Constant rate infusion device and method

Abstract

The application discloses a constant-speed infusion device and method, wherein the device comprises: an infusion module comprising an infusion bag and an infusion pipeline; a pressurizing module comprising a pressurizing air bag wrapped around the outer periphery of the infusion module, the pressurizing air bag being connected with an external high-pressure gas source through a gas inlet pipeline; a pressure regulating module comprising a first-stage pressure regulating mechanism, a second-stage pressure regulating mechanism and an automatic switching mechanism arranged on the gas inlet pipeline; and a detection module comprising a first air pressure detection mechanism for detecting the air pressure value in the pressurizing air bag in real time. The application simplifies the operation steps, realizes rapid and seamless continuous infusion, and can guarantee the stability and safety of the infusion process through real-time monitoring of the air pressure condition and rapid switching of the automatic switching mechanism.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to a constant-rate infusion device and method. Background Technology

[0002] Intravenous infusion is one of the most basic and common treatment methods in clinical medicine. Currently, commonly used infusion devices are mainly divided into gravity infusion sets and pressurized infusion sets, and among these devices, soft infusion bags and soft bottles are the main containers for clinical infusion therapy.

[0003] In traditional gravity-feed infusion sets, due to differences in material and shape between soft infusion bags and bottles, the hydrostatic pressure and deformation of the bags and bottles after filling with medication fluctuate randomly. This randomness stems from various physical factors, such as the flatness of the bag's suspension posture, uneven material thickness, the formation and unfolding of wrinkles during infusion, and the different deformation patterns exhibited by the amount of residual medication in the bag at different stages (full bag, half bag, nearly empty). This leads to the following clinical problems: First, during infusion, the infusion bag may randomly collapse or wrinkle, causing sudden or fluctuating changes in internal pressure, resulting in inconsistent flow rates rather than a smooth, linear change, making it impossible to maintain a constant infusion rate. Second, for time-dependent drugs (such as antibiotics, vasoactive drugs like nitroglycerin, antihypertensive drugs, and certain chemotherapy drugs), continuous, constant-rate infusion is required to maintain stable blood drug concentrations. Fluctuations in the flow rate of soft infusion bags and bottles may cause peak-to-trough fluctuations in blood drug concentrations, affecting efficacy or increasing the risk of side effects. This may interfere with the treatment of critically ill patients who require precise calculation of fluid intake and output (such as those with heart or kidney failure). Third, traditional gravity-feed infusion sets require nurses to frequently check and adjust the drip rate to ensure it remains within acceptable limits, significantly increasing the workload of nursing staff.

[0004] To overcome the limitations of gravity-based infusion, some existing technologies disclose infusion devices that employ pressurization or constant pressure control. For example, the invention patent with authorization announcement number CN117138157A discloses a piston-type blood transfusion pressurization device, which uses a piston block. When the air bag is inflated, the air bag pushes the piston block to the left, and the squeezing surface of the piston block can apply pressure to the bagged medicine solution to achieve the purpose of pressurization for infusion. Alternatively, an inflatable ball can be used as an inflation device, and the air bag is inflated by squeezing the inflatable ball. These pressurization devices are prone to pressure fluctuations and flow rate reduction when the piston moves and the inflator is manually squeezed. At the same time, when it is necessary to change the infusion bag, the existing constant pressure infusion device usually requires several manual operations: first, the gas source needs to be turned off, then the residual gas in the pressurization bag needs to be released manually, the empty bag needs to be removed and a new bag needs to be inserted, and then it needs to be re-inflated and wait for the pressure to stabilize. This process is time-consuming, and after re-establishing the constant pressure state, it is often necessary to recalibrate or set the infusion parameters, which cannot achieve rapid replacement and may cause risks such as backflow in the tubing. On the other hand, it is difficult to intuitively determine whether the infusion has been completed, which increases the monitoring burden.

[0005] In existing technologies, some constant pressure infusion devices that use closed-loop control need to calculate the required inflation rate or gas replenishment volume in real time based on the target infusion drip rate, and establish a complex mathematical model to convert the relationship between the infusion rate and the inflation rate. This places high demands on the system's computing power and can easily lead to control delays. Summary of the Invention

[0006] Therefore, in order to solve the above problems, the present invention provides a constant-rate infusion device and method.

[0007] This invention is achieved through the following technical solution: A constant-rate infusion device includes: An infusion module includes an infusion bag and an infusion tubing connected to the bottom of the infusion bag; A pressurization module is used to apply constant pressure to the infusion bag for constant-rate infusion, including a pressurization airbag wrapped around the periphery of the infusion module, the pressurization airbag being connected to an external high-pressure air source through an air inlet pipe; The pressure regulating module is used to regulate the internal air pressure of the pressurized airbag, including a first-stage pressure regulating mechanism, a second-stage pressure regulating mechanism and an automatic switching mechanism installed on the air intake pipe; The output air pressure value of the first-stage pressure regulating mechanism is greater than the output air pressure value of the second-stage pressure regulating mechanism; The automatic switching mechanism includes an inflation position and an deflation position. When the automatic switching mechanism is adjusted to the inflation position, the pressurized airbag inflates and the deflation passage is closed simultaneously. When the automatic switching mechanism is adjusted to the deflation position, the pressurized airbag stops inflating and the deflation passage is opened simultaneously. The detection module includes a first air pressure detection mechanism for real-time detection of the air pressure value inside the pressurized airbag.

[0008] Preferably, it also includes a control module, wherein the first-stage pressure regulating mechanism, the second-stage pressure regulating mechanism, the automatic switching mechanism, and the first air pressure detection mechanism are all connected to the control module.

[0009] Preferably, it also includes an overpressure protection device and an alert module. The overpressure protection device includes a second air pressure detection mechanism, which is connected to the control module and is used to output an overpressure signal to the control module when the air pressure inside the pressurized airbag reaches the maximum safe air pressure. The alert module is used to issue an alarm signal when the infusion status is abnormal or the infusion is completed.

[0010] Preferably, the system also includes a positioning sensor disposed within the pressurized airbag. The positioning sensor is connected to the control module and is used to detect whether the infusion bag inside the pressurized airbag is properly assembled and to send a positioning signal to the control module.

[0011] The constant-rate infusion method, using the constant-rate infusion device described above, includes the following steps: S1: The infusion bag to be infused is placed into the pressurized airbag. The automatic switching mechanism is switched to the inflation position. The external high-pressure gas source introduces high-pressure gas into the air inlet pipe. The first-stage pressure regulating mechanism independently controls the pressurization speed of the pressurized airbag with a preset output value. S2: When the internal air pressure of the pressurized airbag reaches the preset infusion air pressure value, the output air pressure value of the second-stage pressure regulating mechanism is adjusted to the scale where the target infusion rate is located, so that the infusion bag infuses at a constant infusion rate. S3: When the first air pressure detection mechanism detects that the air pressure inside the pressurized airbag has reached the target air pressure value, the automatic switching mechanism switches to the exhaust position. At this time, the pressurized airbag stops inflating and simultaneously controls the pressurized airbag to depressurize until the air pressure inside the pressurized airbag is balanced with the atmospheric pressure. S4: Remove the infusion bag after the infusion has been completed, and repeat the above steps.

[0012] Preferably, the correspondence between the output air pressure and the infusion flow rate of the second-stage pressure regulating mechanism is pre-calibrated, and the scale of the second-stage pressure regulating mechanism is re-marked from the air pressure value to the infusion flow rate value based on this relationship.

[0013] Preferably, the preset output value of the first-stage pressure regulating mechanism is located between the gas pressure value required for the target infusion rate and the maximum range of the second-stage pressure regulating mechanism.

[0014] Preferably, in step S4, when the first air pressure detection mechanism detects that the air pressure value inside the pressurized airbag has reached the target air pressure value, the prompting module issues an alarm signal.

[0015] Preferably, in step S4, when the overpressure protection device detects that the air pressure inside the pressurized airbag has reached the maximum safe air pressure, the automatic switching mechanism automatically switches to the exhaust position.

[0016] Preferably, in step S2, when the positioning sensor detects that the infusion bag to be infused is placed into the pressurized airbag and assembled in place, the automatic switching mechanism automatically switches to the inflation position.

[0017] The beneficial effects of the technical solution of this invention are mainly reflected in: 1. In the constant-speed infusion device, the automatic switching mechanism includes an inflation position and an venting position. The automatic switching mechanism can synchronously control the inflation and venting passages. At the same time, the automatic switching mechanism can also automatically switch the inflation and venting states according to the air pressure value inside the pressurized airbag. This not only simplifies the operation steps and realizes rapid and seamless continuous infusion, but also ensures the safety of the entire workflow.

[0018] 2. By using an external high-pressure air source combined with a two-stage pressure regulating mechanism to control the output pressure to the pressurizing air bag, the pressurizing bag can fit tightly against the gradually flattening infusion bag, providing a stable external pressure and achieving constant pressure and constant speed infusion throughout the process. This avoids pressure fluctuations and flow rate attenuation caused by piston movement friction or manual inflation. At the same time, by precisely adjusting the output air pressure of the pressure regulating mechanism, when the ordinary gravity infusion speed cannot reach the target infusion speed, the pressurizing air bag can be used to apply pressure to the infusion bag to achieve the required target infusion speed.

[0019] 3. The first-stage pressure regulating mechanism in the two-stage pressure regulating mechanism limits the maximum output pressure within a safe threshold in advance, while the second-stage pressure regulating mechanism performs fine adjustment, effectively eliminating the risk of high pressure damage caused by the failure of a single pressure regulating element. Combined with the real-time monitoring of the first air pressure detection mechanism, the prompt module, and the overpressure protection device, and the rapid switching of the automatic switching mechanism, the stability and safety of the infusion process can be further guaranteed.

[0020] 4. By converting the scale unit of the second-stage pressure regulating mechanism from air pressure value to the corresponding infusion flow rate, the conversion of the scale unit can help the operator to directly and accurately adjust the required infusion rate when using the constant-speed infusion device, without complicated calculations, simplifying the operation of the entire system and preventing control delay.

[0021] 5. In the constant-speed infusion device, the pressurizing airbag is directly connected to an external high-pressure air source through the air inlet pipe. The pressure is controlled by a two-stage pressure regulating mechanism, which can be adapted to most medical scenarios, such as hospital oxygen supply or compressed air systems and other common high-pressure air sources, thereby expanding the product's applicability. Attached Figure Description

[0022] Figure 1This is a flowchart of the constant-rate infusion method of the present invention; Figure 2 This is a schematic diagram of the structure of a constant-rate infusion device in one embodiment of the present invention; Figure 3 This is a schematic diagram of the second-stage pressure regulating mechanism in one embodiment of the present invention; Figure 4 This is a schematic diagram showing the connection state of the rigid sleeve, the pressure bladder, and the infusion bag in one embodiment of the present invention; Figure 5 yes Figure 4 Cross-sectional view along line AA (at this time, the internal air pressure of the pressurized airbag reaches the preset infusion air pressure value). Figure 6 yes Figure 4 A cross-sectional view along line AA (at this point, the internal air pressure of the pressurized airbag reaches the target air pressure value). Detailed Implementation

[0023] To make the objectives, advantages, and features of the present invention clearer and more detailed, the following non-limiting description of preferred embodiments will be illustrated and explained. These embodiments are merely typical examples of applying the technical solutions of the present invention; all technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present invention.

[0024] It should also be noted that in the description of the solution, the terms "center", "upper", "lower", "left", "right", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0025] Furthermore, the terms "first" and "second" in this invention are used for descriptive purposes only and should not be construed as indicating or implying a ranking of importance, or implicitly specifying the number of technical features shown. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] This invention discloses a constant-rate infusion device, comprising: The infusion module includes an infusion bag 3 and an infusion tubing 5 connected to the bottom of the infusion bag 3. The infusion bag 3 can be a conventional soft infusion bag 3 or a soft bottle, which will not be described in detail here.

[0027] In some embodiments, a bottle stopper puncturer is provided at the connection end between the infusion tubing 5 and the infusion bag 3. By inserting the bottle stopper puncturer into the infusion bag 3, the inside of the infusion bag 3 is connected to the infusion tubing 5. When a new infusion bag 3 needs to be replaced, the bottle stopper puncturer is pulled out from the infusion bag 3 after the infusion is completed and inserted into the new infusion bag 3. In some embodiments, a drug solution filter 6 that can automatically stop the infusion is also provided on the infusion tubing 5. The drug solution filter 6 is used to filter drug impurities, filter out mixed air bubbles, and automatically stop the infusion to prevent blood from flowing back into the infusion tubing if it is not replaced or removed in time after the infusion is completed. Both the bottle stopper puncturer and the drug solution filter 6 are existing products and will not be described in detail here.

[0028] The pressurization module is used to apply a constant pressure to the infusion bag 3 for constant-rate infusion. It includes a pressurization airbag 2 wrapped around the periphery of the infusion module. The pressurization airbag 2 is connected to an external high-pressure air source through an air inlet pipe 4. In some embodiments, the end of the air inlet pipe 4 connected to the external high-pressure air source is connected to a connector. The model of the connector can be matched according to the external high-pressure air source equipment to be connected, which will not be described in detail here.

[0029] In some embodiments, the pressure bladder 2 is disposed inside a rigid sleeve 1 to fix the outside of the pressure bladder 2. When the pressure bladder 2 is inflated, the gas inside the pressure bladder 2 will cause the pressure bladder 2 to expand evenly toward its inner periphery, thereby wrapping the infusion bag 3.

[0030] The pressure regulating module is used to regulate the internal air pressure of the pressurized airbag 2, and includes a first-stage pressure regulating mechanism, a second-stage pressure regulating mechanism, and an automatic switching mechanism installed on the air intake pipe 4.

[0031] The output pressure of the first-stage pressure regulating mechanism is greater than that of the second-stage pressure regulating mechanism. Therefore, by first setting the first-stage pressure control through the first-stage pressure regulating mechanism and then precisely regulating it through the second-stage pressure regulating mechanism, on the one hand, accurate constant-rate infusion can be ensured and the stability of infusion can be improved. On the other hand, by simultaneously regulating the internal pressure of the pressurizing airbag 2 through the two-stage pressure regulating mechanisms, the safety of infusion can be avoided due to the failure of a single component. The first-stage pressure regulating mechanism can also prevent the high-pressure air source pressure from exceeding the maximum range of the second-stage pressure regulating mechanism and causing it to be damaged. The automatic switching mechanism includes an inflation position and an deflation position. When the automatic switching mechanism is adjusted to the inflation position, the pressure bag 2 inflates and the deflation passage is closed simultaneously. When the automatic switching mechanism is adjusted to the deflation position, the pressure bag 2 stops inflating and the deflation passage is opened simultaneously. By quickly switching the inflation and deflation states of the pressure bag 2 through the automatic switching mechanism, the infusion bag 3 can be replaced quickly, and inflation can be stopped quickly in abnormal conditions to ensure the safety performance of the entire device. By dynamically replenishing the pressurizing bladder 2 with an equal volume of gas in real time according to the liquid loss in the infusion bag 3 using the pressure regulating module, a constant pressure is maintained on the infusion bag 3 by the pressurizing bladder 2 throughout the entire infusion cycle, thus ensuring a highly consistent infusion drip rate. This is particularly suitable for critical drugs that require long-term, constant-rate infusion. When the liquid in the infusion bag 3 decreases, causing a drop in pressure, the device can still use the principle of automatically maintaining pressure balance with pressurized gas to accurately maintain the constant pressure required for the infusion drip rate. This fundamentally solves the problem of drip rate fluctuation caused by pressure decay in traditional pressurizing devices, which results in a fast-then-slow drip rate and large fluctuations, thus improving infusion accuracy and safety.

[0032] The detection module includes a first pressure detection mechanism for real-time detection of the air pressure value inside the pressurized airbag 2. In some embodiments, the first pressure detection mechanism may use existing pressure detection products, such as pressure gauges, which will not be described in detail here.

[0033] In some embodiments, the correspondence between the output gas pressure and infusion flow rate of the second-stage pressure regulating mechanism is pre-calibrated, and the scale of the second-stage pressure regulating mechanism is re-marked from gas pressure value to infusion flow rate value based on this relationship. The pressure regulation accuracy of the second-stage pressure regulating mechanism should be greater than that of the first-stage pressure regulating mechanism. The conversion between gas pressure value and infusion rate can be obtained through pre-testing. The output pressure value of the first-stage pressure regulating mechanism can be set according to the maximum range of the second-stage pressure regulating mechanism. The output pressure of the first-stage pressure regulating mechanism should be less than or equal to the maximum range of the second-stage pressure regulating mechanism to avoid damage to the second-stage pressure regulating mechanism caused by high-pressure gas. In a preferred embodiment, the output pressure value of the first-stage pressure regulating mechanism is adjusted to 280 mmHg to 300 mmHg (approximately 37.3 mmHg). The pressurized gas source (kPa~40kPa) enters the 500mL sleeve-type pressurizing bladder 2 through the second-stage pressure regulating mechanism. After the pressurizing bladder 2 is inflated, it wraps around and clamps the soft infusion bag 3, and dynamically compensates for the loss of liquid inside the soft infusion bag 3 with an equal volume of gas, so as to achieve constant-speed infusion. The infusion tubing 5 is made of TPE material (brand: Teknor Apex Medalist MD-53200). Under the condition that the tubing size is φ4.0mm (outer diameter) × 3.0mm (inner diameter), the formula for the correspondence between the infusion set flow rate and the pressurization value of the pressurizing bladder 2 obtained by testing is: flow rate Q = 1.1 × pressurization value. According to this formula, the unit infusion flow rate corresponding to the unit gas pressure value on the second-stage pressure regulating mechanism can be calculated, so as to mark the scale on the second-stage pressure regulating mechanism. In actual use, the operator can directly adjust the unit infusion flow rate according to the required infusion speed.

[0034] like Figure 2 , Figure 3 As shown, in some embodiments, the first-stage pressure regulating mechanism and the second-stage pressure regulating mechanism adopt manually adjustable pressure regulating products, such as a first knob-type pressure regulating valve 7 and a second knob-type pressure regulating valve 8 equipped with a pressure gauge. The operator can directly adjust the pressure manually. The second knob-type pressure regulating valve 8 includes a pressure gauge 801, on which a corresponding drip rate scale 802 is marked. The drip rate scale 802 is the unit infusion flow rate, that is, the drip rate of infusion per minute. In addition, the corresponding output gas pressure value can also be marked on the drip rate scale. The second knob-type pressure regulating valve is also provided with a pressure regulating knob 803, through which the required infusion drip rate can be directly and manually adjusted.

[0035] In other embodiments, a control module is also included. The first-stage pressure regulating mechanism, the second-stage pressure regulating mechanism, the automatic switching mechanism, and the first air pressure detection mechanism are all connected to the control module. The control module receives the air pressure detection signal sent by the first air pressure detection mechanism according to the air pressure, and outputs an air pressure control signal according to the air pressure detection signal to control the first-stage pressure regulating mechanism, the second-stage pressure regulating mechanism, and the automatic switching mechanism.

[0036] In some embodiments, a prompting module is further included, which is used to issue an alarm signal when the infusion status is abnormal or the infusion is completed. In some embodiments, the prompting module may be a buzzer alarm or a light alarm installed on the first pressure detection mechanism, or a pressure detection mechanism product with built-in alarm function. In a preferred embodiment, the prompting module is also connected to a call system, which controls the call system to issue a prompt when the infusion status is abnormal or the infusion is completed; details are not elaborated here.

[0037] In some embodiments, an overpressure protection device is further included, comprising a second air pressure detection mechanism, used to output an overpressure signal to the control module when the air pressure inside the pressurized airbag 2 reaches the maximum safe air pressure. Upon receiving the overpressure signal, the control module controls the automatic switching mechanism to switch to the exhaust position. In one embodiment, the automatic switching mechanism may also be a product with built-in overpressure protection, such as a two-position three-way solenoid valve. This two-position three-way solenoid valve is connected to the air intake pipe 4 and the pressurized airbag 2 respectively. In addition, it includes an exhaust port. The two-position three-way solenoid valve can simultaneously control the connection of two passages and the closure of the other passage. For example, when the automatic switching mechanism is in the inflation position, it controls the air intake pipe 4 to connect with the pressurized airbag 2, and the exhaust port is closed. At this time, the air intake pipe 4 inflates the pressurized airbag 2. When the automatic switching mechanism switches to the exhaust position, it controls the pressurized airbag 2 to connect with the exhaust port, and the air intake pipe 4 is closed. At this time, the pressurized airbag 2 exhausts air, and the air intake pipe 4 no longer inflates the pressurized airbag 2. Figure 2 As shown, in some other embodiments, the automatic switching mechanism may also be a product with two-position three-way function for air pressure, such as a three-way valve 9, and the inflation position and deflation position may be switched manually, which will not be described in detail here.

[0038] In some embodiments, a positioning sensor disposed within the pressurized airbag 2 is further included to detect whether the infusion bag 3 within the pressurized airbag 2 is properly assembled. The positioning sensor is connected to the control module and sends a positioning signal to the control module after sensing that the infusion bag 3 is in position. The positioning sensor may be an existing photoelectric sensor or a contact sensor (touch switch), etc., which will not be elaborated here.

[0039] like Figure 1As shown, the present invention also discloses a constant-rate infusion method, which uses the constant-rate infusion device described above, and includes the following steps: S1: The infusion bag 3 to be infused is placed into the pressurized air bag 2. The automatic switching mechanism is switched to the inflation position, and high-pressure gas is introduced into the air inlet pipe 4 from the external high-pressure gas source. Figure 5 As shown, the first-stage pressure regulating mechanism independently controls the pressurization speed of the pressurizing airbag 2 with a preset output value, thereby enabling the pressurizing airbag 2 to inflate quickly to fix the infusion bag 3 and to quickly adhere the pressurizing airbag 2 to the surface of the infusion bag 3.

[0040] S2: When the internal pressure of the pressurizing airbag 2 reaches the preset infusion pressure value, the output pressure of the second-stage pressure regulating mechanism is adjusted to the scale corresponding to the target infusion rate, so that the infusion bag 3 infuses at a constant infusion rate; in some embodiments, after the controller obtains the target infusion rate, it can control the second-stage pressure regulating mechanism to automatically adjust to the target infusion rate when the internal pressure of the pressurizing airbag 2 reaches the preset infusion pressure value; for example Figure 3 As shown, in some other embodiments, when the second-stage pressure regulating mechanism uses a second knob-type pressure regulating valve 8 that can be manually adjusted, when the internal air pressure value of the pressurizing airbag 2 reaches the preset infusion air pressure value, the system issues a prompt signal, and the operator can directly adjust the second knob-type pressure regulating valve 8 to the scale where the target infusion rate is located by manual adjustment.

[0041] The second-stage pressure regulating mechanism is used to finely adjust the output pressure to the pressurizing airbag 2, thereby adapting to the infusion rate of the infusion bag 3. This allows the pressurizing airbag 2 to dynamically compensate for the loss of liquid in the infusion bag 3 throughout the infusion process with an equal volume of gas. This ensures that the pressurizing airbag fits tightly against the gradually flattening infusion bag 3, providing a stable external pressure and achieving constant pressure and constant speed infusion throughout the process. At the same time, since the pressurizing airbag 2 increases pressure at a constant rate, when the infusion rate of the infusion bag 3 does not reach the target infusion rate, the pressurizing airbag 2 expands its volume as the pressure increases and applies pressure to the infusion bag 3, thereby precisely controlling the infusion rate.

[0042] S3: As Figure 6 As shown, when the first air pressure detection mechanism detects that the air pressure inside the pressurizing airbag 2 has reached the target air pressure value, the infusion bag 3 is flattened. The control module controls the automatic switching mechanism to switch to the exhaust position. At this time, the pressurizing airbag 2 stops inflating and simultaneously controls the pressurizing airbag 2 to depressurize until the air pressure inside the pressurizing airbag 2 is balanced with the atmospheric pressure. At this time, the pressure exerted by the pressurizing airbag 2 on the infusion bag 3 disappears, making it easy to remove the infusion bag 3 after the infusion is completed from the pressurizing airbag 2. S4: Remove the infusion bag 3 after the infusion has been completed, and repeat the above steps.

[0043] In some embodiments, the correspondence between the output air pressure and the infusion flow rate of the second-stage pressure regulating mechanism is pre-calibrated, and the scale of the second-stage pressure regulating mechanism is re-marked from the air pressure value to the infusion flow rate value based on this relationship.

[0044] In some embodiments, the preset output value of the first-stage pressure regulating mechanism is located between the gas pressure value required for the target infusion rate and the maximum range of the second-stage pressure regulating mechanism. The preset output value of the first-stage pressure regulating mechanism is less than or equal to the maximum range of the second-stage pressure regulating mechanism. On the one hand, this can prevent damage caused by the input pressure of the second-stage pressure regulating mechanism exceeding its maximum range. On the other hand, controlling the output pressure of the first-stage pressure regulating mechanism can also ensure the safety of the infusion operation and prevent safety accidents caused by the failure of the second-stage pressure regulating mechanism.

[0045] In some embodiments, in step S4, when the first air pressure detection mechanism detects that the air pressure value inside the pressurized air bag 2 has reached the target air pressure value, the prompting module issues an alarm signal, thereby prompting the operator to replace the infusion bag 3; in a preferred embodiment, when the target air pressure value is reached, the medicine in the infusion bag 3 has not been completely emptied, thereby providing time for the operator to replace the infusion bag 3. The setting of the target air pressure value can be adjusted according to actual needs, which will not be elaborated here.

[0046] In some embodiments, in step S4, when the overpressure protection device detects that the air pressure inside the pressurized airbag 2 has reached the maximum safe air pressure, the overpressure protection device sends an overpressure signal to the control module, and the control module controls the automatic switching mechanism to automatically switch to the exhaust position, thereby preventing the pressurized airbag 2 from being damaged due to excessive pressure and ensuring the safety of the infusion process.

[0047] In some embodiments, in step S2, when the positioning sensor senses that the infusion bag 3 to be infused is placed into the pressurized air bag 2 and assembled in place, the positioning sensor sends a positioning signal to the control module, and the control module controls the automatic switching mechanism to automatically switch to the inflation position, thereby shortening the replacement time of the infusion bag 3 and the inflation preparation time, and improving the replacement efficiency.

[0048] This invention has many other embodiments, and all technical solutions formed by equivalent transformations or equivalent transformations fall within the protection scope of this invention.

Claims

1. A constant-rate infusion device, characterized in that: include: An infusion module includes an infusion bag and an infusion tubing connected to the bottom of the infusion bag; A pressurization module is used to apply constant pressure to the infusion bag for constant-rate infusion, including a pressurization airbag wrapped around the periphery of the infusion module, the pressurization airbag being connected to an external high-pressure air source through an air inlet pipe; The pressure regulating module is used to regulate the internal air pressure of the pressurized airbag, including a first-stage pressure regulating mechanism, a second-stage pressure regulating mechanism and an automatic switching mechanism installed on the air intake pipe; The output air pressure value of the first-stage pressure regulating mechanism is greater than the output air pressure value of the second-stage pressure regulating mechanism; The automatic switching mechanism includes an inflation position and an deflation position. When the automatic switching mechanism is adjusted to the inflation position, the pressurized airbag inflates and the deflation passage is closed simultaneously. When the automatic switching mechanism is adjusted to the deflation position, the pressurized airbag stops inflating and the deflation passage is opened simultaneously. The detection module includes a first air pressure detection mechanism for real-time detection of the air pressure value inside the pressurized airbag.

2. The constant-rate infusion device according to claim 1, characterized in that: It also includes a control module, and the first-stage pressure regulating mechanism, the second-stage pressure regulating mechanism, the automatic switching mechanism, and the first air pressure detection mechanism are all connected to the control module.

3. The constant-rate infusion device according to claim 2, characterized in that: It also includes an overpressure protection device and an alert module. The overpressure protection device includes a second air pressure detection mechanism, which is connected to the control module and is used to output an overpressure signal to the control module when the air pressure inside the pressurized airbag reaches the maximum safe air pressure. The alert module is used to issue an alarm signal when the infusion status is abnormal or when the infusion is completed.

4. The constant-rate infusion device according to claim 3, characterized in that: It also includes a positioning sensor installed inside the pressurized airbag. The positioning sensor is connected to the control module and is used to detect whether the infusion bag inside the pressurized airbag is properly assembled and to send a positioning signal to the control module.

5. A constant-rate infusion method, characterized in that: The constant-rate infusion device as described in any one of claims 1-4 includes the following steps: S1: The infusion bag to be infused is placed into the pressurized airbag. The automatic switching mechanism is switched to the inflation position. The external high-pressure gas source introduces high-pressure gas into the air inlet pipe. The first-stage pressure regulating mechanism independently controls the pressurization speed of the pressurized airbag with a preset output value. S2: When the internal air pressure of the pressurized airbag reaches the preset infusion air pressure value, the output air pressure value of the second-stage pressure regulating mechanism is adjusted to the scale where the target infusion rate is located, so that the infusion bag infuses at a constant infusion rate. S3: When the first air pressure detection mechanism detects that the air pressure inside the pressurized airbag has reached the target air pressure value, the automatic switching mechanism switches to the exhaust position. At this time, the pressurized airbag stops inflating and simultaneously controls the pressurized airbag to depressurize until the air pressure inside the pressurized airbag is balanced with the atmospheric pressure. S4: Remove the infusion bag after the infusion has been completed, and repeat the above steps.

6. The constant-rate infusion device according to claim 5, characterized in that: The correspondence between the output air pressure and the infusion flow rate of the second-stage pressure regulating mechanism is pre-calibrated, and the scale of the second-stage pressure regulating mechanism is re-marked from the air pressure value to the infusion flow rate value based on this relationship.

7. The constant-rate infusion method according to claim 6, characterized in that: The preset output value of the first-stage pressure regulating mechanism is located between the gas pressure required for the target infusion rate and the maximum range of the second-stage pressure regulating mechanism.

8. The constant-rate infusion method according to claim 5, characterized in that: In step S4, when the first air pressure detection mechanism detects that the air pressure value inside the pressurized airbag has reached the target air pressure value, the prompting module issues an alarm signal.

9. The constant-rate infusion method according to claim 5, characterized in that: In step S4, when the overpressure protection device detects that the air pressure inside the pressurized airbag has reached the maximum safe air pressure, the automatic switching mechanism automatically switches to the exhaust position.

10. The constant-rate infusion method according to claim 5, characterized in that: In step S2, when the positioning sensor detects that the infusion bag to be infused is placed into the pressurized air bag and assembled in place, the automatic switching mechanism automatically switches to the inflation position.

Images