CN108025131B

CN108025131B - Infusion pump

Info

Publication number: CN108025131B
Application number: CN201680051831.9A
Authority: CN
Inventors: 林裕马
Original assignee: JMS Co Ltd
Current assignee: JMS Co Ltd
Priority date: 2015-09-11
Filing date: 2016-09-12
Publication date: 2021-07-30
Anticipated expiration: 2036-09-12
Also published as: KR20180048990A; KR102113934B1; CN108025131A; JPWO2017043093A1; WO2017043093A1; JP6773038B2

Abstract

The drive unit (40) moves the upstream occlusion member (31) and the downstream occlusion member (35) in the pressing direction to occlude the infusion tube (102), and then moves the pressing member (32) with a predetermined force in the pressing direction to increase the internal pressure of the infusion tube (102). Then, a predetermined amount of the pressing member (34) is moved in the pressing direction, and the downstream blocking member (35) is moved in the direction opposite to the pressing direction to open the downstream side of the infusion tube (102).

Description

Infusion pump

Technical Field

The present invention relates to an infusion pump for delivering a liquid medicine at a predetermined flow rate, and more particularly to the technical field of the structure of a pump mechanism.

Background

In general, in infusion therapy for infusing a medical fluid to a patient, an infusion pump that delivers a medical fluid at a predetermined flow rate set in advance is sometimes used. The infusion pump includes a main body including a pump mechanism configured to deliver the drug solution by pressing the tube, and a door provided to cover an infusion tube provided in the pump mechanism. The infusion of the liquid medicine is started by opening the door before use, setting the infusion tube in the pump mechanism and closing the door, and then operating the pump mechanism. On the other hand, after the liquid medicine is administered or when the infusion is interrupted, the infusion tube can be removed after the door is opened (see patent documents 1 and 2).

The pump mechanism in patent document 1 includes a plurality of finger-like members and a cam shaft. The finger-like members are arranged in this order from the upstream side to the downstream side of the infusion tube, and the tube is pressed by the finger-like members. Driving a finger with the camshaft. When the finger-shaped members are driven by the cam shaft, the cam shaft drives the finger-shaped members disposed on the most upstream side and the finger-shaped members disposed on the most downstream side, respectively, to ensure complete flattening of the infusion tube. On the other hand, the cam shaft drives the finger-like member on the most upstream side and the finger-like member on the most downstream side, respectively, so as to ensure that the infusion tube is not completely crushed. The widths of the finger-like members disposed on the most upstream side and the finger-like members disposed on the most downstream side are set to be wider than those of the other finger-like members.

In patent document 2, a pressurizing member for making the pressure in the infusion tube higher than the external air pressure is provided on the upstream side of the pump mechanism. The pump mechanism is comprised of a plurality of finger-like members and a cam. The pressing member is also composed of a plurality of finger-like members and a cam. The flow rate of the chemical liquid sent out by the pressurizing member is larger than the flow rate of the chemical liquid sent out by the pump mechanism.

Patent document 1: japanese patent publication No. 3595136

Patent document 2: japanese patent publication No. 5720193

Disclosure of Invention

Technical problems to be solved by the invention

In patent document 1, finger-like members for completely flattening the tube and finger-like members for not completely flattening the tube are provided, and the finger-like members for completely flattening the tube are made wider. Therefore, even if the infusion tube is expanded when collapsed, the occluded state of the infusion tube can be maintained.

However, in the case of using a pump mechanism including a finger-like member and delivering a drug solution by pressing the infusion tube, if the same portion of the infusion tube is pressed by the pump mechanism for a long time, the portion may be deteriorated and the elastic force may be reduced, which may make it difficult to return to the original shape.

In contrast, as in patent document 2, it is conceivable that the pressurizing member is provided on the upstream side of the pump mechanism, and the flow rate of the chemical solution sent out by the pressurizing member is larger than the flow rate of the chemical solution sent out by the pump mechanism, and that the infusion tube is easily returned to its original shape after that.

However, the pressing member, like the pump mechanism, includes a plurality of fingers and cams, and thus the pressing member and the pump mechanism are approximately the same size. Therefore, patent document 2 discloses a configuration in which two pump mechanisms are arranged in series in the longitudinal direction of the infusion tube. As a result, the infusion pump is difficult to be miniaturized.

The present invention has been made to solve the above problems. The purpose is as follows: the infusion pump can be miniaturized while compensating for the reduction of the restoring force caused by the deterioration of the infusion tube and delivering a liquid medicine at a predetermined flow rate.

Technical solution for solving technical problem

In order to achieve the above object, in the present invention, the medical fluid can be delivered at a predetermined flow rate by pressing the infusion tube with a predetermined force to increase the internal pressure of the infusion tube and pressing the infusion tube with a predetermined amount at the downstream side of the infusion tube.

A first aspect of the present invention is an infusion pump including a pump mechanism that pushes an infusion tube to deliver a liquid medicine in the infusion tube at a predetermined flow rate. The method is characterized in that: the pump mechanism includes: an upstream-side closing member, a downstream-side closing member, a pressing member, and a driving unit. The upstream occlusion member presses the infusion tube to completely occlude the infusion tube. The downstream blocking member is provided on the downstream side of the infusion tube apart from the upstream blocking member, and presses the infusion tube to completely block the infusion tube. The pressing member is disposed between the upstream occlusion member and the downstream occlusion member, and presses the infusion tube. The drive unit reciprocates the upstream occlusion member, the downstream occlusion member, and the pressing member in a pressing direction of the infusion tube and in a direction opposite to the pressing direction. The driving unit moves the upstream blocking member and the downstream blocking member in a pressing direction, then moves the pressing member in the pressing direction, and then moves the downstream blocking member in a direction opposite to the pressing direction.

According to this configuration, after the pump mechanism starts operating, the upstream occlusion member and the downstream occlusion member move in the pressing direction, and therefore the upstream portion and the downstream portion of the infusion tube are completely occluded by the upstream occlusion member and the downstream occlusion member, respectively. Thereafter, the pressing member is moved in the pressing direction. The internal pressure of the infusion tube can be increased by the pressing member. Thus, the reduction in the restoring force due to the deterioration of the infusion tube is compensated between the upstream occlusion member and the downstream occlusion member, and the infusion tube is restored to its original shape. As a result, the resulting flow rate will be accurate.

Thus, the mechanism for compensating for the decrease in the restoring force due to the deterioration of the infusion tube can be incorporated into the pump mechanism. Therefore, it is not necessary to provide a pressurizing member including a plurality of finger-like members and a cam as in patent document 2, in addition to the pump mechanism.

The invention of the second aspect is characterized in that: in the invention of the first aspect, the pressing means includes a prescribed-force pressing means and a prescribed-amount pressing means. The predetermined-force pressing member is disposed between the predetermined-force pressing member and the downstream occlusion member, and presses the infusion tube by a predetermined amount before the infusion tube is completely occluded by the predetermined force. The driving unit moves the upstream closing member and the downstream closing member in a pressing direction, then moves the predetermined-force pressing member in the pressing direction, and then moves the predetermined-force pressing member in the pressing direction and moves the downstream closing member in a direction opposite to the pressing direction.

According to this configuration, the upstream occlusion member and the downstream occlusion member move in the pressing direction, and the pressing member moves in the pressing direction after the upstream site and the downstream site of the infusion tube are completely occluded by the upstream occlusion member and the downstream occlusion member, respectively. Since the predetermined-force pressing member presses the infusion tube with a predetermined force, the internal pressure of the infusion tube can be increased between the upstream occlusion member and the downstream occlusion part by the pressing force until the infusion tube is completely occluded. Thus, the reduction in the restoring force due to the deterioration of the infusion tube is compensated between the upstream occlusion member and the downstream occlusion member, and the infusion tube is restored to its original shape. Then, after the predetermined amount of pressing member is moved in the pressing direction, the downstream blocking member is moved in the direction opposite to the pressing direction to open the downstream side of the infusion tube. Since the predetermined-amount pressing member presses the infusion tube by a predetermined amount, the amount of crush of the infusion tube becomes a predetermined amount. As a result, the resulting flow rate will be accurate.

The invention of the third aspect is characterized in that: in the second aspect of the present invention, the pump mechanism includes an intermediate blocking member located between the predetermined-force pressing member and the predetermined-amount pressing member, and the intermediate blocking member presses the infusion tube to completely block the infusion tube. The driving unit is configured to: the intermediate blocking member is driven to reciprocate in a pressing direction of the infusion tube and in a direction opposite to the pressing direction. The driving unit moves the intermediate closing member in the pressing direction after moving the predetermined-force pressing member in the pressing direction and before moving the predetermined-force pressing member in the pressing direction.

According to this configuration, before the predetermined amount pressing member is moved in the pressing direction, the upstream side of the infusion tube, which is upstream of the predetermined amount pressing member, is completely blocked by the intermediate blocking member. Therefore, the liquid medicine in the infusion tube can be prevented from escaping to the upstream side when the predetermined amount of pressing member is moved in the pressing direction, and the flow rate can be obtained more accurately.

The invention of the fourth aspect is characterized in that: in the third aspect of the invention, the driving unit moves the upstream closing member and the predetermined force pressing member in the direction opposite to the pressing direction after moving the intermediate closing member in the pressing direction.

According to this configuration, after the infusion tube is completely blocked by the intermediate blocking member, the upstream blocking member and the predetermined force pressing member are moved in the direction opposite to the pressing direction, and the medical fluid to be delivered next can be introduced into the upstream infusion tube upstream of the intermediate blocking member and stored therein. This enables the liquid chemical to be smoothly and continuously delivered.

The invention of the fifth aspect is characterized in that: in the invention according to any one of the first to fourth aspects, an elastic member that elastically deforms in the pressing direction is provided in the predetermined-force pressing member. The pressing force for pressing by the predetermined force pressing member is set by the elastic member.

According to this configuration, the pressing force of the pressing member can be easily set to a predetermined force by the elastic force of the elastic member.

Effects of the invention

According to the first aspect of the present invention, the internal pressure of the infusion tube can be increased after the infusion tube is completely occluded by moving the upstream occlusion member and the downstream occlusion member of the pump mechanism in the pressing direction. Thus, a decrease in the restoring force due to the deterioration of the infusion tube can be compensated for. Therefore, it is possible to compensate for the reduction in the restoring force due to the deterioration of the infusion tube and to deliver a predetermined flow rate of the liquid medicine without providing a pressurizing member including a plurality of finger-like members and a cam as in patent document 2 in addition to the pump mechanism, and thus it is possible to downsize the infusion pump.

According to the second aspect of the present invention, the predetermined amount of the pressing member is moved in the pressing direction, so that the liquid medicine can be delivered at an accurate flow rate by making the predetermined amount of the crushed liquid in the infusion tube.

According to the third aspect of the present invention, the infusion tube can be completely occluded by providing the intermediate occlusion member between the predetermined-force pressing member and the predetermined-amount pressing member, and moving the intermediate occlusion member in the pressing direction after moving the predetermined-force pressing member in the pressing direction and before moving the predetermined-amount pressing member in the pressing direction. Thus, the liquid medicine in the infusion tube can be prevented from escaping to the upstream side when the predetermined amount of pressing member is moved in the pressing direction, and the flow rate can be obtained more accurately.

According to the fourth aspect of the invention, after the infusion tube is completely occluded by the intermediate occlusion member, the upstream occlusion member and the predetermined force pressing member can be moved in the direction opposite to the pressing direction. In this way, the liquid chemical to be subsequently dispensed can be introduced into the upstream side transfusion tube upstream of the intermediate blocking member and stored therein. Therefore, the liquid medicine can be smoothly and continuously delivered.

According to the fifth aspect of the present invention, the predetermined force can be set by the elastic member provided in the predetermined force pressing member, and therefore, the structure can be simplified.

Drawings

Fig. 1 is a perspective view of an infusion pump according to an embodiment as viewed from below.

Fig. 2 is a schematic view of an infusion set.

Fig. 3 is a view equivalent to fig. 1 showing a state after the door is in the open position.

Fig. 4 is a diagram showing the operating condition of the pump mechanism.

Fig. 5 is a sectional view taken along line V-V in fig. 6.

Fig. 6 is a schematic diagram for explaining the operation of the pump mechanism in the downstream side clogging step (a of fig. 4).

Fig. 7 is a schematic diagram for explaining the operation of the pump mechanism in the upstream side clogging step (B of fig. 4).

Fig. 8 is a schematic configuration diagram for explaining an operation state of the pump mechanism in the predetermined-force pressing step (C in fig. 4).

Fig. 9 is a schematic diagram for explaining the operation of the pump mechanism in the intermediate portion clogging step (D in fig. 4).

Fig. 10 is a schematic diagram illustrating an operation of the pump mechanism in the liquid feeding step (E in fig. 4).

Fig. 11 is a schematic configuration diagram for explaining the operation of the pump mechanism in the chemical solution storage step (F in fig. 4).

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following preferred embodiments are merely examples to explain the present invention in nature, and are not intended to limit the present invention, its application, or uses.

Fig. 1 shows an infusion pump 1 according to an embodiment of the present invention. The infusion pump 1 is a medical device used for infusion treatment by an infusion set 100 (shown in fig. 2) for medical institutions, and includes a main body 10 and a door 20. In this embodiment, the infusion set 100 will be described before the infusion pump 1 is described.

As shown in fig. 2, the infusion set 100 includes: a transfusion bag 101 for storing various kinds of medical liquids to be transfused to a patient, a transfusion tube 102 extending from the transfusion bag 101, a drip tube 103 provided in the middle of the transfusion tube 102, and a puncture needle 104 provided at the distal end portion of the transfusion tube 102. The infusion tube 102 is made of a known resin material having toughness and capable of elastic deformation. A roller clamp 105 is provided between the drip tube 103 and the puncture needle 104 of the infusion tube 102. The roller clamp 105, also called a pincer, is a structure well known in the art, and a detailed description thereof is omitted here.

(Structure of body portion)

As shown in fig. 3, a pump mechanism 30 is provided on the front surface 11 of the main body 10 of the infusion pump 1 in the vicinity of a substantially central portion in the vertical direction. As will be described in detail later, the pump mechanism 30 is constituted by: the medical fluid in the infusion tube 102 can be delivered at a predetermined flow rate by pressing the infusion tube 102.

A hose fitting groove 13 into which the liquid supply tube 102 is fitted is formed in the front surface 11 of the main body 10. The hose fitting groove 13 extends in the vertical direction in the vicinity of the substantially central portion of the main body 10 in the lateral direction. The upper end of the hose fitting groove 13 is open on the upper surface of the main body 10, and the lower end of the hose fitting groove 13 is open on the lower surface of the main body 10. Therefore, the infusion tube 102 fitted into the hose fitting groove 13 extends from the upper surface and the lower surface of the main body 10. Since the pump mechanism 30 is located at the middle portion in the vertical direction of the hose fitting groove 13, the infusion tube 102 fitted into the hose fitting groove 13 is disposed on the pump mechanism 30.

In the description of the embodiment, the vertical direction of the infusion pump 1 is the vertical direction in fig. 1 and 3, and the horizontal direction of the infusion pump 1 is the horizontal direction in fig. 1 and 3, but the state of the infusion pump 1 when in use may not be the state shown in fig. 1 and 3. For example, when the infusion pump 1 is used, the front surface 11 of the infusion pump 1 can be made substantially horizontal. In this case, the front surface 11 is an upper surface of the body portion 10.

(Structure of door)

Next, the structure of the door 20 will be described. The door 20 is formed in a size that can cover substantially the entire front surface 11 of the body portion 10 from the front. The left edge of the door 20 is attached to the main body 10 via a hinge (not shown) having a pivot shaft extending in the vertical direction, and the left edge of the door 20 is pivoted about the pivot shaft, whereby the door 20 can be switched between a closed position (shown in fig. 1) and an open position (shown in fig. 3). In the closed position, the portion of the infusion tube 102 disposed within the pump mechanism 30 is covered; in the open position, the portion of the infusion tube 102 disposed within the pump mechanism 30 is exposed.

The door 20 may be large enough to cover only the portion of the infusion tube 102 that is pressed by the pump mechanism 30. The opening and closing direction of the door 20 may be any direction.

As shown in fig. 5 and the like, when the door 20 is in the closed position, the inner surface of the door 20 supports a portion of the infusion tube 102 disposed at the pump mechanism 30 and presses the portion from the front. Thus, the pressing force of the pump mechanism 30 is not released, and can be transmitted to the infusion tube 102 to deform the infusion tube 102 sufficiently. As shown in fig. 1, the door 20 is provided with an opening/closing lever 21, and the door 20 can be opened or closed by operating the opening/closing lever 21.

(Structure of Pump mechanism)

Next, the structure of the pump mechanism 30 will be described. The pump mechanism 30 is a finger pump mechanism that delivers the liquid medicine by reciprocating a plurality of finger-like members. That is, as shown in fig. 6, the pump mechanism 30 includes: an upstream closing member 31, a predetermined force pressing member 32, an intermediate closing member 33, a predetermined force pressing member 34, a downstream closing member 35, and a driving unit 40 for driving these members 31 to 35. The upstream closing member 31, the predetermined force pressing member 32, the intermediate closing member 33, the predetermined force pressing member 34, and the downstream closing member 35 are finger-like members. As shown in fig. 3, these members are housed in a frame-shaped member 38 that is long in the vertical direction and are independently movable in the front-rear direction of the infusion pump 1 (the pressing direction of the infusion tube 102). The frame-like member 38 is attached to the main body 10 so as to be detachable at any time, and the frame-like member 38 can be easily repaired or the like.

The upstream occlusion member 31 is disposed above the frame-like member 38, and presses the infusion tube 102 to completely occlude the infusion tube 102. The distal end surface of the upstream occlusion member 31 is a pressing surface that presses the outer surface of the infusion tube 102. As shown in fig. 5, a roller 31a is provided at the rear end of the upstream blocking member 31, and the roller 31a is rotatable about a support shaft 31b extending in the vertical direction. The support shaft 31b is attached to a rear end of the upstream closing member 31 via a stay, not shown.

As shown in fig. 6, the downstream blocking member 35 is disposed below the frame-like member 38 away from the upstream blocking member 31 toward the downstream side of the infusion tube 102. The downstream occlusion member 35 is used to press the infusion tube 102 to completely occlude the infusion tube 102, as with the upstream occlusion member 31. The downstream closing member 35 has the same structure as the upstream closing member 31, and has a roller 35a at a rear end portion.

The predetermined force pressing member 32 is disposed between the upstream occlusion member 31 and the downstream occlusion member 35, and presses the infusion tube 102 with a predetermined force until the infusion tube is completely occluded. The width of the distal end surface (pressing surface) of the predetermined force pressing member 32 is set to be equal to the width of the upstream closing member 31. On the other hand, the dimension of the infusion tube 102 positioned on the distal end surface of the predetermined force pressing member 32 in the longitudinal direction is set to be longer than the dimension of the upstream occlusion member 31 in the same direction. Therefore, the range in which the infusion tube 102 is pressed by the predetermined-force pressing member 32 is increased.

The predetermined force pressing member 32 is provided with

springs

32c, 32c for elastic members that elastically deform in the pressing direction, and the pressing force with which the predetermined force pressing member 32 presses the infusion tube 102 is set by these

springs

32c, 32 c. One end portions (front end portions) of the

springs

32c, 32c are fixed to the rear side of the prescribed-force pressing member 32, and are arranged so as to ensure that the contracting direction is the moving direction of the prescribed-force pressing member 32. A plate member 32d is fixed to the other end (rear end) of the

springs

32c, 32 c. The roller 32a is held in contact with the sheet 32 d. With such a configuration, even when the roller 32a is moved by a predetermined amount in the pressing direction of the infusion tube 102, the

springs

32c and 32c contact the infusion tube 102 with the distal end surface of the pressing member 32 by a predetermined force, and contract by receiving the reaction force from the infusion tube 102. Thus, the amount of movement of the distal end surface of the predetermined force pressing member 32 is limited, and the amount of movement of the distal end surface of the predetermined force pressing member 32 is smaller than the amount of movement of the roller 32 a. Instead of the spring 32c, for example, rubber may be provided, or both the spring 32c and rubber may be provided.

The predetermined amount pressing member 34 is disposed between the predetermined force pressing member 32 and the downstream blocking member 35, and presses the infusion tube 102 by a predetermined amount. In this embodiment, the predetermined amount of pressing member 34 is moved to ensure that the infusion tube 102 is pressed until it is completely occluded. The predetermined-amount pressing member 34 has substantially the same configuration as the upstream-side occluding member 31, and the dimension of the infusion tube 102 positioned on the distal end surface of the predetermined-amount pressing member 34 in the longitudinal direction is set to be longer than the dimension of the upstream-side occluding member 31 in the same direction. Therefore, the range in which the infusion tube 102 is pressed by the predetermined-force pressing member 32 is increased. The predetermined-amount pressing unit 34 also includes a roller 34 a.

The intermediate blocking member 33 is disposed between the predetermined force pressing member 32 and the predetermined amount pressing member 34, and presses the infusion tube 102 to completely block the infusion tube 102. The intermediate closing member 33 has the same structure as the upstream closing member 31, and as shown in fig. 6, a roller 33a is provided at the rear end of the intermediate closing member 33.

The driving unit 40 is configured to drive the upstream occlusion member 31, the predetermined force pressing member 32, the intermediate occlusion member 33, the predetermined force pressing member 34, and the downstream occlusion member 35 so as to reciprocate these members in a pressing direction (forward) of the infusion tube 102 and in a direction opposite to the pressing direction (backward). The driving section 40 includes a motor 41, a drive shaft 42 driven by the motor 41 to rotate, and first to fifth cam plates 43 to 47. The drive shaft 42 extends in the vertical direction, which is the arrangement direction of the upstream closing member 31, the predetermined force pressing member 32, the intermediate closing member 33, the predetermined force pressing member 34, and the downstream closing member 35. An output shaft of the motor 41 is coupled to an end of the drive shaft 42. The motor 41 is controlled by a control device (not shown) incorporated in the main body 10, and the rotation speed of the motor 41 is switched between a stop and a rotation or changed.

The first to fifth cam plates 43 to 47 are fixed to the drive shaft 42 and rotate by the same amount when the drive shaft 42 is driven. The first cam plate 43 is a cam plate that drives the upstream blocking member 31, and the roller 31a of the upstream blocking member 31 is held in contact with the outer peripheral surface of the first cam plate 43. The position of the upstream side blocking member 31 in the front-rear direction is changed by the shape of the outer peripheral surface of the first cam plate 43. Although not shown, the urging member constantly urges the upstream blocking member 31 in a direction approaching the first cam plate 43, and the roller 31a of the upstream blocking member 31 constantly keeps in contact with the outer peripheral surface of the first cam plate 43.

The roller 32a of the predetermined force pressing member 32 is held in contact with the outer peripheral surface of the second cam plate 44. The position of the prescribed-force pressing member 32 in the front-rear direction is changed by the shape of the outer peripheral surface of the second cam plate 44. Although not shown, the biasing member biases the predetermined force pressing member 32 in a direction to approach the second cam plate 44, and the roller 32a of the predetermined force pressing member 32 is kept in contact with the outer peripheral surface of the second cam plate 44.

The roller 33a of the intermediate blocking member 33 is held in contact with the outer peripheral surface of the third cam plate 45. The position of the intermediate blocking member 33 in the front-rear direction is changed by the shape of the outer peripheral surface of the third cam plate 45. Although not shown, the urging member constantly urges the intermediate closing member 33 in a direction to approach the third cam plate 45, and the roller 33a of the intermediate closing member 33 constantly keeps in contact with the outer peripheral surface of the third cam plate 45.

The roller 34a of the predetermined amount pressing member 34 is held in contact with the outer peripheral surface of the fourth cam plate 46. The position of the prescribed amount pressing member 34 in the front-rear direction is changed by the shape of the outer peripheral surface of the fourth cam plate 46. Although not shown, the urging member constantly urges the predetermined-amount pressing member 34 in a direction approaching the fourth cam plate 46, and the roller 34a of the predetermined-amount pressing member 34 constantly keeps in contact with the outer peripheral surface of the fourth cam plate 46.

The roller 35a of the downstream side blocking member 35 is held in contact with the outer peripheral surface of the fifth cam plate 47. The position of the downstream-side blocking member 35 in the front-rear direction is changed by the shape of the outer peripheral surface of the fifth cam plate 47. Although not shown, the urging member constantly urges the downstream blocking member 35 in a direction approaching the fifth cam plate 47, and the roller 35a of the downstream blocking member 35 constantly keeps in contact with the outer peripheral surface of the fifth cam plate 47.

The shapes of the outer peripheral surfaces of the first to fifth cam plates 43 to 47 are set so that the upstream closing member 31, the predetermined force pressing member 32, the intermediate closing member 33, the predetermined force pressing member 34, and the downstream closing member 35 can be moved at different timings, and the following steps are sequentially performed.

(downstream side clogging step)

The downstream side occlusion step shown in fig. 4a and 6 is a step of completely occluding the downstream side of the portion of the infusion tube 102 disposed on the pump mechanism 30. In this step, the upstream closing member 31, the predetermined force pressing member 32, the intermediate closing member 33, and the predetermined force pressing member 34 are moved to the side opposite to the pressing side, and the downstream closing member 35 is moved in the pressing direction. The downstream side of the infusion tube 102 is thereby completely occluded.

(upstream side clogging step)

The upstream side occlusion step shown in fig. 4B and 7 is a step of completely occluding the upstream side of the portion of the infusion tube 102 disposed on the pump mechanism 30. In this step, the predetermined-force pressing member 32, the intermediate closing member 33, and the predetermined-amount pressing member 34 are moved to the side opposite to the pressing side, and the upstream closing member 31 is moved to the pressing direction, while keeping the state where the downstream closing member 35 is moved in the pressing direction. The downstream side of the infusion tube 102 is thereby completely occluded.

(prescribed force pressing step)

The predetermined-force pressing step shown in fig. 4C and 8 is a step of pressing a portion of the infusion tube 102 between the portion blocked by the upstream-side blocking member 31 and the portion blocked by the downstream-side blocking member 35 with the predetermined-force pressing member 32. In this step, the intermediate closing member 33 and the predetermined amount pressing member 34 are moved to the side opposite to the pressing side, and the upstream closing member 31 and the downstream closing member 35 are moved to the pressing direction, and in this state, the predetermined force pressing member 32 is moved to the pressing direction. Thus, the infusion tube 102 is pressed by the distal end surface of the predetermined force pressing member 32, and the

springs

32c and 32c contract. The amount of movement of the second cam plate 44 to move the predetermined-force pressing member 32 is set to ensure that the predetermined-force pressing member 32 stops before the infusion tube 102 is completely occluded.

The pressing step with the predetermined force can increase the internal pressure of the infusion tube 102. In this way, the reduction in the restoring force due to the deterioration of the infusion tube 102 between the upstream occlusion member 31 and the downstream occlusion member 35 is compensated, and the infusion tube 102 is restored to its original shape, so that the amount of the liquid medicine in the downstream infusion tube 102 is always a constant amount downstream of the predetermined force pressing member 32.

In the predetermined-force pressing step, the predetermined-force pressing member 32 is stopped before the infusion tube 102 is completely occluded. Therefore, the load imposed on the infusion tube 102 can be reduced, and degradation can be suppressed.

(intermediate portion clogging step)

The intermediate portion occlusion step shown in fig. 4D and 9 is a step of completely occluding the infusion tube 102 on the downstream side of the predetermined force pressing member 32. In this step, the intermediate closing member 33 is moved in the pressing direction while maintaining the state in which the predetermined amount pressing member 34 is moved in the opposite direction to the pressing direction and the upstream closing member 31, the downstream closing member 35, and the predetermined force pressing member 32 are moved in the pressing direction. The infusion tube 102 is completely blocked at the downstream side of the predetermined force pressing member 32.

(liquid feeding step)

The liquid feeding step shown in fig. 4E and 10 is a step of feeding the liquid chemical on the downstream side of the portion of the infusion tube 102 blocked by the intermediate blocking member 33. In this step, the upstream side closing member 31 and the predetermined force pressing member 32 are moved in the direction opposite to the pressing direction while maintaining the state in which the intermediate closing member 33 is moved in the pressing direction. Then, the predetermined amount pressing member 34 is moved in the pressing direction, and at the same time, the downstream blocking member 35 is moved in the direction opposite to the pressing direction to open the downstream side of the infusion tube 102. When the predetermined amount pressing member 34 is moved in the pressing direction, the infusion tube 102 is pressed, and the medical fluid inside is delivered. At this time, the predetermined amount of the pressing member 34 is moved in the pressing direction until the infusion tube 102 is completely closed, and thus the amount of the chemical solution to be delivered can be constant. By moving the upstream occlusion member 31 and the predetermined force pressing member 32 in the direction opposite to the pressing direction, the liquid chemical to be subsequently delivered can be caused to flow into the upstream infusion tube 102 upstream of the intermediate occlusion member 33 and be stored therein.

In the liquid feeding step, the predetermined amount pressing member 34 and the downstream blocking member 35 may be moved simultaneously, but the present invention is not limited thereto, and one of the predetermined amount pressing member 34 and the downstream blocking member 35 may be moved at a timing earlier than the other.

(liquid medicine storage step)

In the chemical solution storing step shown in fig. 4F and 11, the downstream closing member 35 is moved in the pressing direction while maintaining the state in which the upstream closing member 31 and the predetermined force pressing member 32 are moved in the direction opposite to the pressing direction and the intermediate closing member 33 and the predetermined force pressing member 34 are moved in the pressing direction. In this way, since the downstream side of the infusion tube 102 is completely blocked, the medical fluid can be stored in the upstream side of the infusion tube 102 from the downstream blocking member 35.

After the chemical solution reserving step, the downstream side blocking step is performed by moving the intermediate blocking member 33 and the predetermined amount pressing member 34 in a direction opposite to the pressing direction. By changing the rotational speed of the drive shaft 42 of the drive unit 40, the flow rate of the chemical liquid can be changed.

(action and Effect of the embodiment)

As described above, according to the infusion pump 1 of the present embodiment, the internal pressure of the infusion tube 102 can be increased by moving the upstream blocking member 31 and the downstream blocking member 35 of the pump mechanism 30 in the pressing direction to completely block the infusion tube 102 and then moving the predetermined-force pressing member 32 in the pressing direction. Thus, the shape of the infusion tube 102 can be restored by compensating for the decrease in the restoring force due to the deterioration of the infusion tube 102.

By moving the downstream blocking member 35 in the direction opposite to the pressing direction and moving the predetermined amount pressing member 34 in the pressing direction, the liquid medicine can be delivered at an accurate flow rate with the amount of squashed the infusion tube 102 being a predetermined amount.

Therefore, it is possible to compensate for a decrease in the restoring force due to the deterioration of the infusion tube 102 and to deliver a predetermined flow rate of the medical fluid without providing a pressurizing member including a plurality of finger-like members and a cam as in patent document 2 in addition to the pump mechanism 30. Therefore, the infusion pump can be miniaturized.

The infusion tube 102 can be completely occluded by providing the intermediate occlusion member 33 between the predetermined-force pressing member 32 and the predetermined-amount pressing member 34, and moving the intermediate occlusion member 33 in the pressing direction after moving the predetermined-force pressing member 32 in the pressing direction and before moving the predetermined-amount pressing member 34 in the pressing direction. Thus, the liquid medicine in the infusion tube 102 can be prevented from escaping to the upstream side when the predetermined amount of the pressing member 34 is moved in the pressing direction, and the obtained flow rate can be more accurate.

The intermediate closing member 33 can be omitted. In this case, the elastic force of the elastic member may be set so as not to move the predetermined-force pressing member 32 backward, or the predetermined-force pressing member 34 may be moved in the pressing direction by locking the predetermined-force pressing member 32 by a known locking mechanism.

After the infusion tube 102 is completely occluded by the intermediate occlusion member 33, the upstream occlusion member 31 and the predetermined force pressing member 32 can be moved in the direction opposite to the pressing direction. Thus, the medical fluid to be delivered next can be introduced and stored in the upstream side of the infusion tube 102 from the intermediate blocking member 33. Therefore, the liquid medicine can be smoothly and continuously delivered.

The predetermined-force pressing member 32 and the intermediate blocking member 33 can be simultaneously moved in the pressing direction of the infusion tube 102.

A stroke amount detection sensor (not shown) for detecting the stroke amount of the predetermined force pressing member 32 (the pressing amount of the infusion tube 102) may be provided. That is, when the stroke amount of the predetermined force pressing member 32 is detected as a stroke amount for completely blocking the infusion tube 102 after the infusion tube 102 is pressed by the predetermined force pressing member 32, it is possible to determine that the infusion tube 102 is in an abnormal state (for example, the infusion tube 102 is excessively collapsed, and medical fluid leaks due to a defective blocking on the upstream side or the downstream side). When the stroke amount of the predetermined force pressing member 32 is larger than the stroke amount for completely blocking the infusion tube 102, it can be determined that the infusion tube 102 has not been placed yet. That is, by detecting the stroke amount of the predetermined force pressing member 32, the presence or absence of the infusion tube 102 can be detected.

In the above embodiment, the predetermined force pressing member 32 and the predetermined amount pressing member 34 are provided, but the present invention is not limited thereto, and either one of them may be omitted. By pressing the infusion tube 102 in the occluded state with the predetermined-force pressing member 32 and the predetermined-amount pressing member 34, it is possible to compensate for a decrease in the restoring force due to deterioration of the infusion tube 102 and restore the shape of the infusion tube 102.

The above embodiments are merely examples in all respects and should not be construed as limiting. Furthermore, all changes and modifications that fall within the scope of the appended claims are intended to be embraced therein.

Industrial applicability-

As described above, the infusion pump according to the present invention can be used, for example, when a medical solution is administered to a patient.

-description of symbols-

1 infusion pump

10 body part

20 door

30 pump mechanism

31 upstream side blocking member

32 specified force pressing member

32c spring (elastic component)

33 intermediate closing member

34 specified amount pressing member

35 downstream side blocking member

40 drive part

102 infusion tube

Claims

1. An infusion pump comprising a pump mechanism for pushing an infusion tube to deliver a liquid medicine in the infusion tube at a predetermined flow rate, characterized in that:

the pump mechanism includes: an upstream side blocking member, a downstream side blocking member, a first pressing member and a second pressing member, and a driving section,

the upstream occlusion member presses the infusion tube to completely occlude the infusion tube,

the downstream blocking member is provided on the downstream side of the infusion tube apart from the upstream blocking member, and presses the infusion tube to completely block the infusion tube,

the first pressing member and the second pressing member are disposed between the upstream occlusion member and the downstream occlusion member, and press the infusion tube,

the first pressing member is a predetermined force pressing member which presses the infusion tube with a predetermined force until the infusion tube is completely occluded,

the second pressing member is a predetermined amount pressing member that is disposed between the predetermined force pressing member and the downstream occlusion member and presses the infusion tube by a predetermined amount,

the drive unit reciprocates the upstream occlusion member, the downstream occlusion member, and the first and second pressing members in a pressing direction of the infusion tube and in a direction opposite to the pressing direction,

the driving unit moves the upstream closing member and the downstream closing member in a pressing direction, then moves the first pressing member in the pressing direction, and then moves the second pressing member in the pressing direction and moves the downstream closing member in a direction opposite to the pressing direction.

2. The infusion pump of claim 1, wherein:

the pump mechanism includes an intermediate blocking member located between the predetermined force pressing member and the predetermined amount pressing member, the intermediate blocking member presses the infusion tube to completely block the infusion tube,

the driving unit is configured to: driving the intermediate blocking member to reciprocate in a pressing direction of the infusion tube and in a direction opposite to the pressing direction,

the driving unit moves the intermediate closing member in the pressing direction after moving the predetermined-force pressing member in the pressing direction and before moving the predetermined-force pressing member in the pressing direction.

3. The infusion pump of claim 2, wherein:

the driving unit moves the upstream closing member and the predetermined force pressing member in a direction opposite to the pressing direction after moving the intermediate closing member in the pressing direction.

4. The infusion pump according to any one of claims 1 to 3, wherein:

an elastic member elastically deformed in a pressing direction is provided to the predetermined force pressing member,

the pressing force for pressing by the predetermined force pressing member is set by the elastic member.