Calcium compensation tube for citric acid anticoagulation and pressure stabilizing device

Abstract

The invention relates to a calcium compensating pipe and pressure stabilizing device for citric acid anticoagulation, which comprises an artery pipeline connecting end, a citric acid container connecting end, a citric acid pump extruding section and a pressure balancing section, the artery pipeline connecting end is connected with an artery pipeline, and the citric acid container connecting end is connected with a citric acid container. The citric acid pump extrusion section is closer to the citric acid pump extrusion section container connecting end relative to the balance pressure section, the balance pressure section comprises a first pipeline and a second pipeline, the first pipeline is directly connected with the citric acid pump extrusion section, and at least one end of the second pipeline is connected with the first pipeline. And the second pipeline is provided with a volume change interval, so that the volume is increased or decreased under the action of external force and is recovered after the external force is removed. The volume of the volume change section becomes larger or smaller under the action of external force, unstable liquid flow of the peristaltic pump can be balanced, pulsating pressure changes generated by the peristaltic pump are balanced through the balance pressure section, and frequent alarming and interference on treatment continuity are avoided.

Description

Technical Field

[0001] The present invention belongs to the field of medical devices, and in particular relates to a calcium compensation tube and a voltage stabilizing device for citrate anticoagulation. Background Art

[0002] Continuous renal replacement therapy (CRRT) is a blood purification technology used for critically ill patients. It is widely used to treat critically ill patients with conditions such as acute kidney injury and renal insufficiency. Citrate is often used as an anticoagulant in CRRT, but citrate can chelate calcium ions in the blood, leading to hypocalcemia. Therefore, calcium compensation is an essential step in the CRRT process.

[0003] Existing conventional tubing is prone to pressure anomalies during use due to the pulsation generated by the peristaltic pump, which leads to frequent alarms and disrupts treatment continuity. Due to the lack of flexibility in length and pressure adjustment, medical staff must manually adjust the tubing length and set the appropriate pressure range to ensure proper operation. This not only increases operational complexity but also increases uncertainty and risk during patient treatment.

[0004] Some peristaltic pumps use multiple rollers to reduce pulsation, but this significantly reduces efficiency and still results in some fluctuations. Some peristaltic pumps also have complex smoothing mechanisms, making them unsuitable for single-use continuous renal replacement therapy. Complex structures also increase costs.

[0005] Chinese patent CN217854012U discloses a dual-circuit citrate anticoagulation blood line with an alarm function, but it does not solve the pulsation problem of the peristaltic pump. Chinese patent CN113368328B discloses a blood purification device with built-in intelligent citrate anticoagulation technology, which has the same problem of frequent alarms. Summary of the Invention

[0006] In view of the above-mentioned prior art, the purpose of the present invention is to optimize and stabilize the pressure reduction alarm of the existing calcium compensation tube for CRRT citrate anticoagulation.

[0007] The technical solution of the present invention is implemented as follows: a calcium compensation tube for citrate anticoagulation includes an arterial pipeline connecting end, a citric acid container connecting end, a citric acid pump extrusion section and a balanced pressure section. The arterial pipeline connecting end is connected to the arterial pipeline, the citric acid container connecting end is connected to the citric acid container, the citric acid pump extrusion section is closer to the citric acid pump extrusion section container connecting end relative to the balanced pressure section, the balanced pressure section includes a first pipe and a second pipe, the first pipe is directly connected to the citric acid pump extrusion section, at least one end of the second pipe is connected to the first pipe, and the second pipe is provided with a volume change range so that the volume increases or decreases under the action of external force and the volume is restored after the external force is removed.

[0008] The beneficial effect of such a design is that the volume change interval makes the volume increase or decrease under the action of external force, which can balance the unstable liquid flow of the peristaltic pump, that is, when the liquid flow generated by the peristaltic pump becomes smaller, the volume of the volume change interval becomes smaller, and the liquid enters the first pipe closed liquid flow change. The liquid flow rate is stable and the pressure generated is also relatively stable. The balanced pressure section is used to balance the pulsating pressure changes generated by the peristaltic pump to avoid frequent alarms and interference with the continuity of treatment.

[0009] Furthermore, the volume change interval includes a first change section and a second change section. When the volume of the first change section increases, the volume of the second change section decreases, and when the volume of the second change section increases, the volume of the first change section decreases. This design can achieve cyclic changes, and the first and second change sections complement each other, allowing pressure and flow to be adjusted as needed.

[0010] Furthermore, the first changing section and the second changing section are oppositely arranged on both sides of the first pipe and are in communication with the first pipe, so that the pressure change adjustment is more timely and accurate.

[0011] Furthermore, the first changing section and the second changing section are connected in series and in parallel with the first pipeline, so that a separate pressure regulating pipeline can be formed, which has little impact on the first pipeline.

[0012] A pressure stabilizing device for a calcium compensation tube for citrate anticoagulation includes two sets of cam transmission structures. The cam rotates at a certain speed to drive the extrusion cylinder to move back and forth at a certain speed to extrude the first change section or the second change section. The cam is provided with a cam groove, and a guide wheel is provided in the cam groove. The guide wheel is fixed to the moving rod. The moving rod is provided with an extrusion cylinder that moves synchronously. The curve function of the cam recovery stroke is:

[0013]

[0014] When the cam rotation angular velocity and angle are the same as the peristaltic pump speed, the curve function of the cam extrusion stroke is:

[0015]

[0016] The cam is used to control the speed, which can reduce or avoid the pulsation generated by the peristaltic pump and cause pressure instability.

[0017] Furthermore, the first or second changing section is provided with a cylindrical elastic section, and the elastic section is provided with an extrusion cylinder. During an extrusion stroke, the extrusion cylinder is driven by the first driving device to compress the elastic section, causing the cross-section of the elastic section to change from a circle to a line. During a recovery stroke, when the extrusion cylinder moves away from the elastic section, the cross-section of the elastic section changes from a line to a circle. The peristaltic pump also uses a circular tube, which facilitates calculations.

[0018] Furthermore, the first driving device is a cam, so that the cam rotates at a certain speed to drive the extrusion cylinder to move back and forth at a certain speed. This is convenient to control and relatively stable.

[0019] Furthermore, the first changing section or the second changing section is provided with a piston section, which is provided with a movable piston and achieves volume change by the back-and-forth movement of the piston. The piston is driven by a second driving device to move back and forth in a straight line to complete the extrusion stroke and the recovery stroke. In this way, the speed can be adjusted as needed.

[0020] Furthermore, when the first changing section is in the extrusion stroke, the second changing section is in the recovery stroke. When the first changing section is in the recovery stroke, the second changing section is in the extrusion stroke. The volume change of the elastic section or piston section during the extrusion stroke causes a flow change opposite to the flow change of the peristaltic pump rotating at a constant speed, keeping the total flow at a stable value. During the recovery stroke, the volume change per unit time of the elastic section or piston section remains constant. The peristaltic pump's two pulsation cycles equal the sum of the recovery stroke and the extrusion stroke. This results in a more stable pressure.

[0021] Furthermore, the second driving device is a servo motor that drives the screw slider to achieve linear back and forth movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic three-dimensional diagram of a calcium compensation tube and a voltage stabilizing device for citrate anticoagulation according to the present invention;

[0023] Figure 2 This is a schematic cross-sectional view of a calcium compensation tube and a voltage stabilizing device for citrate anticoagulation according to the present invention;

[0024] Figure 3 This is a schematic diagram of a calcium compensation tube for citrate anticoagulation and a voltage stabilizing device according to the present invention, wherein the first changing section is in an extrusion state;

[0025] Figure 4 This is a schematic cross-sectional view of the elastic section of a calcium compensation tube for citrate anticoagulation according to the present invention before extrusion;

[0026] Figure 5 This is a schematic diagram of a cross-section of an elastic section of a calcium compensation tube for citrate anticoagulation according to the present invention;

[0027] Figure 6 This is a schematic diagram of a state in which the elastic section of a calcium compensation tube for citrate anticoagulation of the present invention is squeezed into a straight line;

[0028] Figure 7 This is a three-dimensional schematic diagram of a calcium compensation tube for citrate anticoagulation according to the present invention;

[0029] Figure 8 This is a schematic cross-sectional view of a calcium compensation tube for citrate anticoagulation according to the present invention. DETAILED DESCRIPTION

[0030] As needed, detailed embodiments of the present invention are disclosed herein, but it should be understood that the disclosed embodiments are merely exemplary of the present invention, and the present invention may be implemented in different and alternative forms. The accompanying drawings are not necessarily drawn to scale, and certain features may be exaggerated or reduced to show the details of a particular component. Therefore, the specific structural and functional details disclosed herein should not be understood as having a limiting meaning, but merely as a representative basis to teach those skilled in the art to adopt the present invention differently. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention.

[0031] like Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, a calcium compensation tube for citrate anticoagulation includes an arterial line connection end 1, a citrate container connection end 2, a citrate pump extrusion section 3 and a pressure balance section 4. The arterial line connection end 1 is connected to the arterial line, the citrate container connection end 2 is connected to the citrate container 5, the citrate pump extrusion section 3 is closer to the container connection end of the citrate pump extrusion section 3 relative to the pressure balance section 4, the pressure balance section 4 includes a first pipe 41 and a second pipe 42, the first pipe 41 is directly connected to the citrate pump extrusion section 3, at least one end of the second pipe 42 is connected to the first pipe 41, and the second pipe 42 is provided with a volume change interval 43 so that the volume increases or decreases under the action of an external force and recovers after the external force is removed.

[0032] During use, the citric acid container connection end 2 is connected to the citric acid container 5, which can provide citric acid. The arterial line connection end 1 is connected to the arterial line. The peristaltic pump 8 is provided in the citric acid pump extrusion section 3. A drive device is provided in the volume change section 43 of the second conduit 42 to generate a certain force on the volume change section 43, so that the volume of the volume change section 43 changes at a certain rate. The drive device can be a servo motor.

[0033] In one embodiment, volume variation section 43 includes a first variation section 44 and a second variation section 45. When the volume of first variation section 44 increases, the volume of second variation section 45 decreases, and when the volume of second variation section 45 increases, the volume of first variation section 44 decreases. Independent drive devices can be provided for first variation section 44 and second variation section 45 to operate independently.

[0034] In one embodiment, the first changing section 44 and the second changing section 45 are connected in series and then in parallel with the first pipe 41 .

[0035] In one embodiment, the first changing section 44 or the second changing section 45 is provided with a cylindrical elastic section 46, and the elastic section 46 is provided with an extrusion cylinder. In the extrusion stroke, the extrusion cylinder is driven by the first driving device to extrude the elastic section 46, so that the cross-section of the elastic section 46 changes from a circle to a straight line. When the extrusion cylinder moves away from the elastic section 46 in the recovery stroke, the cross-section of the elastic section 46 changes from a straight line to a circle.

[0036] In one embodiment, the first driving device is a cam 7, which rotates at a certain speed to drive the extrusion cylinder 71 to move back and forth at a certain speed. The cam 7 is provided with a cam groove 72, and a guide wheel 73 is provided in the cam groove 72. The guide wheel 73 is fixed to the upper moving rod 74 and is provided with the extrusion cylinder 71 that moves synchronously. Figure 2 As shown, the first change section 44 and the second change section 45 are not squeezed by the squeezing cylinder 71. Figure 3 As shown, the first changing section 44 is squeezed by the squeezing cylinder 71 , while the second changing section 45 is not squeezed by the squeezing cylinder 71 .

[0037] In one embodiment, when the first changing section 44 is in the extrusion stroke, the second changing section 45 is in the recovery stroke. When the first changing section 44 is in the recovery stroke, the second changing section 45 is in the extrusion stroke. The flow change caused by the volume change of the elastic section 46 or the piston section during the extrusion stroke is opposite to the flow change of the peristaltic pump 8 rotating at a constant speed, so that the total flow is at a stable value. During the recovery stroke, the volume change per unit time of the elastic section 46 or the piston section is a constant value. The two pulsation cycle times of the peristaltic pump 8 are equal to the sum of the time of a recovery stroke and an extrusion stroke.

[0038] like Figure 4 As shown, before the extrusion cylinder 71 extrudes the elastic section 46, the cross section of the elastic section 46 is circular, as shown in FIG. Figure 5 As shown, after the elastic section 46 is squeezed by the extrusion cylinder 71, the cross section of the elastic section 46 is an irregular shape, but in the case of very good elasticity, it can be approximately regarded as a semicircle and a rectangle, such as Figure 6 As shown, after the extrusion cylinder 71 squeezes the elastic section 46 to the bottom, the cross-section of the elastic section 46 forms a straight line. Furthermore, this design suppresses pulsation in the peristaltic pump 8, and even small errors are acceptable; the smaller the error, the more stable the pressure. The citric acid pump extrusion section 3 in the peristaltic pump 8 also exhibits this variation pattern, but its cross-section changes from a straight line to a cylinder, so the same formula can be used for calculation.

[0039] In one embodiment, the cam 7 is designed according to the following method:

[0040] To reduce pulsation, the volume change during the recovery stroke is uniform.

[0041] Assume that the moving distance of the extrusion cylinder 71 is L, the inner diameter of the hose is r, and the deformation length of the hose on one side is i. The value varies for different materials, so it is assumed to be 2L. In order to calculate the functional relationship of the cross-sectional area of the hose, it can be approximately assumed that the hose is squeezed by the extrusion cylinder 71 into a combination of two semicircles and a rectangle.

[0042] Rectangular part: The length of the rectangle is The width is 2r-L, then the area of the rectangle is rectangle

[0043] Two semicircle parts: Two semicircles can be put together to form a circle with a radius of The area of a circle is

[0044] At this time, the cross-sectional area of the hose is the sum of the rectangular area and the circular area, that is:

[0045]

[0046] The original volume of the deformed part is: v1=πr 2 ×2L×2=4πr 2 L

[0047] The volume after deformation is:

[0048]

[0049] The volume change is:

[0050]

[0051] The purpose of this application is to ensure that the volume changes smoothly so that there will be no pulse phenomenon. Therefore, assuming that the volume change per unit time is a certain value k, the moving speed of the extrusion cylinder 71 is

[0052] right Derivative Depend on have to

[0053] If the movement of the extrusion cylinder 71 is realized by the cam 7, and the cam 7 rotates at a constant speed C, the rotation angle of the cam 7 is θ=ωt

[0054] Known Deformed to πL 2 dL=kdt

[0055] Integrate both sides Available ω is replaced by t Solve

[0056] In the polar coordinate system, assuming that the base circle radius of cam 7 is R0, the relationship between the polar coordinate equation ρ of the cam 7 profile curve and L is ρ=R0+L

[0057] so 0≤θ≤θ1( is the cam 7 rotation angle corresponding to L=2r).

[0058] Since the cross-sectional area of the peristaltic pump 8 is expanded from a straight line to a circle, the corresponding compensation scheme is to change from a circle to a straight line. The speed of one extrusion stroke needs to be calculated according to the speed of the peristaltic pump 8. For the convenience of calculation, it is assumed that the pipe diameter is r. Figure 6 、 Figure 5 and Figure 4 The effect of the roller 6 of the peristaltic pump 8 on the flow rate is due to the fact that the roller 6 is constantly moving away from the extrusion section 3 of the citric acid pump during the rolling process. Suppressing this change can stabilize the pressure. Assuming that the volume difference of this change is V4, the radius of the peristaltic pump 8 is R, and the angular velocity is ω, the volume difference V4 is:

[0059]

[0060]

[0061] The volume change per unit time is

[0062]

[0063] Right now

[0064]

[0065] Assuming the stroke of cam 7 is L, the volume change is

[0066]

[0067] v4=v3=πL 2

[0068]

[0069] The cam 7 mechanism converts the rotational motion of the cam 7 into the linear motion of the follower. Assuming that the cam 7 rotates around the axis at the same constant angular velocity ω, the rotation angle of the cam 7 θ = wt

[0070]

[0071] In the cam 7 mechanism, if the rotation center of the cam 7 is the polar coordinate origin, the starting position of the follower is the polar axis direction. Assuming the base circle radius of the cam 7 is R0, the relationship between the polar coordinate equation ρ of the cam 7 profile curve and L is ρ=R0+L

[0072]

[0073] like Figure 7 and Figure 8 As shown, in one embodiment, a first changing section 44 and a second changing section 45 are disposed oppositely to each other on either side of a first conduit 41 and communicate with the first conduit 41. The first changing section 44 or the second changing section 45 is provided with a piston section 47. The piston section 47 is provided with a movable piston. Volume changes are achieved through the reciprocating movement of the piston. The piston is driven by a second driving device 48 to move linearly back and forth to achieve an extrusion stroke and a recovery stroke.

Claims

1. A calcium compensation tube for citrate anticoagulation, characterized in that: The invention comprises an arterial line connection end (1), a citric acid container connection end (2), a citric acid pump extrusion section (3) and a pressure balance section (4), wherein the arterial line connection end (1) is connected to the arterial line, the citric acid container connection end (2) is connected to the citric acid container (5), the citric acid pump extrusion section (3) is closer to the container connection end of the citric acid pump extrusion section (3) than the pressure balance section (4), and the pressure balance section (4) comprises a first pipe (41) and a second pipe (42), wherein the first pipe (41) is directly connected to the citric acid pump extrusion section (3), and at least one end of the second pipe (42) is connected to the first pipe (41), and the second pipe (42) is provided with a volume change section (43) so that the volume increases or decreases under the action of an external force and recovers the volume after the external force is removed.

2. The calcium compensation tube for citrate anticoagulation according to claim 1, characterized in that: The volume change interval (43) includes a first change section (44) and a second change section (45), and when the volume of the first change section (44) increases, the volume of the second change section (45) decreases, and when the volume of the second change section (45) increases, the volume of the first change section (44) decreases.

3. The calcium compensation tube for citrate anticoagulation according to claim 2, characterized in that: The first changing section (44) and the second changing section (45) are arranged opposite to each other on both sides of the first pipe (41) and are in communication with the first pipe (41).

4. The calcium compensation tube for citrate anticoagulation according to claim 3, characterized in that: The first changing section (44) and the second changing section (45) are connected in series and then connected in parallel with the first pipeline (41).

5. A voltage stabilizing device for a calcium compensating tube for citrate anticoagulation, using the calcium compensating tube for citrate anticoagulation according to any one of claims 1 to 4, characterized in that: The first change section (44) or the second change section (45) of the calcium compensation tube for citrate anticoagulation is provided with a cylindrical elastic section (46), and the elastic section (46) is provided with the extrusion cylinder (71). During the extrusion stroke, the extrusion cylinder (71) is driven by the first driving device to squeeze the elastic section (46), so that the cross section of the elastic section (46) changes from a circle to a straight line. During the recovery stroke, when the extrusion cylinder (71) moves away from the elastic section (46), the cross section of the elastic section (46) changes from a straight line to a circle.

6. The voltage stabilizing device for the calcium compensation tube for citrate anticoagulation according to claim 5, characterized in that: The first driving device is a cam (7), which enables the cam (7) to rotate at a certain speed and drive the extrusion cylinder (71) to move back and forth at a certain speed.

7. The voltage stabilizing device for the calcium compensation tube for citrate anticoagulation according to claim 6, characterized in that: The first changing section (44) or the second changing section (45) is provided with a piston section (47), the piston section (47) is provided with a movable piston and realizes volume change by the back and forth movement of the piston, and the piston is driven by a second driving device (48) to realize linear back and forth movement to complete the extrusion stroke and the recovery stroke.

8. The voltage stabilizing device for the calcium compensation tube for citrate anticoagulation according to claim 6, characterized in that: When the first changing section (44) is in the extrusion stroke, the second changing section (45) is in the recovery stroke. When the first changing section (44) is in the recovery stroke, the second changing section (45) is in the extrusion stroke. During the extrusion stroke, the flow change caused by the volume change of the elastic section (46) or the piston section (47) is opposite to the flow change of the peristaltic pump (8) rotating at a constant speed, so that the total flow is at a stable value. During the recovery stroke, the volume change per unit time of the elastic section (46) or the piston section (47) is a constant value. The two pulsation cycle times of the peristaltic pump (8) are equal to the sum of the time of a recovery stroke and an extrusion stroke.

9. The voltage stabilizing device for the calcium compensation tube for citrate anticoagulation according to claim 8, characterized in that: The pressure stabilizing device comprises two groups of cam (7) transmission structures. The cam (7) rotates at a certain speed to drive the extrusion cylinder (71) to move back and forth at a certain speed to extrude the first change section (44) or the second change section (45). The cam (7) is provided with a cam groove (72). A guide wheel (73) is provided in the cam groove (72). The guide wheel (73) is fixed on a moving rod (74). The moving rod (74) is provided with an extrusion cylinder (71) that moves synchronously. The curve function of the cam (7) recovery stroke is: 0≤θ≤θ1,θ (1) is the angular range of the extrusion stroke of the cam (7), When the cam (7) rotational angular velocity and angle are the same as the speed of the peristaltic pump (8), the curve function of the extrusion stroke of the cam (7) is: The speed is controlled by a cam (7).

10. The voltage stabilizing device for the calcium compensation tube for citrate anticoagulation according to claim 7, characterized in that: The second driving device (48) is a servo motor driving the screw slider to achieve linear back and forth movement.

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