syringe pump

Abstract

The injection pump comprises a processor, a moving mechanism and a position detection mechanism. The moving mechanism comprises a screw rod, a nut, a shaft sleeve and a shaft sleeve driving element. The shaft sleeve driving element drives the shaft sleeve to move, so that the shaft sleeve is out of pressing the nut and the nut is out of engagement with the screw rod when the shaft sleeve moves to a second position. The position detection mechanism comprises an inductive element and a trigger baffle. One of the inductive element and the trigger baffle moves synchronously with the shaft sleeve driving element, and the other of the inductive element and the trigger baffle moves synchronously with the shaft sleeve. The injection pump redefines the critical engagement blocked state of the screw rod and the nut as "tooth tip to tooth tip" as acceptable normal infusion condition instead of alarm prompt through the position detection mechanism to identify the shaft sleeve position, so as to completely eliminate such unnecessary alarm events from the detection logic root and significantly reduce the response burden of medical staff.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to an infusion pump. Background Technology

[0002] An infusion pump is a medical device that enables the delivery of micro-volume, constant-speed, and highly precise drug solutions. It has key applications in intensive care units (ICUs), anesthesiology departments, and precision drug delivery scenarios. Its infusion accuracy and operational reliability are directly related to the patient's treatment safety and health.

[0003] In the mechanical system of an injection pump, the transmission clutch mechanism is the core actuator, which converts the rotational motion of the drive motor into the linear propulsion motion of the syringe piston. Currently, this mechanism commonly uses a lead screw and nut transmission method, that is, the rotation of the lead screw precisely drives the nut to move linearly along its axis, thereby pushing the syringe to complete the continuous infusion of the drug solution.

[0004] However, existing transmission clutch mechanisms have revealed a technical problem during long-term clinical use and reliability testing. Specifically, during the thread engagement of the lead screw and nut, a critical engagement state of "cushion-to-cushion" may occur, where the tips of the lead screw thread and the nut thread are exactly opposite each other and abut against each other. When this state occurs, the actual axial displacement of the nut will not accurately match the theoretical rotation angle of the lead screw, causing the nut to fail to move to the preset trigger position, thereby triggering an alarm on the injection pump.

[0005] To reduce the occurrence of such alarm events, a common improvement approach in existing technologies is to miniaturize the thread size of the lead screw and nut. Theoretically, when the thread size is designed to be sufficiently small, the probability of thread-to-thread misalignment during meshing is reduced to some extent. However, this approach has several inherent drawbacks. First, reducing the thread size directly decreases the effective contact area of ​​the threaded pair. Under the same axial load conditions, this leads to a sharp increase in local contact stress at the threaded parts, easily causing accelerated wear of the lead screw and nut, severely shortening the service life of core components, and thus increasing equipment maintenance costs. Second, small-sized threads place extremely stringent requirements on thread machining accuracy and surface quality, directly increasing mold manufacturing and machining costs, which is detrimental to the industrialization and promotion of the product. Therefore, although miniaturizing the thread size of the lead screw and nut can reduce the probability of "thread-to-thread misalignment" to some extent, it cannot completely eliminate it. Summary of the Invention

[0006] The primary objective of this invention is to solve at least one of the above-mentioned problems by providing an injection pump.

[0007] To achieve the various objectives of the embodiments of the present invention, the embodiments of the present invention adopt the following technical solutions: An injection pump is provided to suit one of the purposes of embodiments of the present invention, including a processor, a motion mechanism, and an alignment detection mechanism; The action mechanism includes a lead screw, a nut, a bushing, and a bushing drive component. The bushing drive component drives the bushing to move so that when the bushing moves to the second position, the bushing releases the pressure on the nut, causing it to disengage from the lead screw. The alignment detection mechanism includes a sensor and a trigger baffle. One of the sensor and the trigger baffle moves synchronously with the bushing drive, while the other of the sensor and the trigger baffle moves synchronously with the bushing. During the reset process, when the bushing is in the third position between the first position and the second position, the bushing drive is correspondingly stopped on one side of the bushing. At this time, the sensing element triggers the first signal, wherein the first signal is at least one of the conditions for starting the infusion of the injection pump.

[0008] In some embodiments, during the reset movement, when the bushing moves to the first position, the bushing presses against the nut, causing it to engage with the lead screw, and the bushing drive also stops on one side of the bushing. At this time, the sensing element triggers the first signal.

[0009] In some embodiments, the bushing is fitted onto the nut, the nut including at least one screw block, the first end of the screw block being threaded; when the bushing moves to the second position of the nut, the bushing releases the pressure on the first end of the screw block, causing the first end of the screw block to tilt up and disengage from the lead screw; when the bushing moves to the first position of the nut, the bushing presses down on the first end of the nut, causing it to engage with the lead screw; when the bushing remains in the third position of the nut, the bushing presses down on the first end of the nut, causing it to engage with the lead screw.

[0010] In some embodiments, the nut includes a plurality of screw blocks, a shell, a fastening elastic element, and a pin. The plurality of screw blocks are movably connected to the shell via the pin, and the second ends of the plurality of screw blocks are pivotally mounted on the shell via the fastening elastic element.

[0011] In some embodiments, during the reset movement, when the bushing moves to the first position or stays at the third position, the trigger baffle is within the sensing range of the sensing element.

[0012] In some embodiments, the device further includes a push rod and a handle. The bushing drive includes an electromagnet and a support base. One end of the push rod is connected to the support base, and the other end of the push rod is linked to the handle. The support base is used to fix the electromagnet and the sensing element. The handle is used to receive external torque and convert it into driving torque to drive the push rod to move the electromagnet and the sensing element synchronously. The electromagnet is used to directly or indirectly drive the bushing to the second position during the disengagement process.

[0013] In some embodiments, during the disengagement process, the trigger baffle gradually moves away from the sensing range of the sensor and remains outside the sensing range, and the sensor triggers a second signal.

[0014] In some embodiments, the device further includes a suction plate and a connecting plate. The connecting plate is provided on the bushing, and the suction plate and the connecting plate are movably connected. After the electromagnet is energized, the suction plate is magnetically attracted, which in turn drives the connecting plate and the bushing to move, so that the bushing reaches the second position.

[0015] In some embodiments, there is a preset movable gap between the suction plate and the connecting plate; during the disengagement movement, the movable gap between the suction plate and the connecting plate remains unchanged; during the reset movement, when the bushing moves to the first position or stays at the third position, the suction plate abuts against the connecting plate to eliminate the movable gap.

[0016] In some embodiments, the connecting piece is provided with a through hole, and the suction piece is provided with a connecting shaft, which passes through the through hole to realize the movable connection between the suction piece and the connecting piece.

[0017] In some embodiments, a return spring and a clutch spring are further included; the return spring is sleeved and one end abuts against the push rod, and the other end abuts against the support seat; the clutch spring is sleeved and one end abuts against the bushing, and the other end abuts against the nut; during the reset movement, the return spring and the clutch spring respectively push the electromagnet and the bushing to move until the bushing moves to the first position or stays in the third position, and the electromagnet or the support seat abuts against and stays on one side of the bushing.

[0018] In some embodiments, the bushing drive includes a motor that receives instructions from the processor to drive the bushing to move axially along the lead screw or rotate circumferentially around the nut; or The bushing drive includes an electromagnetic lock, which has a protrusion for pushing the bushing to move axially along the lead screw.

[0019] The aforementioned "cushion-to-cushion" critical state is merely a temporary inability to mesh due to the cusp-to-cushion alignment of the screw thread and nut thread. However, this state does not substantially affect the infusion operation or safety of the syringe pump. After infusion is initiated, once the screw is rotated, the cusp-to-cushion phenomenon automatically disappears, and the nut's threads smoothly fall into the screw's thread groove, restoring normal meshing. Based on this, this embodiment of the invention redefines the "meshing state" and sets the position and linkage relationship of the alignment detection mechanism and the bushing in the detection logic. When the bushing is stuck in the third position, corresponding to the critical meshing obstruction state of the screw and nut "cushion-to-cushion," instead of the first position of normal meshing, the alignment detection mechanism can still generate and output the first signal instead of triggering an alarm. This brings the critical meshing obstruction state into the normal infusion condition range, reducing such unnecessary alarm events and significantly reducing the additional workload of medical staff caused by these alarm events, thereby improving clinical work efficiency. Attached Figure Description

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of the injection pump according to an embodiment of the present invention.

[0021] Figure 2 This is a partial structural schematic diagram of the injection pump from a first-view perspective according to an embodiment of the present invention.

[0022] Figure 3 This is a partial structural schematic diagram of the injection pump from a second perspective according to an embodiment of the present invention.

[0023] Figure 4 This is a partial structural diagram of the injection pump from a third-view perspective according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of a partial structure (without bushing) of the injection pump from a fourth perspective according to an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of the screw block of the injection pump according to an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of the bushing structure of the injection pump according to an embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of the action mechanism of the injection pump according to an embodiment of the present invention.

[0028] Figure 9This is a schematic diagram of the infusion mechanism (outer shell not shown) of the syringe pump according to an embodiment of the present invention. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0030] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or components, nor does it exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or wireless coupling. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0031] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0032] This invention provides an injection pump 10 for driving a syringe to deliver precise drug infusion. (In conjunction with...) Figure 1 and Figure 2The infusion pump 10 includes a processor (not shown), a moving mechanism 200, an alignment detection mechanism, and an infusion mechanism 400. The moving mechanism 200 is drive-connected to the infusion mechanism 400, and the plunger of the syringe is mounted on the infusion mechanism 400. The processor is electrically connected to the moving mechanism 200 and controls its movement. The moving mechanism 200 is mechanically connected to the infusion mechanism 400. When the moving mechanism 200 moves under the control of the processor, it drives the infusion mechanism 400 to move linearly along a preset infusion direction. Simultaneously, the infusion mechanism 400 pushes the plunger of the syringe to move linearly along its axial direction, thereby achieving a continuous and stable infusion of the medication from the syringe to the patient. Similarly, under the control of the processor, the moving mechanism 200 can also drive the infusion mechanism 400 to move linearly in the opposite direction of the infusion direction, causing the plunger of the syringe to move linearly along its axial direction, achieving a backflow effect.

[0033] Specifically, in combination Figure 2 The action mechanism 200 includes a lead screw 210, a nut 220, a bushing 230, and a bushing drive component 240. The lead screw 210 and nut 220 cooperate to form a screw mechanism, and the nut 220 is connected to the infusion mechanism 400 via a transmission connection. Taking the infusion operation as an example, when the lead screw 210 is driven to rotate by a motor, it drives the nut 220 to move linearly along the axial direction of the lead screw 210. The linear movement of the nut 220 further synchronously drives the infusion mechanism 400 to move linearly in the same direction. The infusion mechanism 400 then transmits this linear movement to the plunger of the syringe, pushing the plunger forward within the syringe barrel, thereby precisely pushing the medication in the syringe to the recipient at a set flow rate. Through this transmission chain, the infusion pump 10 can achieve micro-volume, stable, and continuous medication infusion, meeting the stringent requirements for infusion accuracy in clinical scenarios such as intensive care, anesthesia, and precision drug delivery.

[0034] Combination Figure 6 The nut 220 includes at least one screw block 221, which includes a fixing plate 2211 and teeth 2212 disposed on the fixing plate 2211. The teeth 2212 are provided with a plurality of threads spaced apart along the axial direction, which are used to mesh with the thread of the lead screw 210. Specifically, the plurality of threads of the teeth 2212 are arranged sequentially along the axial direction of the lead screw 210, and adjacent threads form grooves that match the thread of the lead screw 210. When the screw block 221 and the lead screw 210 are in a meshing state, the thread of the lead screw 210 is embedded in the grooves, thereby realizing motion transmission.

[0035] The nut 220 may include one or more screw blocks 221. In some examples, the nut 220 includes a single screw block 221, the teeth 2212 of which directly mesh with the lead screw 210. When the lead screw 210 rotates, it drives the nut 220 to move axially as a whole through this single screw block 221. In some examples, the nut 220 includes multiple screw blocks 221, which are spaced apart along the same circumferential direction, and the teeth 2212 of each screw block 221 mesh with the lead screw 210. Specifically, the number of screw blocks 221 can be two, three, or four. By setting multiple screw blocks 221, on the one hand, the total contact area of ​​the threaded pair is increased, which is beneficial to improving the load-bearing capacity and transmission smoothness; on the other hand, the simultaneous meshing of multiple screw blocks 221 with the lead screw 210 allows the remaining screw blocks 221 to maintain transmission continuity when any screw block 221 experiences meshing gaps due to wear or vibration, thereby improving the fault tolerance and operational reliability of the transmission mechanism.

[0036] In some embodiments, combined with Figure 5 and Figure 8 The actuating mechanism 200 also includes a screw housing 250, which is used to accommodate and limit the screw blocks 221. Specifically, the screw housing 250 has a corresponding insertion slot 251 for each screw block 221, and the screw block 221 is inserted into the corresponding insertion slot 251. The insertion slot 251 is adapted to the fixing plate 2211 and is used to limit the screw block 221 radially and / or circumferentially, ensuring that the screw block 221 can only make limited displacement in a preset direction (e.g., a direction perpendicular to the axis of the lead screw 210) within the insertion slot 251, so as to prevent the screw block 221 from wobbling left and right when it meshes with the lead screw 210, which helps to improve the transmission stability of the actuating mechanism 200. Through the limiting function of the insertion slot 251, the screw block 221 can stably maintain precise engagement with the lead screw 210 in the working state. When it is necessary to disengage (e.g., when changing the syringe), the screw block 221 can smoothly disengage from the lead screw 210 under the guidance of the insertion slot 251, thereby realizing flexible switching between the engagement and disengagement states. The design of the insertion slot 251 effectively prevents the screw block 221 from shifting or shaking during operation, ensuring the long-term stability of transmission accuracy.

[0037] Combination Figure 8The action mechanism 200 also includes a fastening elastic element 247 and a pin 246. The nut 220 includes a plurality of screw blocks 221, each screw block 221 corresponding to at least one pin 246. Specifically, a pivot hole 2215 is provided on the second end 2214 of the screw block 221, and a mating hole is provided on the screw shell 250 at the position corresponding to the pivot hole 2215. The pin 246 passes through the pivot hole 2215 and the mating hole, thereby movably connecting the screw block 221 and the screw shell 250. Through the above-mentioned pin connection structure, the screw block 221 can use the pin 246 as a fulcrum to swing up and down relative to the screw shell 250 around the axis of the pin 246 within the insertion groove 251, thereby allowing the teeth 2212 provided on the first end 2213 of the screw block 221 to move closer to or further away from the lead screw 210.

[0038] The fastening elastic element 247 is a ring-shaped component, which is simultaneously sleeved on the outer periphery of the second ends 2214 of the multiple screw blocks 221, and is used to apply a radially inward contraction tightening force to the second ends 2214 of the multiple screw blocks 221. When the fastening elastic element 247 is sleeved on the second ends 2214 of the multiple screw blocks 221, its elastic contraction force causes the second ends 2214 of the multiple screw blocks 221 to converge together. Since the screw blocks 221 use the pin 246 as a fulcrum, the convergence of the second ends 2214 will cause the first end 2213 to tilt away from the lead screw 210 using the pin 246 as a fulcrum, thereby driving the teeth 2212 provided on the first end 2213 to move away from the lead screw 210, so that the teeth 2212 separate from the threads of the lead screw 210, realizing the disengagement of the screw blocks 221 and the lead screw 210. In other words, the fastening elastic element 247, through its elastic contraction, keeps the screw block 221 in a normally open state, disengaged from the lead screw 210. When the bushing 230 moves to the first position and presses the first end 2213 of the screw block 221, it overcomes the elastic force of the fastening elastic element 247, causing the teeth 2212 to engage with the lead screw 210. When the bushing 230 leaves the first end 2213, the elastic force of the fastening elastic element 247 causes the screw block 221 to automatically return to the disengaged state. In one embodiment, the fastening elastic element 247 is a ring spring.

[0039] Combination Figure 6 and Figure 5The fixing plate 2211 of the screw block 221 is generally flat. The fixing plate 2211 has two opposing ends along the axial direction of the lead screw 210, namely a first end 2213 and a second end 2214. The second end 2214 is raised relative to the first end 2213, and teeth 2212 are provided on the first end 2213. The bushing 230 is fitted onto the nut 220, and the bushing 230 can move relative to the nut 220 along the axial direction of the lead screw 210. Specifically, in some examples, the bushing 230 is fitted outside the nut 220 and the screw housing 250; in other examples, the bushing 230 is positioned inside the nut 220 and the screw housing 250, that is, the nut 220 and the screw housing 250 are fitted outside the bushing 230.

[0040] Specifically, when the bushing 230 moves along the axial direction of the lead screw 210 to the first position of the nut 220, the bushing 230 presses against the first end 2213 of the fixing plate 2211 of the screw block 221, applying a force toward the lead screw 210 to the first end 2213, and overcoming the force applied by the fastening elastic member 247 to the second end 2214 of the screw block 221, so that the teeth 2212 provided on the first end 2213 move toward the lead screw 210 and are embedded in the thread of the lead screw 210, thereby achieving a stable engagement between the screw block 221 and the lead screw 210.

[0041] When the bushing 230 moves along the axial direction of the lead screw 210 to the second position of the nut 220, the bushing 230 switches to pressing against the second end 2214 of the fixing plate 2211 of the screw block 221. Since the fixing plate 2211 is roughly flat and the second end 2214 is raised relative to the first end 2213, when the bushing 230 applies force to the second end 2214, with the pin 246 inserted on the fixing plate 2211 as the center, the first end 2213 will be raised in the opposite direction relative to the second end 2214, thereby driving the teeth 2212 provided on the first end 2213 away from the lead screw 210, so that the teeth 2212 disengage from the thread of the lead screw 210, realizing the disengagement of the screw block 221 from the lead screw 210. At this time, the nut 220 is freed from the rotational constraint of the lead screw 210 and can move freely along the axial direction.

[0042] Furthermore, as the bushing 230 moves from the second position to the first position of the nut 220, the pressure exerted by the bushing 230 on the second end 2214 gradually decreases, and the first end 2213 of the screw block 221 gradually approaches the lead screw 210. The teeth 2212 on the first end 2213 then gradually approach the lead screw 210, thus entering the engagement transition stage. During this process, if the tips of the threads of the teeth 2212 are exactly opposite to the tips of the threads on the lead screw 210, they will form a tip-to-tip abutment, preventing the teeth 2212 from further engaging in the thread of the lead screw 210, and the screw block 221 and the lead screw 210 cannot complete full engagement. In this case, the position of the bushing 230 axially above the nut 220 is defined as the third position. The third position is located between the first and second positions, and is closer to the first position than the second position. In other words, when the bushing 230 is in the third position, the screw block 221 and the lead screw 210 are in a critical engagement and obstructed state due to the abutment of the tooth tips. The bushing 230 can neither fully engage as it is in the first position of the nut 220, nor can it fully disengage as it is in the second position of the nut 220.

[0043] It should be noted that the critical state of tooth tip-to-tooth tip abutting between the thread tips of the threaded part 2212 and the threaded part 210, forming a point-to-point engagement, is not an inescapable permanent fault state. When the bushing 230 is in the third position, i.e., the threaded block 221 and the threaded part 210 are in a state of obstructed engagement due to the point tip abutting, the processor controls the injection pump 10 to start the infusion operation, and the injection pump 10 drives the threaded part 210 to rotate circumferentially around its own axis. During the rotation of the threaded part 210, the thread of the threaded part 210 slides circumferentially relative to the thread of the threaded part 2212. As the rotation angle accumulates, the thread of the threaded part 210 will slide into the groove between adjacent threads on the threaded part 2212, that is, the thread of the threaded part 210 is embedded in the groove of the threaded part 2212, thereby switching the threaded part 2212 and the threaded part 210 from the critical state of point tip abutting to the normal thread engagement state.

[0044] In other words, when the bushing 230 is in the third position of the nut 220, although the teeth 2212 and the lead screw 210 cannot mesh temporarily due to the cusps of the teeth abutting, this state does not constitute a substantial obstacle to the infusion operation. By starting the infusion program of the syringe pump 10, the active rotation of the lead screw 210 can automatically eliminate the cusp abutting phenomenon, allowing the teeth 2212 to smoothly fall into the thread groove of the lead screw 210, achieving normal meshing between the two. Subsequently, the rotational movement of the lead screw 210 will drive the nut 220 to move precisely in a straight line along the axial direction of the lead screw 210. The nut 220, in turn, drives the infusion mechanism 400, which is connected to it, to advance in the same direction. The infusion mechanism 400 pushes the plunger of the syringe forward in the syringe barrel, thereby achieving a continuous and stable infusion of the drug from the syringe to the patient.

[0045] As can be seen, in this embodiment of the invention, the critical state of "cusp-to-cusp" is merely a temporary transitional phenomenon that may occur during engagement. This phenomenon can be automatically eliminated by the active rotation of the lead screw 210 without human intervention or additional disengagement. Therefore, when the infusion pump 10 faces cusp abutment, it can reliably complete engagement and start infusion without triggering an alarm, ensuring the continuity of clinical use without affecting the safety of the equipment.

[0046] In this embodiment of the invention, the lead screw 210 and nut 220 of the injection pump 10 are configured to switch between an engaged state and an unengaged state to adapt to the needs of two different working conditions: syringe installation and drug infusion. When the syringe needs to be installed on the injection pump 10, the bushing 230 moves to the second end 2214 of the screw block 221, so that the bushing 230 releases the pressure on the first end 2213 of the screw block 221. When the fastening elastic element 247 is sleeved on the second end 2214 of the multiple screw blocks 221, its elastic contraction force causes the second ends 2214 of the multiple screw blocks 221 to come together. With the pin 246 as the fulcrum, the coming together of the second ends 2214 will cause the first end 2213 to tilt away from the lead screw 210 with the pin 246 as the fulcrum. This will drive the teeth 2212 provided on the first end 2213 to move away from the lead screw 210, so that the teeth 2212 and the threads of the lead screw 210 are separated, realizing the disengagement of the screw block 221 and the lead screw 210. In this state, the nut 220 is no longer constrained by the rotation of the lead screw 210, and can therefore move freely in a straight line along the axial direction of the lead screw 210. Since the nut 220 is connected to the infusion mechanism 400, the infusion mechanism 400 gains axial freedom synchronously with the nut 220, and can move freely in the same direction. For example, the infusion mechanism 400 can retract or move away from the syringe, thereby freeing up sufficient installation space on the syringe pump 10 so that the operator can easily install the syringe barrel into the corresponding mounting position of the infusion mechanism 400. For example, after the syringe barrel is installed, the infusion mechanism 400 can be driven to quickly approach the initial position of the syringe plunger, thereby shortening the time required for the syringe plunger to complete clamping and fixing.

[0047] When the syringe is reliably installed on the injection pump 10 (including at least the fixing of the injection pump barrel and plunger) and the drug infusion needs to be started, the drive sleeve 230 moves to the first end 2213 of the screw block 221. The sleeve 230 presses against the first end 2213, causing the teeth 2212 on the first end 2213 to re-engage with the lead screw 210. Specifically, by applying a force opposite to the aforementioned direction to the screw block 221, the teeth 2212 re-engage with the lead screw 210. The processor controls the motor to operate, and the motor drives the lead screw 210 to rotate circumferentially around its axis. The lead screw 210 drives the nut 220 to move linearly along its axial direction. The linear motion of the nut 220 is synchronously transmitted to the infusion mechanism 400 connected to it, driving the infusion mechanism 400 to advance in the same direction. The infusion mechanism 400 then pushes the plunger of the syringe forward in the syringe barrel, continuously pushing the liquid medicine in the syringe into the patient's body at a preset flow rate and dose, thereby completing the precise infusion of the injection solution.

[0048] In this embodiment of the invention, the injection pump 10 is further provided with an alignment detection mechanism. This mechanism detects the position of the bushing 230 along the axial direction of the lead screw 210 and outputs a detection signal based on this position to indicate whether the lead screw 210 and the screw block 221 are in a driveable engagement or disengagement state. Specifically, the alignment detection mechanism is configured to generate different detection signals corresponding to different positions of the bushing 230 along the axial direction of the nut 220. The processor is electrically connected to the alignment detection mechanism and is used to receive the detection signals and determine the current position of the bushing 230 based on the detection signals.

[0049] As can be seen, in this embodiment of the invention, the processor can determine the meshing state between the screw block 221 and the lead screw 210 according to the detection signal fed back by the alignment detection mechanism, and control the injection pump 10 to perform corresponding operations based on the determination result.

[0050] Specifically, when the alignment detection mechanism detects that the bushing 230 is in the first or third position axially above the nut 220, the processor determines that the screw block 221 and the lead screw 210 are in a meshing state. This "meshing state" encompasses both full meshing and critical meshing resistance. The first position corresponds to full meshing of the screw block 221 and the lead screw 210, while the third position corresponds to critical meshing resistance due to "tooth-to-tooth" contact. Regardless of whether the bushing 230 is in the first or third position, it indicates that the screw block 221 and the lead screw 210 have met the basic conditions for motion transmission, meaning the injection pump 10 is ready to start infusion. Therefore, this determination constitutes one of the conditions for starting infusion with the injection pump 10, and the processor can control the injection pump 10 to start or continue precisely infusing the medication.

[0051] When the alignment detection mechanism detects that the bushing 230 is in the second position axially above the nut 220, the processor determines that the screw block 221 and the lead screw 210 are in a disengaged state. In this state, the teeth of the screw block 221 have completely disengaged from the lead screw 210, and the nut 220 is no longer constrained by the rotation of the lead screw 210, allowing it to move freely along the axial direction of the lead screw 210. This disengaged state provides the operator with the necessary conditions to perform syringe installation or removal operations; that is, the processor determines that the syringe installation space has been cleared, allowing the operator to install the syringe on the injection pump 10 or remove a used syringe from the injection pump 10.

[0052] Through the aforementioned state judgment and control logic based on the position of bushing 230, the injection pump 10 achieves automatic identification of engagement / disengagement states and automatic adaptation of corresponding operations, effectively improving the ease of operation and intelligence level of the equipment.

[0053] As a specific implementation of the present invention, combined with Figure 3 The alignment detection mechanism includes a sensor 310 and a trigger baffle 320. The sensor 310 and the trigger baffle 320 are arranged opposite to each other and can be installed on different moving parts to reflect the positional change of the bushing 230 through relative displacement.

[0054] In some embodiments, the sensing element 310 is connected to the bushing drive element 240, so that the bushing drive element 240 can synchronously drive the sensing element 310 to move; correspondingly, the trigger baffle 320 is connected to the bushing 230, so that the bushing 230 can synchronously drive the trigger baffle 320 to move. Because the sensing element 310 is connected to the bushing drive element 240, when the bushing 230 moves along the axial direction of the lead screw 210, the trigger baffle 320 moves synchronously with the bushing 230, so that the relative position between the sensing element 310 and the bushing drive element 240 changes accordingly, and the sensing element 310 can generate a corresponding detection signal according to the relative position relationship with the trigger baffle 320.

[0055] In some embodiments, the sensing element 310 can also be connected to the bushing 230, with the bushing 230 synchronously driving the sensing element 310 to move; while the trigger baffle 320 is connected to the bushing drive element 240, with the bushing drive element 240 synchronously driving the trigger baffle 320 to move. Both of the above embodiments can realize the function of detecting the position of the bushing 230 by the relative displacement between the sensing element 310 and the trigger baffle 320. Those skilled in the art can flexibly choose according to the actual structural layout and design requirements.

[0056] To facilitate the description and understanding of the present invention, the following description will take the connection method of the sensing element 310 connected to the bushing drive element 240 and the trigger baffle 320 connected to the bushing 230 as an example. However, this example does not constitute any limitation on the protection scope of the embodiments of the present invention. Any technical solution that uses equivalent or equivalent substitution methods to realize the position detection of the bushing 230 should fall within the scope of the present invention.

[0057] In this embodiment of the invention, the sensing element 310 is connected to the bushing drive element 240, so that the sensing element 310 can move synchronously with the bushing drive element 240; the trigger baffle 320 is connected to the bushing 230, so that the trigger baffle 320 can move synchronously with the bushing 230. Through the above connection configuration, the relative positional relationship between the sensing element 310 and the trigger baffle 320 directly reflects the real-time positional state of the bushing 230 relative to the bushing drive element 240.

[0058] When the bushing 230 is in the first or third position, the trigger baffle 320, which is fixedly connected to it, moves to the corresponding position along with the bushing 230; at the same time, the sensing element 310, which moves synchronously with the bushing drive 240, also moves to the corresponding position. Since the first and third positions both place the trigger baffle 320 within the sensing range of the sensing element 310 in the axial position of the bushing 230, the sensing element 310 can reliably sense the trigger baffle 320 and generate a corresponding detection signal, regardless of whether the bushing 230 is in the fully engaged first position or in the critically engaged third position where the engagement is blocked due to "tooth-to-tooth" contact.

[0059] The processor can acquire the detection signal output by the alignment detection mechanism in real time and accurately. Based on the detection signal, the processor automatically determines the engagement state (including fully engaged, critically engaged but blocked, and disengaged) between the lead screw 210 and the nut 220. This determination provides a reliable signal basis for the subsequent execution of control logic by the syringe pump 10, such as syringe installation, drug infusion initiation, and abnormal state identification, ensuring the orderly connection and accurate execution of each operation step. This effectively improves the intelligence level and operational safety of the syringe pump 10, and reduces the risk of equipment misoperation due to misjudgment of position status.

[0060] In this embodiment of the invention, the alignment detection mechanism is configured to generate different detection signals based on the relative positional relationship between the sensing element 310 and the trigger baffle 320, so that the processor can determine the positional state of the bushing 230 and thus determine the meshing state between the lead screw 210 and the screw block 221.

[0061] When the bushing 230 moves to the first position, that is, when the bushing 230 presses against the first end 2213 of the screw block 221, the teeth 2212 on the first end 2213 overcome the elastic force of the fastening elastic element 247 and press against the lead screw 210, and are fully engaged with the thread of the lead screw 210. At this time, the nut 220 and the lead screw 210 establish a stable transmission connection. At this time, the trigger baffle 320 on the bushing 230 is within the sensing range of the sensing element 310. After the sensing element 310 detects the trigger baffle 320, it generates a first signal and uploads the first signal to the processor. After receiving the first signal, the processor determines that the lead screw 210 and the screw block 221 are currently engaged, thereby determining that the injection pump 10 has the basic conditions for starting infusion. Based on this, the processor can control the injection pump 10 to start or continue to perform precise infusion of the drug solution.

[0062] When the bushing 230 is in the second position, that is, when the bushing 230 presses against the second end 2214 of the screw block 221, the first end 2213 of the screw block 221 is raised relative to the second end 2214 with the pin 246 as the fulcrum. This causes the teeth 2212 on the first end 2213 to completely disengage from the thread of the lead screw 210, and the lead screw 210 and the screw block 221 are in a completely disengaged state. At this time, the bushing 230 moves along the axial direction of the lead screw 210 to a position away from the bushing drive member 240. At this time, the trigger baffle 320 on the bushing 230 is outside the sensing range of the sensor 310 fixedly set on the bushing drive member 240. The sensor 310 cannot detect the trigger baffle 320, generates a second signal different from the first signal, and uploads the second signal to the processor. After receiving the second signal, the processor determines that the lead screw 210 and the screw block 221 are currently disengaged, and accordingly determines that the syringe pump 10 is currently in a state where the syringe can be installed or removed. In this state, the nut 220 is no longer constrained by the rotation of the lead screw 210 and can move freely along the axial direction of the lead screw 210. The operator can manually or through the control of the syringe pump processor move the infusion mechanism 400, which is connected to the nut 220, to make room for installation, thereby facilitating the installation or removal of the syringe.

[0063] Specifically, when the bushing 230 is in the third position, that is, when the tips of the threads on the toothed part 2212 and the tips of the threads on the lead screw 210 are exactly opposite each other, forming a "tip-to-tip" abutment, and the two are in a critical meshing and obstructed state, the bushing 230 cannot continue to move towards the first position due to the obstruction of the screw block 221. At this time, the actual axial position of the bushing 230 is between the first position and the second position, and is closer to the first position than the second position. In this position, although the bushing 230 has not completely reached the first position, the trigger baffle 320 provided on the bushing 230 is also within the sensing range of the sensing element 310. After the sensing element 310 detects the trigger baffle 320, it generates a first signal and uploads the first signal to the processor. In other words, even if the bushing 230 fails to reach the first position due to tooth tip abutment, its alignment detection mechanism 300 still identifies the third position as an infusion-ready position equivalent to the first position through the relative position of the sensing element 310 and the trigger baffle 320, ensuring that the processor can still receive a signal that allows infusion to start even when the critical engagement is blocked.

[0064] In other words, the signal triggered by the sensor 310 when the bushing 230 is in the third position is the same as the signal triggered when the bushing 230 is in the first position; both are the first signal. After receiving the first signal, the processor determines, based on this signal, that the screw block 221 and the lead screw 210 have met the basic conditions for realizing motion transmission, that is, the syringe pump 10 has the prerequisite for starting infusion. Therefore, this determination constitutes one of the conditions for starting infusion by the syringe pump 10, and the processor can control the syringe pump 10 to start or continue to perform precise infusion of the drug solution. When the syringe pump 10 performs infusion, the processor drives the lead screw 210 to rotate to eliminate the tooth tip collision phenomenon, and after achieving full engagement, pushes the plunger of the syringe to perform drug infusion.

[0065] Therefore, when the bushing 230 is in the first or third position, the sensor 310 triggers the generation of the same first signal to indicate that the lead screw 210 and the screw block 221 are in an operable infusion engagement state. In other words, the alignment detection mechanism of this embodiment of the invention unifies the two states of "full engagement" and "critical engagement blocked but engagement can be achieved by driving the lead screw 210 to rotate" into the judgment category of allowable infusion, thereby ensuring that when a "cusp-to-cusp" critical state occurs, the injection pump 10 can still start infusion normally, and will not prohibit infusion or trigger an alarm due to misjudgment as a disengagement state. The invention concept aims to eliminate the impact of the cusp-to-cusp critical state on the normal operation of the injection pump 10, effectively avoids the problem of infusion interruption or false alarm caused by engagement blockage, and significantly improves the intelligence level of the injection pump 10.

[0066] In specific embodiments of the present invention, the assembly relationship between the bushing 230 and the nut 220 can adopt various structural forms, as long as the functional requirement of the bushing 230 being able to move relative to the nut 220 along the axial direction of the lead screw 210, thereby driving the screw block 221 to switch between an engaged state and a disengaged state, is met. As an optional implementation, the bushing 230 is sleeved on the outer periphery of the nut 220, that is, the bushing 230 covers the outer side of the nut 220 with a clearance fit or a sliding fit, and the inner wall of the bushing 230 is adapted to the outer wall of the nut 220, so that the bushing 230 can slide relative to the nut 220 along the axial direction of the lead screw 210. When the bushing 230 moves to the first position axially above the nut 220, the bushing 230 presses against the screw block 221, forcing the teeth of the screw block 221 to mesh with the lead screw 210, thereby putting the nut 220 and the lead screw 210 in a transmission engagement state. When the bushing 230 moves to the second position, the bushing 230 releases its pressure on the screw block 221, and the teeth of the screw block 221 disengage from the lead screw 210, thereby disengaging the nut 220 from the lead screw 210. Thus, by switching the bushing 230 between different positions, the engagement and disengagement states between the lead screw 210 and the nut 220 can be flexibly switched.

[0067] As another optional implementation, the nut 220 is disposed on the outside of the bushing 230, that is, the bushing 230 passes through the inside of the nut 220, and the outer wall of the bushing 230 is adapted to the inner wall of the nut 220. Similarly, the bushing 230 can slide relative to the nut 220 along the axial direction of the lead screw 210 to achieve the switching between the first position and the second position.

[0068] Both of the above assembly methods can realize the function of the bushing 230 moving relative to the nut 220 along the axial direction of the lead screw 210. Those skilled in the art can flexibly select and set according to specific factors such as the overall structural layout, spatial dimensions and transmission accuracy requirements of the injection pump 10.

[0069] In this embodiment, the movement of the bushing 230 relative to the nut 220 along the axial direction of the lead screw 210 can also be implemented in various ways. In one optional implementation, the bushing 230 moves linearly along the axial direction of the lead screw 210, that is, the bushing 230 translates along the axial direction of the lead screw 210 under the action of an external driving force, so as to switch between a first position and a second position.

[0070] As another feasible embodiment of the bushing 230, the inner wall of the bushing 230 can be configured to have different radial dimensions in different regions. Specifically, a first region and a second region are sequentially arranged along the circumference of the inner wall of the bushing 230, wherein the radial dimension of the first region is greater than that of the second region, that is, the inner diameter of the first region is greater than that of the second region, so that the inner wall of the bushing 230 forms a profile with alternating radial dimensions in the circumferential direction.

[0071] The bushing 230 rotates relative to the nut 220 around the axis of the lead screw 210. By utilizing the difference in radial dimensions of different regions of its inner wall, the bushing 230 can selectively push or release the screw block 221, thereby driving the nut 220 to move closer to or further away from the lead screw 210 in the radial direction, thus achieving the switching between the engagement and disengagement states. Specifically, when engagement is required, the bushing 230 is rotated so that its first region abuts against the screw block 221. Due to the large radial dimension of the first region, the inner wall of the bushing 230 applies a thrust towards the screw block 221 in this region, forcing the teeth of the screw block 221 to press against the screw rod 210 and engage with the thread of the screw rod 210. When disengagement is required, the bushing 230 is rotated so that its second region is opposite to the screw block 221. Due to the small radial dimension of the second region, the inner wall of the bushing 230 provides clearance for the screw block 221 in this region. Under the action of its own elastic restoring force or external reset force, the screw block 221 can retract outward, causing its teeth to disengage from the thread of the screw rod 210, thereby achieving disengagement.

[0072] In other words, the bushing 230, by providing regions with different radial dimensions on its inner wall, drives the nut 220 to generate radial displacement through rotation, thereby achieving engagement or disengagement with the lead screw 210. Compared to the aforementioned method where the bushing 230 moves linearly along the axial direction to drive the screw block 221 to switch engagement states, this embodiment achieves the same function through rotational motion, providing another compact and flexible implementation form for the transmission clutch mechanism. Those skilled in the art can make a reasonable selection based on the overall structural layout and spatial size requirements of the injection pump 10.

[0073] Regardless of the aforementioned motion mode, the bushing 230 can change its pressing position and force direction on the screw block 221 by adjusting its axial or circumferential position relative to the nut 220, thereby driving the teeth 2212 of the screw block 221 to engage or disengage with the lead screw 210. The aforementioned multiple motion modes provide more flexible design options for the transmission clutch mechanism, facilitating the optimization of the injection pump 10's structural compactness and ease of operation according to specific application scenarios.

[0074] In this embodiment of the invention, combined with Figure 2 The bushing 230 is sleeved on the outer periphery of the screw block 221, and the bushing 230 is configured to move linearly along the axial direction of the lead screw 210, so that the bushing 230 is in different positions relative to the screw block 221 in the axial direction of the lead screw 210, such as the first position or the second position mentioned above. By switching the bushing 230 between the above-mentioned different positions, the pressing state of the bushing 230 against the screw block 221 can be changed accordingly, thereby driving the teeth 2212 of the screw block 221 to engage or disengage with the lead screw 210.

[0075] The bushing drive 240 is connected to the bushing 230 in a transmission manner, and is used to drive the bushing 230 to move from the first position to the second position in response to the control signal of the processor. Specifically, when the bushing drive 240 drives the bushing 230 to move from the first position to the second position, the pressing part of the bushing 230 against the screw block 221 switches from the first end 2213 to the second end 2214, so that the first end 2213 of the screw block 221 is raised relative to the second end 2214, and the teeth 2212 provided on the first end 2213 move away from the lead screw 210, thereby realizing the conversion of the screw block 221 and the lead screw 210 from the meshing state to the disengaging state.

[0076] As a specific embodiment of the bushing 230, combined with Figure 7 and Figure 8 A connecting piece 231 is provided on the outer periphery of the bushing 230. The bushing drive component 240 includes an electromagnet 241 and a suction piece 242, which is movably connected to the connecting piece 231. Specifically, the connecting piece 231 has a through hole, and the suction piece 242 has a connecting shaft 243, which passes through the through hole, thereby realizing the movable connection between the suction piece 242 and the connecting piece 231. To prevent the connecting piece 231 from accidentally falling off the connecting shaft 243 during movement, a retaining spring 244 is provided at the end of the connecting shaft 243. The radial dimension of the retaining spring 244 is larger than the diameter of the through hole, thereby providing axial limiting for the connecting piece 231. Furthermore, there is a preset movable gap between the suction piece 242 and the connecting piece 231, allowing them to move relative to each other within a certain range without rigid contact.

[0077] During the disengagement process between the nut 220 and the lead screw 210, a force is first applied to the electromagnet 241, causing it to move towards the second position. Subsequently, the processor controls the electromagnet 241 to be energized, generating an electromagnetic attraction that draws the magnetic plate 242. Since the plate 242 is movably connected to the connecting plate 231, the plate 242, under the electromagnetic attraction, drives the connecting plate 231 to move synchronously, thereby causing the bushing 230 to move axially along the lead screw 210 until the bushing 230 reaches the second position, achieving complete disengagement between the lead screw 210 and the nut 220.

[0078] During the reset process of nut 220 and lead screw 210 from the disengaged state to the engaged state, bushing 230 moves from the second position to the first position under the action of external torque. Bushing 230 drives the connecting piece 231 mounted on it to move synchronously. The connecting piece 231 drives the suction piece 242 through the connecting shaft 243. The suction piece 242 further drives the electromagnet 241 magnetically attracted to it to move synchronously until bushing 230 moves to the first position or stops at the third position. Only then does the processor control the electromagnet 241 to be de-energized, so that the electromagnet 241 no longer magnetically attracts the suction piece 242. During the above reset process, the suction piece 242 and electromagnet 241 remain in a close contact state due to continuous magnetic attraction. Bushing 230 drives electromagnet 241 to reset together through connecting piece 231 and suction piece 242.

[0079] In this embodiment of the invention, the bushing drive component 240 uses a suction plate 242 as an intermediate transmission element. After the electromagnet 241 is powered on, it first magnetically attracts the suction plate 242, then drives the connecting plate 231 via the suction plate 242, and subsequently drives the bushing 230 from a first position to a second position via the connecting plate 231. Compared to directly attracting and driving the bushing 230 via the electromagnet 241, by using the suction plate 242 as an intermediate transmission element between the electromagnet 241 and the bushing 230, the starting load of the electromagnet 241 can be applied gradually in stages. This prevents the load on the electromagnet 241 from being too large in the initial stage of startup, effectively reducing the starting burden on the electromagnet 241 and avoiding overload or damage to the electromagnet 241 due to excessive instantaneous load. This improves the service life and operational reliability of the bushing drive component 240.

[0080] Furthermore, during the disengagement process, the clearance between the suction plate 242 and the connecting plate 231 remains constant, meaning that they always maintain relative movement within the preset clearance range without contacting each other during this stage. During the reset process, when the bushing 230 moves to the first position or stays in the third position, the suction plate 242 abuts against the connecting plate 231, thereby eliminating the clearance. In other words, the clearance setting allows for a floating transmission between the suction plate 242 and the connecting plate 231 during the disengagement phase, avoiding rigid impact; while during the reset phase, when the bushing 230 reaches the first position or stays in the third position, the suction plate 242 and the connecting plate 231 eliminate the clearance through contact, ensuring the rigidity of the transmission chain and facilitating accurate detection of the bushing 230 position by the alignment detection mechanism.

[0081] Of course, in other embodiments of the present invention, the bushing drive component 240 may also omit the suction plate 242 and instead use an electromagnet 241 to directly drive the magnetic bushing 230 to move, thereby simplifying the structure of the bushing drive component 240, reducing the number of parts, and lowering manufacturing costs. Those skilled in the art can make trade-offs between drive reliability, structural complexity, and cost control according to actual design requirements.

[0082] In one specific embodiment, combined with Figure 2 and Figure 3 The electromagnet 241 is also provided with a support structure 260, which includes a support base 261 and a first mounting plate 262 disposed on the support base 261. In one embodiment, the first mounting plate 262 is a circuit board. The bottom end of the support base 261 is fixedly disposed on the electromagnet 241, and the first mounting plate 262 is disposed on the top end of the support base 261. The support base 261 extends from the surface of the electromagnet 241 in a direction away from the electromagnet 241 to support the first mounting plate 262 at a predetermined height. When the bushing 230 is in the first position, the first mounting plate 262 is located directly above the bushing 230, that is, the first mounting plate 262 is disposed opposite to the bushing 230 in the radial direction of the lead screw 210. The sensing element 310 is disposed on the side of the first mounting plate 262 facing the bushing 230 (i.e., the lower surface of the first mounting plate 262), so that when the bushing 230 is in the first position, the trigger baffle 320 disposed on the bushing 230 is exactly within the sensing range of the sensing element 310, so that the sensing element 310 can sense the trigger baffle 320 and generate a corresponding detection signal, thereby improving the detection accuracy and repeatability of the alignment detection mechanism.

[0083] In this embodiment of the invention, when the bushing 230 is in the first position, the lead screw 210 and the screw block 221 are in a stable meshing state, and the electromagnet 241 is in an unenergized state. When it is necessary to switch the lead screw 210 and the screw block 221 from the meshing state to the disengaging state, a first external torque is first applied to the electromagnet 241, causing the electromagnet 241 to move away from the bushing 230. Since the sensing element 310 is fixedly mounted on the electromagnet 241 by the support structure 260, the movement of the electromagnet 241 synchronously drives the sensing element 310 to move away from the bushing 230. As the sensing element 310 moves, the trigger baffle 320 originally mounted on the bushing 230 gradually deviates from the sensing range of the sensing element 310. When the sensing element 310 can no longer sense the trigger baffle 320, the sensing element 310 generates a second signal and uploads the second signal to the processor. After receiving the second signal, the processor determines that the current electromagnet 241 has disengaged from the first position, and the lead screw 210 and the screw block 221 are in or about to be in a disengaged state.

[0084] After receiving the second signal, the processor further controls the electromagnet 241 to be energized. When energized, the electromagnet 241 generates magnetic force, attracting the suction plate 242 to move in the direction of the electromagnet 241, causing the suction plate 242 to engage with the electromagnet 241. Subsequently, the electromagnet 241, through the suction plate 242 attached to it, and via the connecting shaft 243 and connecting plate 231, drags the bushing 230 from the first position to the second position. During the movement of the bushing 230 from the first position to the second position, the pressure point of the bushing 230 on the screw block 221 gradually switches from the first end 2213 to the second end 2214, causing the first end 2213 of the screw block 221 to tilt relative to the second end 2214. The teeth 2212 on the first end 2213 then move away from the lead screw 210, thus achieving a complete transition between the lead screw 210 and the screw block 221 from an engaged state to a disengaged state. After the lead screw 210 disengages from the screw block 221, the nut 220 is no longer constrained by the rotation of the lead screw 210. The operator can freely move the nut 220 and its transmission-connected infusion mechanism 400 along the axial direction of the lead screw 210 to make sufficient installation space for installing the syringe on the infusion mechanism 400.

[0085] In this embodiment, combined with Figure 2 The action mechanism 200 also includes a clutch elastic element 270, which is elastically connected to the bushing 230 to provide a reset driving force for the bushing 230. When the bushing 230 moves from the first position to the second position under the action of an external force, the bushing 230 compresses the clutch elastic element 270, causing the clutch elastic element 270 to undergo elastic deformation and accumulate a first elastic reset torque. Specifically, one end of the clutch elastic element 270 abuts against or is fixedly connected to the bushing 230, and the other end is fixedly disposed with the screw housing 250. When the bushing 230 moves in the direction of the second position, the bushing 230 squeezes the clutch elastic element 270, causing the clutch elastic element 270 to be compressed and store elastic potential energy.

[0086] When the lead screw 210 and the screw block 221 need to re-engage from the disengaged state to the engaged state, the first external torque applied to the electromagnet 241 is stopped, and the clutch elastic element 270 releases its accumulated first elastic reset torque. Under the action of the first elastic reset torque, the clutch elastic element 270 pushes the bushing 230 to move from the second position to the first position. During the reset movement, depending on the actual meshing relationship between the teeth 2212 of the screw block 221 and the thread of the lead screw 210, the bushing 230 may move to the first position or remain in the third position. When the bushing 230 moves to the first position, it indicates that the tooth 2212 has been successfully engaged in the thread of the lead screw 210, and the lead screw 210 and the screw block 221 are in a fully engaged state. If the tooth tip of the thread of the tooth 2212 is exactly opposite to the tooth tip of the thread on the lead screw 210 to form a tooth tip-to-tooth contact, the lead screw 210 and the screw block 221 are in a critical engagement and resistance state, then it indicates that the bushing 230 has moved to the third position.

[0087] As the bushing 230 resets under the push of the clutch elastic element 270, the electromagnet 241 receives a second external torque, causing the electromagnet 241 to move synchronously towards the first position along with the reset movement of the bushing 230. Since the sensing element 310 is disposed on the electromagnet 241, the movement of the electromagnet 241 synchronously drives the displacement of the sensing element 310. When the bushing 230 moves to the first position, the electromagnet 241 moves accordingly to the corresponding position, and the sensing element 310 moves with the electromagnet 241 to the range where it can sense the trigger baffle 320. The sensing element 310 senses the trigger baffle 320 and generates a first signal.

[0088] Similarly, when the bushing 230 can only move to the third position due to the tooth tip abutting, the electromagnet 241 also moves to the corresponding position in sync, and the sensing element 310 can also sense the trigger baffle 320 and generate the first signal.

[0089] The sensor 310 uploads a first signal to the processor, which determines, based on the first signal, whether the lead screw 210 and the screw block 221 have completed engagement or are in a state where engagement can be completed. Regardless of whether the first signal indicates that the bushing 230 is in the first position or the third position, it means that the screw block 221 and the lead screw 210 have met the basic conditions for realizing motion transmission, that is, the infusion pump 10 has the prerequisite for starting infusion. Therefore, this determination result constitutes one of the conditions for starting infusion of the infusion pump 10, and the processor can control the infusion pump 10 to start or continue to perform precise infusion of the drug solution.

[0090] With the aforementioned clutch elastic element 270, the bushing 230 can automatically reset from the second position to the first position or stay in the third position under the action of the first elastic reset torque without external power, realizing the automatic switching of the transmission clutch mechanism between the disengaged state and the engaged state or the critical engagement resistance state, simplifying the operation process.

[0091] Since the sensing element 310 is fixedly mounted on the electromagnet 241 and the trigger baffle 320 is fixedly mounted on the bushing 230, when the bushing 230 moves from the second position to the first position under the drive of the clutch elastic element 270, the bushing 230 drives the electromagnet 241 to move synchronously through the connecting piece 231 and the suction piece 242. During this process, the sensing element 310 mounted on the electromagnet 241 and the trigger baffle 320 mounted on the bushing 230 maintain an accurate correspondence in their relative positions, that is, the movement trajectory of the sensing element 310 with the electromagnet 241 matches the movement trajectory of the trigger baffle 320 with the bushing 230.

[0092] Therefore, regardless of whether the bushing 230 ultimately stops at the first or third position due to actual engagement, the trigger baffle 320 remains within the sensing range of the sensing element 310, and the sensing element 310 can detect the trigger baffle 320 and generate the first signal. This configuration ensures that the processor can accurately determine whether the injection pump 10 is in an executable infusion state, regardless of whether the bushing 230 is in the first or third position. This effectively avoids signal loss or misjudgment caused by critical engagement obstruction, significantly improving the detection reliability of the alignment detection mechanism and the accuracy of the processor's state judgment.

[0093] In some embodiments, the electromagnet 241 remains energized and held during the reset movement of the bushing 230 from the second position to the first position. When the clutch elastic member 270 releases its accumulated first elastic reset torque and pushes the bushing 230 to move from the second position to the first position, due to the continuous magnetic attraction between the electromagnet 241 and the suction plate 242, the bushing 230, through the cooperation of the connecting plate 231, the connecting shaft 243, and the suction plate 242, synchronously drives the electromagnet 241 to move in the same direction during its movement, causing the electromagnet 241 to move together with the bushing 230 toward the first or third position. In other words, the electromagnet 241 does not move independently during this reset phase, but passively follows the synchronous displacement of the bushing 230 under the drive of the bushing 230, thereby ensuring that the relative positional relationship between the sensing element 310 on the electromagnet 241 and the trigger stop 320 on the bushing 230 remains stable.

[0094] In one specific embodiment, the clutch elastic element 270 is a clutch spring 271. The clutch spring 271 is sleeved on the outer periphery of the bushing 230, with one end of the clutch spring 271 abutting or fixedly connected to the bushing 230, and the other end fixedly connected to the screw housing 250. When the bushing 230 moves from the first position to the second position under the drive of an external force, the bushing 230 is displaced along the axial direction of the lead screw 210, thereby squeezing the clutch spring 271 and causing the clutch spring 271 to undergo compression deformation along its axial direction. During this process, the clutch spring 271 converts the externally input mechanical energy into elastic potential energy and stores it, that is, accumulates the first elastic restoring torque.

[0095] When the external driving force acting on the bushing 230 is released, the clutch spring 271 releases its accumulated first elastic restoring torque, converting elastic potential energy into kinetic energy, driving the bushing 230 to reset in the opposite direction, i.e., from the second position to the first position. Using the clutch spring 271 as the clutch elastic element 270 has advantages such as simple structure, low cost, rapid response, and stable torque output, which helps to ensure the reliability and consistency of the reset movement of the bushing 230.

[0096] In this embodiment of the invention, combined with Figure 1-3 The infusion mechanism 400 includes a handle 410 and a push rod 420. An electromagnet 241 is mounted on a support base 261. Both ends of the push rod 420 are linked to the handle 410 and the support base 261, respectively; one end of the push rod 420 is connected to the handle 410, and the other end is connected to the support base 261. The handle 410 receives a first external torque and converts it into a driving torque to move the push rod 420. After receiving the driving torque, the push rod 420 moves linearly along its axis, thereby pushing the support base 261 towards the second position, causing the support base 261 to move towards the second position. The operator can easily drive the electromagnet 241 and the bushing 230 by manually operating the handle 410, switching the lead screw 210 and the screw block 221 from an engaged state to a disengaged state to meet the operational needs of syringe installation, disassembly, or infusion.

[0097] Combination Figure 5 A return spring 430 is fitted onto the push rod 420. One end of the return spring 430 abuts against the push rod 420, and the other end abuts against the support base 261. When the push rod 420 pushes the electromagnet 241 to move in the direction of the second position under the drive of an external force, the push rod 420 moves synchronously with the electromagnet 241. During this process, the push rod 420 compresses the return spring 430, causing the return spring 430 to undergo compression deformation and accumulate a second elastic return torque.

[0098] When it is necessary to restore the lead screw 210 and screw block 221 to the engaged state, the operator no longer applies force to the handle 410, meaning the handle 410 no longer receives the first external torque. At this time, the return spring 430 releases its stored second elastic return torque, converting elastic potential energy into kinetic energy, driving the push rod 420 to move in the opposite direction to the handle 410, i.e., towards the direction of the first position. Driven by the second elastic return torque, the push rod 420 moves the electromagnet 241 towards the direction of the first position.

[0099] Additionally, the release of the accumulated second elastic torque by the return spring 430 will push the electromagnet 241 to move, causing the electromagnet 241 to push the suction plate 242 to eliminate the gap between it and the connecting plate 231. This allows the sensor 310 on the electromagnet 241 to sense the trigger stop plate 320 on the connecting plate 231. Specifically, during the reset movement of the electromagnet 241 with the push rod 420, the sensor 310 on the electromagnet 241 moves synchronously. When the sensor 310 re-enters the range where it can sense the trigger stop plate 320, the sensor 310 generates a first signal and uploads it to the processor so that the processor can determine that the lead screw 210 and the screw block 221 are in an executable injection state.

[0100] Through the cooperative structure of the handle 410, push rod 420 and return spring 430, the transmission clutch mechanism realizes manual switching and automatic reset between the engagement and disengagement states. It is easy to operate and highly reliable. It can complete the state switching without an additional power source, which helps to simplify the equipment structure and reduce manufacturing costs.

[0101] In a further embodiment, combined with Figure 1 and Figure 9 The handle 410 is connected to the push rod 420 via a transmission mechanism. When the operator applies a first external torque to the handle 410, the handle 410 transmits the motion to the push rod 420 through the transmission mechanism, thereby driving the push rod 420 to move linearly along its axis. The transmission mechanism can be any suitable form, such as a rack and pinion mechanism, linkage mechanism, cam mechanism, or rope pulley mechanism, depending on the specific structural requirements, as long as it can convert the motion of the handle 410 into the linear motion of the push rod 420. Through the design of the handle 410 and the transmission mechanism, the operator can drive the push rod 420 more easily and effortlessly. At the same time, the handle 410 and the transmission mechanism provide a certain force amplification effect, further reducing the difficulty of operation and improving the user experience.

[0102] In another embodiment, the syringe pump 10 further includes a power source, which is connected to the electromagnet 241 via a transmission connection and is electrically connected to the processor. When the lead screw 210 and the screw block 221 need to switch from an engaged state to a disengaged state, the processor controls the power source to start working. Under the control of the processor, the power source outputs driving force to drive the electromagnet 241 to move from a first position to a second position. Compared with the aforementioned manual operation implementation, this embodiment achieves electrification and automated control of the position switching of the electromagnet 241 by introducing a power source, which can further reduce the workload of operators. It is especially suitable for high-intensity clinical use scenarios that require frequent syringe changes, and is conducive to improving the working efficiency and ease of use of the equipment.

[0103] In this embodiment, a motor is recommended as the power source. The motor can convert rotary motion into linear motion to drive the electromagnet 241 through a lead screw drive, gear drive, or worm gear drive. Of course, the specific type of power source is not limited to the above-listed examples. Those skilled in the art can select any suitable power component, such as a cylinder, hydraulic cylinder, or piezoelectric actuator, according to actual design requirements, as long as it can achieve the function of driving the electromagnet 241 to move linearly along the axis of the lead screw 210. The above-listed examples should not be construed as limiting the scope of protection of this invention.

[0104] In some embodiments, the bushing drive 240 may also use an electromagnetic lock instead of the combination structure of electromagnet 241 and suction plate 242 in the aforementioned embodiments. The electromagnetic lock includes a retractable protrusion that extends in a predetermined direction when the electromagnetic lock is energized, for directly pushing the bushing 230 or pushing the bushing 230 to move axially along the lead screw 210 via an intermediate transmission element (e.g., connecting piece 231). Specifically, when the electromagnetic lock is energized, the protrusion extends and acts on the bushing 230, driving the bushing 230 to move from a first position to a second position, thereby realizing the disengagement between the lead screw 210 and the nut 220; when the electromagnetic lock is de-energized, the protrusion retracts, and the bushing 230 resets under the action of the clutch elastic element 270. Compared with the combination scheme of electromagnet and suction plate, using an electromagnetic lock can further simplify the number of parts and the length of the transmission chain of the bushing drive 240, which is beneficial to reduce structural complexity and manufacturing cost, while providing a more direct linear driving force output. Of course, those skilled in the art will understand that the electromagnetic lock is only an alternative implementation of the bushing drive 240 and does not constitute a limitation on the scope of protection of the present invention. Any power element that can drive the bushing 230 to move linearly along the axial direction can be used as an alternative to the bushing drive 240.

[0105] In this embodiment of the invention, combined with Figure 4The alignment detection mechanism also includes a detection element 330 and a trigger element 340, which are used to cooperate with the aforementioned sensing element 310 and trigger baffle 320 to form a redundant detection mechanism, so as to further improve the accuracy and reliability of judging the position status of the bushing 230.

[0106] Specifically, the syringe pump 10 also has a second mounting plate 350 inside, which is fixed to the screw housing 250. The detection element 330 or the trigger element 340 is disposed on the second mounting plate 350. In one embodiment, the second mounting plate 350 is a circuit board. In an optional embodiment, the detection element 330 is fixedly disposed on the second mounting plate 350, and the trigger element 340 is disposed on the bushing 230. The bushing 230 can drive the trigger element 340 to move synchronously along the axial direction of the lead screw 210. The detection element 330 generates a corresponding detection signal by detecting whether the trigger element 340 is within its sensing range, so that the processor can determine whether the lead screw 210 and the nut 220 are disengaged after receiving the corresponding detection signal.

[0107] In another optional embodiment, the trigger 340 is fixedly mounted on the second mounting plate 350, and the detection element 330 is mounted on the bushing 230. The bushing 230 can drive the detection element 330 to move synchronously. The detection element 330 generates a corresponding detection signal by detecting whether the fixedly mounted trigger 340 is within its sensing range. Both of the above embodiments can realize the function of reflecting the position state of the bushing 230 by the relative position change between the detection element 330 and the trigger 340. Those skilled in the art can flexibly choose according to the actual structural layout and design requirements.

[0108] To facilitate the description and understanding of the present invention, the following description will take the example of the detection element 330 being fixedly disposed on the second mounting plate 350 and the trigger element 340 being disposed on the bushing 230. However, this example does not constitute any limitation on the scope of protection of the present invention.

[0109] Specifically, when the bushing 230 is in the first or third position, the trigger 340 mounted on the bushing 230 moves with the bushing 230 to a position corresponding to the detection element 330. The detection element 330 can detect the trigger 340 and generate a third signal. When the bushing 230 is in the second position, the trigger 340 moves with the bushing 230 to an area deviating from the sensing range of the detection element 330. The detection element 330 cannot detect the trigger 340 and generates a fourth signal different from the third signal. In other words, the detection element 330 and the trigger 340 work together to distinguish whether the bushing 230 is in an executable input position (i.e., the first or third position) or a non-executable input position (i.e., the second position), thereby providing the processor with another independent basis for determining the position status of the bushing 230.

[0110] Based on this, the processor receives dual signals from the sensor 310 and the detector 330, and performs a comprehensive judgment and mutual verification between the two. Specifically, when the bushing 230 is in the first or third position, the processor simultaneously receives the first signal output by the sensor 310 and the third signal output by the detector 330. The processor compares and verifies the first and third signals. If both indicate that the bushing 230 is in an operable infusion position, the processor comprehensively judges that the screw 210 and the screw block 221 are in a mutually meshing state (including both fully meshed and critically meshed but blocked situations). Regardless of whether the bushing 230 is in the first or third position, it indicates that the screw block 221 and the screw 210 have met the basic conditions for realizing motion transmission, that is, the injection pump 10 has the prerequisite for starting infusion. Therefore, this judgment result constitutes one of the conditions for starting infusion of the injection pump 10, and the processor can control the injection pump 10 to start or continue to perform precise infusion of the drug solution. By verifying the first and third signals, misjudgments caused by the failure of a single detection element or signal abnormality can be effectively avoided, significantly improving the reliability of status judgment.

[0111] When the bushing 230 is in the second position, the processor simultaneously receives the second signal output by the sensor 310 and the fourth signal output by the detector 330. The processor compares and verifies the second and fourth signals. If both indicate that the bushing 230 is in a non-operable infusion position, the processor determines that the lead screw 210 and the screw block 221 are in a disengaged state. At this time, the processor can control the syringe pump 10 to prohibit infusion operations and allow the operator to install or remove the syringe.

[0112] In some embodiments, the alignment detection mechanism may experience inconsistencies in the output signal types of the sensing element 310 and the detection element 330 due to differences in structural configuration or signal logic. For example, when the bushing 230 is in the second position, the relative positional relationship between the sensing element 310 and the trigger baffle 320 allows the sensing element 310 to sense the trigger baffle 320, resulting in the sensing element 310 generating a first signal instead of a second signal. In this case, the processor receives both the first signal output by the sensing element 310 and the fourth signal output by the detection element 330. Since the first and fourth signals logically constitute a contradictory combination, the processor, based on a comprehensive judgment of both, can still correctly identify that the bushing 230 is actually in the second position, rather than the first or third position. In other words, by cross-validating the signals from the sensing element 310 and the detection element 330, the processor can eliminate ambiguity caused by a single signal based on the logical relationship of the signal combination, even when the two signals are not completely consistent, thereby accurately determining the true position of the bushing 230.

[0113] Through the above-mentioned dual-path detection and signal verification mechanism, the alignment detection mechanism can not only distinguish whether the bushing 230 is in the first, second, or third position, but also verify and correct the signal of the other detection element when any detection element malfunctions or the signal is abnormal. This effectively avoids erroneous operation caused by misjudgment of a single signal source and further improves the safety and reliability of the injection pump 10.

[0114] In one embodiment, the types of sensing element 310 and detection element 330 can be flexibly selected according to actual design requirements, as long as they can detect the position state of trigger baffle 320 and trigger element 340 through non-contact or contact methods and generate corresponding electrical signals. As an optional implementation, both sensing element 310 and detection element 330 are photoelectric sensors, and correspondingly, trigger baffle 320 and trigger element 340 are light-blocking plates. Photoelectric sensors typically include a light emitting end and a light receiving end arranged opposite each other. When the light-blocking plate moves with the bushing 230 to between the emitting end and the receiving end of the photoelectric sensor, the light-blocking plate blocks the light path, preventing the receiving end of the photoelectric sensor from receiving the light signal, thereby outputting a corresponding detection signal; when the light-blocking plate moves out of the sensing area of ​​the photoelectric sensor, the light path of the photoelectric sensor is restored to conduction, and its output signal switches accordingly.

[0115] In another embodiment, both the sensing element 310 and the detection element 330 are microswitches, and correspondingly, both the trigger stop 320 and the trigger element 340 are contacts. A microswitch is a contact switch with a small travel distance and an internal elastic contact mechanism. When the contact on the sleeve 230 moves with the sleeve 230 to abut against the contact of the microswitch, the contact state of the microswitch switches, for example, from normally open to normally closed, or vice versa, thereby outputting a corresponding electrical signal. When the contact moves with the sleeve 230 and disengages from the microswitch, the microswitch returns to its initial contact state, and its output signal switches accordingly.

[0116] Those skilled in the art will understand that the aforementioned photoelectric sensor and micro switch are merely exemplary embodiments of the sensing element 310 and the detection element 330, and are not intended to limit their types. In other embodiments, the sensing element 310 and the detection element 330 may also be any other suitable sensing element such as a Hall sensor, an inductive proximity switch, a capacitive proximity switch, or a reed switch, as long as they can respond to changes in the position of the trigger baffle 320 or the trigger element 340 and output a corresponding detection signal. Similarly, the specific structural form of the trigger baffle 320 and the trigger element 340 should be designed to match the type of the selected sensing element. For example, when a Hall sensor is used, the trigger baffle 320 or the trigger element 340 should be a magnetic element.

[0117] In one specific embodiment, combined with Figure 4The handle 410 is equipped with a clamping mechanism 450, which is used to clamp and fix the plunger of the syringe, so as to realize a detachable connection between the infusion mechanism 400 and the syringe plunger. The nut 220 is connected to the handle 410 via a push rod 420, that is, the nut 220 transmits the driving force to the handle 410 through the push rod 420. When the nut 220 is engaged with the lead screw 210, the lead screw 210 rotates circumferentially around its own axis under the drive of the motor. The rotational motion is converted into linear motion of the nut 220 along the axial direction of the lead screw 210 through the thread engagement. The linear motion of the nut 220 is transmitted to the handle 410 through the push rod 420 connected to it, driving the handle 410 to make synchronous linear motion in the same direction. Since the plunger of the syringe has been clamped and fixed on the clamping mechanism 450, the linear movement of the handle 410 will push the plunger forward along its axis in the syringe barrel, so that the liquid medicine inside the syringe is continuously and at a constant speed pushed into the patient's body through the infusion line under the squeezing action of the plunger, thus completing the precise infusion of the liquid medicine.

[0118] In a further embodiment, combined with Figure 1 The syringe pump 10 also includes a housing 500, the interior of which is formed a mounting cavity. The actuating mechanism 200 and the alignment detection mechanism are both installed in the internal cavity of the housing 500, providing protection and support for these mechanisms through the housing 500. The handle 410 is located outside the housing 500. A mounting groove 510 is also formed on the outer surface of the housing 500. The mounting groove 510 is arranged along the extension direction of the syringe, and the mounting groove 510 and the clamping mechanism 450 are arranged along the same axis to facilitate the mounting of the syringe.

[0119] Specifically, combined Figure 1 and Figure 4 The syringe barrel is installed in the mounting groove 510, which provides positioning and support for the syringe barrel, ensuring its stable position during infusion. Simultaneously, the syringe plunger extends axially along the syringe barrel, with its end protruding from the syringe barrel and positioned on the clamping mechanism 450, which clamps and secures the plunger end. Through the cooperation between the mounting groove 510 of the housing 500 and the clamping mechanism 450 on the handle 410, the syringe is reliably mounted on the injection pump 10, maintaining a precise relative position between the syringe barrel and the handle 410 during infusion, thereby ensuring the accuracy of the handle 410's movement when pushing the plunger.

[0120] In summary, the injection pump provided by this invention can still generate a corresponding signal indicating that injection is possible when the thread tip of the screw block and the thread tip of the lead screw are in a critical abutment state. This allows the injection pump to start normally without interrupting the injection start operation due to an alarm triggered by the critical state. This effectively overcomes the false alarm problem caused by thread tip abutment in the prior art and significantly improves the reliability and intelligence of the injection pump under complex working conditions.

[0121] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions as those in the present invention.

[0122] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. An injection pump, characterized in that, This includes the processor, the motion mechanism, and the alignment detection mechanism; The action mechanism includes a lead screw, a nut, a bushing, and a bushing drive component. The bushing drive component drives the bushing to move so that when the bushing moves to the second position, the bushing releases the pressure on the nut, causing it to disengage from the lead screw. The alignment detection mechanism includes a sensor and a trigger baffle. One of the sensor and the trigger baffle moves synchronously with the bushing drive, while the other of the sensor and the trigger baffle moves synchronously with the bushing. During the reset process, when the bushing is in the third position between the first position and the second position, the bushing drive is correspondingly stopped on one side of the bushing. At this time, the sensing element triggers the first signal, wherein the first signal is at least one of the conditions for starting the infusion of the injection pump.

2. The syringe pump as described in claim 1, characterized in that, During the reset process, when the bushing moves to the first position, the bushing presses against the nut, causing it to engage with the lead screw. The bushing drive also stops on one side of the bushing. At this time, the sensor triggers the first signal.

3. The syringe pump as described in claim 2, characterized in that, The bushing is fitted onto the nut, which includes at least one screw block. The first end of the screw block is threaded. When the bushing moves to the second position of the nut, it releases the pressure on the first end of the screw block, causing the first end of the screw block to tilt up and disengage from the lead screw. When the bushing moves to the first position of the nut, it presses the first end of the nut, causing it to engage with the lead screw. When the bushing stops at the third position of the nut, it presses the first end of the nut, causing it to engage with the lead screw.

4. The syringe pump as described in claim 3, characterized in that, The nut includes multiple screw blocks, a screw shell, a fastening elastic element, and a pin. The multiple screw blocks are movably connected to the screw shell through the pin, and the second end of the multiple screw blocks is pivotally mounted on the screw shell through the fastening elastic element.

5. The syringe pump as described in claim 2, characterized in that, During the reset movement, when the bushing moves to the first position or stays at the third position, the trigger baffle is within the sensing range of the sensing element.

6. The syringe pump according to any one of claims 1-5, characterized in that, It also includes a push rod and a handle. The bushing drive includes an electromagnet and a support base. One end of the push rod is connected to the support base, and the other end of the push rod is linked to the handle. The support base is used to fix the electromagnet and the sensing element. The handle is used to receive external torque and convert it into driving torque to drive the push rod to move the electromagnet and the sensing element synchronously. The electromagnet is used to directly or indirectly drive the bushing to move to the second position during the disengagement process.

7. The syringe pump as claimed in claim 6, characterized in that, During the disengagement process, the trigger baffle gradually moves away from the sensing range of the sensor and remains outside the sensing range, at which point the sensor triggers a second signal.

8. The syringe pump as described in claim 6, characterized in that, It also includes a suction plate and a connecting plate. The connecting plate is provided on the bushing, and the suction plate and the connecting plate are movably connected. After the electromagnet is energized, the suction plate is magnetically attracted, which in turn drives the connecting plate and the bushing to move, so that the bushing reaches the second position.

9. The syringe pump as claimed in claim 8, characterized in that, There is a preset movable gap between the suction plate and the connecting plate; during the disengagement movement, the movable gap between the suction plate and the connecting plate remains unchanged; during the reset movement, when the bushing moves to the first position or stays at the third position, the suction plate abuts against the connecting plate to eliminate the movable gap.

10. The syringe pump as claimed in claim 9, characterized in that, The connecting piece is provided with a through hole, and the suction piece is provided with a connecting shaft. The connecting shaft passes through the through hole to realize the movable connection between the suction piece and the connecting piece.

11. The syringe pump as claimed in claim 6, characterized in that, It also includes a return spring and a clutch spring; the return spring is sleeved and one end abuts against the push rod, and the other end abuts against the support seat; the clutch spring is sleeved and one end abuts against the bushing, and the other end abuts against the nut; during the reset movement, the return spring and the clutch spring respectively push the electromagnet and the bushing to move until the bushing moves to the first position or stays in the third position, and the electromagnet or the support seat abuts against and stays on one side of the bushing.

12. The syringe pump according to any one of claims 1-5, characterized in that, The bushing drive includes a motor, which receives instructions from the processor to drive the bushing to move axially along the lead screw or rotate circumferentially around the nut. or The bushing drive includes an electromagnetic lock, which has a protrusion for pushing the bushing to move axially along the lead screw.

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