A hardware limit protection circuit for a syringe pump

Abstract

The utility model relates to a kind of injection pump hardware limit protection circuit, including, power supply control part, the power supply control part includes P type MOS tube Q7, N type triode Q6, resistance R7 and resistance R6, the both ends of resistance R6 are respectively with the grid and source electrode of P type MOS tube Q7 connection, the grid of P type MOS tube Q7 connects the collector of N type triode Q6, the emitter of N type triode Q6 is grounded, resistance R7 one end is connected with the base of N type triode Q6;Direction control part, the direction control part includes positive limit branch, reverse limit branch and P type triode Q10, the positive limit branch and reverse limit branch one end is connected with the base of N type triode Q6, the positive limit branch and reverse limit branch other end is connected with P type triode Q10;The utility model relies on circuit structure to judge to execute operating state with application condition, adopt small signal control large current, device is more small and exquisite, meet the space limit requirement of product, device selection is also relatively cheap.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, specifically a hardware limit protection circuit for an infusion pump. Background Technology

[0002] An infusion pump is a device used to push the piston of a syringe to inject fluid, achieving high-precision, stable, and pulsation-free liquid delivery. The syringe's advancement position is detected by a displacement sensor circuit, and a microprocessor controls the operation and stopping of the infusion pump's drive motor based on set parameters and sensor position information. In case of sensor failure, incorrect parameter settings, or abnormal microprocessor program operation, the infusion pump may exceed the predetermined advancement position, damaging the syringe and infusion pump equipment, causing adverse consequences. Limit switches are typically used for limiting movement, but limit switches with current switching capabilities are usually large and expensive, making them unsuitable for installation in precision infusion pump products. Utility Model Content

[0003] The purpose of this section is to provide a protection scheme for the operation of an injection pump. This scheme provides pure hardware protection independent of software when the injection pump exceeds its propulsion range, shutting off the motor and providing protection in both the propulsion and retraction directions. The software can be deactivated by running in the opposite direction. This prevents the injection pump from exceeding the predetermined propulsion position due to sensor failure, incorrect parameter settings, or abnormal microprocessor program operation, which could damage the syringe or injection pump and cause adverse consequences.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a hardware limit protection circuit for an injection pump, comprising,

[0005] The power control section includes a P-type MOSFET Q7, an N-type transistor Q6, a resistor R7, and a resistor R6. The two ends of the resistor R6 are connected to the gate and source of the P-type MOSFET Q7, respectively. The gate of the P-type MOSFET Q7 is connected to the collector of the N-type transistor Q6. The emitter of the N-type transistor Q6 is grounded. One end of the resistor R7 is connected to the base of the N-type transistor Q6.

[0006] The direction control section includes a forward limiting branch, a reverse limiting branch, and a P-type transistor Q10. One end of the forward limiting branch and the reverse limiting branch are connected to the base of an N-type transistor Q6, and the other end of the forward limiting branch and the reverse limiting branch are connected to the P-type transistor Q10.

[0007] As a preferred technical solution for a hardware limit protection circuit of an injection pump, the positive limit branch includes a limit switch SW3, a resistor R8, and an N-type transistor Q8. One end of the resistor R8 is connected to the limit switch SW3, and the other end is connected to the base of the N-type transistor Q8. The emitter of the N-type transistor Q8 is grounded, and the collector of the N-type transistor Q8 is connected to the base of the N-type transistor Q6.

[0008] As a preferred technical solution for a hardware limit protection circuit of an injection pump, the reverse limit branch includes a limit switch SW4, a resistor R9, and an N-type transistor Q9. One end of the resistor R9 is connected to the limit switch SW4, and the other end is connected to the base of the N-type transistor Q9. The emitter of the N-type transistor Q9 is grounded, and the collector of the N-type transistor Q9 is connected to the base of the N-type transistor Q6.

[0009] As a preferred technical solution for the hardware limit protection circuit of an injection pump, the emitter of the P-type transistor Q10 is connected to the control level VCC, and the base of the P-type transistor Q10 is connected to one end of the resistor R10.

[0010] As a preferred technical solution for a hardware limit protection circuit for an injection pump, the other end of the limit switch SW3 is connected to the other end of the resistor R10, and the other end of the limit switch SW4 is connected to the collector of the P-type transistor Q10.

[0011] As a preferred technical solution for the hardware limit protection circuit of an injection pump, the other end of the limit switch SW3 is connected to the collector of the P-type transistor Q10, and the other end of the limit switch SW4 is connected to the other end of the resistor R10.

[0012] As a preferred technical solution for a hardware limit protection circuit for an injection pump, it also includes a motor module. The motor module is provided with a power control terminal and a motor direction control terminal. A P-type MOSFET Q7 is provided between the power control terminal and the power supply VMOTOR. The power supply VMOTOR is connected to the source of the P-type MOSFET Q7, and the power control terminal is connected to the drain of the P-type MOSFET Q7.

[0013] As a preferred technical solution for the hardware limit protection circuit of an injection pump, it also includes a motor power control signal Vctr and a motor direction control signal DIR. The motor power control signal Vctr is connected to the other end of resistor R7, and the motor direction control signal DIR is connected to the other end of resistor R10 and the motor direction control terminal.

[0014] The beneficial effects of this utility model are: This utility model relies on the circuit structure to judge the application conditions and execute the operating state, uses a small signal to control a large current, the device is more compact, meets the space constraints of the product, and the device selection is also cheaper. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0016] Figure 1 This is a schematic diagram of a control circuit structure according to the present invention;

[0017] Figure 2 This is a schematic diagram of the circuit structure for another control method in this utility model.

[0018] Reference numerals: Power control section 100, Direction control section 200, Power control terminal 1, Motor direction control terminal 2, Motor speed control terminal 3. Detailed Implementation

[0019] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0022] Secondly, this utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, actual manufacturing should include the three-dimensional spatial dimensions of length, width, and depth.

[0023] Example 1

[0024] Reference Figures 1-2 This embodiment provides a hardware limit protection circuit for an injection pump, including:

[0025] The power control section 100 includes a P-type MOSFET Q7, an N-type transistor Q6, resistors R7 and R6. The two ends of resistor R6 are connected to the gate and source of the P-type MOSFET Q7, respectively. The gate of the P-type MOSFET Q7 is connected to the collector of the N-type transistor Q6. The emitter of the N-type transistor Q6 is grounded. One end of resistor R7 is connected to the base of the N-type transistor Q6. The direction control section 200 includes a forward limiting branch, a reverse limiting branch, and a P-type transistor Q10. One end of the forward limiting branch and the reverse limiting branch are connected to the base of the N-type transistor Q6, and the other end of the forward limiting branch and the reverse limiting branch are connected to the P-type transistor Q10.

[0026] The positive limit circuit includes a limit switch SW3, a resistor R8, and an N-type transistor Q8. One end of the resistor R8 is connected to the limit switch SW3, and the other end is connected to the base of the N-type transistor Q8. The emitter of the N-type transistor Q8 is grounded, and the collector of the N-type transistor Q8 is connected to the base of the N-type transistor Q6.

[0027] The reverse limit branch includes limit switch SW4, resistor R9 and N-type transistor Q9. One end of resistor R9 is connected to limit switch SW4 and the other end is connected to the base of N-type transistor Q9. The emitter of N-type transistor Q9 is grounded and the collector of N-type transistor Q9 is connected to the base of N-type transistor Q6.

[0028] It should be noted that limit switches SW3 and SW4 are respectively set at both ends of the injection pump for limiting. Furthermore, the end where limit switch SW3 is located is in the direction of forward movement of the injection pump, and is used for forward limiting. The end where limit switch SW4 is located is in the direction of reverse movement of the injection pump, and is used for reverse limiting.

[0029] The emitter of the P-type transistor Q10 is connected to the control level VCC, and the base of the P-type transistor Q10 is connected to one end of the resistor R10.

[0030] The other end of limit switch SW3 is connected to the other end of resistor R10, and the other end of limit switch SW4 is connected to the collector of P-type transistor Q10. This is used when the motor direction control signal DIR is high during forward control and low during reverse control.

[0031] As an alternative connection scheme: the other end of limit switch SW3 is connected to the collector of P-type transistor Q10, and the other end of limit switch SW4 is connected to the other end of resistor R10. This is used when the motor direction control signal DIR is set to a low level for forward control and a high level for reverse control.

[0032] It also includes a motor module, which has a power control terminal 1 and a motor direction control terminal 2. A P-type MOSFET Q7 is provided between the power control terminal 1 and the power supply VMOTOR. The power supply VMOTOR is connected to the source of the P-type MOSFET Q7, and the power control terminal 1 is connected to the drain of the P-type MOSFET Q7.

[0033] The power control terminal 1 is used to supply power to the motor module, the motor direction control terminal 2 is used to control the motor to rotate forward or backward, and the motor module is also equipped with a motor speed control terminal 3 to control the motor speed.

[0034] It also includes a motor power control signal Vctr and a motor direction control signal DIR. The motor power control signal Vctr is connected to the other end of resistor R7, and the motor direction control signal DIR is connected to the other end of resistor R10 and motor direction control terminal 2.

[0035] It utilizes MOSFETs to control the switching of the motor module power supply. The protection control signal, after being NOT processed, is ANDed with the normal motor power supply control signal to control the MOSFET. When a limit signal is applied, the limit signal, after being NOT processed, becomes "0," and after being ANDed with the normal motor power supply control signal ("1"), it becomes "0," thus turning off the motor module power supply MOSFET. The limit signal is obtained by calculating the limit switch and the motor direction signal, and consists of two signals: a forward limit signal and a reverse limit signal.

[0036] The limit switch uses a three-way micro-motion detection switch, which is installed at the normal operating limit position of the pump body. The motor rotation direction is controlled by the high and low level control motor module drive circuit.

[0037] Option 1, where the control method involves a high level for forward operation and a low level for reverse operation, is solved by performing a AND operation on the motor direction control signal and the forward limit switch in series to generate a forward limit protection control signal; and by performing a AND operation on the inverted motor direction control signal and the reverse limit switch in series to generate a reverse limit protection control signal. The forward and reverse limit protection control signals are then output in parallel and ANDed with the normal motor power control signal.

[0038] When the positive control signal level is high and the positive limit switch is activated, the positive limit protection control signal is valid. After the NOT logic, it becomes 0. When ANDed with the normal motor power control signal, the result is 0, and the motor module power MOSFET is turned off. When the signal direction is reversed and the control level is low, the above result becomes 1, and the motor module power MOSFET is turned on, and the motor can reverse normally.

[0039] When the reverse control signal level is low, it becomes high after inversion. When the reverse limit switch is activated, the reverse limit protection control signal is valid. After NOT logic, it becomes 0. When ANDed with the normal motor power control signal, the result is 0, and the motor module power MOSFET is turned off. When the signal direction is reversed and the control level is high, the above result becomes 1, and the motor module power MOSFET is turned on, and the motor can rotate normally in the forward direction.

[0040] Option 2, where the control method involves a low-level control signal for forward operation and a high-level control signal for reverse operation, involves inverting the motor direction control signal and performing a AND operation with the forward limit switch to generate a forward limit protection control signal. Similarly, a AND operation is performed with the reverse limit switch in series with the motor direction control signal to generate a reverse limit protection control signal. The forward and reverse limit protection control signals are then output in parallel and ANDed with the normal motor power control signal.

[0041] When the positive control signal is low and then inverted to high, and the positive limit switch is activated, the positive limit protection control signal is valid. After the NOT logic, it becomes 0. When ANDed with the normal motor power control signal, the result is 0, and the motor module power MOSFET is turned off. When the signal direction is reversed and the control level is high, the above result becomes 1, and the motor module power MOSFET is turned on, and the motor can reverse normally.

[0042] When the reverse control signal is high and the reverse limit switch is activated, the reverse limit protection control signal is valid. After NOT logic, it becomes 0. When ANDed with the normal motor power control signal, the result is 0, and the motor module power MOSFET is turned off. When the signal direction is reversed and the control level is low, the above result becomes 1, and the motor module power MOSFET is turned on, allowing the motor to rotate normally in the forward direction.

[0043] In summary, when the infusion pump exceeds its propulsion range, the above-mentioned circuitry can implement pure hardware protection independently of the software, shutting off the motor operation, providing protection in both the propulsion and retraction directions, and allowing the software to be run in the opposite direction to deactivate the protection. This prevents the infusion pump from exceeding the predetermined propulsion position due to sensor malfunction, incorrect parameter settings, or abnormal microprocessor program operation, which could damage the syringe, infusion pump equipment, and cause adverse consequences.

[0044] Specifically, as shown in the figure, this utility model utilizes a MOSFET for switching control of the motor module power supply. The protection control signal, after being NOT processed, is ANDed with the normal motor power supply control signal to control the MOSFET. When a limit signal is implemented, the limit signal, after being NOT processed, becomes "0," and after being ANDed with the normal motor power supply control signal "1," it becomes "0," thereby turning off the motor module power supply MOSFET and stopping the motor for protection. The limit signal is obtained by calculating the limit switch and the motor direction signal, and consists of two signals: a forward limit signal and a reverse limit signal.

[0045] The limit switch uses a three-way micro-motion detection switch, which is installed at the normal operating limit position of the pump body. The motor rotation direction is realized by high and low level control of the motor module drive circuit; the motor module direction control can be designed as high and low level control.

[0046] There are two logic levels for the control level, as detailed below:

[0047] 1. The control method is as follows: the control level is high for forward operation and low for reverse operation. Figure 1 As shown,

[0048] When the motor is running in the forward direction, the motor power control signal Vctr is at a high level, the P-type transistor Q10 is unbiased and cut off, and the reverse limit switch SW4 circuit does not function.

[0049] When the motor is running in the forward direction, the motor direction control signal DIR is at a high level, and pins 2 and 3 of the forward limit switch SW3 provide a high level. When the limit position is reached, the forward limit switch SW3 is turned on, and pins 1 and 4 of the forward limit switch SW3 output a high level. The N-type transistor Q8 is forward biased, and the CE junction is turned on. The bypass of the base signal of the N-type transistor Q6 makes the motor power control signal invalid. The N-type transistor Q6 is not forward biased and is cut off. The P-type MOSFET Q7 has no pull-down drive and is cut off. The power supply VMOTOR cannot be delivered to the motor module power supply, and the motor stops running in the forward direction. When the limit position is not reached, the forward limit switch SW3 circuit does not function, the motor power control signal Vctr is successfully delivered to the N-type transistor Q6, the N-type transistor Q6 is turned on, the P-type MOSFET Q7 is turned on, the power supply VMOTOR is delivered to the motor module power supply, and the motor runs normally in the forward direction.

[0050] When the signal direction is reversed and the control level is low, pins 2 and 3 of the forward limit switch SW3 become low. N-type transistor Q8 is not forward biased and is cut off, releasing its effect on N-type transistor Q6. Since the motor power control signal is valid, N-type transistor Q6 is forward biased, and the CE junction is turned on. P-type MOSFET Q7 is pulled down and turned on, and the power supply VMOTOR is normally delivered to the motor module, causing the motor to run in reverse.

[0051] At this time, P-type transistor Q10 is forward biased and conducts. The control level VCC voltage is sent to pins 2 and 3 of the reverse limit switch SW4. When the limit position is reached, the reverse limit switch SW4 conducts, and pins 1 and 4 of SW4 output a high level. N-type transistor Q9 is forward biased and the CE junction is conducted, bypassing the base signal of N-type transistor Q6, making the motor power control signal invalid. N-type transistor Q6 is not forward biased and is cut off. P-type MOSFET Q7 has no pull-down drive and is cut off. Power supply VMOTOR cannot be sent to the motor module power supply, and the motor reverses and stops.

[0052] When the signal direction is reversed, the motor direction control signal DIR changes to a high level, the P-type transistor Q10 is unbiased and cut off, the reverse limit switch SW4 circuit does not function, and the protection is released.

[0053] It should be noted that, Figure 2 middle components and Figure 1 All components correspond completely; for ease of understanding... Figure 2 Each component in the middle is renumbered. Figure 2 and Figure 1 The difference in the connections lies in the different connection positions of limit switches SW4 and SW3 with P-type transistor Q10. Specifically: Figure 1 The other end of the limit switch SW3 is connected to the other end of the resistor R10, and the other end of the limit switch SW4 is connected to the collector of the P-type transistor Q10. Figure 2 The other end of the middle limit switch SW3 (SW1) is connected to the collector of the P-type transistor Q10, and the other end of the limit switch SW4 (SW2) is connected to the other end of the resistor R10.

[0054] Specifically, Figure 2 The working principle is as follows:

[0055] II. The control method is as follows: forward operation control level is low, and reverse operation control level is high. Figure 2 As shown.

[0056] When the motor is running in the forward direction, the motor direction control signal DIR is at a low level, and the reverse limit switch SW2 circuit does not function.

[0057] When the motor is running in the forward direction, the motor direction control signal DIR is low, the P-type transistor Q5 is forward biased and conducts, and the control level VCC is sent to pins 2 and 3 of the forward limit switch SW1. When the limit position is reached, the forward limit switch SW1 conducts, and pins 1 and 4 of the forward limit switch SW1 output a high level, the N-type transistor Q3 is forward biased, the CE junction conducts, the bypass N-type transistor Q2 base signal makes the motor power control signal Vctr invalid, the N-type transistor Q2 is not forward biased and is cut off, the P-type MOSFET Q1 has no pull-down drive and is cut off, the power supply VMOTOR cannot be sent to the motor module power supply, and the motor stops running in the forward direction; when the limit position is not reached, the forward limit switch circuit 1 does not function, Vctr is successfully sent to the N-type transistor Q2, the N-type transistor Q2 conducts, the P-type MOSFET Q1 conducts, the power supply VMOTOR is sent to the motor module power supply, and the motor runs normally in the forward direction.

[0058] When the motor direction control signal DIR reverses and the motor needs to be driven to reverse, the motor direction control signal DIR is at a high level. P-type transistor Q5 is not forward biased and is cut off. Therefore, there is no voltage at pins 2 and 3 of the forward limit switch SW1, and no voltage at pins 1 and 4 of the forward limit switch SW1. N-type transistor Q3 is not forward biased and is cut off, releasing the effect on N-type transistor Q2. Since the motor power control signal Vctr is valid, N-type transistor Q2 is forward biased, and the CE junction is turned on. P-type MOSFET Q1 is pulled down and turned on. The power supply VMOTOR is normally delivered to the motor module, and the motor runs in reverse.

[0059] When the reverse limit position is reached, the reverse limit switch SW2 is turned on, and pins 1 and 4 of the reverse limit switch SW2 output a high level. The N-type transistor Q4 is forward biased, the CE junction is turned on, and the base signal of the N-type transistor Q2 is bypassed, making the motor power control signal Vctr invalid. The N-type transistor Q2 is not forward biased and is cut off. The P-type MOSFET Q1 is not pulled down and is cut off. The power supply VMOTOR cannot be delivered to the motor module power supply, and the motor stops in reverse.

[0060] When the motor reverses direction, the motor direction control signal DIR changes to a low level, the reverse limit switch SW2 circuit becomes ineffective, and the protection is released.

[0061] This invention employs a pure hardware circuit scheme for stroke displacement protection of an injection pump. It can operate independently of software and still provide protection in the event of sensor failure or software malfunction. Furthermore, it uses a small signal to control a large current, making the device more compact and meeting the space constraints of the product. The device selection is also more cost-effective.

[0062] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A hardware limit protection circuit for an injection pump, characterized in that: include, The power control section (100) includes a P-type MOSFET Q7, an N-type transistor Q6, a resistor R7, and a resistor R6. The two ends of the resistor R6 are connected to the gate and source of the P-type MOSFET Q7, respectively. The gate of the P-type MOSFET Q7 is connected to the collector of the N-type transistor Q6. The emitter of the N-type transistor Q6 is grounded. One end of the resistor R7 is connected to the base of the N-type transistor Q6. The direction control section (200) includes a forward limiting branch, a reverse limiting branch, and a P-type transistor Q10. One end of the forward limiting branch and the reverse limiting branch is connected to the base of an N-type transistor Q6, and the other end of the forward limiting branch and the reverse limiting branch is connected to the P-type transistor Q10.

2. The hardware limit protection circuit for the syringe pump according to claim 1, characterized in that: The positive limit branch includes a limit switch SW3, a resistor R8, and an N-type transistor Q8. One end of the resistor R8 is connected to the limit switch SW3, and the other end is connected to the base of the N-type transistor Q8. The emitter of the N-type transistor Q8 is grounded, and the collector of the N-type transistor Q8 is connected to the base of the N-type transistor Q6.

3. The hardware limit protection circuit for the injection pump according to claim 2, characterized in that: The reverse limit branch includes a limit switch SW4, a resistor R9, and an N-type transistor Q9. One end of the resistor R9 is connected to the limit switch SW4, and the other end is connected to the base of the N-type transistor Q9. The emitter of the N-type transistor Q9 is grounded, and the collector of the N-type transistor Q9 is connected to the base of the N-type transistor Q6.

4. The hardware limit protection circuit for the injection pump according to claim 3, characterized in that: The emitter of the P-type transistor Q10 is connected to the control level VCC, and the base of the P-type transistor Q10 is connected to one end of the resistor R10.

5. The hardware limit protection circuit for the injection pump according to claim 4, characterized in that: The other end of the limit switch SW3 is connected to the other end of the resistor R10, and the other end of the limit switch SW4 is connected to the collector of the P-type transistor Q10.

6. The hardware limit protection circuit for the injection pump according to claim 4, characterized in that: The other end of the limit switch SW3 is connected to the collector of the P-type transistor Q10, and the other end of the limit switch SW4 is connected to the other end of the resistor R10.

7. The hardware limit protection circuit for the syringe pump according to claim 6, characterized in that: It also includes a motor module, which is provided with a power control terminal (1) and a motor direction control terminal (2). A P-type MOS transistor Q7 is provided between the power control terminal (1) and the power supply VMOTOR. The power supply VMOTOR is connected to the source of the P-type MOS transistor Q7, and the power control terminal (1) is connected to the drain of the P-type MOS transistor Q7.

8. The hardware limit protection circuit for the syringe pump according to claim 7, characterized in that: It also includes a motor power control signal Vctr and a motor direction control signal DIR. The motor power control signal Vctr is connected to the other end of resistor R7, and the motor direction control signal DIR is connected to the other end of resistor R10 and the motor direction control terminal (2).

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