Central venous pressure measuring device

Abstract

The invention discloses a central venous pressure measuring device, and relates to the technical field of medical apparatus and instruments, and the device comprises a measuring assembly which is used for communicating with a central venous catheter to measure the central venous pressure; the supporting assembly is arranged on one side of the measuring assembly, and the supporting assembly is used for supporting the measuring assembly and adjusting the height of the measuring assembly; the base is fixedly arranged at the bottom end of the supporting assembly, and the base is used for positioning and supporting the supporting assembly. The central venous pressure measuring device provided by the invention can assist a nurse in measuring the central venous pressure of a patient, can adapt to positioning of zeroing points on patients with various body widths, and is convenient to observe measured values, so that the measurement operation of the central venous pressure is more flexible and convenient, the working intensity of the nurse is reduced, and the working efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a central venous pressure measuring device. Background Art

[0002] Central venous pressure is the pressure of the superior and inferior vena cava entering the right atrium. It is measured through a catheter in the superior and inferior vena cava or right atrium. It reflects the right atrial pressure and is one of the main indicators for clinical observation of hemodynamics. It is affected by three factors: cardiac function, circulating blood volume, and vascular tension. The blood pressure in the right atrium and the large veins in the chest cavity is usually called central venous pressure. Determining CVP is of great significance for understanding the effective circulating blood volume and cardiac function, and is a commonly used monitoring indicator in intensive care units and surgical wards.

[0003] In the prior art, the artificial water column method is generally used clinically for measurement, that is, the patient lies flat and removes the infusion set that is infusing on the infusion bottle so that the upper end of the infusion set is connected to the atmospheric pressure (or another infusion set filled with normal saline is taken), and the lower end of the infusion set is directly connected to the external port of the central venous catheter. The liquid in the infusion tube is 0.9% normal saline, and its bottom end is flush with the fourth intercostal space of the mid-axillary line as the zero adjustment point (marked). When the horizontal plane of the water column in the infusion set rapidly drops to no longer drop, the height (cmH20) of the liquid level to the set zero point is the central venous pressure value.

[0004] The current artificial water column method for measuring central venous pressure in clinical practice has the following problems in actual use: clinical nurses are required to manually find the zeroing point on the patient, and in order to ensure that the lower end of the infusion set is at the same horizontal plane as the zeroing point and to accurately measure the height of the liquid level in the infusion set, two rulers need to be used at the same time to check the distance between the lower end of the infusion set and the zeroing point and to measure the height of the liquid level in the infusion set from the zeroing point, respectively. This not only increases the workload of nurses and increases the difficulty of their work, but also the error rate of this artificial measurement is difficult to control, which not only leads to inaccurate measurement values, but also reduces work efficiency, resulting in inflexible and inconvenient measurement work, and is difficult to meet usage requirements. For this reason, a central venous pressure measuring device is proposed. Summary of the invention

[0005] The object of the present invention is to provide a central venous pressure measuring device to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solution: a central venous pressure measuring device, comprising:

[0007] A measuring component, the measuring component is used to communicate with a central venous catheter to measure central venous pressure;

[0008] A support assembly, which is disposed on one side of the measuring assembly and is used for supporting and adjusting the height of the measuring assembly;

[0009] The base is fixedly arranged at the bottom end of the support assembly, and the base is used for positioning and supporting the support assembly.

[0010] Preferably, the measuring assembly includes a liquid storage tube and a connecting hose connected to the bottom end of the liquid storage tube, the liquid storage tube is made of a transparent material, and a scale bar for the height of the liquid level in the liquid storage tube is provided on the liquid storage tube.

[0011] Preferably, a floating plate is movably provided in the inner cavity of the liquid storage tube, a retaining frame is fixedly connected to the middle of the top end of the floating plate, a right-angle prism is fixedly provided on the inner side of the retaining frame, and a second infrared emitter is fixedly provided above the liquid storage tube, and the second infrared emitter is used to emit infrared rays to the middle of the top end of the right-angle prism.

[0012] Preferably, the inner wall of the liquid storage tube is provided with an inclined convex strip, the inclined convex strip and the liquid storage tube are an integrally formed structure, the scale bar is arranged on the inclined surface of the inclined convex strip facing the right-angle prism, and the side wall of the floating plate is provided with a notch matching the inclined convex strip.

[0013] Preferably, the support assembly includes a positioning column, a connecting frame that can move axially along the positioning column is fixedly provided on the outer wall of the measuring assembly, an infrared emitter 1 is fixedly provided on the bottom of the outer wall of the connecting frame, and the infrared emitter 1 is used to display the horizontal position of the bottom of the measuring assembly.

[0014] Preferably, a linear groove is provided on the outer wall of the positioning column, and the inner wall of the linear groove facing the connecting frame is continuous serrated. The top and bottom of the inner side of the connecting frame are provided with locking mechanisms that can extend into the linear groove. The two locking mechanisms are axially symmetrically arranged, and the locking mechanisms are used to limit and lock the connecting frame at the position of the outer wall of the positioning column.

[0015] Preferably, the locking mechanism includes a rotatable traveling gear connected inside the connecting frame, one side of the traveling gear extends into the connecting frame and is meshed with the inner wall of the connecting frame, the side wall of the traveling gear is fixedly connected to a ratchet, and two ratchets are provided with a vertically liftable supporting seat at opposite sides, the side wall of the supporting seat is connected to a rotatable ratchet, and an elastic member is fixedly connected between the end of the ratchet and the supporting seat.

[0016] Preferably, an elastic tension spring is fixedly connected to the side between the two bearing seats, a rotatable special-shaped wheel is provided between the two bearing seats, the outer wall of the special-shaped wheel is in contact with the opposite side of the two bearing seats, the outer wall of the special-shaped wheel has two axially symmetrical protrusions, a driving shaft is fixedly connected to the middle part of the special-shaped wheel, and one end of the driving shaft extends to the outside of the connecting frame.

[0017] Preferably, one end of the driving shaft extending to the outside of the connecting frame is fixedly connected to a turning handle, and a rectangular through groove is provided at the end of the turning handle away from the driving shaft, a cross block is movably connected in the rectangular through groove, and an elastic compression spring is fixedly connected between the cross block and the rectangular through groove, and an arc groove is provided on the side of the connecting frame facing the turning handle, and limiting grooves are provided at both ends and the middle of the side walls of the arc groove, and one end of the cross block can extend to the inner side of the arc groove.

[0018] Preferably, the base includes a clamping seat, the end of the clamping seat away from the positioning column is in a downwardly bent U-shape, an extrusion disk is movably provided on the inner side of the clamping seat, a threaded handle is threadedly inserted at the bottom end of the clamping seat, and the top end of the threaded handle extends to the inner side of the clamping seat and is rotatably connected to the bottom end of the extrusion disk.

[0019] Technical effects and advantages of the present invention:

[0020] (1) The central venous pressure measuring device provided by the present invention can assist nurses in measuring the central venous pressure of patients, can adapt to the positioning of the zero point on patients of various body widths, and is convenient for observing the measured values, making the measurement operation of the central venous pressure more flexible and convenient, which helps to reduce the workload of nurses and improve work efficiency;

[0021] (2) The present invention provides a floating plate, a right-angle prism, an infrared emitter, an inclined convex strip, and a scale bar on the inclined convex strip on the liquid storage tube. The floating plate can always float on the liquid surface, infrared rays are refracted to the scale bar of the inclined convex strip through the right-angle prism, and the inclined convex strip acts as a limit guide on the floating plate. Compared with the method of obtaining the measured value by observing the position of the liquid surface on the scale bar, the present invention can observe the measured value more conveniently, intuitively, and accurately, which helps to improve the convenience and accuracy of obtaining the measured value.

[0022] (3) The present invention configures a ratchet on the side wall of the traveling gear, and then utilizes the bearing of the ratchet by the bearing seat and the elastic resetting of the ratchet by the elastic member, and finally drives the special-shaped wheel having two axially symmetrically distributed arc protrusions on the side wall to rotate through the driving shaft, so as to drive the two bearing seats to realize the bidirectional locking of the two ratchet teeth, or realize the unidirectional locking of a single ratchet teeth, so as to realize the unidirectional movement limit and the bidirectional locking limit of the connecting frame on the positioning column, thereby making the height adjustment of the measuring component more accurate and stable, and improving the quality of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 It is a schematic diagram of a partial three-dimensional cross-sectional structure of the liquid storage tube of the present invention.

[0025] Figure 3 It is a schematic diagram of the partial front cross-sectional structure of the positioning column and the connecting frame of the present invention.

[0026] Figure 4 For the present invention Figure 3 Schematic diagram of the local enlarged structure at point B.

[0027] Figure 5 For the present invention Figure 1 Schematic diagram of the local enlarged structure at point A.

[0028] Figure 6 It is a schematic diagram of the three-dimensional structure of the bearing seat of the present invention.

[0029] In the figure: 100, base; 101, clamping seat; 102, extrusion plate; 103, threaded handle;

[0030] 200, measuring assembly; 201, liquid storage tube; 202, connecting hose; 203, floating plate; 204, retaining frame; 205, right-angle prism; 206, inclined convex strip; 207, infrared emitter 2; 208, scale bar;

[0031] 300, support assembly; 301, positioning column; 302, connecting frame; 303, linear slot; 304, ratchet; 305, bearing seat; 306, ratchet; 307, elastic member; 308, special-shaped wheel; 309, driving shaft; 310, elastic tension spring; 311, turning handle; 312, arc slot; 313, limit slot; 314, rectangular through slot; 315, cross block; 316, infrared transmitter 1; 317, elastic compression spring; 318, walking gear; 319, slide rail; 320, sliding sleeve. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The present invention provides Figure 1-6 A central venous pressure measuring device as shown;

[0034] like Figure 1The device comprises a measuring assembly 200, a supporting assembly 300 and a base 100. The measuring assembly 200 is used to communicate with a central venous catheter to measure central venous pressure. The supporting assembly 300 is arranged on one side of the measuring assembly 200. The supporting assembly 300 is used to support and adjust the height of the measuring assembly 200. The base 100 is fixedly arranged at the bottom end of the supporting assembly 300. The base 100 is used to position and support the supporting assembly 300.

[0035] The base 100 is used to support the support component 300 so that the support component 300 is placed stably. Then, the support component 300 supports and adjusts the height of the measuring component 200 so that the lower end of the measuring component 200 can be flush with the fourth intercostal space of the patient's mid-axillary line as the zero adjustment point. Finally, the measuring component 200 can be connected to the external port of the central venous catheter on the patient and the physiological saline loaded in the measuring component 200 to measure the patient's central venous pressure.

[0036] like Figure 1-2As shown, the measuring assembly 200 includes a liquid storage tube 201 and a connecting hose 202 connected to the bottom end of the liquid storage tube 201. The connecting hose 202 can be provided with an infusion tube switch to control the flow of liquid in the connecting hose 202. At the same time, the connecting hose 202 can also be provided with a tube clamp to facilitate the connection of the connecting hose 202 with the external structure, so that after one end of the connecting hose 202 is connected to the external port of the central venous catheter on the patient, the position of the connecting hose 202 can be positioned by the tube clamp. The liquid storage tube 201 is made of transparent material. The liquid storage tube 201 made of transparent material can be convenient for observing the internal situation of the device. The liquid storage tube 201 is provided with a scale bar 208 for the height of the liquid level in the liquid storage tube 201. The scale bar 208 can intuitively display the volume of different height positions in the liquid storage tube 201; the inner cavity of the liquid storage tube 201 is movably provided with a floating plate 203, and the floating plate 203 is provided with water filtering holes throughout, which can avoid the accumulation of liquid on the floating plate 203 and avoid affecting the accuracy of detecting the liquid level through the height of the floating plate 203. The middle part of the top of the floating plate 203 is fixedly connected with a retaining The holder 204 is provided with a right angle prism 205 fixedly disposed inside the holder 204, and an infrared emitter 207 is fixedly disposed above the liquid storage tube 201. The infrared emitter 207 is used to emit infrared rays toward the middle of the top of the right angle prism 205. The infrared emitter 207 has a switch and a battery. The infrared emitter 207 emits an infrared beam vertically downward, and the positioning effect of the holder 204 on the right angle prism 205 is utilized so that the infrared beam can be vertically injected from the upper surface of the right angle prism 205 and pass through the right angle prism 205. The refraction of the prism 205 causes the infrared light beam to be emitted horizontally from one side of the right-angle prism 205 and illuminate the corresponding position of the scale bar 208, so that the nurse (or nursing staff) can visually judge the height of the liquid level in the liquid storage tube 201 by observing the position of the infrared light beam on the scale bar 208. Compared with the traditional method of observing the position between the liquid level and the scale bar 208, the infrared light beam illumination method of this embodiment is more intuitive and convenient, and can effectively reduce the defect problem of increased measurement value error caused by irregular observation action;The inner wall of the liquid storage tube 201 is provided with an inclined convex strip 206, and the inclined convex strip 206 and the liquid storage tube 201 are an integrally formed structure. The inclined convex strip 206 and the liquid storage tube 201 are integrally formed so that when the liquid storage tube 201 is manufactured, the existence of the inclined convex strip 206 can be allowed to ensure the accuracy of the internal space volume of the liquid storage tube 201. The scale bar 208 is set on the inclined surface of the inclined convex strip 206 on one side facing the right-angle prism 205. The side wall of the floating plate 203 is provided with a notch matching the inclined convex strip 206. The inclined convex strip 206 can adjust the floating plate 203 on the liquid storage tube 20 1 plays a role of limiting and guiding, so that the floating plate 203 is not easy to get stuck and rotate, so that the stability of the floating plate 203 can be enhanced to ensure that the infrared light beam is always irradiated on the inclined surface of the inclined convex strip 206. At the same time, because the scale bar 208 is located on the inclined surface of the inclined convex strip 206, the infrared light beam can be refracted by the right-angle prism 205 and directly irradiated on the scale bar 208 of the inclined convex strip 206. The inclined surface of the inclined convex strip 206 can be used to facilitate external personnel to view, thereby further improving the accuracy of observation of the measured value;

[0037] In the above embodiment, the end of the connecting hose 202 away from the liquid storage tube 201 is connected to the external port of the central venous catheter on the patient, and a predetermined volume of physiological saline is injected into the liquid storage tube 201. Then, the switch on the connecting hose 202 is turned on to allow the physiological saline in the liquid storage tube 201 to flow in the connecting hose 202 until the liquid level in the liquid storage tube 201 stops changing. By observing the infrared light beam emitted by the infrared emitter 207, which is refracted by the right-angle prism 205 and irradiated onto the scale bar 208 of the inclined convex strip 206, the nurse can read the position of the infrared light beam on the scale bar 208 according to the position of the infrared light beam on the scale bar 208. The measured value of the patient's central venous pressure is obtained (since the height of the infrared light beam from the liquid surface after refraction is constant, the liquid surface height value only needs to be obtained by subtracting the height of the infrared light beam from the bottom of the floating plate 203 obtained by previous calibration). In this way, there is no need to control the observation angle during observation, which is less difficult and the obtained value has higher accuracy. In addition, due to the limiting effect of the inclined convex strip 206 on the floating plate 203, the infrared light beam can always be irradiated on the inclined convex strip 206, and the floating plate 203 can always be suspended above the liquid surface, thereby making it more convenient to obtain the measured value.

[0038] like Figure 1 and Figure 3 As shown, the support assembly 300 includes a positioning column 301, and a connecting frame 302 that can move axially along the positioning column 301 is fixedly disposed on the outer wall of the measuring assembly 200. Figure 1The connecting frame 302 may be composed of two circular rings and a vertical plate, the vertical plate is fixed to the two circular ring side walls spaced apart from each other, an infrared emitter 316 is fixedly provided at the bottom of the outer wall of the connecting frame 302, and the infrared emitter 316 is used to display the horizontal position of the bottom of the measuring component 200; a linear slot 303 is provided on the outer wall of the positioning column 301, and the inner wall of the linear slot 303 facing the side of the connecting frame 302 is continuous and serrated, and a locking mechanism that can be extended into the linear slot 303 is provided at the top and bottom of the inner side of the connecting frame 302, and the two locking mechanisms are axially symmetrically arranged, and the locking mechanism is used to lock the connecting frame 302 on the positioning column 301 The outer wall position limit lock, the measuring component 200 can be moved up and down along the outer wall of the positioning column 301 through the connecting frame 302, and then the locking mechanism is used to lock the position of the connecting frame 302 on the positioning column 301, so as to adjust the height of the measuring component 200. At the same time, the infrared transmitter 316 is used to facilitate the nurse to understand whether the bottom of the measuring component 200 is aligned with the zero adjustment point on the patient. In this way, the nurse only needs to manually understand the position of the zero adjustment point on the patient in advance. During subsequent adjustments, it is only necessary to align the infrared light emitted by the infrared transmitter 316 with the point. There is no need to use a ruler for measurement, and the operation is more convenient and efficient.

[0039] like Figure 3 , Figure 4 and Figure 6As shown, the locking mechanism includes a rotatable traveling gear 318 connected inside the connecting frame 302, one side of the traveling gear 318 extends into the connecting frame 302 and meshes with the inner wall of the connecting frame 302, the side wall of the traveling gear 318 is fixedly connected with a ratchet 304, and two ratchet wheels 304 are provided with a vertically liftable bearing seat 305 at one side opposite to each other, the side wall of the bearing seat 305 is connected with a rotatable ratchet 306, and an elastic member 307 is fixedly connected between the end of the ratchet 306 and the bearing seat 305; an elastic tension spring 310 is fixedly connected to the side between the two bearing seats 305, and a rotatable special-shaped wheel 308 is provided between the two bearing seats 305, and the outer wall of the special-shaped wheel 308 is in contact with the opposite side of the two bearing seats 305, and the outer wall of the special-shaped wheel 308 is in contact with the opposite side of the two bearing seats 305. The wall has two axially symmetrical protrusions, and a driving shaft 309 is fixedly connected to the middle of the special-shaped wheel 308, and one end of the driving shaft 309 extends to the outside of the connecting frame 302; through the meshing of the traveling gear 318 with the inner wall of one side of the linear slot 303, the connecting frame 302 can drive the traveling gear 318 to rotate clockwise or counterclockwise during the up and down movement. This not only makes the lifting process of the connecting frame 302 more stable, but also makes it easier to control the accuracy of the lifting and lowering adjustment position; when the connecting frame 302 moves upward, it is only necessary to manually rotate the driving shaft 309 to drive the special-shaped wheel 308 to rotate clockwise by a certain angle, so that the arc protrusion at the bottom of the special-shaped wheel 308 can be separated from the bearing seat 305 at the lower position, and the outer wall of the arc protrusion at the top of the special-shaped wheel 308 can be moved in a clockwise or counterclockwise manner. The old ratchet 306 on the upper support seat 305 is in contact with the outer wall of the upper support seat 305, and the lower support seat 305 can drive the ratchet teeth 306 thereon to separate from the corresponding ratchet wheels 304, thereby releasing the restriction on the counterclockwise rotation of the lower travel gear 318. In this way, the two travel gears 318 can rotate counterclockwise and the connecting frame 302 can move upward on the outer wall of the positioning column 301. Since the ratchet teeth 306 on the upper support seat 305 are still engaged with the corresponding ratchet wheels 304, the travel gears 318 can be prevented from rotating clockwise, so that when the connecting frame 302 moves upward, it can play a limit locking role in its downward movement, thereby avoiding misoperation that causes the connecting frame 302 to move downward during or after adjustment; similarly, when the connecting frame 302 needs to be lowered, it only needs to drive the special-shaped wheels 30 By rotating the two traveling gears 318 counterclockwise for a certain angle in the original initial position, the two traveling gears 318 can rotate counterclockwise but cannot rotate clockwise; in addition, when the special-shaped wheel 308 is in the initial position, the two arc-shaped protrusions on its side wall are both in contact with the two bearing seats 305, and with the action of the elastic tension spring 310, the special-shaped wheel 308 can always maintain contact with the outer wall of the bearing seat 305 during rotation, making the driving process more stable; in addition, in some embodiments, a sliding sleeve 320 can be configured on the side of the bearing seat 305 away from the driving shaft 309, and the sliding sleeve 320 can be movably inserted into the sliding rail 319 fixed to the inner wall of the connecting frame 302, so that the bearing seat 305 can be limited and guided in the moving direction, thereby enhancing the stability of the lifting process of the bearing seat 305.

[0040] like Figure 5 As shown, the end of the drive shaft 309 extending to the outside of the connecting frame 302 is fixedly connected to a handle 311, and a rectangular through slot 314 is provided at the end of the handle 311 away from the drive shaft 309, and a cross block 315 is movably connected in the rectangular through slot 314, and an elastic compression spring 317 is fixedly connected between the cross block 315 and the rectangular through slot 314, and an arc slot 312 is provided on the side of the connecting frame 302 facing the handle 311, and limited slots 313 are provided at both ends and the middle of the side wall of the arc slot 312, and one end of the cross block 315 can extend to the inner side of the arc slot 312; in the present embodiment, in the initial state (the state in which the connecting frame 302 cannot move upward or downward), the handle 311 is in a horizontal position, and at this time, the end of the cross block 315 extending into the arc slot 312 enters the middle position of the arc slot 312 due to the thrust of the elastic compression spring 317. When the handle 311 is in the upper position, the ratchet wheel 304 is unlocked, so that the connecting frame 302 can move downward but cannot move upward; on the contrary, when the handle 311 is rotated to the downward position, the connecting frame 302 can move upward but cannot move downward, so that the stability and accuracy of the lifting and lowering adjustment of the connecting frame 302 can be increased, and the protection of the adjustment process is higher.

[0041] like Figure 1 As shown, the base 100 includes a clamping seat 101, and the end of the clamping seat 101 away from the positioning column 301 is in a U-shape that is bent downward, and its opening faces one side. An extrusion plate 102 is movably provided on the inner side of the clamping seat 101, and a threaded handle 103 is threadedly inserted at the bottom end of the clamping seat 101. The top of the threaded handle 103 extends to the inner side of the clamping seat 101 and is rotatably connected to the bottom end of the extrusion plate 102. By clamping the clamping seat 101 with the U-shaped bending portion on the bed frame, and then manually rotating the threaded handle 103 clockwise, the threaded handle 103 drives the extrusion plate 102 to move upward, so that the bed frame can be clamped by cooperating with the extrusion plate 102 at the top position inside the base 100, thereby meeting the installation and fixation of the base 100 at the side position of the bed. Compared with direct placement, it is more stable and has higher adaptability, and can be adapted to locking and fixing use in various environments.

[0042] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A central venous pressure measuring device, characterized in that: include: A measuring component (200), the measuring component (200) being connected to a central venous catheter to measure central venous pressure; A support assembly (300), wherein the support assembly (300) is arranged on one side of the measuring assembly (200), and the support assembly (300) is used for supporting the measuring assembly (200) and adjusting its height; A base (100), wherein the base (100) is fixedly arranged at the bottom end of the support assembly (300), and the base (100) is used for positioning and supporting the support assembly (300).

2. A central venous pressure measuring device according to claim 1, characterized in that: The measuring assembly (200) comprises a liquid storage tube (201) and a connecting hose (202) connected to the bottom end of the liquid storage tube (201); the liquid storage tube (201) is made of a transparent material, and a scale bar (208) for indicating the height of the liquid level in the liquid storage tube (201) is provided on the liquid storage tube (201).

3. A central venous pressure measuring device according to claim 2, characterized in that: A floating plate (203) is movably provided in the inner cavity of the liquid storage tube (201); a retaining frame (204) is fixedly connected to the middle of the top end of the floating plate (203); a right-angle prism (205) is fixedly provided inside the retaining frame (204); and a second infrared emitter (207) is fixedly provided above the liquid storage tube (201); the second infrared emitter (207) is used to emit infrared rays toward the middle of the top end of the right-angle prism (205).

4. A central venous pressure measuring device according to claim 3, characterized in that: The inner wall of the liquid storage tube (201) is provided with an inclined convex strip (206), the inclined convex strip (206) and the liquid storage tube (201) are an integrally formed structure, the scale bar (208) is arranged on a side inclined surface of the inclined convex strip (206) facing the right-angle prism (205), and the side wall of the floating plate (203) is provided with a notch matching the inclined convex strip (206).

5. A central venous pressure measuring device according to claim 1, characterized in that: The support assembly (300) comprises a positioning column (301), a connecting frame (302) which is axially movable along the positioning column (301) is fixedly provided on the outer wall of the measuring assembly (200), an infrared emitter 1 (316) is fixedly provided on the bottom of the outer wall of the connecting frame (302), and the infrared emitter 1 (316) is used to display the horizontal position of the bottom of the measuring assembly (200).

6. A central venous pressure measuring device according to claim 5, characterized in that: The outer wall of the positioning column (301) is provided with a linear groove (303), and the inner wall of the linear groove (303) facing the connecting frame (302) is in a continuous sawtooth shape. The top and bottom of the inner side of the connecting frame (302) are both provided with locking mechanisms that can extend into the linear groove (303), and the two locking mechanisms are axially symmetrically arranged. The locking mechanisms are used for limiting and locking the connecting frame (302) at the outer wall position of the positioning column (301).

7. A central venous pressure measuring device according to claim 6, characterized in that: The locking mechanism comprises a rotatable running gear (318) connected inside the connecting frame (302), one side of the running gear (318) extends into the connecting frame (302) and is meshed with the inner wall of the connecting frame (302), a ratchet (304) is fixedly connected to the side wall of the running gear (318), and a vertically liftable bearing seat (305) is provided at opposite sides of the two ratchet wheels (304), a rotatable ratchet (306) is connected to the side wall of the bearing seat (305), and an elastic member (307) is fixedly connected between the end of the ratchet (306) and the bearing seat (305).

8. A central venous pressure measuring device according to claim 7, characterized in that: An elastic tension spring (310) is fixedly connected to the side between the two bearing seats (305), and a rotatable special-shaped wheel (308) is provided between the two bearing seats (305). The outer wall of the special-shaped wheel (308) is in contact with the opposite side of the two bearing seats (305), and the outer wall of the special-shaped wheel (308) has two axially symmetrical protrusions. A driving shaft (309) is fixedly connected to the middle of the special-shaped wheel (308), and one end of the driving shaft (309) extends to the outside of the connecting frame (302).

9. A central venous pressure measuring device according to claim 8, characterized in that: One end of the driving shaft (309) extending to the outside of the connecting frame (302) is fixedly connected to a handle (311); a rectangular through slot (314) is provided at the end of the handle (311) away from the driving shaft (309); a cross block (315) is movably connected in the rectangular through slot (314); an elastic compression spring (317) is fixedly connected between the cross block (315) and the rectangular through slot (314); a circular arc slot (312) is provided on one side of the connecting frame (302) facing the handle (311); both ends and the middle of the side wall of the circular arc slot (312) are provided with limiting slots (313); one end of the cross block (315) can extend to the inside of the circular arc slot (312).

10. A central venous pressure measuring device according to claim 5, characterized in that: The base (100) comprises a clamping seat (101), the end of the clamping seat (101) away from the positioning column (301) is in a downwardly bent U-shape, an extrusion disk (102) is movably provided inside the clamping seat (101), a threaded handle (103) is threadedly inserted at the bottom end of the clamping seat (101), and the top end of the threaded handle (103) extends to the inside of the clamping seat (101) and is rotatably connected to the bottom end of the extrusion disk (102).

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