Tube pump

Abstract

To provide a tube pump capable of minimizing liquid leakage due to residual pressure inside an elastic tube generated when liquid delivery is turned off.SOLUTION: Tube pumps A1, A2, A3 include a guide surface 111 having an arc-shaped inner surface shape, an elastic tube 12 arranged along the guide surface 111, and a rotor 13 that rotates around a rotational axis 131, which is a center position of an arc constituting the guide surface 111, and that has a plurality of rollers 14 supported at equal intervals in a circumferential direction, where the rotation of the rotor 13 causes the rollers 14 to squeeze and deform the elastic tube 12 between itself and the guide surface 111. The guide surface 111 or an outer peripheral surface 141 of the roller 14 has inclined part 112, 142 that are inclined with respect to an axial line L1 of the rotational axis 131 in a cross section along the rotational axis 131 of the rotor 13.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a tube pump, and more particularly to a tube pump suitable for administering TLA anesthesia during treatment of varicose veins, for example. [Background technology]

[0002] A typical configuration of a tube pump, as shown in Patent Document 1, involves placing an elastic tube along a guide surface with an arc-shaped inner surface, and squeezing and deforming the elastic tube between the guide surface with a plurality of rollers supported at equal intervals circumferentially on a rotor that rotates around the center of the arc that makes up the guide surface as its rotation axis. A narrowed section formed in the elastic tube by the pressing force of the rollers moves forward in the liquid transfer direction as the rotor rotates, thereby transferring the liquid in the elastic tube.

[0003] When this type of tube pump is used for TLA anesthesia, the inlet side of the elastic tube is connected to an anesthetic liquid container via an infusion tube, and the outlet side of the elastic tube is connected to an injection needle via an infusion tube. The fluid delivery by this tube pump is controlled by, for example, an ON / OFF operation using a foot pedal. That is, when the foot pedal is turned ON, the rotor rotates at a predetermined speed, and when the foot pedal is turned OFF, the rotor stops.

[0004] However, this type of tube pump is prone to excess fluid being pumped from the outlet due to residual pressure in the elastic tube, even when the foot pedal is turned off to stop the rotor rotation. For example, when administering TLA anesthesia using this type of tube pump, even after the needle is removed from the patient's leg and the foot pedal is turned off, the anesthetic fluid continues to leak from the tip of the needle for several seconds. This is undesirable, as it contaminates the medical treatment site with anesthetic fluid and leads to waste of anesthetic fluid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO 2017 / 159841 publication Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention was devised in light of the above circumstances, and its objective is to provide a tube pump that can minimize liquid leakage caused by residual pressure in the elastic tube when the liquid delivery is turned off. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs the following technical means.

[0008] In other words, the tube pump provided by the present invention includes a guide surface shaped like an arcuate inner surface, an elastic tube arranged along the guide surface, and a rotor that rotates around the center position of the arc that constitutes the guide surface as its rotation axis and has a plurality of rollers supported at equal intervals circumferentially, and in which the rotation of the rotor causes the rollers to squeeze and deform the elastic tube between the guide surface, the guide surface or the outer surface of the rollers is characterized in that, in a cross section along the rotation axis of the rotor, the guide surface or the outer surface of the roller has an inclined portion that is inclined with respect to the axis of the rotation axis.

[0009] In a preferred embodiment, the inclined portion is formed on the guide surface and includes a first inclined portion on one side of the guide surface in the axial direction of the rotation shaft, the distance to the axis becoming shorter as the guide surface moves toward that side, and a second inclined portion on the other side of the guide surface in the axial direction of the rotation shaft, the distance to the axis becoming shorter as the guide surface moves toward the other side.

[0010] In a preferred embodiment, the inclined portion is formed on the outer peripheral surface of the roller and includes a first inclined portion on one side of the outer peripheral surface in the axial direction of the rotation shaft, the distance to the axis becoming shorter as the outer peripheral surface moves toward that side, and a second inclined portion on the other side of the outer peripheral surface in the axial direction of the rotation shaft, the distance to the axis becoming shorter as the outer peripheral surface moves toward that other side.

[0011] In a preferred embodiment, the inclination angle of the inclined portion is 2 to 6 degrees, and preferably 3 to 4 degrees.

[0012] In a preferred embodiment, the inlet side of the elastic tube is connected to an anesthetic liquid container via an infusion tube, the outlet side of the elastic tube is connected to an injection needle via an infusion tube, and the rotation of the rotor is turned on and off by a foot pedal. [Effects of the Invention]

[0013] In the tube pump having the above configuration, the portion of the elastic tube that is clamped between the guide surface and the outer peripheral surface of the roller has an inclined portion that is inclined with respect to the axis of the rotor's rotation shaft, so that the internal space of the elastic tube is not completely crushed, and a state in which a certain amount of liquid can flow between before and after the clamped portion is ensured. Therefore, the residual pressure in the elastic tube is relieved at the moment when the state switches from the liquid delivery ON state in which the rotor rotates to the liquid delivery OFF state in which the rotor stops rotating, and the amount of excess liquid delivered from the outlet of the elastic tube when the liquid delivery OFF state is reduced.

[0014] Other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the drawings. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a front view showing the overall appearance of a tube pump according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] 3 is a view seen from the direction of arrow III in FIG. 2, with the opening / closing cover omitted. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] 4 is a view showing a main part of a tube pump according to a second embodiment of the present invention, and corresponds to a cross section taken along line IV-IV in FIG. [Figure 6] 4 is a view showing a main part of a tube pump according to a third embodiment of the present invention, and corresponds to a cross section taken along line IV-IV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Preferred embodiments of the present invention will now be described in detail with reference to the drawings.

[0017] FIG. 1 shows an example of the overall configuration of a tube pump A1 according to the present invention, and FIGS. 2 and 3 show essential parts of a first embodiment of the present invention. This tube pump A1 is configured for use in TLA anesthesia. This tube pump A1 includes a housing 20 incorporating a pump mechanism 10 (described in detail below), an infusion tube 31 connected to the supply side of the pump mechanism 10 and leading to an anesthetic liquid container 30, an infusion tube 41 connected to the discharge side of the pump mechanism 10 and leading to an injection needle 40, and a foot pedal 50 for operating the liquid delivery ON / OFF. On the front of the housing 20, there are arranged an open / close cover 21 for attaching or replacing an elastic tube 12 of the pump mechanism 10 (described below), and switches 22 such as a power switch and a dial for adjusting the liquid delivery rate.

[0018] 2 and 3, pump mechanism 10 basically includes guide surface 111 having an arcuate inner surface, elastic tube 12 arranged along guide surface 111, and rotor 13 having four rollers 14 supported at equal intervals in the circumferential direction of rotation. Guide surface 111 is formed above rotor 13 and faces downward, and the central angle of the arc constituting guide surface 111 is set to approximately 120° to 150°. This guide surface 111 is also formed on the underside of guide block 11, which is supported on base plate 23 so as to be slidable in the up and down direction. Guide block 11 is configured to move up and down in conjunction with the opening and closing of openable cover 21, for example via a link mechanism (not shown). That is, when the openable cover 21 is opened, the guide block 11 and the guide surface 111 are retracted upward in conjunction with this, and when the openable cover 21 is closed, the guide block 11 is moved downward in conjunction with this, and the guide surface 111 is set to the pump operating position, which is the appropriate position for sandwiching the elastic tube 12 with a predetermined pressure between it and the roller 14 of the rotor 13. The guide surface 111 has a predetermined width in the direction of the axis L1 of the rotation shaft 131 of the rotor 13, and is characterized by a cross-sectional shape along the rotation shaft 131, which will be described in more detail below.

[0019] The rotor 13 is rotated counterclockwise in FIG. 3 around the rotation shaft 131 by an electric motor 15 with a speed reduction mechanism disposed behind the base plate 23. The electric motor 15 may be, for example, a DC brush motor. The rotor 13 has a front flange 132 and a rear flange 133. The rollers 14 are rotatably supported by roller pins 143 that are fitted between the flanges 132 and 133. In this embodiment, four rollers 14 are provided at equal intervals around the rotation shaft 131 of the rotor 13, i.e., at 90° intervals. Each roller 14 also has a rotating body shape with a predetermined axial length corresponding to the axial width of the guide surface 111 of the rotation shaft 131. When the guide surface 111 is in the pump operating position, the center of the arc that defines the guide surface 111 coincides with the rotation shaft 131 of the rotor 13.

[0020] The elastic tube 12 is made of, for example, PVC (polyvinyl chloride) and is capable of moderate elastic deformation. This elastic tube 12 is provided with connection bushings (a liquid supply side connection bushing 121 and a discharge side connection bushing 122) on both ends, and as shown in Fig. 3, the elastic tube 12 is arranged so as to pass between the guide surface 111 and the rotor 13 while being aligned with the guide surface 111, and the connection bushings 121, 122 on both ends are attached by engaging with an upright wall 231 integral with the base plate 23. The liquid supply side connection bushing 121 is connected to the infusion tube 31 connected to the anesthetic liquid container 30, and the discharge side connection bushing 122 is connected to the infusion tube 41 connected to the injection needle 40.

[0021] When the pump mechanism 10 is operated while the infusion tube 31 or the elastic tube 12 connected to the anesthetic liquid container 30 is filled with anesthetic liquid, as the rotor 13 rotates, the roller 14 presses the elastic tube 12 against the guide surface 111, squeezing and deforming the elastic tube 12, thereby sending the anesthetic liquid in the elastic tube 12 toward the injection needle 40 via the infusion tube 41.

[0022] 4 shows a cross section along the rotation shaft 131 of the rotor 13 of the pump mechanism 10. As can be seen from the figure, the outer peripheral surface 141 of the roller 14 is parallel to the axis L1 of the rotation shaft 131 of the rotor 13, while the guide surface 111 has an inclined portion 112 inclined with respect to the axis L1 of the rotation shaft 131 of the rotor 13. In this embodiment, the guide surface 111 includes a first inclined portion 112a on one side (the right side in FIG. 4) of the guide surface 111 in the direction of the axis L1 of the rotation shaft 131, the distance to the axis L1 becoming shorter as the guide surface 111 approaches the one side, and a second inclined portion 112b on the other side (the left side in FIG. 4) of the guide surface 111 in the direction of the axis L1 of the rotation shaft 131, the distance to the axis L1 becoming shorter as the guide surface 111 approaches the other side. That is, guide surface 111 has a generally V-shaped downward recess in its cross section, and this cross-sectional shape is uniform throughout the entire portion of guide surface 111 extending in the arc direction. However, the inclination angle α of first inclined portion 112a and second inclined portion 112b is set to about 2 to 6°, and preferably about 3 to 4°. Note that first inclined portion 112a and second inclined portion 112b are not limited to a combination of straight lines in the cross section as in this embodiment, but may be a combination of concave curves in the cross section, so that guide surface 112 as a whole is a concave curved surface in the cross section.

[0023] Next, the operation of the tube pump A1 having the above configuration will be described.

[0024] As described above, when the rotor 13 rotates, the rollers 14 press the elastic tube 12 against the guide surface 111, squeezing and deforming the elastic tube 12, thereby sending the anesthetic liquid inside the elastic tube 12 toward the injection needle 40. In the tube pump A1 configured as described above, the water-stopping function is improved when the rotation of the rotor 13 is stopped, i.e., when the liquid delivery OFF operation is performed. That is, at the portion of the elastic tube 12 that is clamped between the guide surface 111 and the outer circumferential surface 141 of the roller 14, the guide surface 111 has concave inclined portions 142a, 142b in cross section, so that the internal space of the elastic tube 12 is not completely crushed, as shown in detail in Fig. 4, and a state in which the anesthetic liquid can circulate to some extent between the front and rear of the clamped portion is ensured. Therefore, the residual pressure in the elastic tube 12 is alleviated at the moment when the liquid delivery state switches from the ON state in which the rotor 13 rotates to the OFF state in which the rotor 13 stops rotating, and the amount of excess liquid delivered from the discharge side of the elastic tube 12 when the liquid delivery state is OFF can be reduced.

[0025] Therefore, when the tube pump A1 having the above configuration is used for TLA anesthesia administration, the phenomenon in which anesthetic liquid continues to leak from the tip of the injection needle 40 for several seconds when the foot pedal 50 is turned off can be prevented or reduced.

[0026] Furthermore, in this embodiment, the inclined portions 112a, 112b provided on the guide surface 111 are concave in cross section, so that they perform a centering function that positions the elastic tube 12 in the center of the width of the guide surface 111 when the rotor 13 rotates, preventing problems such as the elastic tube 12 accidentally falling off from the clamped state between the guide surface 111 and the roller 14 toward the rotation axis 131 of the rotor 13 while the pump mechanism 10 is operating.

[0027] FIG. 5 shows a main part of a tube pump A2 according to a second embodiment of the present invention, and corresponds to a cross section taken along line IV-IV in FIG.

[0028] As can be seen from FIG. 5, in this embodiment, the guide surface 111 is parallel to the axis L1 of the rotation shaft 131 of the rotor 13, while the outer peripheral surface 141 of the roller 14 has an inclined portion 142 inclined with respect to the axis L1 of the rotation shaft 131 of the rotor 13. In this embodiment, the outer peripheral surface 141 of the roller 14 includes a first inclined portion 142a on one side (the right side in FIG. 5) of the axis L1 direction of the rotation shaft 131 of the roller 14, the distance to the axis L1 becoming shorter as it approaches the one side, and a second inclined portion 142b on the other side (the left side in FIG. 5) of the outer peripheral surface 141 of the roller 14 in the axis L1 direction of the rotation shaft 131 of the roller 14, the distance to the axis L1 becoming shorter as it approaches the other side. That is, the outer peripheral surface 141 of the roller 14 has a substantially V-shaped recess formed in a cross section along the rotation shaft 131 of the rotor 13. However, the first inclined portion 14 The inclination angle α of the first inclined portion 142a and the second inclined portion 142b is set to 2 to 6°, preferably 3 to 4°, as in the first embodiment. Note that the first inclined portion 142a and the second inclined portion 142b are not limited to a combination of straight lines in the cross section as in this embodiment, but may be a combination of concave curves in the cross section, so that the guide surface 142 as a whole is a concave curved surface in the cross section.

[0029] In this embodiment, too, the same effects as those described above for the first embodiment can be expected. That is, at the portion of elastic tube 12 that is clamped between guide surface 111 and outer peripheral surface 141 of roller 14, outer peripheral surface 141 of roller 14 has concave inclined portions 142a, 142b in cross section, so that the internal space of elastic tube 12 is not completely crushed, as shown in detail in Fig. 5, and a state is ensured in which the anesthetic liquid can circulate to some extent between before and after the clamped portion. Therefore, the residual pressure in elastic tube 12 at the moment when the liquid delivery state is switched from the liquid delivery ON state in which rotor 13 rotates to the liquid delivery OFF state in which rotor 13 stops rotating is alleviated, and the amount of excess liquid delivered from the discharge side of elastic tube 12 when liquid delivery is OFF can be reduced. Furthermore, in this embodiment, the outer peripheral surface 141 of the roller 14 has concave inclined portions 142a, 142b in cross section, and therefore, as in the first embodiment, a centering function is exerted that attempts to position the elastic tube 12 in the widthwise center of the guide surface 111 when the rotor 13 rotates, thereby preventing the occurrence of problems such as the elastic tube 12 accidentally falling off from the clamped state between the guide surface 111 and the roller 14 toward the rotation axis 131 of the rotor 13 while the pump mechanism 10 is operating.

[0030] FIG. 6 shows a main part of a tube pump A3 according to a third embodiment of the present invention, and corresponds to a cross section taken along line IV-IV in FIG.

[0031] As can be seen from FIG. 6 , in this embodiment, the outer peripheral surface 141 of the roller 14 is parallel to the axis L1 of the rotation shaft 131 of the rotor 13, while the guide surface 111 has an inclined portion 112 that extends across substantially the entire width of the rotor 13 in the direction of the axis L1. The inclination angle α of the inclined portion 112 gradually increases from one side (the right side in the figure) of the rotation shaft 131 to the other side (the left side in FIG. 6 ) in the axial direction of the rotation shaft 131. As in the above-described embodiments, the inclined portion 112 has an inclination angle α of 2 to 6°, preferably 3 to 4°. The inclined portion 112 may be formed to extend linearly in cross section as shown in the figure, or may be formed to extend in a concave or convex curve in cross section. In this embodiment, as shown in the figure, a downward flange 113 is formed on the edge of the guide surface 111 on the other side (the left side in FIG. 6 ) of the rotation shaft 131 to prevent the elastic tube 12 from falling off.

[0032] In this embodiment, too, the same effects as those described above for the first embodiment can be expected. That is, the portion of elastic tube 12 that is clamped between guide surface 111 and outer peripheral surface 141 of roller 14 has inclined portion 112 that is inclined in cross section on guide surface 111, so the internal space of elastic tube 12 is not completely crushed, and a state is ensured in which the anesthetic liquid can circulate to some extent between before and after the clamped portion. Therefore, the residual pressure in elastic tube 12 at the moment when the state switches from the liquid delivery ON state in which rotor 13 rotates to the liquid delivery OFF state in which rotor 13 stops rotating is alleviated, and the amount of excess liquid delivered from the discharge side of elastic tube 12 when liquid delivery OFF is turned off can be reduced.

[0033] Of course, the present invention is not limited to the above-described embodiments, and all modifications within the scope of the claims are included in the scope of the present invention.

[0034] In each of the above-described embodiments, either the guide surface 111 or the outer peripheral surface 141 of the roller 14 has the inclined portion 112, 142, but it is also possible to configure both the guide surface 111 and the outer peripheral surface 141 of the roller 14 to have the inclined portion 112, 142.

[0035] Furthermore, the tube pumps A1, A2, and A3 according to the above-described embodiments are configured to be used for TLA anesthesia administration, but the tube pump according to the present invention may be used for any purpose. [Explanation of symbols]

[0036] A1, A2, A3 tube pump α is the inclination angle (of the inclined portion 142) L1 axis (rotation axis 131) 10 Pump mechanism 11 Guide Block 111 Guide surface 112 Slope 112a 1st slope 112b 2nd slope 113 Downward flange 13 12 Elastic tube 121 Connection bush (supply side) 122 Connection bush (discharge side) 13 rotor 131 Rotation axis 132 Front flange 133 Rear flange 14 Laura 141 Outer surface 142 Slope 142a 1st slope 142b 2nd slope 143 Roller pin 15 Electric motor 20 Case 21 Opening and closing cover 22 Switches 23 Base plate 231 Standing up 30 Anesthetic liquid container 31 Infusion tube 40 Syringe needle 41 Infusion tube 50 Foot Pedal

Claims

1. A tube pump including a guide surface having an arcuate inner surface, an elastic tube arranged along the guide surface, and a rotor that rotates around a rotation axis that is the center position of the arc constituting the guide surface and has a plurality of rollers supported at equal intervals in the circumferential direction, wherein the rollers squeeze and deform the elastic tube between the guide surface and the rotor as the rotor rotates, A tube pump characterized in that the guide surface or the outer peripheral surface of the roller has an inclined portion that is inclined with respect to the axis of the rotation shaft in a cross section along the rotation shaft of the rotor.

2. 2. The tube pump according to claim 1, wherein the inclined portion is formed on the guide surface and includes a first inclined portion on one side of the guide surface in the axial direction of the rotation shaft, the distance to the axis becoming shorter as the guide surface moves toward that side, and a second inclined portion on the other side of the guide surface in the axial direction of the rotation shaft, the distance to the axis becoming shorter as the guide surface moves toward that other side.

3. 2. The tube pump according to claim 1, wherein the inclined portion is formed on the outer surface of the roller, and includes a first inclined portion on one side of the outer surface in the axial direction of the rotating shaft, the distance to the axis becoming shorter as the outer surface moves toward that side, and a second inclined portion on the other side of the outer surface in the axial direction of the rotating shaft, the distance to the axis becoming shorter as the outer surface moves toward that other side.

4. 2. The tube pump according to claim 1, wherein the inclination angle of the inclined portion is 2 to 6 degrees, preferably 3 to 4 degrees.

5. 5. A tube pump according to claim 1, wherein the inlet side of the elastic tube is connected to an anesthetic liquid container via an infusion tube, the outlet side of the elastic tube is connected to an injection needle via an infusion tube, and the rotation of the rotor is turned on and off by a foot pedal.

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