Water column pressure gauge based on visible light guidance and ultrasonic ranging and measuring method thereof

Abstract

The invention discloses a water column pressure gauge based on visible light guidance and ultrasonic ranging and a measuring method thereof. The water column pressure gauge comprises a main control module, an ultrasonic ranging module, a line casting light generator, a universal horizontal bead, an adjusting support and a power module. The power supply module is used for providing a driving power supply; the adjusting bracket is used for fixing the whole water column pressure gauge on a support; the projection light generator is used for emitting a visible light surface to position an anatomical zero point; the universal horizontal bead is used for providing visual reference for a horizontal state; the ultrasonic ranging module is used for automatically measuring the distance to the liquid level of a water column; the master control module is used for controlling the on-off state of the line casting light generator and processing distance data collected by the ultrasonic ranging module so as to calculate and output a central vein pressure value. The anatomical zero point can be quickly and accurately positioned, liquid level height data can be automatically and objectively obtained, and meanwhile the anatomical zero point positioning device is simple in structure and easy to use and popularize.

Description

Technical Field

[0001] This invention relates to the field of medical testing equipment technology, and in particular to a water column pressure gauge based on visible light guidance and ultrasonic ranging, and its measurement method. Background Technology

[0002] Central venous pressure (CVP) is a crucial clinical indicator for assessing a patient's circulating blood volume and cardiac function. Accurate measurement is critical for fluid management, cardiac function assessment, and treatment decisions in critically ill patients. Currently, commonly used CVP measurement methods in clinical practice mainly include the traditional water column manometer method and the electronic sensor method. The traditional water column manometer relies on the principle of physical connection, reading the height of the water column. However, its zero-point positioning depends on the operator visually estimating the patient's mid-axillary line, which is easily affected by viewing angle, lighting, and human judgment, leading to positioning errors. Furthermore, fluid level fluctuations require manual interpretation, resulting in strong subjectivity and the inability to record and track data digitally in real time, hindering dynamic monitoring and data management. While electronic sensor solutions have emerged in recent years, enabling automatic measurement and digital output, they often integrate high-precision tilt sensors, complex signal processing circuits, and attitude compensation algorithms, resulting in complex equipment structures and high costs. Moreover, they still require stable power supplies and calibration maintenance during use, limiting their widespread adoption in primary healthcare and bedside care settings. Therefore, there is an urgent clinical need for a CVP measurement device that strikes a balance between measurement accuracy, ease of operation, and cost control. Summary of the Invention

[0003] The purpose of this invention is to provide a water column pressure gauge and its measurement method based on visible light guidance and ultrasonic ranging. This invention can achieve rapid and accurate positioning of the zero point, and can automatically and objectively acquire liquid level height data. Furthermore, it has a simple structure, is easy to use, and is readily applicable.

[0004] The technical solution provided by this invention is as follows: a water column pressure gauge based on visible light guidance and ultrasonic ranging, including a main control module, an ultrasonic ranging module, a projection light generator, a universal level bead, an adjustment bracket, and a power supply module; The power module is used to provide drive power; The adjusting bracket is used to fix the water column pressure gauge as a whole onto the support and to provide fixed points for each module and the pipeline to be tested. The beam generator is located at the bottom of the adjustment bracket and is used to emit visible light to accurately locate the anatomical zero point on the patient's body surface. The universal level ball is set on the top reference plane of the adjustment bracket to provide a visual reference for the user to manually adjust the water column pressure gauge to a horizontal state; The ultrasonic ranging module is mounted on the adjusting bracket, with its ranging direction facing the water column tube to be measured, and is used to automatically measure the distance to the water column surface. The main control module is electrically connected to the projection light generator and the ultrasonic ranging module, respectively, and is used to control the opening and closing of the projection light generator, process the distance data collected by the ultrasonic ranging module to calculate and output the central venous pressure value, and realize human-computer interaction through the operation panel.

[0005] The aforementioned water column pressure gauge based on visible light guidance and ultrasonic ranging includes an adjustment bracket comprising a main support and a bed rail fixing mechanism; the bed rail fixing mechanism includes a fixing clamp and fastening bolts for fixing the entire device to the bed rail; the main support provides fixed support for the power module, ultrasonic ranging module, projection light generator, and universal level bead.

[0006] The aforementioned water column pressure gauge based on visible light guidance and ultrasonic ranging also includes a height adjustment mechanism in the adjusting bracket; the height adjustment mechanism includes a magnetic guide rail A, a magnetic guide rail B and a metal slider that can slide relative to the magnetic guide rails, all disposed inside the main bracket; the metal slider is connected to the fixing clamp of the bed rail fixing mechanism via a universal memory connecting tube.

[0007] The aforementioned water column pressure gauge based on visible light guidance and ultrasonic ranging further includes a pipe fixing component in the adjusting bracket; the pipe fixing component includes a pipe fixing clip, which is made of transparent material and has a groove in the middle for keeping the pipe to be measured vertically fixed; the pipe fixing clip is detachably fixed to the main bracket.

[0008] The aforementioned water column pressure gauge based on visible light guidance and ultrasonic ranging further includes magnetic beads symmetrically arranged on both sides of the pipe fixing clamp; the main support is provided with a magnetic part or metal part that attracts the magnetic beads, so that the pipe fixing clamp is magnetically fixed in the corresponding groove of the main support.

[0009] The aforementioned water column pressure gauge based on visible light guidance and ultrasonic ranging uses a visible light projector based on an LED light source to generate a visible light surface to form a clear indicator line on the patient's body surface.

[0010] In the aforementioned water column pressure gauge based on visible light guidance and ultrasonic ranging, the ultrasonic ranging module is installed at the top of the fixing groove inside the main support, and its ranging direction is perpendicular to the cross-section of the water column pipe to be measured.

[0011] The measurement method based on a water column pressure gauge using visible light guidance and ultrasonic ranging, as described above, is characterized by the following steps: S1: The water column pressure gauge is fixed to the bed rail using the adjusting bracket; S2: Fix the water column tube to be tested onto the adjusting bracket; S3: Turn on the power and the projection light generator, and adjust the height and angle of the adjustment bracket so that the visible light emitted by the projection light generator is aligned with the anatomical zero point of the patient. S4: Observe the universal leveling bead and manually fine-tune the posture of the adjusting bracket until the bubble is centered, so that the device is in a horizontal state; S5: Activate the ultrasonic ranging module to measure the distance to the water column surface; S6: The main control module processes the distance data, calculates and outputs the central venous pressure measurement value.

[0012] Compared with the prior art, the present invention has the following significant advantages: 1. This invention generates clear indicator lines using an LED visible light projector, enabling precise positioning of the anatomical zero point and avoiding the interference of perspective, light, and human judgment errors caused by traditional visual positioning. It utilizes a universal level bead to provide an intuitive horizontal calibration reference, ensuring the measurement reference plane is horizontal and eliminating systematic errors caused by equipment tilt. Combined with an ultrasonic ranging module, it automatically collects liquid surface distance data, avoiding the subjectivity of manually interpreting liquid surface fluctuations and achieving digital output of measurement data, providing accurate and traceable objective evidence for clinical diagnosis.

[0013] 2. This invention uses LED visible light instead of laser as the positioning light source, eliminating any radiation safety risks and removing concerns for medical staff and patients. It also avoids the problem of lasers becoming blurry in strong light environments, maintaining clear visibility under normal indoor lighting conditions, and is suitable for various clinical treatment environments. The universal horizontal bead is sealed with waterproof adhesive and protected by a transparent protective cover, making it robust and durable, able to withstand high-frequency clinical operations and cleaning maintenance, further improving its stability.

[0014] 3. This invention replaces the traditional electronic tilt sensor (IMU) with a mechanical universal leveling ball, eliminating the need for complex attitude compensation algorithms and signal processing circuits. While ensuring the accuracy of horizontal calibration, it significantly reduces hardware costs and software development complexity. The adjustment bracket adopts a simple and reliable connection structure such as magnetic rails and magnetic bead adsorption, simplifying the assembly process. Moreover, all modules are selected from mature and universal components, eliminating the need for high-precision customized components, further controlling production and maintenance costs, and making it more suitable for widespread application in primary healthcare institutions.

[0015] 4. This invention can be quickly fixed to the bed rail using a fixing clip and fastening bolt. The tube fixing clip is made of transparent material and has a magnetic adsorption design, which facilitates the quick installation and observation of the tube to be tested. The overall operation process is clear. Measurement can be completed by only three core operations: visible light positioning, leveling with a level bead, and ultrasonic ranging. No professional training is required to operate it, which effectively reduces the workload of medical staff and improves the efficiency of bedside nursing. Attached Figure Description

[0016] Figure 1 This is a functional block diagram of the water column pressure gauge of the present invention. Figure 2 This is a schematic diagram of the structure of the water column pressure gauge of the present invention; Figure 3 A schematic diagram of the main control module; Figure 4 A schematic diagram of the measurement method of the present invention.

[0017] 1. Main control module; 2. Fixing clamp; 3. Fastening bolt; 4. Universal memory connecting tube; 5. Metal slider; 6. Magnetic guide rail A; 7. Magnetic guide rail B; 8. Power module; 9. Projection light generator; 10. Magnetic bead; 11. Pipe fixing clamp; 12. Ultrasonic ranging module; 13. Main support frame; 14. Universal horizontal ball; 15. Protective shell; 16. Display screen; 17. Switch button; 18. Function selection button; 19. Reset / measurement button. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0019] Example: A water column pressure gauge based on visible light guidance and ultrasonic ranging, such as Figure 1 and Figure 2 As shown, it includes a main control module 1, an ultrasonic ranging module 12, a projection light generator 9, a universal level bead 14, an adjustment bracket, and a power supply module 8. The main control module 1, acting as the control center, integrates data processing, module driving, and human-computer interaction functions, such as... Figure 3As shown, the system specifically includes a protective housing 15, a display screen 16, a power switch 17, a function selection button 18, a reset / measurement button 19, and a control circuit board. The protective housing 15 is made of medical-grade ABS material, providing drop resistance and easy cleaning. The display screen 16 uses a high-brightness LCD screen, clearly displaying measured values, liquid level fluctuation waveforms, and historical records. The control circuit board employs a double-layer PCB design, onboard with a low-power MCU chip, a power management unit, a data storage unit, a signal interface unit, and a button / display screen driver unit. The MCU chip is the core processing unit, converting ultrasonic ranging data into central venous pressure values ​​(unit: cmH2O) using a preset algorithm. The power management unit provides stable voltage output and low battery detection. The data storage unit supports up to 100 sets of historical measurement data storage. The signal interface unit establishes an electrical connection with the ultrasonic ranging module 12, the projection light generator 9, and the power module 8 via wires, ensuring stable signal transmission. The button / display driver unit includes a button driver circuit and a display driver chip. The button driver circuit adopts an independent I / O port connection design, with each button corresponding to an independent signal channel on the control circuit board. It is equipped with pull-up resistors and filter capacitors to form an anti-bounce filter circuit, which can effectively filter out erroneous signals caused by button mechanical jitter. The display driver chip is a low-power LCD driver chip (such as HT1621), which is connected to the MCU chip on the control circuit board via the SPI communication protocol. It supports 8-bit / 16-bit data transmission, and its driving capability covers the display requirements of high-brightness LCD screens. Moreover, its operating current is ≤5mA, which meets the low-power design requirements of the device.

[0020] The ultrasonic ranging module 12 uses an industrial-grade high-precision sensor with a measurement range of 5-50cm and an error of ≤±0.1cm, meeting the accuracy requirements for clinical CVP measurement (normal range 5-12cmH2O). This module is installed at the top of the fixing slot inside the main support 13, with the ranging direction perpendicular to the cross-section of the water column to be measured, ensuring the measurement path is perpendicular to the liquid surface and avoiding distance deviation caused by oblique projection. The module surface is covered with a waterproof and dustproof membrane, allowing it to withstand cleaning and disinfection operations in a clinical environment and extending its service life.

[0021] The projection light generator 9 uses an LED light source visible light projector with a power of ≤5W, generating a visible light surface with a width of ≤2mm. Under normal indoor lighting conditions, it can form a clear indicator line on the patient's body surface. This module is fixed to the bottom of the adjustable bracket, and the light emission direction can be finely adjusted with the bracket angle. Its advantages include no radiation risk, making it more suitable for frequent clinical use compared to laser positioning, and maintaining clear indication even in strong light environments, thus solving the problem of traditional laser positioning being easily interfered with by light.

[0022] The universal leveling bead 14 is a mechanical leveling calibration component. It is sealed and fixed in a circular groove on the reference plane at the top of the adjustment bracket with waterproof adhesive. The upper surface is covered with a transparent acrylic protective cover, which ensures clear observation and prevents liquid ingress or physical damage. This leveling bead can sense the tilt of the device 360°. When the bubble is centered, the device's level error is ≤0.5°, providing a stable reference for measurement. It requires no power supply or algorithm compensation and achieves rapid leveling through intuitive visual feedback. Compared with electronic tilt sensors, it reduces costs and increases reliability.

[0023] Power module 8 adopts a replaceable power supply design, compatible with button batteries, AA dry batteries, or rechargeable lithium batteries. It is electrically connected to each power module via wires, and the output voltage is stable at 3.3-5V. The module has a low battery reminder function; when the voltage drops below 3V, the display screen 16 will show a warning sign. In a fully charged state, it can work continuously for ≥8 hours, meeting the needs of single-shift clinical use. Battery replacement does not require disassembling the device, making operation convenient.

[0024] The adjustment bracket serves as the support and adjustment platform for the device. It is constructed from a combination of lightweight aluminum alloy and engineering plastics, balancing strength and portability. Specifically, it includes the main support frame 13, a bed rail fixing mechanism, a height adjustment mechanism, and pipeline fixing components. These components work together to achieve device fixation, position adjustment, and pipeline limiting functions. The main support 13 is a hollow frame structure with a pre-reserved magnetic guide rail mounting groove inside and module fixing points and pipeline fixing grooves on the outside. It can simultaneously support core components such as the power module 8 and the ultrasonic ranging module 12, and its layout is reasonable, without obstructing the ranging path and the field of view.

[0025] The bed rail fixing mechanism consists of a fixing clip 2 and a fastening bolt 3. The opening width of the fixing clip 2 can be adjusted within the range of 2-5cm to adapt to different specifications of hospital bed rails. It is fixed by tightening the fastening bolt 3. After clamping, the anti-slip force is ≥5N, ensuring that the device does not loosen during clinical operation.

[0026] The height adjustment mechanism includes magnetic rails A6 and B7 and a metal slider 5. The magnetic rails are arranged vertically along the main support 13. The metal slider 5 can slide along the rails, with an adjustment range of 10-30cm, to meet the anatomical zero-point positioning needs of patients of different heights. The metal slider 5 is connected to the bed rail fixing mechanism through a universal memory connecting tube 4. This connecting tube can be bent 360° and maintain a fixed angle, which is convenient for fine-tuning the horizontal posture of the device.

[0027] The pipeline fixing assembly consists of a transparent pipeline fixing clamp 112 and symmetrically arranged magnetic beads 10. The pipeline fixing clamp 112 has a groove width of 0.8-1.2cm in the middle, which can clamp the water column pipe to be tested and keep it in a vertical state. The transparent material makes it easy to observe the liquid level inside the pipe. The magnetic beads 10 are attracted to the magnetic / metal part of the main support 13 with an attraction force ≥3N, which enables the pipeline fixing clamp 112 to be quickly disassembled and installed, and is suitable for pipelines of different diameters to be tested.

[0028] Based on the water column pressure gauge described above, such as Figure 4 As shown, the specific implementation process of its measurement method is as follows: S1: Attach the fixing clip 2 of the adjustment bracket to the bed railing, adjust the width of the clip according to the thickness of the bed railing, and tighten the fastening bolt 3 to ensure that the device is stable and does not shake. S2: Insert the water column tube to be tested into the middle groove of the pipe fixing clamp 112, and fix the pipe fixing clamp 112 to the corresponding groove of the main support 13 by magnetic bead 10 to ensure that the water column tube is vertical and without bends, and that there are no air bubbles on the liquid surface inside the tube. S3: Press the switch button 17 of the main control module 1 to turn on the power module 8 and the projection light generator 9. Adjust the height of the main support 13 by sliding the metal slider 5 and adjust the angle by bending the universal memory connecting tube 4 so that the visible light surface emitted by the projection light generator 9 is accurately aligned with the intersection of the patient's mid-axillary line and the fourth intercostal space (anatomical zero point). S4: Observe the position of the bubble in the universal level bead 14, and manually fine-tune the posture of the universal memory connecting tube 4 and the metal slider 5 until the bubble is centered. At this time, the device is in a horizontal measurement state. S5: Press the reset / measurement button 19 to start the ultrasonic ranging module 12. The module emits ultrasonic waves toward the water column surface and receives the reflected signals, continuously collecting 10 sets of distance data (sampling frequency of 10Hz) and automatically filtering out abnormal values. S6: The main control module 1 averages the effective distance data and calculates the CVP value by combining it with the preset formula (Central Venous Pressure Value = Reference Distance - Measurement Distance, where the reference distance is the vertical distance from the ultrasound module to the anatomical zero point when the device is horizontal). The measurement result is output through the display screen 16. The display mode can be switched through the function selection button 18 to view real-time values, liquid level fluctuation waveforms, or historical measurement records (up to 100 sets of data can be stored).

[0029] In summary, this invention achieves precise marking of the anatomical zero point through the visible light surface of the projection light generator 9, solving the positioning error problem of traditional visual measurement; the mechanical leveling of the universal level bead 14 ensures the horizontality of the measurement reference plane, eliminating system tilt error; the ultrasonic ranging module 12 automatically collects distance data under a stable reference, avoiding the subjectivity of manual interpretation; the main control module 1 integrates and rapidly processes the signals from each module, realizing the digital output of the measurement results. The entire process requires no complex operation training, medical staff can complete a single measurement in a short time, and the measurement accuracy is comparable to that of electronic sensor solutions, while the cost is lower, taking into account both clinical practicality and widespread applicability.

Claims

1. A water column pressure gauge based on visible light guidance and ultrasonic ranging, characterized in that, Includes a main control module (1), an ultrasonic ranging module (12), a projection light generator (9), a universal level bead (14), an adjustment bracket, and a power supply module (8). The power module (8) is used to provide drive power; The adjusting bracket is used to fix the water column pressure gauge as a whole onto the support and to provide fixed points for each module and the pipeline to be tested. The projection light generator (9) is located at the bottom of the adjustment bracket and is used to emit visible light to accurately locate the anatomical zero point on the patient's body surface. The universal level ball (14) is set on the top reference plane of the adjustment bracket to provide a visual reference for the user to manually adjust the water column pressure gauge to a horizontal state; The ultrasonic ranging module (12) is mounted on the adjusting bracket, with its ranging direction facing the water column tube to be measured, and is used to automatically measure the distance to the water column surface; The main control module (1) is electrically connected to the projection light generator (9) and the ultrasonic ranging module (12) respectively. It is used to control the opening and closing of the projection light generator (9), process the distance data collected by the ultrasonic ranging module (12) to calculate and output the central venous pressure value, and realize human-computer interaction through the operation panel.

2. The water column pressure gauge based on visible light guidance and ultrasonic ranging according to claim 1, characterized in that, The adjustable bracket includes a main bracket (13) and a bed rail fixing mechanism; the bed rail fixing mechanism includes a fixing clip (2) and a fastening bolt (3) for fixing the device as a whole to the bed rail; the main bracket (13) provides fixed support for the power module (8), ultrasonic ranging module (12), projection light generator (9) and universal level ball (14).

3. The water column pressure gauge based on visible light guidance and ultrasonic ranging according to claim 2, characterized in that, The adjustable bracket also includes a height adjustment mechanism; the height adjustment mechanism includes a magnetic guide rail A (6), a magnetic guide rail B (7) disposed inside the main bracket (13) and a metal slider (5) that can slide relative to the magnetic guide rail; the metal slider (5) is connected to the fixing clip (2) of the bed rail fixing mechanism via a universal memory connecting tube (4).

4. The water column pressure gauge based on visible light guidance and ultrasonic ranging according to claim 2, characterized in that, The adjusting bracket also includes a pipeline fixing component; the pipeline fixing component includes a pipeline fixing clip (11), the pipeline fixing clip (11) is made of transparent material, and a groove is provided in the middle of the pipeline fixing clip (11) for keeping the pipeline to be tested vertically fixed; the pipeline fixing clip (11) is detachably fixed to the main bracket (13).

5. The water column pressure gauge based on visible light guidance and ultrasonic ranging according to claim 4, characterized in that, The pipeline fixing assembly also includes magnetic beads (10) symmetrically arranged on both sides of the pipeline fixing clamp (11); the main support (13) is provided with a magnetic part or metal part that attracts the magnetic beads (10), so that the pipeline fixing clamp (11) is fixed in the corresponding groove of the main support (13) by magnetic attraction.

6. The water column pressure gauge based on visible light guidance and ultrasonic ranging according to claim 1, characterized in that, The line-projection light generator (9) is a visible light projector based on an LED light source, used to generate a visible light surface to form a clear indicator line on the patient's body surface.

7. The water column pressure gauge based on visible light guidance and ultrasonic ranging according to claim 1, characterized in that, The ultrasonic ranging module (12) is installed at the top of the fixing groove inside the main support (13), and its ranging direction is perpendicular to the cross-section of the water column pipe to be measured.

8. The measurement method of a water column pressure gauge based on visible light guidance and ultrasonic ranging according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1: The water column pressure gauge is fixed to the bed rail using the adjusting bracket; S2: Fix the water column tube to be tested onto the adjusting bracket; S3: Turn on the power and the projection light generator, and adjust the height and angle of the adjustment bracket so that the visible light emitted by the projection light generator is aligned with the anatomical zero point of the patient. S4: Observe the universal leveling bead and manually fine-tune the posture of the adjusting bracket until the bubble is centered, so that the device is in a horizontal state; S5: Activate the ultrasonic ranging module to measure the distance to the water column surface; S6: The main control module processes the distance data, calculates and outputs the central venous pressure measurement value.

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