JP2762861B2 - Infusion pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called peristaltic infusion pump, and more particularly to an infusion pump provided with a detection mechanism for detecting a blocked state of a tube.

[0002]

2. Description of the Related Art Conventionally, as a peristaltic infusion pump, for example, a rotating shaft rotatably supported in a casing, a plurality of cam members provided on an outer peripheral portion of the rotating shaft, and interlocking with these cam members A plurality of fingers that move forward and backward in the radial direction of the rotation shaft to press the flexible tube, and a detection mechanism that detects the closed state of the tube, and the detection mechanism is A detection unit that can be displaced in the radial direction of the rotating shaft in accordance with a change in the amount of bulging of the tube, and a detection unit that detects the amount of displacement of the detection unit; Is known that feeds liquid from the downstream side (for example, see
-205060). In the infusion pump disclosed in the above publication, apart from the plurality of fingers, a plate-shaped member as a detected portion is arranged at a central position where the plurality of fingers are arranged, and this plate-shaped member is connected to a tube by a spring. I try to make it abut. Further, a magnet is buried in the other end of the plate member, and a Hall element as a detection unit is provided at a position facing the magnet. Since the swelling amount of the tube fluctuates according to the fluctuation of the liquid pressure in the tube, the fluctuation amount is detected by the Hall element as the displacement amount of the plate-like member. As a result, when the tube is closed, the bulging amount of the tube, that is, the displacement amount of the plate-like member becomes larger than when the tube is closed, so that it is possible to detect that the tube is closed.

[0003]

However, in the above-mentioned conventional infusion pump, since the fingers exist at positions vertically adjacent to the plate-like member as the detection target, the amount of swelling of the tube at the time of normal and at the time of blockage is increased. Was detected as the amount of displacement between the plate member and the finger at the upper and lower adjacent positions in the forward and backward directions, and therefore, the displacement amount of the plate member between normal time and when the tube was closed was small. . In addition, since the detection of the displacement of the plate-like member is detected as the relative displacement in the direction of reciprocation with the finger at the upper and lower adjacent positions, the detection of the closed state of the tube tends to be delayed. Therefore, such a conventional device has a disadvantage that the detection accuracy by the detection mechanism is deteriorated.

[0004]

[Means for Solving the Problems] In view of such circumstances,
The present invention provides a rotating shaft rotatably supported in a casing, a plurality of cam members provided on an outer peripheral portion of the rotating shaft, and advancing and retreating in the radial direction of the rotating shaft in conjunction with each of the cam members. The system includes a plurality of fingers for pressing a flexible tube and a detection mechanism for detecting a closed state of the tube. The detection mechanism is brought into contact with the tube and rotated according to a change in the amount of swelling of the tube. An infusion configured to include a detected part that can be displaced in the radial direction of the shaft and a detection part that detects the amount of displacement of the detected part, and feeds the liquid from the upstream side to the downstream side through the tube. In the pump, a drive unit that engages the one of the fingers with the cam member and moves forward and backward in the radial direction of the rotation shaft;
A main body portion that is provided to be able to advance and retreat in the radial direction of the rotation shaft and abuts on the tube, and is elastically mounted over the drive portion and the main body portion so that the drive portion and the main body portion are separated from each other. And a biasing spring, and the main body is also used as a detected part of the detection mechanism.

[0005]

According to such a configuration, the displacement of the main body as the detected portion is detected by the detecting portion of the detecting mechanism while performing the original pump operation. For this reason, it is possible to detect a minute change in the bulging amount of the tube between the normal time and the time when the tube is closed, and to immediately detect the closed state of the tube. Therefore, the detection accuracy of the detection mechanism can be improved as compared with the above-described conventional case.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a peristaltic infusion pump according to the present invention. The infusion pump 1 includes a box-shaped casing 2, and a left surface of the casing 2 is open. The opening on the left side of the casing 2 is closed by a lid 3 urged rightward by a spring.
The flexible tube 4 is held at the center of the right end face in the above. A pair of bearings 5, 5 ′ are attached to upper and lower positions in the casing 2, and the pair of bearings 5, 5 ′ rotatably support a rotating shaft 6 oriented in the vertical direction. A plurality of cam members 7 are provided at predetermined intervals in the axial direction of the outer peripheral portion of the rotary shaft 6, and each of the cam members 7 has a finger F1 to F
11 are engaged with each other. The rotating shaft 6
Are linked to a motor (not shown). When the motor is rotated in one direction, the rotating shaft 6 is rotated clockwise in FIG. The fingers F1 to F11 are moved forward and backward in the radial direction of the rotating shaft 6. At this time, the fingers F1 to F11 are sequentially arranged from the most upstream finger F1 to the downstream fingers F2 to F11.
Are moved back and forth, so that each finger F1
The tube 4 is successively pressed from the upstream side to the downstream side by the front end of F11. Thereby, the infusion pump 1 is connected via the tube 4.
The liquid in a container (not shown) provided on the upstream side (upper side) can be supplied to the downstream side (lower side) of the infusion pump 1.

In this embodiment, the casing 2
A detection mechanism 10 for detecting the closed state of the tube 4 is provided at the lower end of the inside. The detection mechanism 10 includes a main body Fb of the finger F11 located at the most downstream side (lower side).
Is also used as the detected part. A magnet 11 is buried in the right end of the main body Fb, and a casing 2 facing the magnet 11 is provided.
A Hall element 12 as a detection unit is attached to the lower side of the. As shown in FIG. 2, the main body portion Fb of the finger F11 as the detected portion is formed with the above-mentioned engagement recessed portion Fa, and a stepped hole Fc is formed in the left end surface of the engagement recessed portion Fa. ing. And this stepped hole Fc
An engaging member 13 having a T-shaped cross section is slidably fitted therein, and a spring 14 is elastically mounted between the engaging member 13 and the bottom of the stepped hole Fc. The spring 14 urges the engaging member 13 and the main body Fb in a direction away from each other, so that the distal end surface of the engaging member 13 is pressed against the cam member 7. In this embodiment, the spring 1
As 4, the elasticity of the tube 4 is slightly stronger than that of the tube 4.
We adopt what we have. With this configuration, in a normal state in which the tube 4 shown in FIG. 2 is not closed, the cam surface of the cam member 7 comes into pressure contact with the distal end surface of the engaging member 13 and at the same time, engages with the engaging member 13. Is engaged with the right end surface of the engagement recessed portion Fa on the opposite side to the position of the right side. In this normal state, since the fluid pressure in the tube 4 is low, the tube 4 is crushed in the radial direction by the tip of the main body Fb of the finger F11 that pressed the tube 4.

On the other hand, when the tube 4 is closed for some reason, the fluid pressure in the tube 4 increases, so that the amount of collapse of the tube 4 due to the tip of the main body Fb is the same as that in the normal case. It becomes smaller than the case. That is, when the tube 4 is closed, the amount of swelling of the tube 4 increases as compared with a normal state. At this time, since the spring 14 is compressed, the main body portion Fb as the detecting portion is moved with respect to the cam member 7 and the engaging member 13.
It will be relatively moved toward the right side of FIG. The fluctuation of the swelling amount of the tube 4 between the normal state and the closed state of the tube 4 appears as a fluctuation in the distance between the magnet 11 provided in the main body portion Fb and the Hall element 12, and is detected by the Hall element 12. Magnet 11
In a case where the distance between the tube 4 and the Hall element 12 is shorter than a predetermined distance, it is possible to detect that the tube 4 is in a closed state. As described above, in the present embodiment, since the main body portion Fb of the finger F11 located at the most downstream side is also used as the detected portion of the detection mechanism 10, the normal state in which the tube 4 is not closed and the tube 4 Is compared with the state in which the finger F1 is closed.
The displacement amount of No. 1 is larger than that of the related art. That is, in the related art, since the plate-shaped member as the detection target is provided at the center position where the fingers are arranged, the fingers are present at positions vertically adjacent to the plate-shaped member. Therefore, the tube 4 when comparing the normal state and the tube 4 closed state
The fluctuation of the bulging amount of the plate member is small, and the displacement amount of the plate-shaped member as the detected portion is small. Therefore, such a conventional device has a disadvantage that the detection accuracy by the detection mechanism is deteriorated.

[0009] In contrast to such a conventional technique, in the present embodiment, there is no other finger at a downstream position adjacent to the main body portion Fb as a portion to be detected. The variation in the amount of bulging of the tube 4 becomes large, and as a result, the
It is easy to detect the amount of displacement. Moreover, the main body portion Fb as the detected portion performs the original pump operation,
Since the displacement amount is detected by the Hall element 12,
The closed state of the tube can be immediately detected based on the displacement amount of the main body Fb. Therefore, the detection accuracy of the detection mechanism 10 when detecting the closed state of the tube 4 can be improved as compared with the above-described conventional case. Further, in this embodiment, since the main body portion Fb of the finger F11 is also used as the detected portion of the detection mechanism 10, a plate-shaped member as the detected portion is provided separately from the original finger as in the conventional case. As compared with the conventional one, the casing can be downsized, and the infusion pump can be downsized. In the above-described embodiment, the finger F11 on the most downstream side is set as the detected part of the detection mechanism 10, but any of the other fingers F1-F10 is replaced with the finger F11.
11 and may be used also as a detected part of the detection mechanism 10.

[0010]

As described above, according to the present invention, the effect that the detection accuracy of the detection mechanism can be improved as compared with the related art is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Infusion pump 2 Casing 4 Tube 6 Rotating shaft 7 Cam member 10 Detection mechanism 12 Hall element (detection part) 13 Engagement member (drive part) 14 Spring F1-F11 Finger Fb Main body part of finger F11 at the most downstream side (detected) Part)

Claims (1)

(57) [Claims] A rotary shaft rotatably supported in a casing; a plurality of cam members provided on an outer peripheral portion of the rotary shaft;
A plurality of fingers that move forward and backward in the radial direction of the rotating shaft in association with each of the cam members to press the flexible tube, and a detection mechanism that detects a closed state of the tube; A detection unit that can be displaced in the radial direction of the rotating shaft in accordance with a change in the bulging amount of the tube in contact with the tube, and a detection unit that detects the amount of displacement of the detected unit; In an infusion pump that feeds liquid from an upstream side to a downstream side through a tube, a driving unit that engages with any one of the fingers and moves forward and backward in a radial direction of a rotation shaft, The drive unit is provided so as to be able to advance and retreat in the radial direction of the rotation shaft and is in contact with the tube, and the drive unit and the body unit are elastically mounted over the drive unit and the body unit. If they are biased away from each other Infusion pump, characterized in that constructed, and the body portion, and also used as the detected portion of the detection mechanism from the.