A flow rate calibration system

Abstract

This disclosure provides a flow rate calibration system, comprising: a flow rate calibration device including a power unit and a main pipeline connected to the power unit, the power unit driving liquid to flow in the main pipeline at a predetermined speed; a flow rate guidewire configured to be inserted into the main pipeline to measure the fluid flow rate in the main pipeline; a demodulator connected to an optical fiber of the flow rate guidewire, configured to obtain cavity length curves of a first temperature sensor and a second temperature sensor of the flow rate guidewire based on the optical signal when a thermally diluted liquid is injected into the main pipeline; and a calibration module configured to determine calibration coefficients based on a standard flow rate obtained by the flow rate calibration device and a measured flow rate obtained by measuring the flow rate guidewire. The flow rate calibration system of this disclosure improves the measurement accuracy of the flow rate guidewire.

Description

Technical Field

[0001] This disclosure relates to a flow velocity calibration system. Background Technology

[0002] As a key area of ​​development in modern medicine, flow velocity guidewires are receiving increasing attention. Testing and calibration of flow velocity guidewires are crucial steps before they are put into use. Currently, there is a lack of calibration systems for flow velocity guidewires; therefore, researching and designing a high-precision flow velocity calibration system is essential to improving the accuracy of flow velocity measurements. Summary of the Invention

[0003] Therefore, the purpose of this disclosure is to provide a flow rate calibration system that improves the accuracy of flow rate calibration and testing.

[0004] The above objective is achieved by using the flow rate calibration system described below.

[0005] This disclosure provides a flow rate calibration system, comprising: a flow rate calibration device including a power unit and a main pipeline connected to the power unit, the power unit driving liquid to flow in the main pipeline at a predetermined speed; a flow rate guidewire configured to be inserted into the main pipeline to measure the fluid flow rate of the main pipeline; a demodulator connected to an optical fiber of the flow rate guidewire, configured to obtain cavity length curves of a first temperature sensor and a second temperature sensor of the flow rate guidewire based on the optical signal when a thermally diluted liquid is injected into the main pipeline; and a calibration module configured to determine a calibration coefficient based on a standard flow rate obtained by the flow rate calibration device and a measured flow rate obtained by measuring the flow rate guidewire.

[0006] In one embodiment, the flow rate calibration device includes a weighing device and a standard flow rate calculation module. The weighing device is configured to weigh the liquid output from the main pipeline, and the standard flow rate calculation module is configured to acquire the weight data of the weighing device and determine the standard flow rate based on the weight of the liquid output from the main pipeline per unit time.

[0007] In one embodiment, the flow rate calibration device further includes a liquid storage cylinder; the outlet of the liquid storage cylinder is connected to the input end of the main pipeline, a piston is disposed inside the liquid storage cylinder, and liquid is stored between the piston and the outlet of the liquid storage cylinder; the power device is configured to drive the piston to move, the power device includes a motor and a ball screw, the output shaft of the motor is connected to the ball screw, the ball screw is connected to the piston, and the motor drives the ball screw to push the piston to move.

[0008] In one embodiment, the flow rate calibration device includes a standard flow rate calculation module, which is configured to determine the standard flow rate according to the following formula: V=S1*dl / (S2*dt), where V is the standard flow rate, S1 is the cross-sectional area of ​​the liquid storage cylinder, S2 is the cross-sectional area of ​​the main pipeline, and dl / dt is the moving speed of the piston.

[0009] In one embodiment, the standard flow rate calculation module is configured to control the motor to change the motor speed at a preset frequency.

[0010] In one embodiment, the standard flow rate calculation module is configured to determine the standard flow rate according to the following formula: V=R*S*S1 / S2, where V is the standard flow rate, R is the real-time rotational speed of the motor, S is the lead of the ball screw, S1 is the cross-sectional area of ​​the liquid storage cylinder, and S2 is the cross-sectional area of ​​the main pipeline.

[0011] In one embodiment, the flow guidewire includes a guidewire body, the guidewire body including a tube wall and an inner cavity defined by the tube wall; a first temperature sensor and a second temperature sensor are disposed in series in the inner cavity.

[0012] In one embodiment, the demodulator includes: a light source configured to emit light and transmit it to the first temperature sensor and the second temperature sensor via the first optical fiber; a birefringent optical component configured to receive modulated light returned from the first optical fiber and interfere with the modulated light to form contrast-enhanced interference light, wherein the modulated light is formed by the interference of light emitted by the light source with the first temperature sensor and the second temperature sensor; a photodetector configured to receive the contrast-enhanced interference light and form an optical signal curve; and a signal processing unit configured to receive the optical signal curve and process it to obtain cavity length curves of the first temperature sensor and the second temperature sensor.

[0013] In one embodiment, the demodulator includes a flow rate calculation module configured to obtain the measured flow rate based on the time difference between the flow of the thermally diluted liquid injected into the main pipeline from a first temperature sensor to a second temperature sensor on the flow rate guidewire and the distance between the first temperature sensor and the second temperature sensor, wherein the time difference is obtained based on the cavity length curve.

[0014] In one embodiment, the flow rate calculation module is configured to calculate the time difference by obtaining a first time point when the first temperature sensor of the flow rate guide wire reaches its lowest temperature and a second time point when the second temperature sensor reaches its lowest temperature, and obtaining the time difference from the difference between the first time point and the second time point.

[0015] The flow velocity calibration system disclosed herein can provide a stable, pulsation-free fluid environment, thereby providing a stable measurement environment and accurate standard flow velocity for flow velocity measurement. By determining the calibration coefficient of the flow velocity guide wire through the flow velocity calibration system, the measurement accuracy of the flow velocity guide wire is improved. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments of this disclosure will be briefly described below. The drawings are merely illustrative of some embodiments of this disclosure and are not intended to limit the scope of all embodiments of this disclosure. In the drawings: Figure 1 A schematic diagram of the structure of a flow rate calibration system according to an embodiment of the present disclosure is shown; Figure 2 The cavity length curve of the flow guide wire during the injection of thermally diluted fluid is shown in the flow rate calibration system according to an embodiment of the present disclosure.

[0017] 1-Motor 2-Ball screw 3-Liquid storage cylinder 4-Main pipe 41-Branch pipe 5-Piston 6-Flow guide wire Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0019] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not necessarily indicate a quantity limitation. The terms “comprising,” “including,” or “having,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected” or “connected,” and similar terms are not limited to the physical or mechanical connection or connection shown in the drawings, but may include equivalent connections or connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, which may change accordingly when the absolute position of the described object changes.

[0020] This disclosure provides a flow rate calibration system, comprising: a flow rate calibration device including a power unit and a main pipeline connected to the power unit, the power unit driving liquid to flow in the main pipeline at a predetermined speed; a flow rate guidewire configured to be inserted into the main pipeline to measure the fluid flow rate of the main pipeline; a demodulator connected to an optical fiber of the flow rate guidewire, configured to obtain cavity length curves of a first temperature sensor and a second temperature sensor of the flow rate guidewire based on the optical signal when a thermally diluted liquid is injected into the main pipeline; and a calibration module configured to determine a calibration coefficient based on a standard flow rate obtained by the flow rate calibration device and a measured flow rate obtained by measuring the flow rate guidewire.

[0021] The flow rate calibration device disclosed herein includes: a main pipeline 4, including an input end and an output end; a liquid storage cylinder 3, the outlet of which is connected to the input end of the main pipeline, a piston 5 disposed within the liquid storage cylinder, and liquid stored between the piston and the outlet of the liquid storage cylinder; a power unit configured to drive the piston to move, the piston driving the liquid to flow in the liquid storage cylinder and the main pipeline; and a standard flow rate calculation module configured to determine a standard flow rate based on the moving speed of the piston and the ratio of the cross-sectional area of ​​the liquid storage cylinder to that of the main pipeline. The standard flow rate calculation module can be programmed into a computer, which is connected to a motor driver. A flow rate guide wire 6 can enter the main pipeline 4 to measure the fluid flow rate in the main pipeline 4.

[0022] The power unit includes a motor 1 and a ball screw 2. The output shaft of the motor is connected to the ball screw, and the ball screw is connected to the piston. The motor drives the ball screw to move the piston. The motor can be a servo motor or a stepper motor. The piston's movement speed can be calculated by multiplying the motor's rotational speed by the lead of the ball screw.

[0023] The standard flow rate calculation module is configured to determine the standard flow rate according to the following formula: V=S1*dl / (S2*dt), where V is the standard flow rate, S1 is the cross-sectional area of ​​the liquid storage cylinder, S2 is the cross-sectional area of ​​the main pipeline, and dl / dt is the moving speed of the piston.

[0024] The standard flow rate calculation module is configured to control the power unit to change the motor speed at a preset frequency to generate a pulsating flow rate. The motor drives a ball screw to push a piston forward at a constant or variable speed, thereby generating the desired flow rate, such as a constant speed, a sinusoidal flow rate, or a simulated human body flow rate. By changing the rotation speed at a preset frequency, the pulsating blood flow rate of the human heart pumping blood can be simulated, thus accurately calibrating the flow rate measuring device and providing a basis for measuring real-time blood flow rate.

[0025] The standard flow rate calculation module is configured to determine the standard flow rate according to the following formula: V = R * S * S1 / S2, where V is the standard flow rate, R is the real-time rotational speed of the motor, S is the lead of the ball screw, S1 is the cross-sectional area of ​​the liquid storage cylinder, and S2 is the cross-sectional area of ​​the main pipeline. This calculation method allows for the accurate calibration of the flow rate measuring device by obtaining the real-time flow rate of the fluid in the main pipeline.

[0026] For example, if the motor switches between speeds of 0 r / s and 0.64 r / s at a frequency of 3 Hz, the ball screw lead is 5 mm / r, the diameter of the liquid storage cylinder is 100 mm, and the diameter of the main pipeline is 4 mm, then the fluid velocity in the main pipeline will pulsate between 0 and 2 m / s.

[0027] The flow guidewire includes a guidewire body, which includes a tube wall and an inner cavity defined by the tube wall. A first temperature sensor and a second temperature sensor are disposed in series within the inner cavity. The first temperature sensor includes: a first sleeve; a first optical fiber, at least partially located within the first sleeve; a second optical fiber, with a first end located within the first sleeve and disposed opposite to the first optical fiber; and a first temperature sensing cavity defined by the first optical fiber and the first end of the second optical fiber. The second temperature sensor includes: a second sleeve, with a second end of the second optical fiber located within the second sleeve; a reflective end face located within the second sleeve and disposed opposite to the second end of the second optical fiber; and a second temperature sensing cavity defined by the second end of the second optical fiber and the reflective end face.

[0028] The demodulator is connected to the first optical fiber of the flow guide wire and is configured to obtain the cavity length curves of the first temperature sensor and the second temperature sensor based on the optical signal curve when the thermal dilution fluid is injected.

[0029] The demodulator includes: a light source configured to emit light and transmit it to the first temperature sensor and the second temperature sensor via the first optical fiber; a birefringent optical component configured to receive modulated light returned from the first optical fiber and interfere with the modulated light to form contrast-enhanced interference light, wherein the modulated light is formed by the interference of light emitted by the light source with the first temperature sensor and the second temperature sensor; a photodetector configured to receive the contrast-enhanced interference light and form an optical signal curve; and a signal processing unit configured to receive the optical signal curve and process it to obtain the cavity length curves of the first temperature sensor and the second temperature sensor.

[0030] The birefringent optical component includes: a condenser configured to receive the modulated light; a first polarizer disposed downstream of the condenser and configured to split the modulated light into different polarization components; a second polarizer disposed downstream of the first polarizer and configured to combine the different polarization components; and a birefringent element located between the first polarizer and the second polarizer.

[0031] like Figure 2 The figure shows the cavity length curves of the first and second temperature sensors of the flow rate guide wire when the thermal dilution fluid is injected. As can be seen from the figure, the cavity length of the temperature sensing cavity decreases as the temperature of the mixed fluid decreases when the thermal dilution fluid is injected.

[0032] The demodulator includes a flow rate calculation module configured to obtain the measured flow rate based on the time difference between the flow of the thermally diluted liquid injected into the main pipeline from the first temperature sensor to the second temperature sensor of the flow rate guide wire and the distance between the first temperature sensor and the second temperature sensor, wherein the time difference is obtained based on the cavity length curve.

[0033] The flow rate calculation module is configured to calculate the time difference as follows: It acquires the first time point when the first temperature sensor of the flow rate guide wire reaches its lowest temperature and the second time point when the second temperature sensor reaches its lowest temperature; the time difference is obtained from the difference between the first time point and the second time point. Alternatively, the time difference can be calculated from the time point when the temperature of the temperature sensing cavity begins to decrease.

[0034] The flow velocity calibration system disclosed herein can provide a stable, pulsation-free fluid environment, thereby providing a stable measurement environment and accurate standard flow velocity for flow velocity measurement. The flow velocity calibration system improves the measurement accuracy of the flow velocity guidewire.

[0035] Furthermore, the technical features disclosed above are not limited to the combinations of the disclosed features with other features. Those skilled in the art can also make other combinations of the technical features according to the purpose of the disclosure in order to achieve the purpose of this disclosure.

Claims

1. A flow rate calibration system, characterized by, include: A flow rate calibration device includes a power unit and a main pipeline connected to the power unit, the power unit propelling liquid to flow in the main pipeline at a predetermined speed; A flow rate guidewire configured to be inserted into the main pipeline to measure the fluid flow rate of the main pipeline; The demodulator is connected to the optical fiber of the flow guide wire and is configured to obtain the cavity length curves of the first and second temperature sensors of the flow guide wire based on the optical signal when the thermal dilution liquid is injected into the main pipeline. The calibration module is configured to determine calibration coefficients based on the standard flow rate obtained by the flow rate calibration device and the measured flow rate obtained by the flow rate guide wire.

2. The flow rate calibration system of claim 1, wherein, The flow rate calibration device includes a weighing device and a standard flow rate calculation module. The weighing device is configured to weigh the liquid output from the main pipeline, and the standard flow rate calculation module is configured to acquire the weight data of the weighing device and determine the standard flow rate based on the weight of the liquid output from the main pipeline per unit time.

3. The flow rate calibration system according to claim 1, characterized in that, The flow rate calibration device also includes a liquid storage cylinder; The outlet of the liquid storage cylinder is connected to the input end of the main pipeline. A piston is provided inside the liquid storage cylinder, and liquid is stored between the piston and the outlet of the liquid storage cylinder. The power unit is configured to drive the piston to move. The power unit includes a motor and a ball screw. The output shaft of the motor is connected to the ball screw, and the ball screw is connected to the piston. The motor drives the ball screw to push the piston to move.

4. The flow rate calibration system of claim 3, wherein, The flow rate calibration device includes a standard flow rate calculation module, which is configured to determine the standard flow rate according to the following formula: V = S1 * dl / (S2 * dt), Wherein, V is the standard flow rate, S1 is the cross-sectional area of ​​the liquid storage cylinder, S2 is the cross-sectional area of ​​the main pipeline, and dl / dt is the moving speed of the piston.

5. The flow rate calibration system according to claim 4, characterized in that, The standard flow rate calculation module is configured to control the motor to change the motor speed at a preset frequency.

6. The flow rate calibration system according to claim 5, characterized in that, The standard flow rate calculation module is configured to determine the standard flow rate according to the following formula: V=R*S*S1 / S2, Wherein, V is the standard flow rate, R is the real-time rotational speed of the motor, S is the lead of the ball screw, S1 is the cross-sectional area of ​​the liquid storage cylinder, and S2 is the cross-sectional area of ​​the main pipeline.

7. The flow rate calibration system according to claim 1, characterized in that, The flow guide wire includes a guide wire body, which includes a tube wall and an inner cavity defined by the tube wall; a first temperature sensor and a second temperature sensor are arranged in series in the inner cavity.

8. The flow rate calibration system according to claim 1, characterized in that, The demodulator includes: A light source is configured to emit light and transmit it to the first temperature sensor and the second temperature sensor via the first optical fiber. A birefringent optical component is configured to receive modulated light returned from the first optical fiber and interfere with the modulated light to form interference light with improved contrast, wherein the modulated light is formed by the interference of light emitted by the light source with the first temperature sensor and the second temperature sensor; A photodetector configured to receive the contrast-enhanced interference light and form an optical signal curve; The signal processing unit is configured to receive the optical signal curve and process it to obtain the cavity length curves of the first temperature sensor and the second temperature sensor.

9. The flow rate calibration system according to claim 1, characterized in that, The demodulator includes a flow rate calculation module configured to obtain the measured flow rate based on the time difference between the flow of the thermally diluted liquid injected into the main pipeline from the first temperature sensor to the second temperature sensor of the flow rate guide wire and the distance between the first temperature sensor and the second temperature sensor, wherein the time difference is obtained based on the cavity length curve.

10. The flow rate calibration system according to claim 9, characterized in that, The flow rate calculation module is configured to calculate the time difference in the following manner: obtain the first time point when the first temperature sensor of the flow rate guide wire reaches the lowest temperature and the second time point when the second temperature sensor reaches the lowest temperature, and obtain the time difference from the difference between the first time point and the second time point.

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