Flow testing system and method based on pressure feedback

Abstract

The invention relates to the field of blood purification, and discloses a flow testing system and method based on pressure feedback. The test system comprises a pressure detection device, an air filter, a buffer tank, a liquid tank, a volume test device and a flow test device, the buffer tank and the liquid tank are connected together in a fluid communication manner through the Luer female head and the Luer male head; the pressure detection device is connected with the air filter through a pipeline and is used for measuring gas pressure in the pipeline; one end of the air filter is connected with the pressure detection device, and the other end is communicated with the internal space of the buffer tank through a pipeline; the volume testing device is used for testing the volume of the to-be-tested liquid injected into the liquid tank; and the flow testing device is used for testing the flow of the to-be-tested liquid flowing through the liquid tank. Indirect measurement of the liquid flow is achieved through the pressure sensor, rapid, accurate and real-time measurement of the liquid flow can be achieved in complex scenes such as movement and vibration, and use safety and reliability are greatly improved.

Description

Technical Field

[0001] The present application relates to the field of blood purification, and in particular to a flow testing technology based on pressure feedback. Background Art

[0002] Continuous blood purification equipment is the power device for blood purification treatment, and flow detection is the key module for continuous blood purification equipment to achieve stable treatment. During continuous blood purification treatment, dialysate, replacement fluid, waste fluid and other therapeutic fluids will be affected by many external factors, causing their flow to change, so accurate measurement of the liquid flow is required.

[0003] By timely adjusting the speed of the driving pump to achieve precise control of the liquid flow, the dehydration accuracy can be improved and the purpose of stable treatment can be achieved. However, during the treatment process, in order to prevent cross infection, the liquid flow cannot be measured directly and can only be monitored in real time through indirect measurement.

[0004] The commonly used method for measuring liquid flow is to use a weight sensor to provide real-time feedback on the weight of the liquid to obtain the liquid flow. However, since the weight sensor has high requirements for the use environment, it is impossible to complete weight feedback in complex scenarios such as motion and vibration. Therefore, in complex scenarios, continuous blood purification equipment cannot achieve accurate measurement of flow, resulting in the inability to perform safe treatment. In addition, the prior art uses weight changes to infer changes in liquid flow, but due to the different densities of the liquid to be measured, the flow accuracy of the measured liquid will also decrease.

[0005] Therefore, there is an urgent need for a flow testing system that can perform flow testing quickly, accurately and in real time in complex scenarios such as motion and vibration. Summary of the invention

[0006] The purpose of this application is to provide a flow testing system based on pressure feedback, which realizes indirect measurement of liquid flow through a pressure sensor, and can achieve fast, accurate and real-time measurement of liquid flow in complex scenarios such as motion and vibration, greatly improving the safety and reliability of use.

[0007] The embodiment of the present application discloses a flow rate testing system based on pressure feedback, comprising: Pressure testing devices, air filters, buffer tanks, liquid tanks, volume testing devices and flow testing devices; The upper end of the buffer tank is provided with a pipeline, and the lower end of the buffer tank is provided with a Luer female head; the upper end of the liquid tank is provided with a Luer male head, and the buffer tank and the liquid tank are connected together in fluid communication through the Luer female head and the Luer male head; The pressure detection device is connected to the air filter through the pipeline and is used to measure the gas pressure inside the pipeline; One end of the air filter is connected to the pressure detection device, and the other end is connected to the internal space of the buffer tank through the pipeline; the air filter is used to prevent liquid from entering the pressure detection device; The liquid tank is also provided with a liquid inlet and a liquid outlet; the liquid to be tested flows into the liquid tank through the liquid inlet and flows out of the liquid tank through the liquid outlet; The volume testing device is used to test the volume of the liquid to be tested injected into the liquid tank according to the first formula using the gas pressure measured by the pressure detection device; The first formula is: in, is the volume of the buffer tank; is the volume of the liquid tank; is the gas pressure measured by the pressure detection device when no liquid to be tested is injected into the liquid tank; When the gas pressure measured by the pressure detection device is When , the volume of the liquid to be tested injected into the liquid tank; For time; The flow rate testing device is used to test the flow rate of the liquid to be tested flowing through the liquid tank according to the second formula using the volume measured by the volume testing device; The second formula is: in, is the volume of the liquid to be tested injected into the liquid tank measured by the volume testing device, is the flow rate of the liquid to be tested flowing through the liquid tank, For time.

[0008] In another preferred example, the pressure detection device is a pressure sensor.

[0009] In another preferred embodiment, the air filter is an air drying filter.

[0010] In another preferred example, the buffer tank is located above the liquid tank.

[0011] In another preferred example, the liquid inlet and the liquid outlet are both arranged at the lower end of the liquid tank.

[0012] In another preferred embodiment, the liquid to be tested is hemodialysis fluid, replacement fluid or waste fluid.

[0013] In another preferred embodiment, the flow testing system based on pressure feedback is suitable for continuous blood purification equipment.

[0014] In another preferred embodiment, the flow testing system based on pressure feedback is suitable for motion or vibration scenarios.

[0015] In another preferred embodiment, the pipeline, the buffer tank and the liquid tank are all transparent.

[0016] The embodiment of the present application further discloses a flow test method based on pressure feedback, which is applicable to the flow test system based on pressure feedback as described above, and the method comprises the following steps: Measuring the gas pressure inside the buffer tank and the liquid tank by the pressure detection device; According to the first formula, the volume of the liquid to be tested injected into the liquid tank is tested using the gas pressure measured by the pressure detection device; The first formula is: in, is the volume of the buffer tank; is the volume of the liquid tank; is the gas pressure measured by the pressure detection device when no liquid to be tested is injected into the liquid tank; When the gas pressure measured by the pressure detection device is When , the volume of the liquid to be tested injected into the liquid tank; For time; According to the second formula, using the volume measured by the volume testing device, testing the flow rate of the liquid to be tested flowing through the liquid tank; The second formula is: in, is the volume of the liquid to be tested injected into the liquid tank measured by the volume testing device, is the flow rate of the liquid to be tested flowing through the liquid tank, For time.

[0017] It should be understood that within the scope of this application, the above-mentioned technical features of this application and the technical features specifically described below (such as embodiments) can be combined with each other to form a new or preferred technical solution. Due to space limitations, they will not be described one by one here.

[0018] Compared with the prior art, the main differences and effects of the embodiments of the present application are: The present application provides a flow testing system based on pressure feedback, which realizes indirect measurement of liquid flow through a pressure sensor. It can realize fast, accurate and real-time measurement of liquid flow in complex scenarios such as motion and vibration, greatly improving the safety and reliability of use.

[0019] Furthermore, by arranging the buffer tank above the liquid tank so that the buffer tank becomes an extension of the liquid tank, the liquid capacity range inside the liquid tank can be increased, and at the same time, the liquid can be prevented from entering the pressure detection device, thereby playing a protective role.

[0020] Furthermore, by arranging an air filter between the pressure detection device and the buffer tank, it is possible to prevent the liquid to be detected from entering the pressure detection device and causing pressure detection failure.

[0021] Furthermore, the pipeline, buffer tank and liquid tank are all set to be transparent, so as to facilitate the observation of the liquid to be tested in the tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural schematic diagram of a flow rate testing system based on pressure feedback in the first embodiment of the present application; Figure 2 This is a flow chart of a flow testing method based on pressure feedback in the second embodiment of the present application; It should be understood that the drawings in this application are for illustrative purposes only and are not shown to scale unless otherwise specified.

[0023] Reference numerals: 1. Pressure detection device; 2. Air filter; 3. Buffer tank; 4. Luer female connector; 5. Luer male connector; 6. Liquid tank; 7. Liquid inlet; 8. Liquid outlet. DETAILED DESCRIPTION

[0024] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the claims of the present application can be implemented.

[0025] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0026] The first embodiment of the present application relates to a flow testing system based on pressure feedback. Figure 1 It is a structural schematic diagram of the flow test system based on pressure feedback.

[0027] First of all, it should be noted that, as used in this article, the terms "upper end", "top end" and "top" refer to the end of the flow testing system based on pressure feedback that is away from the ground when in actual use; "lower end", "bottom end" and "bottom" refer to the end of the flow testing system based on pressure feedback that is close to the ground when in actual use.

[0028] Specifically, if Figure 1 As shown, the flow test system based on pressure feedback includes: Pressure detection device 1, air filter 2, buffer tank 3, liquid tank 6, volume testing device and flow testing device.

[0029] The upper end of the buffer tank 3 is provided with a pipeline, and the lower end of the buffer tank 3 is provided with a Luer female head 4; the upper end of the liquid tank 6 is provided with a Luer male head 5, and the buffer tank 3 and the liquid tank 6 are connected together in fluid communication through the Luer female head 4 and the Luer male head 5.

[0030] like Figure 1 As shown, the buffer tank 3 is located above the liquid tank 6 .

[0031] That is to say, through the Luer female connector 4 and the Luer male connector 5, the buffer tank 3 and the liquid tank 6 are connected together in a manner that the buffer tank 3 is on the top and the liquid tank 6 is on the bottom so as to be fluidically connected from top to bottom.

[0032] By arranging the buffer tank above the liquid tank and making the buffer tank an extension of the liquid tank, the liquid capacity range inside the liquid tank can be increased, and at the same time, the liquid can be prevented from entering the pressure detection device, thereby playing a protective role.

[0033] The pressure detection device 1 is connected to the air filter 2 via the pipeline and is used to measure the gas pressure inside the pipeline.

[0034] The pipeline is in communication with the inner space of the buffer tank 3 , and thus the gas pressure inside the buffer tank 3 and the liquid tank 6 can be measured by the pressure detection device 1 .

[0035] In this embodiment, preferably, the pressure detection device 1 is a pressure sensor.

[0036] The indirect measurement of liquid flow is achieved through pressure sensors, which is not affected by harsh measurement conditions such as movement and vibration. In other words, the flow test system based on pressure feedback can be applied to complex scenarios such as movement or vibration.

[0037] One end of the air filter 2 is connected to the pressure detection device 1 , and the other end is connected to the inner space of the buffer tank 3 through the pipeline; the air filter 2 is used to prevent liquid from entering the pressure detection device 1 .

[0038] In this embodiment, preferably, the air filter 2 is an air drying filter.

[0039] By arranging an air filter between the pressure detection device and the buffer tank, it is possible to prevent the liquid to be detected from entering the pressure detection device and causing pressure detection failure.

[0040] The liquid tank 6 is also provided with a liquid inlet 7 and a liquid outlet 8 ; the liquid to be tested flows into the liquid tank 6 through the liquid inlet 7 and flows out of the liquid tank 6 through the liquid outlet 8 .

[0041] In this embodiment, preferably, the liquid inlet 7 and the liquid outlet 8 are both arranged at the lower end (bottom) of the liquid tank 6 .

[0042] The liquid tank 6 has one end (upper end) connected to the buffer tank, and two pipelines are arranged at the bottom thereof as a liquid inlet and a liquid outlet, respectively, and is mainly used as a storage device for the liquid to be tested.

[0043] In this embodiment, preferably, the liquid to be tested is hemodialysis fluid, replacement fluid or waste fluid. That is, the flow rate testing system based on pressure feedback is suitable for continuous blood purification equipment, and realizes accurate measurement of liquid flow in the extracorporeal circulation pipeline of the continuous blood purification equipment.

[0044] In addition, in this embodiment, preferably, the pipeline, the buffer tank 3 and the liquid tank 6 are all transparent, so as to facilitate observation of the condition of the liquid to be tested in the tank.

[0045] The volume testing device is used to test the volume of the liquid to be tested injected into the liquid tank 6 according to the first formula using the gas pressure measured by the pressure detection device 1; The first formula is: in, is the volume of the buffer tank 3; is the volume of the liquid tank 6; is the gas pressure measured by the pressure detection device 1 when no liquid to be tested is injected into the liquid tank 6; When the gas pressure measured by the pressure detection device 1 is When , the volume of the liquid to be tested injected into the liquid tank 6; For time.

[0046] The flow rate testing device is used to test the flow rate of the liquid to be tested flowing through the liquid tank 6 according to the second formula using the volume measured by the volume testing device; The second formula is: in, is the volume of the liquid to be tested injected into the liquid tank 6 measured by the volume testing device, is the flow rate of the liquid to be tested flowing through the liquid tank 6, For time.

[0047] Specifically, according to the ideal gas state equation , we can get: therefore, .

[0048] According to the above formula, the pressure detected in real time , the volume of the liquid to be tested injected into the liquid tank can be obtained .

[0049] Accordingly, the volume flow rate of the liquid to be tested injected into the liquid tank can be obtained by calculating the real-time measured liquid volume The curvature of the curve is obtained.

[0050] In this embodiment, preferably, the volume testing device and the flow testing device can be implemented by means of a digital signal processor (DSP), a single-chip microcomputer or a microcontroller unit (MCU), etc., and their implementation methods are all mature technologies in the prior art and will not be further described here.

[0051] In summary, the present application provides a flow testing system based on pressure feedback, which realizes indirect measurement of liquid flow through a pressure sensor. It can realize fast, accurate and real-time measurement of liquid flow in complex scenarios such as motion and vibration, greatly improving the safety and reliability of use.

[0052] Compared with the prior art that uses a weight sensor to indirectly measure the liquid flow rate, the technical solution of the present application uses a pressure sensor to indirectly measure the liquid flow rate. Compared with the prior art, the technical solution of the present application has the following advantages:

[0053] (1) The use scenarios of the flow test system can be expanded. Even if the equipment is in complex environments such as motion and vibration, the liquid flow can be detected in real time; (2) Direct feedback on liquid flow rate. The existing technology generally infers the change of liquid flow rate by weight change. However, due to the different densities of the liquids to be measured, the accuracy of the measured liquid flow rate decreases.

[0054] It should be noted that the various devices mentioned in the various system implementations of the present application are all logical modules. Physically, a logical module can be a physical module, or a part of a physical module, or can be implemented as a combination of multiple physical modules. The physical implementation method of these logical modules themselves is not the most important. The combination of functions implemented by these logical modules is the key to solving the technical problems proposed by the present application. In addition, in order to highlight the innovative part of the present application, the above-mentioned system implementation of the present application does not introduce modules / devices that are not closely related to solving the technical problems proposed by the present application, which does not mean that there are no other modules / devices in the above-mentioned system implementation.

[0055] The second embodiment of the present application relates to a flow testing method based on pressure feedback. Figure 2 It is a flow chart of the flow testing method based on pressure feedback.

[0056] It should be noted that the flow testing method based on pressure feedback is applicable to the flow testing system based on pressure feedback described in the first embodiment of the present application.

[0057] Specifically, if Figure 2 As shown, the flow testing method based on pressure feedback includes the following steps: In step 201 , the gas pressure inside the buffer tank 3 and the liquid tank 6 is measured by the pressure detection device 1 .

[0058] Then, the process proceeds to step 202 , in which the volume of the liquid to be tested injected into the liquid tank 6 is tested using the gas pressure measured by the pressure detection device 1 according to the first formula.

[0059] The first formula is: in, is the volume of the buffer tank 3; is the volume of the liquid tank 6; is the gas pressure measured by the pressure detection device 1 when no liquid to be tested is injected into the liquid tank 6; When the gas pressure measured by the pressure detection device 1 is When , the volume of the liquid to be tested injected into the liquid tank 6; For time.

[0060] Then, the process proceeds to step 203 , in which the flow rate of the liquid to be tested flowing through the liquid tank 6 is tested according to the second formula using the volume measured by the volume testing device.

[0061] The second formula is: in, is the volume of the liquid to be tested injected into the liquid tank 6 measured by the volume testing device, is the flow rate of the liquid to be tested flowing through the liquid tank 6, For time.

[0062] This process ends thereafter.

[0063] In order to better illustrate that the technical solution of the present application has a more excellent technical effect compared with the prior art, the inventor of the present application has verified it through numerous experiments. The following is a comparative example of comparing the present application with a traditional electronic balance. It should be noted that the details listed in the comparative example are mainly for ease of understanding and are not intended to limit the scope of protection of the present application.

[0064] Test tools: vibration table, 2 traditional electronic balances, test system of this application, flow pump, tape, plastic hose, 5L measuring cylinder.

[0065] Test method description: 1. Place an electronic balance on a vibration table and fix the test system of the present application on the electronic balance to ensure that it will not fall off due to vibration.

[0066] 2. Fix another electronic balance on the horizontal ground and place a 5L measuring cylinder filled with water on the electronic balance.

[0067] 3. Connect the peristaltic pump to the test system and the measuring cylinder of the present application through a plastic hose, and pump the liquid in the measuring cylinder into the test system of the present application through the peristaltic pump to measure the weight of the liquid; 4. Clear the two electronic balances and record the data. The display value of the electronic balance on the horizontal ground is the actual value of the liquid to be tested, and the display value of the electronic balance in the vibration table is the measured value of the liquid to be tested by the traditional electronic balance under vibration conditions; the display value of the test system of the present application (referred to as: this system in the following table) is the measured value of the liquid to be tested by the test system of the present invention.

[0068] Experimental data: as shown in the following table.

[0069]

[0070] By analyzing the experimental data in the above table, it can be seen that under vibration conditions, traditional weighing equipment cannot work normally, the test error fluctuates greatly, and the measured value displayed is not of reference value. However, when measured using the flow test system of this application, the error does not exceed 10g.

[0071] In addition, through experiments, the inventors of the present application also found that: After the liquid oscillates, the flow test method based on weighing needs 2 minutes to stabilize before it can be measured, while the flow test method based on pressure feedback in this application can be measured after a few seconds, and the measurement results are faster and more sensitive.

[0072] In a shaking environment, the flow test method based on weighing cannot be measured at all or the measurement result has a large error. However, the flow test method based on pressure feedback in the present application is not affected by the shaking and can still measure accurate results.

[0073] In addition, when the instrument is fixed, the flow test method based on weighing cannot be measured because it cannot be moved, while the flow test method based on pressure feedback of the present application can be conveniently measured, etc.

[0074] In summary, the present application realizes indirect measurement of liquid flow through pressure sensors, which can be used to measure the real-time flow of dialysate, replacement fluid, and waste fluid, so that continuous blood purification equipment can achieve stable treatment in different scenarios.

[0075] The first embodiment is a system implementation method corresponding to the present embodiment, and the present embodiment can be implemented in conjunction with the first embodiment. The relevant technical details mentioned in the first embodiment are still valid in the present embodiment, and are not repeated here to reduce repetition. Accordingly, the relevant technical details mentioned in the present embodiment can also be applied in the first embodiment.

[0076] It should be noted that in the claims and description of this patent, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0077] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application.

Claims

1. A flow test system based on pressure feedback, characterized in that: include: A pressure detection device (1), an air filter (2), a buffer tank (3), a liquid tank (6), a volume testing device and a flow testing device; The upper end of the buffer tank (3) is provided with a pipeline, and the lower end of the buffer tank (3) is provided with a Luer female head (4); the upper end of the liquid tank (6) is provided with a Luer male head (5), and the buffer tank (3) and the liquid tank (6) are connected together in fluid communication via the Luer female head (4) and the Luer male head (5); The pressure detection device (1) is connected to the air filter (2) via the pipeline and is used to measure the gas pressure inside the pipeline; One end of the air filter (2) is connected to the pressure detection device (1), and the other end is connected to the internal space of the buffer tank (3) through the pipeline; the air filter (2) is used to prevent liquid from entering the pressure detection device (1); The liquid tank (6) is also provided with a liquid inlet (7) and a liquid outlet (8); the liquid to be tested flows into the liquid tank (6) through the liquid inlet (7) and flows out of the liquid tank (6) through the liquid outlet (8); The volume testing device is used to test the volume of the liquid to be tested injected into the liquid tank (6) according to the first formula and using the gas pressure measured by the pressure detection device (1); The first formula is: ； in, is the volume of the buffer tank (3); is the volume of the liquid tank (6); is the gas pressure measured by the pressure detection device (1) when no liquid to be tested is injected into the liquid tank (6); When the gas pressure measured by the pressure detection device (1) is When , the volume of the liquid to be tested injected into the liquid tank (6); For time; The flow rate testing device is used to test the flow rate of the liquid to be tested flowing through the liquid tank (6) according to a second formula using the volume measured by the volume testing device; The second formula is: ； in, is the volume of the liquid to be tested injected into the liquid tank (6) measured by the volume testing device, is the flow rate of the liquid to be tested flowing through the liquid tank (6), For time.

2. The flow rate testing system based on pressure feedback according to claim 1, characterized in that: The pressure detection device (1) is a pressure sensor.

3. The flow rate testing system based on pressure feedback according to claim 1, characterized in that: The air filter (2) is an air drying filter.

4. The flow rate testing system based on pressure feedback according to claim 1, characterized in that: The buffer tank (3) is located above the liquid tank (6).

5. According to the flow rate testing system based on pressure feedback according to claim 1, the liquid inlet (7) and the liquid outlet (8) are both arranged at the lower end of the liquid tank (6).

6. The flow rate testing system based on pressure feedback according to claim 1, characterized in that: The liquid to be tested is hemodialysis fluid, replacement fluid or waste fluid.

7. The flow rate testing system based on pressure feedback according to claim 1, characterized in that: The flow rate testing system based on pressure feedback is suitable for continuous blood purification equipment.

8. The flow rate testing system based on pressure feedback according to claim 1, characterized in that: The flow testing system based on pressure feedback is suitable for motion or vibration scenarios.

9. The flow rate testing system based on pressure feedback according to claim 1, characterized in that: The pipeline, the buffer tank (3) and the liquid tank (6) are all transparent.

10. A flow rate testing method based on pressure feedback, applicable to the flow rate testing system based on pressure feedback according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: Measuring the gas pressure inside the buffer tank (3) and the liquid tank (6) by means of the pressure detection device (1); According to the first formula, the volume of the liquid to be tested injected into the liquid tank (6) is tested using the gas pressure measured by the pressure detection device (1); The first formula is: ； in, is the volume of the buffer tank (3); is the volume of the liquid tank (6); is the gas pressure measured by the pressure detection device (1) when no liquid to be tested is injected into the liquid tank (6); When the gas pressure measured by the pressure detection device (1) is When , the volume of the liquid to be tested injected into the liquid tank (6); For time; According to the second formula, using the volume measured by the volume testing device, testing the flow rate of the liquid to be tested flowing through the liquid tank (6); The second formula is: ； in, is the volume of the liquid to be tested injected into the liquid tank (6) measured by the volume testing device, is the flow rate of the liquid to be tested flowing through the liquid tank (6), For time.

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