moves downward close to the first piston 4, the second one-way valve 72 opens, and this unit amount of heparinized saline is then rapidly injected into the body through the second one-way valve 72 and the third one-way valve 73. This one-way intermittent pulse output of "drawing and injecting" creates strong fluid turbulence in the catheter, achieving an excellent intermittent pulse flushing effect.

[0042] Positive pressure needle removal and catheter sealing stage: When flushing is about to end and the catheter is ready to be sealed, the medical staff chooses the stage where the second piston 5 moves towards the first piston 4 (i.e., downward pressure) to remove the puncture needle 32 from the infusion port. During this needle removal process, although the elastic diaphragm at the top of the infusion port will bulge outward due to friction, causing the internal volume to increase momentarily (usually causing negative pressure backflow), since the device is in the downward pressure stroke at this time, heparinized saline is pressed downward into the infusion port, compensating for the volume change caused by the diaphragm bulging outward. Therefore, blood will not flow back. When the puncture needle 32 is completely removed, the servo motor 631 stops again at the full circle position, ensuring that the second piston 5 and the first piston 4 are still in the farthest or closest extreme symmetrical position, thus facilitating the switching of the movement phase and knob operation in the next treatment cycle.

[0043] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

[0045] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. An oncology drug delivery device, comprising a fixed mounting base (1), and a protective shell (2) and a pressure cylinder (3) fixed to one side of the mounting base (1) and arranged from top to bottom, characterized in that: The pressure cylinder (3) is provided with a second piston (5) and a first piston (4) in a sealed sliding manner from top to bottom. A piston shaft (41) is fixed coaxially on the upper side of the first piston (4), and a piston sleeve (51) is fixed coaxially on the upper side of the second piston (5). The piston shaft (41) slides upwards through the second piston (5) and the piston sleeve (51). A liquid supply pipe (33) is laterally connected to the pressure cylinder (3) between the second piston (5) and the first piston (4). A liquid outlet pipe (31) is connected to the bottom of the pressure cylinder (3). The protective shell (2) is equipped with a pressurized sealing integrated switching mechanism (6), and the pressurized cylinder (3) is connected to a liquid control module (7). The pressurized stamping integrated switching mechanism (6) includes two crankshaft assemblies (61) symmetrically arranged in the protective shell (2), a switchable connection assembly (62) connected to the piston sleeve (51) and the piston shaft (41), and a synchronous drive assembly (63) for driving the crankshaft assembly (61) and the switchable connection assembly (62) to move synchronously and symmetrically. The switchable connection assembly (62) includes a first crossbar (621) symmetrically arranged on both sides of the upper part of the piston sleeve (51), a sliding sleeve (622) slidably sleeved on the upper part of the piston shaft (41), and a second crossbar (623) symmetrically arranged on both sides of the sliding sleeve (622). The switchable connection assembly (62) also includes a fixing sleeve (626) fixed on the protective shell (2), the piston shaft (41) extends upward through the fixing sleeve (626), the sliding sleeve (622) has a first knob (625) threaded through it to abut against the piston shaft (41), and the fixing sleeve (626) has a second knob (627) threaded through it to abut against the piston shaft (41). The liquid control module (7) includes a first check valve (71), a second check valve (72), and a third check valve (73). The first check valve (71) is located at the connection between the liquid supply pipe (33) and the pressure cylinder (3), and its one-way flow direction is from the liquid supply pipe (33) to the pressure cylinder (3). The second check valve (72) is installed through the first piston (4), and its one-way flow direction is from the second piston (5) to the liquid outlet pipe (31). The third check valve (73) is located at the connection between the liquid outlet pipe (31) and the pressure cylinder (3), and its one-way flow direction is from the pressure cylinder (3) to the liquid outlet pipe (31).

2. The oncology drug delivery device according to claim 1, characterized in that: Each crankshaft assembly (61) includes a main shaft (611) with both ends rotatably connected to the protective housing (2) and two cranks (612) on the main shaft (611), with the two cranks (612) on the same main shaft (611) arranged 180 degrees opposite each other.

3. The oncology drug delivery device according to claim 2, characterized in that: The second crossbar (623) is located above the first crossbar (621); in the two crankshaft assemblies (61), two cranks (612) that are in the same position and symmetrically distributed are rotatably connected to the two first crossbars (621) through a rotatably connected link (624), and the other two symmetrically distributed cranks (612) are rotatably connected to the two second crossbars (623) through a rotatably connected link (624).

4. The oncology drug delivery device according to claim 3, characterized in that: The synchronous drive assembly (63) includes two gears (632) that are coaxially fixed on the two main shafts (611) and mesh with each other, and a servo motor (631) fixed on the protective shell (2) and used to drive one of the main shafts (611) to rotate, so as to drive the two main shafts (611) to rotate symmetrically in opposite directions.

5. The oncology drug delivery device according to claim 4, characterized in that: The control program of the servo motor (631) is set such that each time the servo motor (631) is turned off, it rotates an integer number of revolutions, so that the first piston (4) and the second piston (5) are in the initial limit symmetrical position each time it stops.

6. The oncology drug delivery device according to claim 5, characterized in that: The end of the liquid outlet tube (31) is connected to a puncture needle (32), and the protective shell (2) has an operation port (21) at the range of motion of the first knob (625).

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