Negative pressure control device and rotary cutting device

Abstract

The utility model discloses a negative pressure control device and a rotary cutting device, the negative pressure control device comprises a controller, a vacuum pump, a proportional valve, a pressure sensing device, a photoelectric coupler and a gas pipeline, the vacuum pump is connected with the gas pipeline, the gas pipeline is provided with the proportional valve, and the proportional valve is used for adjusting the negative pressure generated by the vacuum pump; a pressure sensing device is arranged on the gas pipeline, is connected with the controller and is used for sending the current gas pressure in the gas pipeline to the controller; the controller is connected with the proportional valve and used for obtaining the current conduction state of the proportional valve; the photoelectric coupler is connected with the proportional valve, the proportional valve adjusts the conduction proportion according to the illumination intensity of the photoelectric coupler, the controller sends PWM signals with different duty ratios to the proportional valve according to the current air pressure and the current conduction state of the proportional valve, and the photoelectric coupler emits light to different degrees according to the PWM signals with different duty ratios. Therefore, the conduction proportion of the proportional valve is adjusted. The negative pressure can be adjusted in real time, and data are more accurate.

Description

Technical Field

[0001] The utility model relates to the field of medical devices, and further relates to a negative pressure control device and a rotary cutting device. Background Art

[0002] With the rapid growth of the incidence rate of breast diseases, breast biopsy systems are usually used to help patients determine whether the cells in the area to be examined are cancerous. Hospitals usually use rotary cutting devices to repeatedly cut suspicious lesions and store them in a sample collection device through vacuum suction to obtain histological specimens of the breast.

[0003] However, in traditional methods for controlling vacuum negative pressure, open-loop control is usually adopted. If the negative pressure value changes due to external factors or internal factors, real-time feedback cannot be carried out, which easily leads to inaccurate operation of the rotary cutting device, resulting in poor tissue cutting effect, incomplete sampling, inaccurate sampling, etc., bringing risks to the operation. Summary of the Utility Model

[0004] Aiming at the above technical problems, the purpose of the utility model is to provide a negative pressure control device and a rotary cutting device. The controller respectively obtains the current air pressure in the gas pipeline sent by the pressure sensing device and the current conduction state of the proportional valve, and sends PWM signals with different duty cycles to the proportional valve according to the current air pressure and the current conduction state of the proportional valve, so as to adjust the conduction ratio of the proportional valve, realize real-time feedback and adjustment of the air pressure in the gas pipeline, and realize precise control of the negative pressure.

[0005] To achieve the above purpose, the utility model provides a negative pressure control device, including: a controller, a vacuum pump, a proportional valve, a pressure sensing device, an optocoupler and a gas pipeline.

[0006] The vacuum pump is connected to the gas pipeline, and a proportional valve is arranged on the gas pipeline, and the proportional valve is used to adjust the negative pressure generated by the vacuum pump.

[0007] A pressure sensing device is arranged on the gas pipeline, and the pressure sensing device is connected to the controller and is used to send the current air pressure in the gas pipeline to the controller.

[0008] The controller is connected to the proportional valve and is used to obtain the current conduction state of the proportional valve.

[0009] The optocoupler is connected to the proportional valve. The proportional valve adjusts the conduction ratio according to the light intensity of the optocoupler. The controller sends PWM signals with different duty cycles to the proportional valve according to the current air pressure and the current conduction state of the proportional valve. The optocoupler emits light to different degrees according to the PWM signals with different duty cycles, thereby adjusting the conduction ratio of the proportional valve.

[0010] In some embodiments, it further includes:

[0011] A current detection circuit for detecting the conduction current of the proportional valve and sending the conduction current to the controller. The controller judges the current conduction state of the proportional valve according to the conduction current and adjusts the conduction ratio of the proportional valve according to the current air pressure and the current conduction state of the proportional valve.

[0012] In some embodiments, it further includes:

[0013] A voltage detection circuit for detecting the current air pressure of the pressure sensing device, converting the current air pressure into a current voltage value and sending it to the controller. The controller adjusts the conduction ratio of the proportional valve according to the current voltage value and the current conduction state of the proportional valve.

[0014] In some embodiments, it further includes:

[0015] An amplification and filtering circuit 400. The amplification and filtering circuit 400 is respectively connected to the current detection circuit and the controller. The amplification and filtering circuit 400 is used to amplify the conduction current of the proportional valve and send the processed conduction current to the controller.

[0016] In some embodiments, the amplification and filtering circuit 400 includes:

[0017] A tenth resistor, an eleventh resistor, a ninth capacitor, a first power supply and an operational amplifier;

[0018] The non-inverting input terminal of the operational amplifier is connected to the current detection circuit;

[0019] The output terminal of the first power supply is connected to the first end of the tenth resistor. The second end of the tenth resistor is respectively connected to the first end of the ninth capacitor and the first end of the eleventh resistor. The second end of the ninth capacitor is grounded. The second end of the eleventh resistor is grounded. The second end of the tenth resistor is also connected to the inverting input terminal of the operational amplifier. The output terminal of the operational amplifier is connected to the signal input terminal of the controller.

[0020] In some embodiments, the current detection circuit includes:

[0021] The eighteenth resistor, the first end of the eighteenth resistor is respectively connected to the optocoupler and the amplifying and filtering circuit 400, and the second end of the eighteenth resistor is grounded.

[0022] In some embodiments, the voltage detection circuit includes:

[0023] A thirteenth resistor, a sixteenth resistor, an eighth capacitor, and a second power supply;

[0024] The first pin of the pressure sensing device is connected to the second power supply, the first pin of the pressure sensing device is connected to the first end of the eighth capacitor, the second end of the eighth capacitor is grounded, the second pin of the pressure sensing device is connected to the first end of the thirteenth resistor, the second end of the thirteenth resistor is grounded through the sixteenth resistor, the second end of the thirteenth resistor is connected to the controller, and the third pin of the pressure sensing device is grounded.

[0025] In some embodiments, it further includes:

[0026] A twelfth resistor, the twelfth resistor is used to control the input voltage of the optocoupler, the first end of the twelfth resistor is connected to the signal output end of the controller, and the second end of the twelfth resistor is connected to the optocoupler.

[0027] In some embodiments, it further includes:

[0028] A fourteenth resistor and a seventeenth resistor, the fourteenth resistor and the seventeenth resistor are used to control the output voltage of the amplifying and filtering circuit, the first end of the fourteenth resistor is connected to the amplifying and filtering circuit, the second end of the fourteenth resistor is respectively connected to the first end of the seventeenth resistor and the first input end of the controller, and the second end of the seventeenth resistor is grounded.

[0029] According to another aspect of the present invention, the present invention further provides a rotary cutting device, including: a biopsy needle, a sealed container, and any one of the above-mentioned negative pressure control devices. The output end of the negative pressure control device is connected to the input end of the sealed container. The negative pressure control device is used to generate negative pressure on the sealed container. The output end of the sealed container is connected to the biopsy needle. The sealed container is used to collect the tissue excised by the biopsy needle.

[0030] Compared with the prior art, the negative pressure control device and the rotary cutting device provided by the present invention have the following beneficial effects:

[0031] The controller respectively obtains the current air pressure in the gas pipeline sent by the pressure sensing device and the current conduction state of the proportional valve, and sends PWM signals with different duty cycles to the proportional valve according to the current air pressure and the current conduction state of the proportional valve, so as to adjust the conduction ratio of the proportional valve. Through the interaction between the pressure sensing device and the proportional valve, the real-time feedback and adjustment of the air pressure in the gas pipeline are realized, and the precise control of negative pressure is achieved.

[0032] At the same time, the circuit of the present utility model uses fewer components, has a simple circuit structure and simple wiring, making the operation and later maintenance more convenient, and reducing the economic cost at the same time. Brief Description of the Drawings

[0033] The following will further illustrate the above characteristics, technical features, advantages and their implementation manners of the present utility model in a clear and understandable manner in combination with the drawings of the preferred embodiments.

[0034] Figure 1 is a structural diagram of a negative pressure control device of the present utility model;

[0035] Figure 2 is the overall circuit diagram of a negative pressure control device of the present utility model. Detailed Embodiments

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the specific embodiments of the present utility model will be described below with reference to the drawings. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to these drawings, and other embodiments can be obtained.

[0037] To make the drawings concise, only the parts related to the utility model are schematically shown in each drawing, and they do not represent the actual structure of the product. In addition, for the sake of simplicity and easy understanding of the drawings, in some drawings, components with the same structure or function are only schematically shown for one of them, or only one of them is marked. In this article, "one" not only means "only this one", but also means "more than one" situation.

[0038] It should also be further understood that the term "and / or" used in the specification and claims of the present application refers to any combination and all possible combinations of one or more of the related listed items, and includes these combinations.

[0039] In this text, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "linkage" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0040] In addition, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0041] A breast biopsy system is the most commonly used instrument to help patients determine whether the cells in the area to be examined are cancerous. The rotary cutting device can be used to repeatedly cut the suspicious lesion, and through vacuum aspiration, it is stored in the sample collection device to obtain the histological specimen of the area to be examined for doctors to check. Since it can perform minimally invasive resection biopsy on tumors with a relatively small volume, it belongs to a minimally invasive surgery, and the entire puncture process is carried out under ultrasonic imaging with accurate positioning, and it also supports the collection of multiple consecutive samples. Therefore, it is widely used.

[0042] However, the existing rotary cutting devices, especially breast rotary cutting devices, are usually open-loop controlled and do not support real-time detection of negative pressure. If the negative pressure value changes due to external factors or internal factors, real-time feedback cannot be carried out, let alone real-time adjustment. Users cannot timely grasp the current negative pressure situation, which easily leads to inaccurate operation of the rotary cutting device, resulting in poor tissue cutting effect, or incomplete or inaccurate sampling, bringing risks to the operation.

[0043] Therefore, the embodiments of this application provide a negative pressure control device and a rotary cutting device. The pressure sensing device detects and sends the current air pressure in the gas pipeline to the controller in real time, and the current conduction state of the proportional valve is also sent to the controller in real time. The controller sends PWM (pulse width modulation) signals with different duty cycles to the proportional valve according to the current air pressure and the current conduction state of the proportional valve to adjust the conduction ratio of the proportional valve. Through the interaction between the pressure sensing device and the proportional valve, real-time feedback and adjustment of the air pressure in the gas pipeline are achieved, and precise control of the negative pressure is realized. At the same time, the circuit of the present utility model uses fewer components, has a simple circuit structure and simple wiring, making operation and later maintenance more convenient, and reducing the economic cost at the same time.

[0044] In one embodiment, the present utility model provides a negative pressure control device, comprising: a controller, a vacuum pump, a proportional valve V1, a pressure sensing device 100, an optocoupler U2, and a gas pipeline. The vacuum pump is connected to the gas pipeline, and the proportional valve V1 is arranged on the gas pipeline. The proportional valve V1 is used to adjust the negative pressure generated by the vacuum pump;

[0045] The pressure sensing device 100 is arranged on the gas pipeline. The pressure sensing device 100 is connected to the controller and is used to send the current air pressure in the gas pipeline to the controller;

[0046] The controller is connected to the proportional valve V1 and is used to obtain the current conduction state of the proportional valve V1;

[0047] The optocoupler U2 is connected to the proportional valve V1. The proportional valve V1 adjusts its conduction ratio according to the light intensity of the optocoupler U2. The controller sends PWM signals with different duty cycles to the proportional valve V1 according to the current air pressure and the current conduction state of the proportional valve V1. The optocoupler U2 emits light to different degrees according to the PWM signals with different duty cycles, so as to adjust the conduction ratio of the proportional valve V1.

[0048] Please refer to Figure 1 , which is a structural diagram of a negative pressure control device provided by an embodiment of the present application.

[0049] In implementation, the vacuum pump is connected to the gas pipeline, and the proportional valve V1 and the pressure sensing device 100 are arranged on the gas pipeline. That is, the vacuum pump is connected to the proportional valve V1 through the gas pipeline, the vacuum pump is connected to the pressure sensing device 100 through the gas pipeline, the proportional valve V1 is further connected to the optocoupler U2 that can emit light, the optocoupler U2 is connected to the controller, the optocoupler U2 can emit light to different degrees according to the PWM signals with different duty cycles sent by the controller, the pressure sensing device 100 is connected to the controller, and the pressure sensing device 100 can detect the current voltage of the gas pipeline in real time and send it to the controller.

[0050] In one embodiment, the first end of the optocoupler U2 is connected to the signal output end PUMP_EN of the controller, the second end of the optocoupler U2 is grounded, the third end of the optocoupler U2 is connected to the proportional valve V1, the fourth end of the optocoupler U2 is connected to the first end of the current detection circuit 200, the second end of the current detection circuit 200 is grounded, the fourth end of the optocoupler U2 is further connected to the input end of the amplification and filtering circuit 400, the output end of the amplification and filtering circuit 400 is grounded, and the output end of the amplification and filtering circuit 400 is connected to the signal input end PUMP_ALARM of the controller.

[0051] In a specific embodiment, a vacuum pump is sequentially connected to a proportional valve V1 and a pressure sensing device 100. When the negative pressure control device starts to operate, the vacuum pump generates a negative pressure. The proportional valve V1 adjusts the negative pressure generated by the vacuum pump in real time through a conduction ratio. At the same time, the current conduction state of the proportional valve V1 is sent to the controller in real time; the pressure sensing device 100 detects the current air pressure in the gas pipeline in real time and feeds back the current air pressure to the controller; the controller calculates PWM signals with different duty cycles according to the current air pressure and the current conduction state of the proportional valve V1, and cooperates with the PID algorithm, and sends them to the optocoupler U2. The optocoupler U2 emits light to different degrees according to the PWM signals with different duty cycles. The greater the light intensity of the light-emitting diode of the optocoupler U2, the greater the conduction degree of the receiving tube of the optocoupler U2, and the greater the conduction degree of the proportional valve V1, realizing the adjustment of the conduction ratio of the proportional valve V1 and achieving precise control of the negative pressure.

[0052] In implementation, the PID algorithm refers to a control algorithm that combines proportional, integral, and derivative. The essence of PID control is to perform operations according to the function relationships of proportional, integral, and derivative based on the input deviation value, thereby calculating the control signal and finally achieving effective control of the target object.

[0053] In one embodiment, when the negative pressure generated by the vacuum pump is too high or too low, the air pressure value of the proportional valve V1 changes, which may cause a change in the current conduction state of the proportional valve V1. At the same time, the pressure sensing device 100 sends the detected current air pressure to the controller, and the controller compares the received current air pressure with the preset standard air pressure. If the current air pressure exceeds the safety threshold of the preset standard air pressure, the controller issues PWM signals with different duty cycles to adjust the conduction ratio of the proportional valve V1.

[0054] In one embodiment, the vacuum pump includes: a negative pressure pump.

[0055] In one embodiment, the controller includes: a single-chip microcomputer.

[0056] In one embodiment, the pressure sensing device 100 includes: a high-precision gas pressure sensor.

[0057] It should be noted that the installation positions and the number of installations of the proportional valve V1 and the pressure sensing device 100 can be set according to the actual application scenario and are not limited here.

[0058] In a preferred embodiment, the number of the proportional valve V1 on the gas pipeline is one, the number of the pressure sensing device 100 is one, and the distance from the proportional valve V1 to the vacuum pump on the gas pipeline is less than the distance from the pressure sensing device 100 to the vacuum pump.

[0059] It should be noted that the safety threshold is set according to the actual application scenario and is not limited here.

[0060] Through the interaction between the pressure sensing device 100 and the proportional valve V1, real-time feedback and adjustment of the air pressure in the gas pipeline are achieved, and precise control of the negative pressure is realized.

[0061] Please refer to Figure 2 , which is the overall circuit diagram of a negative pressure control device of the present utility model.

[0062] In one embodiment, the pressure sensing device 100 detects the current air pressure in the gas pipeline in real time. The voltage detection circuit 300 receives the current air pressure, converts the current air pressure into a current voltage value, and sends it to the controller.

[0063] The signal output terminal PUMP_EN of the controller is connected to the first end of the twelfth resistor R12. The second end of the twelfth resistor R12 is connected to the optocoupler U2. The optocoupler U2 is connected to the first end of the proportional valve V1. The second end of the proportional valve V1 is connected to the third power supply. At the same time, the proportional valve V1 is connected to the current detection circuit 200 through the optocoupler U2. After passing through the amplifier and filter circuit 400, the current detection circuit 200 is connected to the signal input terminal PUMP_ALARM of the controller.

[0064] When the circuit is turned on, the controller sends a PWM signal to the optocoupler U2 through the signal output terminal PUMP_EN. The optocoupler U2 emits light of different intensities according to the PWM signals with different duty cycles. At the same time, the larger the duty cycle of the PWM signal, the greater the conduction degree of the optocoupler U2, and the greater the conduction degree of the proportional valve V1 is controlled; the smaller the duty cycle of the PWM signal, the smaller the conduction degree of the optocoupler U2, and the smaller the conduction ratio of the proportional valve V1 is controlled; the conduction ratio of the proportional valve V1 is adjusted by the PWM signals with different duty cycles.

[0065] At the same time, the larger the conduction ratio of the proportional valve V1, the larger the conduction current passing through the current detection circuit 200, indicating that the voltage at the current detection circuit 200 is larger. The voltage at the current detection circuit 200 is sent to the signal input terminal PUMP_ALARM of the controller after passing through the amplifier and filter circuit 400.

[0066] The pressure sensing device 100 detects the current air pressure at the gas pipeline in real time, processes it through the voltage detection circuit 300 to obtain the current voltage value, and sends it to the controller.

[0067] The controller, based on the current voltage value sent by the voltage detection circuit 300 and the voltage value representing the conduction ratio of the proportional valve V1 sent by the amplification and filtering circuit 400, combines the PID algorithm and sends PWM signals with different duty cycles to the optocoupler U2 to adjust the conduction ratio of the proportional valve V1, thereby achieving the control of the negative pressure value.

[0068] In a specific embodiment, the voltage value connected to the third power supply is +12V.

[0069] The controller receives the current voltage value and the conduction current of the proportional valve V1, combines the PID algorithm, and sends PWM signals with different duty cycles to the optocoupler U2 through the signal output terminal PUMP_EN. The light-emitting diode of the optocoupler U2 emits light with different intensities according to the duty cycle of the PWM signal. Specifically, the higher the duty cycle of the PWM signal, the greater the light-emitting intensity of the light-emitting diode of the optocoupler U2, the greater the conduction degree of the receiving tube of the optocoupler U2, and the greater the conduction ratio of the proportional valve V1. That is, by adjusting the duty cycle of the PWM signal, the conduction ratio of the proportional valve V1 is adjusted to achieve the setting of different negative pressure values.

[0070] In an embodiment, the negative pressure control device further includes: a voltage detection circuit 300. The voltage detection circuit 300 is connected to the pressure sensing device 100. The voltage detection device is used to detect the current air pressure of the pressure sensing device 100, convert the current air pressure into a current voltage value and send it to the controller, and the controller adjusts the conduction ratio of the proportional valve V1 according to the current voltage value and the current conduction state of the proportional valve V1.

[0071] In an embodiment, refer to Figure 2 , the voltage detection circuit 300 includes: a thirteenth resistor R13, a sixteenth resistor R16, an eighth capacitor C8, and a second power supply;

[0072] The first pin VS of the pressure sensing device 100 is connected to the second power supply. The first pin VS of the pressure sensing device 100 is connected to the first end of the eighth capacitor C8. The second end of the eighth capacitor C8 is grounded. The second pin V0 of the pressure sensing device 100 is connected to the first end of the thirteenth resistor R13. The second end of the thirteenth resistor R13 is grounded through the sixteenth resistor R16. The second end of the thirteenth resistor R13 is connected to the controller. The third pin COM of the pressure sensing device 100 is grounded.

[0073] In one embodiment, the pressure sensing device 100 is a gas pressure sensor. The first pin VS of the gas pressure sensor is connected to the second power supply to provide the voltage required by the pressure sensor. The second pin VO of the gas pressure sensor is connected to the controller to output the current air pressure detected by the pressure sensor. The third pin COM of the gas pressure sensor represents the common terminal, which plays a role in distributing current in this circuit diagram. The fourth pin NC of the gas pressure sensor indicates an empty pin, which means that this pin is not connected or unused in this circuit diagram.

[0074] In a specific embodiment, the resistance value of the thirteenth resistor R13 is 10 kΩ, the resistance value of the sixteenth resistor R16 is 20 kΩ, the capacitance value of the eighth capacitor C8 is 100 nF, and the voltage value connected to the second power supply is +5V.

[0075] In one embodiment, the negative pressure control device further includes: a current detection circuit 200, which is used to detect the conduction current of the proportional valve V1 and send the conduction current to the controller. The controller determines the current conduction state of the proportional valve V1 according to the conduction current, and adjusts the conduction ratio of the proportional valve V1 according to the current air pressure and the current conduction state of the proportional valve V1.

[0076] In one embodiment, refer to Figure 2 , the current detection circuit 200 includes: the eighteenth resistor R18. The first end of the eighteenth resistor R18 is respectively connected to the optocoupler U2 and the amplification and filtering circuit 400, and the second end of the eighteenth resistor R18 is grounded.

[0077] In a specific embodiment, the resistance value of the eighteenth resistor R18 is 100 kΩ.

[0078] During implementation, the current detection circuit 200 detects the conduction current of the proportional valve V1, and the conduction current is sent to the controller after passing through the amplification and filtering circuit 400.

[0079] In one embodiment, the negative pressure control device further includes: an amplification and filtering circuit 400. The amplification and filtering circuit 400 is respectively connected to the current detection circuit 200 and the controller. The amplification and filtering circuit 400 is used to amplify the conduction current of the proportional valve V1 and send the processed conduction current to the controller.

[0080] In one embodiment, refer to Figure 2 , the amplification and filtering circuit 400 includes: the tenth resistor R10, the eleventh resistor R11, the ninth capacitor C9, the first power supply, and the operational amplifier U3A;

[0081] The non-inverting input terminal of the operational amplifier U3A is connected to the current detection circuit 200;

[0082] The output terminal of the first power supply is connected to the first end of the tenth resistor R10. The second end of the tenth resistor R10 is respectively connected to the first end of the ninth capacitor C9 and the first end of the eleventh resistor R11. The second end of the ninth capacitor C9 is grounded, and the second end of the eleventh resistor R11 is grounded. The second end of the tenth resistor R10 is also connected to the inverting input terminal of the operational amplifier U3A, and the output terminal of the operational amplifier U3A is connected to the signal input terminal of the controller.

[0083] In a specific embodiment, the resistance value of the tenth resistor R10 is 10 kΩ, the resistance value of the eleventh resistor R11 is 10 kΩ, the capacitance value of the ninth capacitor C9 is 104 NF, and the voltage value connected to the first power supply is +5V.

[0084] In one embodiment, the amplification and filtering circuit 400 amplifies and filters the conduction current of the proportional valve V1, so that the signal is transmitted to the controller more accurately.

[0085] In one embodiment, refer to Figure 2 , the negative pressure control device further includes: a twelfth resistor R12, and the twelfth resistor R12 is used to control the input voltage of the optocoupler U2. The first end of the twelfth resistor R12 is connected to the signal output terminal PUMP_EN of the controller, and the second end of the twelfth resistor R12 is connected to the optocoupler U2.

[0086] In a specific embodiment, the resistance value of the twelfth resistor R12 is 500 kΩ.

[0087] In one embodiment, refer to Figure 2 , the negative pressure control device further includes: a fourteenth resistor R14 and a seventeenth resistor R17, and the fourteenth resistor R14 and the seventeenth resistor R17 are used to control the output voltage of the amplification and filtering circuit 400. The first end of the fourteenth resistor R14 is connected to the amplification and filtering circuit 400. The second end of the fourteenth resistor R14 is respectively connected to the first end of the seventeenth resistor R17 and the first input terminal of the controller, and the second end of the seventeenth resistor R17 is grounded.

[0088] The twelfth resistor R12 is used in combination with the fourteenth resistor R14 and the seventeenth resistor R17 to control the voltage at both ends of the proportional valve V1 to be stable.

[0089] In a specific embodiment, the resistance value of the fourteenth resistor R14 is 3.3 kΩ, and the resistance value of the seventeenth resistor R17 is 6.8 kΩ.

[0090] According to another aspect of the present utility model, the present utility model provides a rotary cutting device, comprising: a biopsy needle, a sealed container, and the negative pressure control device provided in any one of the above embodiments. The output end of the negative pressure control device is connected to the input end of the sealed container. The negative pressure control device is used to generate negative pressure on the sealed container. The output end of the sealed container is connected to the biopsy needle. The sealed container is used to collect the tissue excised by the biopsy needle.

[0091] In one embodiment, the current air pressure in the gas pipeline sent by the pressure sensing device in real time is sent to the controller, and the current conduction state of the proportional valve is also sent to the controller in real time. The controller sends PWM signals with different duty cycles to the proportional valve according to the current air pressure and the current conduction state of the proportional valve to adjust the conduction ratio of the proportional valve. Through the interaction between the pressure sensing device and the proportional valve, the real-time feedback and adjustment of the air pressure in the gas pipeline are realized, and the precise control of the negative pressure is achieved. At the same time, the circuit of the present utility model uses fewer components, has a simple circuit structure and simple wiring, making the operation and later maintenance more convenient, and reducing the economic cost at the same time.

[0092] It should be noted that the above embodiments can be freely combined according to needs. The above are only the preferred embodiments of the present utility model. It should be pointed out that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present utility model.

Claims

1. A negative pressure control device, characterized in that including: it includes a controller, a vacuum pump, a proportional valve, a pressure sensing device, an optocoupler, and a gas pipeline; the vacuum pump is connected to the gas pipeline, and a proportional valve is provided on the gas pipeline, and the proportional valve is used to adjust the negative pressure generated by the vacuum pump; a pressure sensing device is provided on the gas pipeline, and the pressure sensing device is connected to the controller and is used to send the current air pressure in the gas pipeline to the controller; the controller is connected to the proportional valve and is used to obtain the current conduction state of the proportional valve; the optocoupler is connected to the proportional valve, and the proportional valve adjusts the conduction ratio according to the light intensity of the optocoupler. The controller sends PWM signals with different duty cycles to the proportional valve according to the current air pressure and the current conduction state of the proportional valve, and the optocoupler emits light to different degrees according to the PWM signals with different duty cycles, so as to adjust the conduction ratio of the proportional valve.

2. The negative pressure control device according to claim 1, characterized in that it further includes: a current detection circuit, which is used to detect the conduction current of the proportional valve and send the conduction current to the controller. The controller judges the current conduction state of the proportional valve according to the conduction current, and adjusts the conduction ratio of the proportional valve according to the current air pressure and the current conduction state of the proportional valve.

3. The negative pressure control device according to claim 1, characterized in that it further includes: a voltage detection circuit, which is used to detect the current air pressure of the pressure sensing device, convert the current air pressure into a current voltage value and send it to the controller. The controller adjusts the conduction ratio of the proportional valve according to the current voltage value and the current conduction state of the proportional valve.

4. The negative pressure control device according to claim 2, characterized in that it further includes: an amplification and filtering circuit, which is respectively connected to the current detection circuit and the controller, and the amplification and filtering circuit is used to amplify the conduction current of the proportional valve and send the processed conduction current to the controller.

5. The negative pressure control device according to claim 4, characterized in that the amplification and filtering circuit includes: a tenth resistor, an eleventh resistor, a ninth capacitor, a first power supply, and an operational amplifier; the non-inverting input terminal of the operational amplifier is connected to the current detection circuit; the output terminal of the first power supply is connected to the first end of the tenth resistor, the second end of the tenth resistor is respectively connected to the first end of the ninth capacitor and the first end of the eleventh resistor, the second end of the ninth capacitor is grounded, the second end of the eleventh resistor is grounded, the second end of the tenth resistor is also connected to the inverting input terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the signal input terminal of the controller.

6. The negative pressure control device according to claim 4, characterized in that the current detection circuit includes: an eighteenth resistor, the first end of the eighteenth resistor is respectively connected to the optocoupler and the amplification and filtering circuit, and the second end of the eighteenth resistor is grounded.

7. A negative pressure control device according to claim 3, characterized in that the voltage detection circuit includes: a thirteenth resistor, a sixteenth resistor, an eighth capacitor, and a second power supply; the first pin of the pressure sensing device is connected to the second power supply, the first pin of the pressure sensing device is connected to the first end of the eighth capacitor, the second end of the eighth capacitor is grounded, the second pin of the pressure sensing device is connected to the first end of the thirteenth resistor, the second end of the thirteenth resistor is grounded through the sixteenth resistor, the second end of the thirteenth resistor is connected to the controller, and the third pin of the pressure sensing device is grounded.

8. A negative pressure control device according to claim 1, characterized in that it further includes: a twelfth resistor, which is used to control the input voltage of the optocoupler. The first end of the twelfth resistor is connected to the signal output end of the controller, and the second end of the twelfth resistor is connected to the optocoupler.

9. A negative pressure control device according to claim 4, characterized in that it further includes: a fourteenth resistor and a seventeenth resistor, which are used to control the output voltage of the amplifier and filter circuit. The first end of the fourteenth resistor is connected to the amplifier and filter circuit, the second end of the fourteenth resistor is respectively connected to the first end of the seventeenth resistor and the first input end of the controller, and the second end of the seventeenth resistor is grounded.

10. A rotary cutting device, characterized in that the rotary cutting device includes: a biopsy needle, a sealed container, and a negative pressure control device according to any one of claims 1-9. The output end of the negative pressure control device is connected to the input end of the sealed container. The negative pressure control device is used to generate negative pressure on the sealed container. The output end of the sealed container is connected to the biopsy needle. The sealed container is used to collect the tissue excised by the biopsy needle.

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