An automatic constant pressure and constant flow liquid bolus device

Abstract

An automatic constant pressure and constant flow liquid injection device, comprising a voltage stabilizing power supply, an electric gas injection mechanism, a gas tank, a liquid medicine tank, an outer shell, an electromagnetic valve, a flow meter, a manual valve, a power switch, further comprising a speed regulating circuit, a control circuit, a prompt circuit, the electric gas injection mechanism, the gas tank, the liquid medicine tank, the electromagnetic valve, the flow meter and the manual valve are installed in the outer shell, the voltage stabilizing power supply, the power switch, the speed regulating circuit, the control circuit and the prompt circuit are installed in a component box and electrically connected with the electric gas injection mechanism, the electromagnetic valve and the flow meter. The present application does not need human to inject liquid, ensures that the liquid medicine entering the human body tissue is in constant pressure and flow rate. Medical staff can also select and set different liquid injection pressure according to the different tolerance of different patients, which brings convenience to medical staff, improves work efficiency and ensures good liquid injection effect. Therefore, the present application has good application prospect.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and in particular to an automatic constant pressure and constant flow liquid injection device. Background Technology

[0002] In clinical medicine, to achieve good treatment or examination results, medical staff often need to manually inject liquid drugs or contrast agents into the patient's lesion site (such as intrathecal injection) using a syringe or an electric syringe. Manual injection of drugs or contrast agents can be inconvenient for medical staff (the above disadvantages are more pronounced when some drugs require a long injection time) and is not conducive to improving work efficiency.

[0003] While existing electric injection devices based on electric pumps can achieve automatic injection, their structural limitations limit them to quantitative injection. This means that if the needle or other parts become blocked during the injection process, the fluid pressure remains constant. This can lead to increased pressure on diseased tissue due to narrowing of the needle, causing significant discomfort and potentially serious medical accidents. Furthermore, even with the same condition, different patients have varying tolerance levels. A single injection method can cause discomfort for patients with poor tolerance, while for those with good tolerance, the inability to adjust the injection rate can negatively impact the injection process. Finally, existing electric injection devices require a mains power supply. While batteries allow operation in areas without electricity, electric pumps consume extremely high power (at least tens of watts). Therefore, relying entirely on battery power not only increases the size and weight of the device, making it inconvenient to carry, but also depletes the battery quickly, significantly limiting its application. In summary, it is particularly necessary to provide an injection device that does not require manual injection, can automatically adjust the injection pressure, and can be used in places without power supply. Summary of the Invention

[0004] To overcome the shortcomings of existing electric liquid injection devices due to structural limitations, as described in the background, this invention provides an automatic constant pressure and constant flow liquid injection device that, through the combined action of relevant mechanisms and circuits, eliminates the need for manual liquid injection. Before injection, medical staff can select different injection pressures based on the patient's tolerance, and the device automatically maintains stable pressure during injection. It can also be used in places without mains power supply (such as inside an ambulance), thus bringing convenience to medical staff, improving work efficiency, and ensuring good liquid injection results.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] An automatic constant pressure and constant flow liquid dispensing device includes a regulated power supply, an electric gas dispensing mechanism, a gas tank, a liquid tank, a housing, solenoid valves, a flow meter, manual valves, and a power switch. Its distinguishing feature is that it also includes a speed regulation circuit, a control circuit, and a prompting circuit. The liquid tank has a dispensing pipe at its upper end. The liquid tank, gas tank, and electric gas dispensing mechanism are installed at the lower end of the housing. Multiple solenoid valves are included; the exhaust pipe of the electric gas dispensing mechanism is connected in parallel to one end of two of the solenoid valves, and the other ends of the other two solenoid valves are connected to one side of the liquid tank and the gas tank, respectively. Two manual valves are included; one end of the first manual valve and one end of the third solenoid valve are connected to… The other side of the liquid tank is connected in parallel. The other end of the third solenoid valve is connected to the inlet of the flow meter. The outlet pipe of the flow meter, the other end of the first manual valve, and a branch pipe are connected in parallel. One end of the injection needle hose used for injection is sleeved on the other side of the branch pipe. The two ends of the second manual valve are respectively installed between the upper ends of the gas tank and the liquid tank. The power switch, voltage regulator, speed regulation circuit, control circuit, and indicator circuit are installed in the component box. The power input terminal of the electric gas filling mechanism is electrically connected to the power output terminal of the speed regulation circuit, and the signal output terminal of the flow meter is electrically connected to the signal input terminal of the control circuit.

[0007] Furthermore, the solenoid valve is a normally closed valve core solenoid valve, and the flow meter has two power input terminals and one signal output terminal.

[0008] Furthermore, the speed control circuit includes an adjustable resistor, a magnetoresistive resistor, a resistor, a bidirectional diode, a bidirectional thyristor, and a capacitor that are electrically connected. One end of the adjustable resistor is connected to the second main electrode of the bidirectional thyristor, the other end of the adjustable resistor is connected to one end of the magnetoresistive resistor, the other end of the magnetoresistive resistor is connected to one end of the capacitor and one end of the resistor, the other end of the resistor is connected to one end of the bidirectional diode, the other end of the bidirectional diode is connected to the control electrode of the bidirectional thyristor, and the other end of the capacitor is connected to the first main electrode of the bidirectional thyristor.

[0009] Furthermore, the control circuit includes an electrically connected resistor, an NPN transistor, and an electromagnet. One end of the first resistor is connected to the collector of the NPN transistor and the positive power input terminal of the electromagnet. The emitter of the NPN transistor is connected to the negative power input terminal of the electromagnet. One end of the second resistor is connected to the base of the NPN transistor. The electromagnet is mounted on the upper end of the magnetoresistor at a distance between the two.

[0010] Furthermore, the prompting circuit includes a pressure switch, a buzzer, and a power switch that are electrically connected. The positive power input terminal of the buzzer is connected to one end of the pressure switch, and the other end of the pressure switch is connected to one end of the power switch.

[0011] The beneficial effects of this invention are as follows: This invention eliminates the need for manual liquid injection. In locations with mains power, compressed air is added to the storage tank via an electric air-filling mechanism. It can also be used normally in locations without power. Normally, the electric air-filling mechanism outputs compressed air into the medication tank, which then drives the medication through the injection needle into the diseased tissue. Under the control of the circuitry, flow meter, and speed regulation circuit, the working mode of the electric air-filling mechanism is automatically adjusted in real time according to the pressure entering the needle, thus ensuring a constant pressure and flow rate of the medication entering the tissue. Furthermore, medical personnel can select and set different injection pressures according to the different tolerance levels of different patients, thereby bringing convenience to medical staff, improving work efficiency, and ensuring good liquid injection results. Based on the above, this invention has good application prospects. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0014] Figure 2 This is the circuit diagram of the present invention. Detailed Implementation

[0015] Figure 1 , 2As shown, an automatic constant pressure and constant flow liquid dispensing device includes a regulated power supply A2, a micro electric gas dispensing mechanism M (electric micro air pump), a gas tank 1, a liquid tank 2, an outer shell 3 (with a hinged cover 31 at the upper end), a solenoid valve, a micro flow meter A1, a manual valve, and a power switch. It also includes a speed control circuit 4, a control circuit 5, and a prompting circuit 6. The upper end of the cylindrical liquid tank 2 has a threaded sealing cover 21. The sealing cover 21 has a dispensing pipe 22 at its upper end, and the dispensing pipe 22 has a threaded dispensing cap at its upper end. 23. The liquid medicine tank 2 and the gas tank 1 are respectively installed on the left and right ends of the outer casing 3 via screws and nuts; the electric gas filling mechanism M is installed on the lower right front end of the outer casing 3 via screws and nuts. There are three solenoid valves. The exhaust pipe of the electric gas filling mechanism M and one end of a three-way pipe 7 are connected via a pipe joint. The second and third ends of the three-way pipe 7 are respectively threaded to one end of two of the solenoid valves DC1 and DC2. The other ends of the two solenoid valves DC1 and DC2 are respectively connected to the upper right end of the liquid medicine tank 2 and the lower right end of the gas tank 1 via a connecting pipe. Connecting pipes are two pipes that communicate with the contents of liquid tank 2 and gas tank 1. A three-way pipe A8, communicating with the interior of liquid tank 2, is welded to the lower left end of liquid tank 2. There are two manual valves. The second and third ends of three-way pipe A8 are threaded to one end of the first manual valve 91 and one end of the third solenoid valve DC3, respectively. The other end of the third solenoid valve DC3 is threaded to the inlet pipe of flow meter A1. The outlet pipe of flow meter A1 is threaded to the first end of the third three-way pipe B10. The other end of the first manual valve 91 is threaded to the third three-way pipe B10. The second end of B10 is connected via a pipe, and a branch pipe 11 is installed inside the third end of the three-way pipe B10. One end of the injection needle hose 12 used for injection is sleeved on the outer end of the branch pipe. The two ends of the second manual valve 92 are respectively installed between the upper left side of the gas tank 1 and the upper right side of the medicine tank 2, and are interconnected with the gas tank 1 and the medicine tank 2 respectively. The power switch, the regulated power supply A2, the speed control circuit 4, the control circuit 5, and the prompting circuit 6 are installed on the circuit board inside the component box 13, and the component box 13 is installed on the upper left front of the outer casing 3.

[0016] Figure 1 , 2As shown, the regulated power supply A2 is a finished AC-to-DC switching power supply module of model 220V / 12V / 500W; the miniature electric gas filling mechanism M is a miniature gas pump of model D35S-22X with a working voltage of 12V; the gas tank 1, the liquid tank 2, and the outer casing 3 are all made of stainless steel; the solenoid valves DC1, DC2, and DC3 are normally closed small solenoid valves with a working voltage of 12V DC and a power of 1W (the liquid input and output pipes are made of stainless steel); the miniature flow meter A1 is a finished flow meter of model STG-025 with a working voltage of 12V DC, which has two power input terminals and one signal output terminal. The signal output terminal can output different current signals depending on the liquid flow rate (the liquid input and output pipes are made of stainless steel); the manual valves 91 and 92 are stainless steel valves; the handle of the power switch is located outside the opening at the front of the component box 13. The speed control circuit includes an adjustable resistor RP (the adjustment handle is located outside the opening at the front of the component box), a magnetoresistor RM, a resistor R2, a bidirectional diode ST, a bidirectional thyristor VS, and a capacitor C, all connected via circuit board wiring. One end of the adjustable resistor RP is connected to the second main electrode of the bidirectional thyristor VS, and the other end of the adjustable resistor RP is connected to pin 3 of one end of the magnetoresistor RM. Pin 4 of the other end of the magnetoresistor RM is connected to one end of the capacitor C and one end of the resistor R2. One end of the resistor R2 is connected to one end of the bidirectional diode ST, and the other end of the bidirectional diode ST is connected to the control electrode of the bidirectional thyristor VS. The other end of the capacitor C is connected to the first main electrode of the bidirectional thyristor VS. The control circuit includes resistors R and R3, an NPN transistor Q1, and a small electromagnet XQ (1W power, 12V operating voltage) connected via circuit board wiring. One end of the first resistor R3 is connected to the collector of the NPN transistor Q1 and the positive power input terminal of the electromagnet XQ. The emitter of the NPN transistor Q1 is connected to the negative power input terminal of the electromagnet XQ. One end of the second resistor R is connected to the base of the NPN transistor Q1. The electromagnet XM is mounted on top of the magnetoresistor RM, with a 1mm gap between them. The indication circuit includes an electrically connected pressure switch D, a buzzer B, and a power switch S5 (the handle is located outside the opening at the front of the component box). The positive power input terminal of the buzzer B is connected to one end of the pressure switch D, and the other end of the pressure switch D is connected to one end of the power switch S5.

[0017] Figure 1 , 2As shown, there are multiple power switches. The power input terminals 1 and 2 of the regulated power supply A2 are connected to the 220V AC power supply via a power cord. One end of the first power switch K is connected to one pole of the 220V AC power supply via a wire. The other end of the first power switch K is connected to one power input terminal of the electric gas filling mechanism M via a wire. The other end of the power input terminal of the electric gas filling mechanism M, one end of the second power switch S1, and the second main electrode of the bidirectional thyristor VS at the power output terminal of the speed control circuit are connected via a wire. The other pole of the 220V AC power supply, the other end of the capacitor C at the power input terminal of the speed control circuit, and the other end of the second power switch S1 are connected via a wire. The positive power output pin 3 of the regulated power supply A2 is connected to the other end of the resistor R3 at the positive power input terminal of the control circuit, the other end of the power switch S5 at the positive power input terminal of the indicator circuit, the positive power input pin 1 of the flow meter A1, one end of the third power switch S2, one end of the fourth power switch S3, one end of the fifth power switch S4, and the positive power input pin 1 of the magnetoresistor RM in the speed control circuit via a wire. The negative power output pin 4 of the regulated power supply A2 is connected to the negative power input terminals of the three solenoid valves DC1, DC2, and DC3, the negative power input pin 2 of the flow meter A2, the emitter of the NPN transistor Q1 at the negative power input terminal of the control circuit, the negative power input terminal of the indicator circuit, the negative power input terminal of the buzzer B, and the negative power input pin 2 of the magnetoresistor RM via a wire. The signal output pin 3 of the flow meter A1 is connected to the other end of the resistor R at the signal input terminal of the control circuit via a wire.

[0018] Figure 1 , 2As shown, after turning on the power switch K, the regulated power supply A2 is energized, and its pins 3 and 4 output a stable 12V DC power supply, which enters the control circuit, the indicator circuit, and the power input terminals of the third, fourth, and fifth power switches and the magnetoresistor RM. Before using this invention, open the liquid filling cap at the top of the liquid container to add the liquid inside, then close the sealing liquid filling cap 23. Place the tubing of the injection needle onto the branch tube 11 for necessary disinfection. After inserting the needle into the patient's diseased tissue, the injection can be performed. The operator turns on the power switches S2 and S4 beforehand, energizing the solenoid valves DC1 and DC3, opening the valve core, and energizing the electric air filling mechanism. Compressed air is added to the liquid container 2, and under the drive of the compressed air, the liquid flows through the flow meter and then into the human tissue (air inside the liquid container does not enter the human tissue). In the speed control circuit, the adjustable resistor RP, magnetoresistive resistor RM, resistor R2, non-polarized capacitor C, resistor R2 and bidirectional trigger diode ST form a phase-shifting trigger sub-circuit. One pole of the 220V AC power supply directly enters one end of the power input of the electric gas filling mechanism M, and the other pole of the 220V AC power supply enters the other end of the power input of the electric gas filling mechanism M through the first and second main electrodes of the bidirectional thyristor VC to form a circuit. When the electric gas filling mechanism M is energized, it adds driving compressed air into the medicine tank. When the 220V AC power supply is in a certain half-cycle, current flows through the magnetoresistor RM and the adjustable resistor RP to charge capacitor C. The voltage across the non-polarized capacitor C rises. When the voltage across capacitor C exceeds the trigger voltage of the bidirectional trigger diode ST, the voltage at capacitor C is reduced and current limited by resistor R2, triggering the bidirectional trigger diode ST and the bidirectional thyristor VS to conduct successively. Then, the bidirectional thyristor VS is cut off when the AC power supply voltage is zero. The firing angle of the bidirectional thyristor VS is determined by the product of the resistance of the magnetoresistor RM, the resistance of the adjustable resistor RP, and the capacitance of capacitor C. The resistance of the magnetoresistor RM varies depending on the magnetism generated by the electromagnet XQ. The greater the liquid flow rate and pressure output from the medicine tank, the greater the resistance. When the liquid flows through flowmeter A1, the current signal output from pin 3 of flowmeter A1 is relatively high. This means that after current limiting by resistor R and amplification by NPN transistor Q1 (with resistor R3 as a bias resistor), the current entering electromagnet XQ is relatively large, resulting in a relatively strong magnetic force generated by electromagnet XQ. Consequently, the resistance value of magnetoresistor RM is relatively large. Conversely, the smaller the liquid flow rate and pressure in the medicine tank, the lower the current signal output from pin 3 of flowmeter A1 when it flows through flowmeter A1. This means that after current limiting by resistor R and amplification by NPN transistor Q1 (with resistor R3 as a bias resistor), the current entering electromagnet XQ is relatively small, resulting in a relatively weak magnetic force generated by electromagnet XQ. Consequently, the resistance value of magnetoresistor RM is relatively small.When the resistance of the magnetoresistor RM changes with the output voltage signal of the flow meter A1 as the liquid flow rate varies, it effectively alters the firing angle of the bidirectional thyristor VS, thereby changing the operating voltage of the electric air dispensing mechanism M. This means it changes the voltage across the electric air dispensing mechanism M, thus regulating its operating voltage. If the compressed air output from the electric air dispensing mechanism M is too high, resulting in an excessive flow rate and velocity of the medication entering the human tissue, the resistance of the magnetoresistor RM increases, the firing angle of the bidirectional thyristor VS decreases, and the voltage input to the electric air dispensing mechanism M decreases. Consequently, the electric air dispensing mechanism M, when energized, outputs relatively low-velocity air into the medication tank, naturally reducing the amount of medication entering the human tissue. If the compressed air output by the electric air dispensing mechanism M is too low, the flow rate and velocity of the medicine entering the human tissue will be too low. This will decrease the resistance value of the magnetoresistive resistor RM, increase the firing angle of the bidirectional thyristor VS, and raise the voltage input to the electric air dispensing mechanism M. When the electric air dispensing mechanism M is energized, it outputs relatively high-velocity air into the medicine tank, thus naturally increasing the amount of medicine entering the human tissue. Through the above, this invention can ensure that the medicine is injected at a constant flow rate and pressure. In this invention, before or during use, medical personnel can adjust the resistance value of the adjustable resistor RP to set the constant pressure and constant flow rate of the medication entering the patient's tissue, based on each patient's different tolerance levels. When the adjustable resistor RP is adjusted to a larger value, the charging time of the capacitor C increases, resulting in a smaller firing angle of the thyristor VS. Consequently, the amount of constant pressure and constant flow medication entering the patient's tissue during subsequent injections will be relatively smaller. Conversely, when the adjustable resistor RP is adjusted to a smaller value, the charging time of the capacitor C decreases, resulting in a larger firing angle of the thyristor VS. Consequently, the amount of constant pressure and constant flow medication entering the patient's tissue during subsequent injections will be relatively larger. Through the above, this invention eliminates the need for manual injection. Under the action of the control circuit, flow meter, and speed regulation circuit, this invention can automatically adjust the working mode of the electric gas-filling mechanism in real time according to the pressure entering the syringe. This ensures that the medication entering the human tissue maintains a constant pressure and flow rate. Furthermore, it allows for the selection and setting of different injection pressures based on different patients' tolerance levels, bringing convenience to medical personnel, improving work efficiency, and ensuring good medication injection results.

[0019] Figure 1 , 2As shown, when not in use, medical personnel can close solenoid valves DC1 and DC3 and turn on power switches S3 and S1. This energizes solenoid valve DC2, opening its internal valve core. With power switch S1 open, the other pole of the 220V power supply directly enters the other power input terminal of the electric gas filling mechanism M. Thus, the electric gas filling mechanism M is uncontrollably energized and operates, adding compressed air to gas tank 1 through the solenoid valve DC3. When the added air volume is sufficient (e.g., 2MPa), the internal contacts of pressure switch D close. This allows the positive terminal of the 12V power supply to enter the positive power input terminal of buzzer B via power switch D. Buzzer B (with power switch S5 open at this time) is energized and sounds, directly indicating to medical personnel that the pressure in gas tank 1 is sufficient. After turning off the 220V main power switch and power switch S5, the electric gas filling mechanism M no longer adds compressed air to gas tank 1, and buzzer B is de-energized and stops sounding. When this invention is used outdoors without a power supply (e.g., due to power failure or inside an ambulance), medical personnel open valves 91 and 92. Compressed air from gas canister 1 flows out, driving the medication through valve 92 to inject it into the patient's tissue. The opening and closing degree of valve 92 can be adjusted by regulating the valve stem, thereby controlling the flow rate and speed of the liquid medication entering the tissue. After injection, valves 91 and 92 are closed (one gas canister can guarantee injection for approximately 20 minutes). Through this, the invention can be used in areas without power supply, making its application more convenient. In the circuit, the resistance values ​​of resistors R2, R3, and R are 240Ω, 47KΩ, and 470Ω, respectively; the bidirectional trigger diode ST is model DB4; the non-polarized capacitor C is 0.1μF / 400V; the bidirectional thyristor VS is model BTA41 / 800B; the NPN transistor Q1 is model 9013; the magnetoresistor RM is model MT10; the pressure switch is an adjustable normally closed contact pressure switch (adjusted to 2MPa in this embodiment); and the buzzer S is a model SF12V active continuous sound buzzer alarm.

[0020] The foregoing has shown and described the basic principles and main features of the present invention, as well as its advantages. It will be apparent to those skilled in the art that the present invention is limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0021] Furthermore, it should be understood that although this specification describes the embodiments, the embodiments do not necessarily contain only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An automatic constant pressure and constant flow liquid dispensing device, comprising a regulated power supply, an electric gas dispensing mechanism, a gas tank, a liquid tank, a housing, a solenoid valve, a flow meter, a manual valve, and a power switch, characterized in that... It also features a speed control circuit, a control circuit, and a notification circuit. The upper end of the liquid medicine tank has a filling pipe. The liquid medicine tank, gas tank, and electric gas filling mechanism are installed at the lower end of the outer casing. There are multiple solenoid valves; the exhaust pipe of the electric gas filling mechanism is connected in parallel to one end of two of the solenoid valves. The other ends of the other two solenoid valves are connected to one side of the liquid medicine tank and the gas tank, respectively. There are two manual valves. One end of the first manual valve and one end of the third solenoid valve are connected in parallel to the other side of the liquid medicine tank. The other end of the third solenoid valve is connected to the inlet of the flow meter. The outlet pipe of the flow meter, the other end of the first manual valve, and a branch pipe are connected in parallel. One end of the injection needle tubing used for injection is fitted onto the outer end of the other side of the branch pipe. The two ends of the second manual valve are respectively installed between the upper ends of the gas tank and the liquid medicine tank. The power switch, regulated power supply, speed control circuit, control circuit, and indicator circuit are installed in the component box. The power input terminal of the electric gas filling mechanism and the power output terminal of the speed control circuit are electrically connected, and the signal output terminal of the flow meter and the signal input terminal of the control circuit are electrically connected. The speed control circuit includes an adjustable resistor, a magnetoresistor, a resistor, a bidirectional diode, a bidirectional thyristor, and a capacitor that are electrically connected. One end of the adjustable resistor is connected to the second main electrode of the bidirectional thyristor, the other end of the adjustable resistor is connected to one end of the magnetoresistor, the other end of the magnetoresistor is connected to one end of the capacitor and one end of the resistor, the other end of the resistor is connected to one end of the bidirectional diode, the other end of the bidirectional diode is connected to the control electrode of the bidirectional thyristor, and the other end of the capacitor is connected to the first main electrode of the bidirectional thyristor.

2. The automatic constant pressure and constant flow liquid dispensing device according to claim 1, characterized in that, The solenoid valve is a normally closed solenoid valve, and the flow meter has two power input terminals and one signal output terminal.

3. The automatic constant pressure and constant flow liquid dispensing device according to claim 1, characterized in that, The control circuit includes an electrically connected resistor, an NPN transistor, and an electromagnet. One end of the first resistor is connected to the collector of the NPN transistor and the positive power input terminal of the electromagnet. The emitter of the NPN transistor is connected to the negative power input terminal of the electromagnet. One end of the second resistor is connected to the base of the NPN transistor. The electromagnet is mounted on the upper end of the magnetoresistor at a distance from it.

4. The automatic constant pressure and constant flow liquid dispensing device according to claim 1, characterized in that, The prompting circuit includes a pressure switch, a buzzer, and a power switch that are electrically connected. The positive power input terminal of the buzzer is connected to one end of the pressure switch, and the other end of the pressure switch is connected to one end of the power switch.

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