A drainage fluid quantitative detection device based on laser Doppler technology

Abstract

The utility model discloses a drainage liquid quantitative detection device based on laser doppler technique, install the casing of drainage tube outer periphery, be provided with laser emission unit, and the light detection unit and receiving unit of laser emission unit electricity is connected, and the signal processing unit of light detection unit and receiving unit electricity is connected on the casing. Through the frequency shift of recording laser scattering on the drainage tube, can nimble statistics arbitrary time node's drainage liquid flow rate and its flow, has improved clinical work efficiency, reduced the risk of the record error, simultaneously, since can record each time point's flow rate and flow, therefore has realized individualized record, makes medical staff can pour drainage liquid in any treatment time period, and the application structure convenience is strong, and the repeated use of special person is convenient, reduces medical cost.

Description

Technical Field

[0001] This utility model relates to the field of monitoring equipment technology, specifically to a quantitative detection device for drainage fluid based on laser Doppler technology. Background Technology

[0002] Surgical patients often have various drainage tubes connected to drainage bags. Currently, the volume of drainage fluid in each drainage bag is measured using a measuring cup, and the data is recorded in a logbook before being entered into a computer. This method is not intelligent enough, mainly due to the following aspects: 1. Measuring drainage fluid with a measuring cup takes a long time, and data entry into the computer system also takes time; 2. The smallest graduation of a standard measuring cup is 50ml. Accurate measurement of small volumes of drainage fluid requires a measuring cup with an even smaller graduation, and preparing multiple measuring cups is inconvenient; 3. After emptying each type of drainage fluid, paper records must be made immediately before entering the corresponding data into the electronic system. This process can easily contaminate the surrounding environment and poses a risk of cross-infection. The above problems reflect the great inconvenience and low efficiency of drainage fluid monitoring and management in the current technology. Furthermore, since the flow rate of drainage fluid is not constant and may vary at different times, the current method of collecting and recording drainage fluid can only calculate the total flow rate within a time period. It cannot focus on sudden increases in drainage flow at a specific moment, nor can it record and monitor the dynamic changes of drainage fluid in real time, resulting in inaccurate records and statistics. Utility Model Content

[0003] Therefore, this invention aims to solve the problem in the prior art where the drainage fluid flow record cannot record and monitor the dynamic changes of the drainage fluid in real time, resulting in inaccurate actual recording and statistics. Thus, it provides a drainage fluid quantitative detection device based on laser Doppler technology.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0005] A device for quantitative detection of drainage fluid based on laser Doppler technology includes a housing installed on the outer periphery of a drainage tube. The housing is equipped with a laser emitting unit, a light detection unit and a receiving unit electrically connected to the laser emitting unit, and a signal processing unit electrically connected to the light detection unit and the receiving unit. The laser emitting unit and the light detection unit are located on opposite sides of the drainage tube. The laser emitting unit is adapted to emit laser light towards the light detection unit. The light detection unit and the receiving unit are adapted to receive the light signal from the laser and convert it into an electrical signal, then send the electrical signal to the signal processing unit. The signal processing unit is adapted to receive the electrical signal and convert it into a digital signal, then process the digital signal to obtain a Doppler signal. The device also includes a control system electrically connected to the signal processing unit, which is adapted to receive the data obtained by the signal processing unit and use it to calculate the flow rate of the drainage fluid in the drainage tube.

[0006] Furthermore, the optical detection unit and the receiving unit include a collimating lens disposed between the laser emitting unit and the drainage tube.

[0007] Furthermore, a beam expander, a collimating lens, and a beam splitter are sequentially arranged between the laser emitting unit and the collimating lens.

[0008] Furthermore, the light detection unit and the receiving unit also include a first focusing lens, a second focusing lens, and a photodetector electrically connected to the signal processing unit, arranged sequentially. The first focusing lens and the second focusing lens are located on opposite sides of the collimating lens, and both the first focusing lens and the second focusing lens are located on the side of the housing where the laser emitting unit is located; the photodetector is located on the other side of the housing.

[0009] Furthermore, the signal processing unit includes an AD acquisition unit electrically connected to the photodetector and a Fourier transform unit electrically connected to the AD acquisition unit.

[0010] Furthermore, the signal processing unit also includes a preamplifier electrically connected between the photodetector and the AD acquisition unit.

[0011] Furthermore, the signal processing unit also includes a filter electrically connected to the preamplifier and the AD acquisition unit.

[0012] Furthermore, the housing is provided with a sensor electrically connected to the control system, the sensor being adapted to detect whether there is liquid flow in the drainage tube.

[0013] Furthermore, the housing is provided with an elastic fixing clip suitable for clamping the drainage tube.

[0014] Furthermore, it also includes an alarm unit electrically connected to the control system.

[0015] The technical solution of this utility model has the following advantages:

[0016] 1. The drainage fluid quantitative detection device based on laser Doppler technology provided by this utility model uses a laser emitting unit that can emit laser light to penetrate the drainage tube and irradiate the drainage fluid with laser light. Tiny particles (such as cells, proteins, etc.) in the drainage fluid will scatter the laser light, and flow rate information can be obtained when the drainage fluid flows. Specifically, the optical signal from the laser is received by the optical detection unit and the receiving unit and converted into an electrical signal, which is then sent to the signal processing unit. The signal processing unit receives the electrical signal and converts it into a digital signal, which is then processed to obtain a Doppler signal. The control system receives the data obtained by the signal processing unit and calculates the flow rate of the drainage fluid in the drainage tube based on the obtained data and the inner diameter of the drainage tube. This method of obtaining the drainage fluid flow rate using a laser in conjunction with the signal processing unit allows for flexible statistical analysis of the drainage fluid flow rate and volume at any time point, effectively improving clinical work efficiency and reducing the risk caused by recording errors. At the same time, because the flow rate and volume can be recorded at each time point, individualized recording is achieved, allowing medical staff to empty the drainage fluid at any time during the treatment period. Furthermore, the structure of this application is highly convenient, facilitating dedicated use by a single person, reducing the risk of cross-infection, and also allowing for repeated use by the same patient, which helps reduce medical costs.

[0017] 2. The quantitative detection device for drainage fluid based on laser Doppler technology provided by this utility model includes a collimating lens located between the laser emitting unit and the drainage tube in the optical detection unit and receiving unit. This configuration allows the emitted laser to be converted into a parallel beam through the collimating lens, thereby enabling the laser to be more stably directed towards the drainage fluid.

[0018] 3. The quantitative detection device for drainage fluid based on laser Doppler technology provided by this utility model includes a beam expander, a collimating lens, and a beam splitter sequentially arranged between the laser emitting unit and the collimating lens. This arrangement allows the laser beam diameter to be increased and the energy density reduced by the beam expander, the beam collimated by the collimating lens to be adjusted into parallel light, and then the parallel light projected onto the beam splitter. The beam splitter separates the parallel beam into a reference beam and a measurement beam, which are then projected onto the light detection unit and the receiving unit.

[0019] 4. The quantitative detection device for drainage fluid based on laser Doppler technology provided by this utility model further includes a first focusing lens (81), a second focusing lens (82), and a photodetector (9) electrically connected to the signal processing unit, arranged sequentially in the optical detection unit and the receiving unit. The first focusing lens (81) and the second focusing lens (82) are located on opposite sides of the collimating lens (6), and both the first focusing lens (81) and the second focusing lens (82) are located on the side of the housing (1) where the laser emitting unit is located; the photodetector (9) is located on the other side of the housing (1). With this arrangement, the emitted light beam is focused by the first focusing lens, then converted into parallel light by the collimating lens, and the parallel light is focused by the second focusing lens and projected onto the photodetector. After receiving the focused light beam, the photodetector converts the optical signal into an electrical signal and sends the electrical signal to the signal processing unit.

[0020] 5. The drainage fluid quantitative detection device based on laser Doppler technology provided by this utility model includes an AD acquisition unit electrically connected to a photodetector and a Fourier transform unit electrically connected to the AD acquisition unit. With this configuration, the AD acquisition unit receives the electrical signal emitted by the photodetector and converts it into a digital signal. The Fourier transform unit then processes the digital signal to obtain a Doppler signal; that is, the initial laser frequency shift is gradually converted into a Doppler frequency shift. Finally, the control system calculates the flow rate of the drainage fluid using the Doppler effect formula.

[0021] 6. The quantitative detection device for drainage fluid based on laser Doppler technology provided by this utility model further includes a preamplifier electrically connected between the photodetector and the AD acquisition unit in its signal processing unit. This configuration allows the preamplifier to amplify the electrical signal output from the photodetector before sending it to the AD acquisition unit, enabling efficient signal transmission and ensuring signal integrity and transmission efficiency.

[0022] 7. The quantitative detection device for drainage fluid based on laser Doppler technology provided by this utility model further includes a filter electrically connected to the preamplifier and the AD acquisition unit in its signal processing unit. This configuration allows for the filtering out of unnecessary interference signals, reducing their impact on the AD acquisition unit and thus improving the stability and dynamic performance of the detection device.

[0023] 8. The drainage fluid quantitative detection device based on laser Doppler technology provided by this utility model has an elastic fixing clamp on the housing (1) suitable for clamping the drainage tube (4). With this setting, drainage tubes of different sizes can be stably clamped by the elastic fixing clamp.

[0024] 9. The drainage fluid quantitative detection device based on laser Doppler technology provided by this utility model also includes an alarm unit electrically connected to the control system. With this configuration, by setting an alarm unit electrically connected to the control system, when the flow rate of the drainage fluid in the drainage tube exceeds the set threshold, the alarm unit will sound an alarm, reminding medical staff to check the drainage status promptly. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the internal structure of a drainage fluid quantitative detection device based on laser Doppler technology provided in this embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the elastic fixing clip in this embodiment;

[0028] Figure 3 for Figure 1 The graph shown is a coordinate graph of flow rate calculated using the Doppler effect formula.

[0029] Explanation of reference numerals in the attached drawings: 1. Housing; 2. Sensor; 3. Elastic clamp; 31. Gripper; 32. Spring; 33. Flexible pad; 4. Drainage tube; 5. Laser emitter; 6. Collimating lens; 7. Beam splitter; 81. First focusing lens; 82. Second focusing lens; 9. Photodetector; 10. Preamplifier; 11. Filter; 12. AD acquisition unit; 13. Fourier transform unit; 14. Beam expander; 15. Collimating lens; 16. Warning light. Detailed Implementation

[0030] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0034] like Figures 1-3 The device for quantitative detection of drainage fluid based on laser Doppler technology includes a housing 1 installed on the outer periphery of a drainage tube 4. The housing 1 is equipped with a laser emitting unit, a light detection unit and a receiving unit electrically connected to the laser emitting unit, and a signal processing unit electrically connected to the light detection unit and the receiving unit. The laser emitting unit and the light detection unit are located on opposite sides of the drainage tube 4. The laser emitting unit is adapted to emit laser light towards the light detection unit. The light detection unit and the receiving unit are adapted to receive the laser light signal and convert it into an electrical signal, then send the electrical signal to the signal processing unit. The signal processing unit is adapted to receive the electrical signal and convert it into a digital signal, then process the digital signal to obtain a Doppler signal. The device also includes a control system electrically connected to the signal processing unit, which is adapted to receive the data obtained by the signal processing unit and calculate the flow rate of the drainage fluid in the drainage tube 4.

[0035] This device for quantitative detection of drainage fluid based on laser Doppler technology uses a laser emitting unit that can emit laser light to penetrate the drainage tube 4 and irradiate the drainage fluid with laser light. Tiny particles (such as cells and proteins) in the drainage fluid will scatter the laser light, and the flow rate information can be obtained when the drainage fluid flows. Specifically, the optical signal from the laser is received by the optical detection unit and the receiving unit and converted into an electrical signal, which is then sent to the signal processing unit. The signal processing unit receives the electrical signal and converts it into a digital signal, which is then processed to obtain a Doppler signal. The control system receives the data obtained by the signal processing unit and calculates the flow rate of the drainage fluid in the drainage tube 4 based on the obtained data and the inner diameter of the drainage tube 4. This method of obtaining the drainage fluid flow rate using a laser in conjunction with the signal processing unit allows for flexible statistical analysis of the drainage fluid flow rate and volume at any time point, effectively improving clinical work efficiency and reducing the risk caused by recording errors. At the same time, because the flow rate and volume can be recorded at each time point, individualized recording is achieved, allowing medical staff to empty the drainage fluid at any treatment time. Furthermore, the structure of this application is highly convenient, facilitating dedicated use by a single person, reducing the risk of cross-infection, and also allowing for repeated use by the same patient, which helps reduce medical costs.

[0036] In this embodiment, the housing 1 is C-shaped, U-shaped, or other similar alternative shapes, and an elastic clamp 3 suitable for holding the drainage tube 4 is provided on the housing 1. Specifically, the elastic clamp 3 includes a jaw 31, a spring 32 located on the jaw 31, and a flexible pad 33 connected to the spring 32 and disposed away from the jaw 31. The inner ring of the jaw 31 forms a groove, and multiple sets of springs 32 are provided on the inner walls of opposite sides of the groove. Each set of springs 32 is provided with an arc-shaped flexible pad 33. This arrangement allows the elastic clamp 3 to adapt to drainage tubes 4 of different sizes. The elastic stress generated by the multiple sets of springs 32, combined with the flexible clamping of the flexible pad 33, can maintain the clamping stability of the drainage tube 4 and prevent the drainage tube 4 from twisting or being damaged. Specifically, the shape of the jaw 31 is C-shaped or U-shaped, etc.

[0037] In this embodiment, an alarm unit electrically connected to the control system is also included. By setting an alarm unit electrically connected to the control system, when the flow rate alarm threshold is set in the control system, the alarm unit will sound an alarm when the flow rate of the drainage fluid in the drainage tube 4 exceeds the set threshold, reminding medical personnel to check the drainage status promptly. Specifically, the alarm unit is a warning light 16 installed on the housing 1, which can emit a flashing light to warn personnel when the flow rate of the drainage fluid in the drainage tube 4 exceeds the threshold set by the control system.

[0038] In this embodiment, the light detection unit and the receiving unit include a collimating lens 6 located between the laser emitting unit and the drainage tube 4. This configuration allows the emitted laser light to be converted into a parallel beam by the collimating lens 6, thereby enabling the laser to be directed more stably towards the drainage fluid. Specifically, the laser emitting unit is a laser emitter 5, which requires a highly coherent, monochromatic light source, such as red visible light (helium-neon laser) with a wavelength of 633 nm, deep red semiconductor laser with a wavelength of 660 nm, blue or blue-green visible light with a wavelength of 488 nm, or other visible light bands with wavelengths of 450-7810 nm.

[0039] In this embodiment, a beam expander 14, a collimating lens 15, and a beam splitter 7 are sequentially arranged between the laser emitter 5 and the collimating lens 6. This arrangement allows the beam expander 14 to increase the laser beam diameter and reduce the energy density, the collimating lens 15 to adjust the expanded beam into parallel light, and then the parallel light to be projected onto the beam splitter 7. The beam splitter 7 then splits the parallel beam into a reference beam and a measurement beam, which are projected onto the light detection unit and the receiving unit, respectively.

[0040] In this embodiment, the light detection unit and receiving unit further include a first focusing lens 81, a second focusing lens 82, and a photodetector 9 electrically connected to the signal processing unit, arranged sequentially. The first focusing lens 81 and the second focusing lens 82 are located on opposite sides of the collimating lens 6, and both are located on the side of the housing 1 where the laser emitter 5 is disposed; the photodetector 9 is disposed on the other side of the housing 1. With this arrangement, the emitted light beam is focused by the first focusing lens 81, converted into parallel light by the collimating lens 6, and then focused by the second focusing lens 82 before being projected onto the photodetector 9. Upon receiving the focused light beam, the photodetector 9 converts the optical signal into an electrical signal and sends the electrical signal to the signal processing unit. Specifically, the photodetector 9 is a miniature photodetector.

[0041] In this embodiment, the signal processing unit includes an AD acquisition unit 12 electrically connected to the photodetector 9 and a Fourier transform unit 13 electrically connected to the AD acquisition unit 12. With this configuration, the AD acquisition unit 12 receives the electrical signal emitted by the photodetector 9 and converts it into a digital signal. The Fourier transform unit 13 then processes the digital signal to obtain a Doppler signal; that is, the initial laser frequency shift is gradually converted into a Doppler frequency shift. Finally, the control system calculates the flow rate of the drainage fluid using the Doppler effect formula.

[0042] Specifically, the signal processing unit also includes a preamplifier 10 electrically connected between the photodetector 9 and the AD acquisition unit 12. This configuration allows the preamplifier 10 to amplify the electrical signal output from the photodetector 9 before sending it to the AD acquisition unit 12, enabling efficient signal transmission and ensuring signal integrity and transmission efficiency.

[0043] Specifically, the signal processing unit also includes a filter 11 electrically connected to the preamplifier 10 and the AD acquisition unit 12. This configuration allows the filter 11 to filter out unnecessary interference signals, reducing their impact on the AD acquisition unit 12 and thus improving the stability and dynamic performance of the detection device.

[0044] In this embodiment, an alarm unit electrically connected to the control system is also included. Specifically, the alarm unit is a warning light 16. With this configuration, by setting the warning light 16 electrically connected to the control system, when the flow rate of the drainage fluid in the drainage tube 4 exceeds the set flow rate alarm threshold, the warning light 16 will continuously flash any visible light to issue a warning, reminding medical staff to check the drainage status in a timely manner. In an alternative embodiment, the alarm unit can also be a buzzer alarm.

[0045] In this embodiment, the laser emitted by the laser emitter 5 passes sequentially through a beam expander, a collimating lens, and a beam splitter. The beam splitter 7 splits the laser into a measurement beam and a reference beam. The measurement beam passes sequentially through a first focusing lens 81, a collimating lens 6, a second focusing lens 82, a photodetector 9, a preamplifier 10, a filter 11, an AD acquisition unit 12, and a Fourier transform unit 13. The detection beam passes sequentially through a collimating lens 6, a photodetector 9, a preamplifier 10, a filter 11, an AD acquisition unit 12, and a Fourier transform unit 13.

[0046] Specifically, the first focusing lens 81, the collimating lens 6, and the second focusing lens 82 are movably mounted on the housing 1. With this configuration, the positions of the first focusing lens 81, the collimating lens 6, and the second focusing lens 82 can be adjusted according to the size and position of the drainage tube 4.

[0047] In this embodiment, the working steps of this laser Doppler-based quantitative detection device for drainage fluid include:

[0048] S1: System initialization: Turn on laser emitter 5 and make it emit highly coherent, monochromatic laser stably. At the same time, start the signal processing unit, set the parameters of preamplifier 10 and filter 11, etc., and complete system initialization.

[0049] S2: Laser irradiation: The parallel laser beam emitted by the laser emitter 5 is directed towards the drainage fluid in the drainage tube 4. The laser beam interacts with the tiny particles in the drainage fluid, producing scattered light.

[0050] S3: Optical path adjustment and signal excitation: After being focused by the first focusing lens 81, the light beam is straightened into parallel light by the collimating lens 6. After being straightened, it can be ensured to be coaxial with the scattered light. Then it passes through the second focusing lens 82 and is received by the photodetector 9. The photodetector 9 converts the optical signal into an electrical signal, which contains Doppler frequency shift information related to the flow rate of the drainage fluid.

[0051] S4: Signal processing: The electrical signal is first amplified by an amplifier, then filtered by a filter 11 to remove noise, and finally the frequency distribution of the signal is obtained by the AD acquisition unit 12 and the Fourier transform unit 13 to determine the Doppler frequency shift.

[0052] S5: Flow rate calculation: Calculate the flow rate of the drainage fluid according to the Doppler effect formula fd, and display or record the measurement results;

[0053] S6: Calculate flow (e.g.) Figure 3 As shown): In a coordinate system with the horizontal axis representing time (seconds / unit) and the vertical axis representing velocity (cm / second), the flow rate of the drainage fluid at different flow velocities can be calculated by combining the area of ​​the curve with the cross-sectional area of ​​the drainage tube 4. The specific method is as follows:

[0054] (1) Calculate the area S of the curve enclosed by the curve and the coordinate axes:

[0055] The area under a specific curve is calculated using GraphPad Prism software; in alternative embodiments, the area of ​​a specified curve may also be calculated using other software or other methods.

[0056] (2) Determine the cross-sectional area of ​​drainage tube 4:

[0057] Calculate the cross-sectional area of ​​drainage tube 4 based on its shape and dimensions. If drainage tube 4 is circular with radius r, the cross-sectional area A = πr. 2 ;

[0058] (3) Calculate the flow rate:

[0059] The drainage fluid flow rate is calculated using the formula Q=SA, where S is the area enclosed by the curve and the coordinate axes, representing the distance the drainage fluid travels within a certain time. A is the cross-sectional area of ​​the drainage tube, and Q is measured in cubic centimeters per second. Different flow velocities correspond to different curve areas, from which the flow rate at different velocities can be obtained.

[0060] In summary, this quantitative detection device for drainage fluid based on laser Doppler technology uses a laser emitter 5 that can emit laser light to penetrate the drainage tube 4 and irradiate the drainage fluid with laser light. Tiny particles (such as cells and proteins) in the drainage fluid will scatter the laser light, and flow rate information can be obtained when the drainage fluid is flowing. Specifically, the optical signal of the laser is received by the optical detection unit and the receiving unit and converted into an electrical signal, which is then sent to the signal processing unit. The signal processing unit receives the electrical signal and converts it into a digital signal, which is then processed to obtain a Doppler signal. The control system receives the data obtained by the signal processing unit and calculates the flow rate of the drainage fluid in the drainage tube 4 based on the obtained data and the inner diameter of the drainage tube 4. This method of obtaining the drainage fluid flow rate using a laser in conjunction with the signal processing unit allows for flexible statistical analysis of the drainage fluid flow rate and volume at any time point, effectively improving clinical work efficiency and reducing the risk caused by recording errors. At the same time, since the flow rate and volume can be recorded at each time point, individualized recording is achieved, allowing medical staff to empty the drainage fluid at any treatment time. Furthermore, this application has a convenient structure, is easy for dedicated use, reduces the risk of cross-infection, and is also easy for the same patient to use repeatedly, which helps to reduce medical costs.

[0061] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A device for quantitative detection of drainage fluid based on laser Doppler technology, characterized in that, The system includes a housing (1) installed on the outer periphery of the drainage tube (4), on which a laser emitting unit, a light detection unit and a receiving unit electrically connected to the laser emitting unit, and a signal processing unit electrically connected to the light detection unit and the receiving unit are provided; the laser emitting unit and the light detection unit are respectively located on opposite sides of the drainage tube (4); the laser emitting unit is adapted to emit laser light in the direction of the light detection unit; the light detection unit and the receiving unit are adapted to receive the light signal of the laser light and convert it into an electrical signal, and then send the electrical signal to the signal processing unit; the signal processing unit is adapted to receive the electrical signal and convert it into a digital signal, and then process the digital signal to obtain a Doppler signal; the system also includes a control system electrically connected to the signal processing unit, which is adapted to receive the data obtained by the signal processing unit and use it to calculate the flow rate of the drainage fluid in the drainage tube (4).

2. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 1, characterized in that, The optical detection unit and receiving unit include a collimating lens (6) disposed between the laser emitting unit and the drainage tube (4).

3. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 2, characterized in that, A beam expander (14), a collimating lens (15), and a beam splitter (7) are sequentially arranged between the laser emitting unit and the collimating lens (6).

4. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 3, characterized in that, The light detection unit and the receiving unit further include a first focusing lens (81), a second focusing lens (82), and a photodetector (9) electrically connected to the signal processing unit, which are arranged in sequence. The first focusing lens (81) and the second focusing lens (82) are located on opposite sides of the collimating lens (6). The first focusing lens (81) and the second focusing lens (82) are both located on the side of the housing (1) where the laser emitting unit is located. The photodetector (9) is located on the other side of the housing (1).

5. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 4, characterized in that, The signal processing unit includes an AD acquisition unit (12) electrically connected to the photodetector (9) and a Fourier transform unit (13) electrically connected to the AD acquisition unit (12).

6. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 5, characterized in that, The signal processing unit also includes a preamplifier (10) electrically connected between the photodetector (9) and the AD acquisition unit (12).

7. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 6, characterized in that, The signal processing unit also includes a filter (11) electrically connected to the preamplifier (10) and the AD acquisition unit (12).

8. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 1, characterized in that, The housing (1) is provided with a sensor (2) that is electrically connected to the control system. The sensor (2) is adapted to detect whether there is liquid flow in the drainage tube (4).

9. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 7, characterized in that, The housing (1) is provided with an elastic fixing clip (3) suitable for clamping the drainage tube (4).

10. The quantitative detection device for drainage fluid based on laser Doppler technology according to claim 1, characterized in that, It also includes an alarm unit that is electrically connected to the control system.

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