WO2020080466A1

WO2020080466A1 - Load detector and clamp unit

Info

Publication number: WO2020080466A1
Application number: PCT/JP2019/040907
Authority: WO
Inventors: 浩司大塚
Original assignee: 株式会社ジェイ・エム・エス
Priority date: 2018-10-19
Filing date: 2019-10-17
Publication date: 2020-04-23
Also published as: JP2020065557A; CN112654378A; JP7135711B2

Abstract

The present invention provides a load detector which can prevent erroneous detection of an output voltage of a load detection sensor. A load detector 66 is provided with a body 61 and a lid part 62 for opening/closing the body 61, and detects, when the lid part 62 is closed, a load based on pressure from a to-be-measured part disposed between the body 61 and the lid part 62. The load detector 66 is provided with: a load part 71 capable of advancing or retreating in the axial direction in response to pressure from the to-be-measured part; a load detection sensor 665 that detects a load from the load part 71 and that is disposed opposite to the leading end of the load part 71; a contact part 72 that is disposed in contact with the outer peripheral surface of the load part 71 so as not to impede movement of the load part 71 in the axial direction; and a connection part 73 that electrically connects the contact part 72 and an earth part 610.

Description

Load detector and clamp unit

The present invention relates to a load detector and a clamp unit that detect a load due to pressure from a measurement object.

Conventionally, a tube through which a liquid flows, a load detection sensor that detects a radial displacement of the tube by a load from a load section, and a detection section that detects blockage of the tube based on a load value of the load detection sensor are provided. A blood purification device equipped with an ironing type pump is known (see, for example, Patent Document 1). Further, the device of Patent Document 1 can detect the negative pressure and the positive pressure of the tube.

JP, 2014-83091, A

When the negative pressure and positive pressure of the tube are detected by detecting the radial displacement of the tube by the load generated by the movement of the load part, static electricity may be generated and the load part may be charged with static electricity. When the load section is charged with static electricity, the output voltage of the load detection sensor may be abnormal due to the influence of static electricity, and the negative pressure and the positive pressure of the tube may be erroneously detected. Therefore, it is desired to prevent erroneous detection of the output voltage of the load detection sensor.

An object of the present invention is to provide a load detector clamp unit that can prevent erroneous detection of the output voltage of the load detection sensor.

The present invention includes a main body and a lid portion that opens and closes the main body, and detects a load due to pressure from a measurement target portion arranged between the main body and the lid portion when the lid portion is closed. A load detector, which is a load part that can be moved back and forth in the axial direction by the pressure from the measurement target part, and a load detection sensor that is arranged to face the tip of the load part and that detects the load from the load part, A load including a contact portion arranged in contact with the outer peripheral surface of the load portion so as not to hinder the axial movement of the load portion, and a connecting portion electrically connecting the contact portion and the ground portion. Regarding the detector.

Moreover, it is preferable that the contact portion is formed in a cylindrical shape.

Moreover, it is preferable to further include a rotation preventing portion for preventing the rotation of the load portion.

The load detector, the measurement target portion is a tube through which a liquid flows, and a clamp portion that can clamp the tube disposed between the main body and the lid portion when the lid portion is closed. The present invention also relates to a clamp unit.

According to the present invention, it is possible to provide a clamp unit that can prevent erroneous detection of the output voltage of the load detection sensor.

It is a figure showing the whole hemodialysis machine composition concerning one embodiment of the present invention. It is a front view which shows the structure of a clamp unit. It is a figure which shows the open state of a clamp unit. It is a perspective view which shows the closed state of a clamp unit. It is the perspective view which looked the clamp unit from the lower side. FIG. 5 is a sectional view taken along the line AA in FIG. 4. FIG. 5 is a sectional view taken along line BB in FIG. 4. It is sectional drawing which shows the structure of a load detection part. It is a perspective view showing the main composition which prevents generation of static electricity in a load primary detecting element. It is a disassembled perspective view of the load detection part shown in FIG. It is a block diagram which shows the structure of a console. It is a graph which shows the example of the output abnormality by the output voltage of a force sensor and the influence of static electricity. It is a perspective view which shows the load shaft of 1st modification, (a) is a side view, (b) is the figure which looked the shaft main body from the front end side. It is a perspective view which shows the load shaft of a 2nd modification, (a) is a side view, (b) is the figure which looked the shaft main body from the front end side. It is a perspective view which shows the load shaft and the C-shaped contact part of 3rd modification, Comprising: (a) is a side view, (b) is the figure which looked at the shaft main body from the front end side. It is a perspective view which shows the load shaft and the rod-shaped contact part of 4th modification, Comprising: (a) is a side view, (b) is the figure which looked at the shaft main body from the front end side.

Hereinafter, a preferred embodiment of a hemodialysis apparatus including the clamp unit 60 of the present invention will be described with reference to the drawings. INDUSTRIAL APPLICABILITY The hemodialysis apparatus of the present invention purifies blood of patients with renal failure and drug poisoning, removes excess water in the blood, and supplements (replenishes) water in the blood as necessary.
First, the overall configuration of the hemodialysis apparatus 1 of this embodiment will be described with reference to FIG. The hemodialyzer 1 as a dialyzer includes a dialyzer 10 as a hemodialyzer, a blood circuit 20, a dialysate circuit 30, a replenisher line 38, and a console 100. The console 100 is provided with an operation panel 70, a clamp unit 60, a part of the blood circuit 20, a part of the dialysate circuit 30, a heater 40 as a temperature control unit, a drug solution pump 231, a replacement fluid pump 39, and a control device 50. Has been done.

The dialyzer 10 includes a container body 11 formed in a tubular shape and a dialysis membrane (not shown) housed inside the container body 11. And a dialysate-side flow path (both not shown). The container body 11 is formed with a blood inlet 111 and a blood outlet 112 that communicate with the blood-side channel, and a dialysate inlet 113 and a dialysate outlet 114 that communicate with the dialysate-side channel.

The blood circuit 20 includes an artery side line 21, a vein side line 22, a drug line 23, and an overflow line 24. The arterial side line 21, the vein side line 22, the drug line 23, and the overflow line 24 are each mainly configured by a flexible tube through which a liquid can flow.

In the present embodiment, the tubes forming the artery side line 21, the vein side line 22, the drug line 23, and the overflow line 24 are flexible tubes such as polyvinyl chloride (PVC) and silicon (Si). It is formed. As the tube, for example, a tube having an outer diameter of 5.5 mm and an inner diameter of 3.3 mm is used. The tube has a hardness of, for example, about 50 to 85 (JIS K7215).

The arterial line 21 has one end connected to the artery of the subject (dialysis patient) and the other end connected to the blood inlet 111 of the dialyzer 10. The console 100 is arranged in the middle of the artery side line 21. In the console 100, the clamp unit 60 and the blood pump 212 are arranged in a portion where the artery side line 21 passes. An arterial side clamp section (clamp section) 65, a load detection section 66, and an arterial side bubble sensor (bubble detection section) 67 are arranged in a portion of the clamp unit 60 through which the artery side line 21 passes. Details of the clamp unit 60 will be described later.

Blood pump 212 is arranged downstream of clamp unit 60 in arterial line 21. The blood pump 212 squeezes the tube that constitutes the artery-side line 21 with a roller, and thereby delivers the liquid such as blood and priming fluid inside the artery-side line 21.

The vein side line 22 has one end connected to the blood outlet 112 of the dialyzer 10 and the other end connected to the vein of the subject (dialysis patient). In the middle of the vein side line 22, the vein side chamber 222 and the console 100 are arranged. In the console 100, the clamp unit 60 is arranged at a portion where the vein side line 22 passes. A vein side clamp portion 69 and a vein side bubble sensor 68 are arranged in a portion of the clamp unit 60 through which the vein side line 22 passes. Details of the clamp unit 60 will be described later.

The vein side chamber 222 is arranged between the dialyzer 10 and the console 100 in the vein side line 22. The vein side chamber 222 stores a predetermined amount (for example, 20 ml) of blood.

The drug line 23 supplies the drug required during hemodialysis to the arterial line 21. One end side (proximal end side) of the drug line 23 is connected to a drug solution pump 231 that delivers a drug, and the other end side (tip end side) is connected between the blood pump 212 and the dialyzer 10 in the arterial side line 21.

The overflow line 24 has one end side (base end side) connected to the vein side chamber 222. The overflow line 24 discharges the physiological saline solution, air and the like flowing through the vein side line 22 to the outside in the priming process. An overflow clamp 241 is arranged in the overflow line 24. The overflow clamp 241 opens and closes the flow path of the overflow line 24.

According to the blood circuit 20 described above, the blood extracted from the artery of the subject (dialysis patient) flows through the artery side line 21 by the blood pump 212 and is introduced into the blood side flow path of the dialyzer 10. The blood introduced into the dialyzer 10 is purified by the dialysate flowing through the dialysate circuit 30 described later through the dialyzing membrane. The blood purified by the dialyzer 10 flows through the vein side line 22 and is returned to the vein of the subject.

In the present embodiment, the dialysate circuit 30 is composed of a so-called closed capacity control type dialysate circuit 30. The dialysate circuit 30 includes a dialysate chamber 31, a dialysate supply line 32, a dialysate introduction line 33, a dialysate outlet line 34, a drain line 35, a bypass line 36, and water removal / reverse filtration. And a pump 37.

The dialysate chamber 31 includes a hard container 311 that can store a fixed volume (for example, 300 ml to 500 ml) of dialysate, and a soft diaphragm (diaphragm) 312 that partitions the interior of the container 311. The interior of the dialysate chamber 31 is partitioned by a diaphragm 312 into a liquid feed storage 313 and a drainage storage 314.

The dialysate supply line 32 has a proximal end connected to a dialysate supply device (not shown) and a distal end connected to the dialysate chamber 31. The dialysate supply line 32 supplies the dialysate to the liquid delivery container 313 of the dialysate chamber 31.

The dialysate introduction line 33 connects the dialysate chamber 31 and the dialysate inlet 113 of the dialyzer 10, and connects the dialysate contained in the solution delivery container 313 of the dialysate chamber 31 to the dialysate-side flow path of the dialyzer 10. To introduce.

The dialysate outlet line 34 connects the dialysate outlet 114 of the dialyzer 10 and the dialysate chamber 31, and leads the dialysate discharged from the dialyzer 10 to the drainage storage portion 314 of the dialysate chamber 31.
The drain line 35 is connected to the dialysate chamber 31 on the proximal end side and drains the drainage of the dialysate stored in the drainage container 314.

The bypass line 36 connects the dialysate outlet line 34 and the drain line 35.
The dewatering / back filtration pump 37 is arranged in the bypass line 36. The water removal / reverse filtration pump 37 sends the dialysate inside the bypass line 36 to the drainage line 35 side (removal direction) and to the dialysate discharge line 34 side (reverse filtration direction). It is composed of a pump that drives liquid.

The heater 40 heats the dialysate flowing through the dialysate circuit 30 to a predetermined temperature.

The replenisher line 38 is a line for directly supplying the dialysate to the blood circuit 20. As shown in FIG. 1, the upstream side of the replenisher line 38 is connected between the dialysate chamber 31 in the dialysate introduction line 33 of the dialysate circuit 30 and the dialysate inlet 113 of the dialyzer 10. The replenisher line 38 is provided with a replenisher clamp 381. As shown by the solid line in FIG. 1, when the downstream side of the replenisher line 38 is connected between the blood pump 212 and the dialyzer 10 in the arterial line 21, predilution type hemofiltration / dialysis is performed. Further, as shown by the broken line in FIG. 1, when the downstream side of the replenisher solution line 38 is connected to the vein side chamber 222 in the vein side line 22, the post-dilution type hemofiltration dialysis is performed.

The clamp unit 60 will be described.
As shown in FIG. 1, the clamp unit 60 is configured as a unit and is attached to the console 100. The clamp unit 60 clamps and holds the tube forming the artery side line 21 and the tube forming the vein side line 22. In the clamp unit 60, on one side in the width direction H, the tubes forming the artery side line 21 are arranged in the vertical direction, and on the other side in the width direction H, the tubes forming the vein side line 22 are arranged in the vertical direction. It is arranged over.

As shown in FIGS. 2 to 5, the clamp unit 60 includes a unit main body 61 (main body), a lid portion 62 that opens and closes the unit main body 61, a hinge portion 63, an opening / closing lever 641, and an opening / closing engagement portion 642. , A substrate 664 (see FIG. 5) and a load detector 66 (load detector). The clamp unit 60 fixes the tube by disposing the tube between the unit body 61 and the lid portion 62. The clamp unit 60 is configured such that the inner surface of the unit main body 61 has the tubes forming the artery side line 21 and the tube forming the vein side line 22 arranged therein, and the inner surface of the unit main body 61 is pressed against the inner surface of the lid portion 62. The tube forming the artery side line 21 and the tube forming the vein side line 22 are fixed.

The inner surface of the lid portion 62 forms a tube fixing portion that fixes the tube forming the artery side line 21 and the tube forming the vein side line 22 with a constant force. In the member forming the inner surface of the lid portion 62, for example, a resin material is used as the material of at least the portion that presses the tube, and ABS resin (acrylonitrile-butadiene-styrene copolymer), ASA resin (butadiene resin of ABS resin) is used. In place of acrylic rubber), synthetic resins such as polypropylene, etc. are used. Accordingly, the inner surface of the lid portion 62 can be fixed with an appropriate holding force that sufficiently holds the tube forming the artery side line 21 and the tube forming the vein side line 22 and does not crush it too much.

As shown in FIG. 2, the hinge portion 63 is arranged at the other end of the clamp unit 60 in the width direction H when the lid portion 62 is closed so that the lid portion 62 can rotate with respect to the unit body 61. Connecting.

The opening / closing lever 641 is provided at one end of the lid portion 62 on one side in the width direction H when the lid portion 62 is closed. As shown in FIG. 3, the opening / closing engagement portion 642 is provided at an end portion on one side in the width direction H of the inner surface of the unit body 61 so that the opening / closing lever 641 can be engaged when the lid portion 62 is closed. By operating the opening / closing lever 641, the unit body 61 and the lid 62 are opened / closed.

As shown in FIG. 3, a main body side arterial tube placement section 611 (tube placement section) and a main body side vein side tube placement section 612 (tube placement section) are formed on the inner surface of the unit main body 61. . The main body side arterial tube placement section 611 and the main body side vein side tube placement section 612 are arranged on the inner surface of the unit main body 61 so as to be spaced apart in the width direction H of the unit main body 61 and extend linearly. The main body side vein side tube placement portion 612 is placed closer to the hinge portion 63 side in the width direction H than the main body side arterial side tube placement portion 611.

As shown in FIG. 5, a board 664 is attached to the outer surface 613 (see FIG. 8) of the unit main body 61. A force sensor 665 (load detection sensor) of the load detection unit 66 is mounted (disposed) on the first surface 664a (see FIG. 8) of the board 664 on the unit body 61 side (see FIG. 8 described later).

As shown in FIG. 3, on the inner surface of the lid portion 62, when the lid portion 62 is closed, the lid portion side arterial tube placement portion 621 that is placed to face the main body side arterial side tube placement portion 611, and the main body side A lid side vein side tube placement portion 622, which is placed so as to face the vein side tube placement portion 612, is formed. The lid side arterial tube placement section 621 and the lid side vein side tube placement section 622 are arranged on the inner surface of the lid section 62 so as to be separated from each other in the width direction H of the lid section 62 and extend linearly. The lid side vein side tube placement portion 622 is placed closer to the hinge portion 63 side in the width direction H than the lid side artery side tube placement portion 621.

When the lid 62 is closed, the tube forming the artery side line 21 is arranged between the main body side arterial tube placement section 611 and the lid side arterial side tube placement section 621, and the main body side vein side tube placement is arranged. The tube forming the vein side line 22 is arranged between the portion 612 and the lid side vein side tube placement portion 622.

Here, first, the configuration provided in the main body side arterial tube placement section 611 and the lid side arterial side tube placement section 621 will be described.
As shown in FIG. 3 and FIG. 6, when the lid 62 is closed, the arterial upstream tube retainer 601 and the artery side along the main body side arterial tube placement part 611 and the lid side arterial side tube placement part 621. A clamp part 65, a load detection part 66, an artery side air bubble sensor 67 and an artery side downstream tube pressing part 602 are arranged. In the present embodiment, the artery-side upstream tube pressing portion 601, the artery-side clamping portion 65, the load detecting portion 66, the artery-side bubble sensor 67, and the artery-side downstream tube pressing portion 602 are arranged in the clamp unit 60 from the upstream side to the downstream side. They are arranged side by side in this order from the lower side to the upper side in FIGS. 1 and 3.

The main body side artery side tube placement portion 611 is placed on the inner surface of the unit main body 61 as shown in FIG. In the main body side arterial tube placement section 611, the arterial side upstream tube holding section is arranged in order from the upstream side to the downstream side (from the lower side to the upper side in FIG. 3) of the liquid flowing through the tube forming the artery side line 21. An arterial-side bubble sensor in which an accommodating recess 601a of 601, an arterial-side movable clamp part 651 of the arterial-side clamp part 65, a load receiving part 662 of the load detecting part 66, and an ultrasonic wave oscillating part 671 of the arterial-side bubble sensor 67 are accommodated inside. The receiving member 672 and the accommodating recess 602a of the artery-side downstream tube pressing portion 602 are arranged side by side.

The lid-side artery-side tube placement portion 621 is placed on the inner surface of the lid portion 62, and is placed so as to face the main-body-side artery-side tube placement portion 611 when the lid portion 62 is closed. The lid-side artery-side tube placement portion 621 sequentially holds the arterial-side upstream tube retainer from the upstream side to the downstream side (from the lower side to the upper side in FIG. 3) of the liquid flowing through the tube forming the artery-side line 21. Arterial side in which the pressing convex portion 601b of the portion 601, the arterial side clamp receiving portion 652 of the arterial side clamping portion 65, the load holding portion 663 of the load detecting portion 66, and the ultrasonic wave receiving portion 673 of the arterial side air bubble sensor 67 are housed inside. The bubble sensor pressing member 674 and the pressing convex portion 602b of the artery-side downstream tube pressing portion 602 are arranged side by side.

The pressing convex portion 601b of the artery-side upstream tube pressing portion 601 is arranged so as to face the accommodating concave portion 601a arranged in the unit main body 61 when the lid portion 62 is closed, and the liquid flowing through the artery-side line 21 in the clamp unit 60. At the upstream side (downward side in FIG. 3) of, the tube forming the artery side line 21 is pressed.

The artery-side clamp receiving portion 652 is arranged so as to face the artery-side movable clamp portion 651 arranged in the unit main body 61 when the lid portion 62 is closed. The artery-side clamp receiving portion 652 and the artery-side movable clamp portion 651 constitute the artery-side clamp portion 65, and hold the tube constituting the artery-side line 21 by sandwiching it.

As shown in FIGS. 3 and 6, the artery-side clamp portion 65 includes an artery-side movable clamp portion 651 arranged in the unit body 61, and a solenoid 653 arranged in the unit body 61 and driving the artery-side movable clamp portion 651. , And an artery-side clamp receiving portion 652 arranged on the lid portion 62. The artery-side clamp receiving portion 652 is formed so as to project from the inner surface of the lid portion 62 and extends in the width direction H.

As shown in FIG. 6, the arterial-side movable clamp portion 651 has a distal end formed in a flat shape extending in the width direction H, and a trapezoid shape in which the width on the distal end side is narrow in a cross section cut in the extending direction of the tube placement portion. To be done. An output shaft 653a of a solenoid 653 is connected to the rear end of the artery-side movable clamp portion 651 so as to be able to move forward and backward. The arterial-side movable clamp section 651 clamps the tube forming the arterial-side line 21 by sandwiching the tube forming the arterial-side line 21 between the tip of the arterial-side clamp section 651 and the tip of the arterial-side clamp receiving section 652 by advancing and retracting the output shaft 653a of the solenoid 653. Alternatively, the artery side line 21 is opened and closed.

The arterial side clamp part 65 configured as described above is arranged between the unit main body 61 and the lid part 62 by the arterial side movable clamp part 651 and the arterial side clamp receiving part 652 during the normal operation of the hemodialysis apparatus 1. The tube forming the arterial line 21 to be clamped is clamped.
Further, the arterial side clamp portion 65 is opened and closed in the priming and blood returning process using physiological saline. The arterial side clamp part 65 moves the arterial side movable clamp part 651 forwards and backwards to crush and open the tube forming the arterial side line 21 and open and close the flow path of the arterial side line 21. On the upstream side of 67, the flow of the liquid flowing through the inside of the tube is made to flow / stop.

The load detection unit 66 can detect the load due to the pressure from the tube forming the artery side line 21 and output it as a voltage value. That is, when the tube is closed, the pressure in the tube becomes positive pressure or negative pressure, the radial direction of the tube changes, and the load changes with it, and as a result, it is detected as a change in voltage value. As shown in FIG. 7, the load detector 66 includes a load retainer 663, a load receiver 662, a force sensor 665 arranged on the substrate 664, and a load absorber 80. The load detection unit 66 constitutes a blockage detection device.

As shown in FIGS. 3, 6, and 7, the load holding portion 663 is arranged to face the load receiving portion 662 arranged in the unit main body 61 when the lid portion 62 is closed, and constitutes the artery side line 21. Hold down the tube. It should be noted that the load holding unit 663 may have a height-adjustable configuration so that when the diameter of the tube is changed, the voltage values output from the load detecting unit 66 can be similar voltage values. Alternatively, the load holding portions having different heights may be exchangeable.

The load receiving portion 662 receives a load due to the pressure from the tube (measurement target portion) that constitutes the artery side line 21 and is pressed by the load pressing portion 663 when the lid 62 is closed. The load receiving portion 662 transmits the load to the force sensor 665 arranged on the substrate 664.

As shown in FIGS. 8 to 10, the load receiving portion 662 includes a top sheet portion 662a, a pressing portion 662b, a load shaft 71 (load portion), a guide cylinder 72 (contact portion), a guide cylinder 72 and an earth. And a connecting member 73 (connecting portion) that connects the sheet metal 610 (earthing portion). The load shaft 71, the guide cylinder 72, the connecting member 73, and the ground sheet metal 610 are formed of a conductive metal member. The ground metal plate 610 is formed in a plate shape and is arranged inside the unit main body 61 (see FIG. 3). As shown in FIG. 9, the ground sheet metal 610 is formed in a substantially C shape with one side open in plan view. The earth metal plate 610 constitutes the earth portion of the clamp unit 60 and is earthed (grounded). For example, it is grounded to the same ground as the power supply used for the clamp unit 60.

As shown in FIG. 8, the surface sheet portion 662a is arranged on the tube side and abuts on the tube forming the artery side line 21 when the lid portion 62 is closed.
The pressing portion 662b, the load shaft 71, and the guide cylinder 72 are arranged in the communication hole 615 of the unit body 61. The communication hole 615 communicates with the inner surface of the unit body 61 and the outer surface 613. The surface sheet portion 662a, the pressing portion 662b, and the load shaft 71 are arranged in this order from the inner surface side of the unit body 61 toward the outer surface 613 side.

The load shaft 71 can be moved forward and backward in the axial direction by the pressure from the tube while being guided by the guide tube 72 inside the guide tube 72 on the outer surface 613 side of the unit body 61 in the communication hole 615 of the unit body 61. Will be placed. As shown in FIG. 10, the load shaft 71 includes a shaft main body 711 formed in a rod shape extending in the axial direction, a top plate portion 712 constituting a top plate of the shaft main body 711, a guide groove 713 (rotation preventing portion), and With.

As shown in FIG. 8, the tip of the shaft body 711 is arranged so as to face the pressing surface of the force sensor 665. As the shaft main body 711 moves back and forth, the force sensor 665 is pressed against the tip of the shaft main body 711.
The top plate portion 712 is connected to the rear end of the shaft body 711 and is formed in a disc shape protruding in the radial direction of the shaft body 711.
The guide groove 713 extends in a groove shape in the axial direction across the outer peripheral surface of the top plate portion 712 and the rear end side portion of the shaft body 711.

The guide cylinder 72 is arranged in contact with the outer peripheral surface of the shaft main body 711 of the load shaft 71 so as not to hinder the axial movement of the load shaft 71. As shown in FIG. 10, the guide cylinder 72 includes a cylindrical cylinder main body 721 extending in the axial direction of the load shaft 71, and an annular radial direction from the outer peripheral surface of the cylinder main body 721 in the axial direction of the cylinder main body 721. It has a protruding cylinder side flange portion 723 and a guide protrusion 724 (rotation preventing portion).

The tube body 721 is formed in a tube shape that surrounds the entire outer peripheral surface of the shaft body 711. One end 722 of the cylinder main body 721 is inserted into a connection hole 732 of the connection member 73, which will be described later, and is connected to the connection member 73. The outer peripheral surface of the one end portion 722 of the cylinder main body 721 is formed by the circular arc surface 722a and the straight surface 722b (rotation restricting portion) being continuous in the circumferential direction.

A shaft body 711 is accommodated inside the barrel body 721 in a state of being slidable in the axial direction. The inner diameter of the cylinder main body 721 is formed slightly larger than the outer diameter of the shaft main body 711 so as not to prevent the load shaft 71 from moving back and forth in the axial direction and to come into contact with the shaft main body 711. More specifically, when the shaft main body 711 moves in the axial direction, the shaft main body 711 contacts the inside of the cylinder main body 721 in a state of being in contact or not in contact with the shaft body 711 in a state in which frictional resistance is hard to be applied. Are arranged. As a result, the guide cylinder 72 is arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the axial movement of the load shaft 71.

The guide protrusion 724 projects in the axial direction from the end surface of the other end of the cylinder body 721 opposite to the one end 722. The guide protrusion 724 is arranged in the guide groove 713 of the load shaft 71. The guide protrusion 724 is arranged in the guide groove 713 of the load shaft 71 to prevent the load shaft 71 from rotating with respect to the guide cylinder 72. The guide cylinder 72 is fixed to the unit main body 61 so that the circumferential position thereof does not move. In the present embodiment, as will be described later, the guide cylinder 72 has a unit in which the straight surface 722b (rotation restricting portion) of the guide cylinder 72 is fitted into the straight surface 732b (rotation restricting portion) of the connecting member 73. The body 61 is fixed so that its circumferential position does not move. Therefore, the guide groove 713 of the load shaft 71 and the guide protrusion 724 of the guide cylinder 72 form a rotation preventing portion that prevents the load shaft 71 from rotating with respect to the force sensor 665 fixed to the unit body 61. Further, the guide protrusion 724 guides the movement of the guide groove 713 of the load shaft 71 when the load shaft 71 advances and retracts inside the guide cylinder 72.

By having the guide groove 713 of the load shaft 71 and the guide protrusion 724 of the guide cylinder 72, the rotation of the load shaft 71 with respect to the guide cylinder 72 is prevented, so that the load shaft 71 and the force sensor 665 are always at the same position in the circumferential direction. Can be contacted with. Therefore, for example, even if the contact point is not the center of the load shaft 71 in the longitudinal direction and the length of the load shaft 71 may vary at each contact position in the circumferential direction, Since the force sensor 665 contacts at the same position in the circumferential direction, a stable load can be continuously applied and the performance can be maintained.

The connecting member 73 electrically connects the guide cylinder 72 and the ground metal plate 610. The connecting member 73 is formed of a plate material that extends in a crank shape in a plan view, and a step portion 731 is formed in the middle of extending in the crank shape. The connecting member 73 has a connecting hole 732 formed at one end portion and a ground connection hole 733 formed at the other end portion.

The connection hole 732 is formed by penetrating the connection member 73 at one end of the connection member 73. The inner peripheral surface of the connecting hole 732 is formed by the arc surface 732a and the straight surface 732b (rotation restricting portion) being continuous. The one end portion 722 of the cylinder body 721 on the outer surface 613 side of the unit body 61 is inserted into the connection hole 732, so that the arc surface 722a and the straight surface 722b of the one end portion 722 of the cylinder body 721 correspond to the corresponding connection hole 732. It fits in the circular arc surface 732a and the straight surface 732b. By fitting the straight surface 722b (rotation restricting portion) of the guide cylinder 72 into the straight surface 732b (rotation restricting portion) of the connecting member 73, the rotation of the guide cylinder 72 with respect to the connecting member 73 is restricted, and thus the guide cylinder 72. Are fixed so that their circumferential positions do not move relative to the unit body 61. In this state, the cylinder side flange portion 723 contacts the upper surface of the connecting member 73, so that the cylinder side flange portion 723 is electrically connected to the connecting member 73, and the cylinder body 721 is connected to the connecting member 73. To be done.

A ground metal plate 610 is connected to the other end of the connecting member 73. In the present embodiment, by connecting the ground connection hole 733 and the connection hole 610 a of the ground sheet metal 610 with the screw 74 while the ground sheet metal 610 is placed on the upper surface of the other end of the connecting member 73. The other end of the connecting member 73 is electrically connected to the ground metal plate 610. As a result, the static electricity generated in the load shaft 71 is released from the guide cylinder 72 to the ground sheet metal 610 via the connecting member 73. The static electricity released to the ground metal plate 610 is grounded (grounded) in the ground metal plate 610.

As shown in FIG. 8, the force sensor 665 is mounted (disposed) on the first surface 664 a formed on the unit body 61 side of the board 664. The force sensor 665 is arranged to face the tip of the load shaft 71, and detects the load due to the pressure from the tube by the load from the load shaft 71. The substrate 664 is attached to the outer surface 613 of the unit body 61. The board 664 is arranged so as to close the communication hole 615 and intersect with the direction in which the communication hole 615 extends. In the board 664, the first surface 664a on the unit body 61 side is brought into contact with the outer surface 613 of the unit body 61, and the second surface 664b on the side opposite to the first surface 664a is formed by two

spring members

82 and 82 described later. It is pressed toward the unit body 61 side.

The force sensor 665 is arranged on the extension line of the communication hole 615 on the outer surface 613 side of the unit main body 61. The load receiving portion 662 is arranged in the communication hole 615 as described above.

When the unit main body 61 is closed by the lid portion 62, the artery side line 21 is provided between the load holding portion 663 and the force sensor 665 of the lid portion 62 from the load holding portion 663 side toward the force sensor 665 side. The constituent tubes and the load receiving portion 662 are arranged in this order.

The force sensor 665 configured as described above moves from the tube via the load receiving portion 662 as the load receiving portion 662 moves in the radial direction of the tube due to the pressure applied from the tube to the load receiving portion 662. The load due to the pressure of is detected. Accordingly, the force sensor 665 outputs the load due to the pressure of the tube forming the artery side line 21 as a voltage.

In the present embodiment, the force sensor 665 detects the load due to the pressure from the tube due to the load from the load shaft 71 both when the tube has a positive pressure and when the tube has a negative pressure. To do.

The load absorbing unit 80 is arranged on the substrate 664 as shown in FIG. In the state where the lid body 62 closes the unit main body 61 and the tube is arranged between the lid portion 62 and the force sensor 665, the load absorbing portion 80 applies a load equal to or more than the allowable load (more than a predetermined value) to the force sensor 665. When applied, it absorbs the load applied to the substrate 664 via the force sensor 665. The load absorbing portion 80 includes two guide posts 81 and 81 (guide members), two spring members 82 and 82 (biasing members), and a connecting member 83 that connects the

spring members

82 and 82.

In the normal use state of the clamp unit 60, when the lid portion 62 is closed, the lid portion 62 presses the tube forming the artery side line 21 toward the force sensor 665 side, so that the force sensor 665 applies a load due to the pressure from the tube. Is detected and the load is output as a voltage value. The detection value detected by the load detection unit 66 is transmitted to the control device 50, and it is determined whether or not the tube is closed. Examples of the case where the tube is blocked include, for example, forgetting to remove the forceps after connecting the blood circuit, clogging of the needle tip due to a thrombus when returning blood during treatment, and blood vessel wall of the needle tip during blood removal / dialysis. And the lack of blood flow due to blood vessel conditions during blood removal / dialysis / returning blood.

As shown in FIGS. 3 and 6, the arterial-side bubble sensor pressing member 674 is arranged so as to face the arterial-side bubble sensor receiving member 672 arranged in the unit main body 61 when the lid 62 is closed. Hold down the tubes that make up the line 21. An ultrasonic wave reception unit 673 is arranged inside the artery-side bubble sensor holding member 674. An ultrasonic oscillator 671 is arranged inside the arterial bubble sensor receiving member 672. The ultrasonic wave receiving unit 673 and the ultrasonic wave oscillating unit 671 form an artery side air bubble sensor 67. The arterial bubble sensor 67 is a sensor that detects the presence or absence of bubbles contained in the liquid flowing inside the artery line 21. The ultrasonic wave receiving unit 673 may be arranged inside the artery-side bubble sensor receiving member 672, and the ultrasonic wave oscillating unit 671 may be arranged inside the artery-side bubble sensor holding member 674.

When the lid 62 is closed, the arterial bubble sensor pressing member 674 (see FIG. 3) presses the tube forming the arterial line 21 against the arterial bubble sensor receiving member 672. The ultrasonic wave receiving unit 673 detects the difference in the transmittance between the liquid and the bubbles by irradiating the liquid flowing in the tube forming the artery side line 21 with the ultrasonic wave generated from the ultrasonic wave oscillating unit 671. Detects the presence of bubbles.

The pressing convex portion 602b of the artery-side downstream tube pressing portion 602 is arranged so as to face the accommodating concave portion 602a arranged in the unit main body 61 when the lid portion 62 is closed, and circulates through the artery-side line 21 in the clamp unit 60. On the downstream side (upper side in FIG. 3) of the liquid, the tube forming the artery side line 21 is pressed.

Next, the configuration provided in the main body side vein side tube placement portion 612 and the lid side vein side tube placement portion 622 when the lid portion 62 is closed will be described.
As shown in FIG. 3, when the lid portion 62 is closed, the vein side upstream tube pressing portion 603 and the vein side air bubble sensor 68 are arranged along the main body side vein side tube placement portion 612 and the lid side vein side tube placement portion 622. The vein side clamp section 69 and the vein side downstream tube holding section 604 are arranged. In the present embodiment, the vein-side upstream tube pressing portion 603, the vein-side bubble sensor 68, the vein-side clamping portion 69, and the vein-side downstream tube pressing portion 604 are arranged in the clamp unit 60 from the upstream side to the downstream side (FIG. 1 and FIG. 1). 3 are arranged in this order from the upper side to the lower side).

The main body side vein side tube arrangement portion 612 is arranged on the inner surface of the unit main body 61 as shown in FIG. The main body side venous tube placement section 612 has a venous side upstream tube holding section in order from the upstream side to the downstream side (from the upper side to the lower side in FIG. 3) of the liquid flowing through the tube forming the vein side line 22. An accommodation recess 603a of 603, a vein side bubble sensor receiving member 682 in which the ultrasonic oscillator 681 of the vein side bubble sensor 68 is accommodated, a vein side movable clamp part 691 of the vein side clamp part 69, a vein side downstream tube pressing part. The accommodation recesses 604a of 604 are arranged side by side.

The lid-side vein-side tube placement portion 622 is placed on the inner surface of the lid portion 62, and is placed so as to face the main-body-side vein-side tube placement portion 612 when the lid portion 62 is closed. The lid-side vein-side tube placement portion 622 sequentially holds the vein-side upstream tube holder from the upstream side to the downstream side (from the upper side to the lower side in FIG. 3) of the liquid flowing through the tube forming the vein side line 22. The holding convex portion 603b of the portion 603, the vein side bubble sensor holding member 684 in which the ultrasonic wave receiving portion 683 of the vein side bubble sensor 68 is housed, the vein side clamp receiving portion 692 of the vein side clamp portion 69, and the vein side downstream tube. The pressing protrusions 604b of the pressing portion 604 are arranged side by side.

The holding convex portion 603b of the vein side upstream tube holding portion 603 is arranged so as to face the housing concave portion 603a arranged in the unit main body 61 when the lid portion 62 is closed, and the liquid flowing through the vein side line 22 in the clamp unit 60. On the upstream side (upper side in FIG. 3) of, the tube forming the vein side line 22 is pressed.

The vein-side bubble sensor pressing member 684 is arranged so as to face the vein-side bubble sensor receiving member 682 arranged in the unit main body 61 when the lid 62 is closed, and presses the tube forming the vein-side line 22. An ultrasonic wave receiving unit 683 is arranged inside the vein-side bubble sensor holding member 684. An ultrasonic wave oscillating unit 681 is arranged inside the vein-side bubble sensor receiving member 682. The ultrasonic wave receiving unit 683 and the ultrasonic wave oscillating unit 681 form a vein side bubble sensor 68. The vein-side bubble sensor 68 is a sensor that detects the presence or absence of bubbles contained in the liquid flowing through the inside of the vein-side line 22. The ultrasonic wave receiving unit 683 may be arranged inside the vein side bubble sensor receiving member 682, and the ultrasonic wave generating unit 681 may be arranged inside the vein side bubble sensor receiving member 684.

When the lid portion 62 is closed, the vein side bubble sensor pressing member 684 (see FIG. 3) presses the tube forming the vein side line 22 against the vein side bubble sensor receiving member 682 side. The ultrasonic wave receiving unit 683 detects the difference in the transmittance between the liquid and the bubbles by irradiating the liquid flowing in the tube forming the vein side line 22 with the ultrasonic wave generated from the ultrasonic wave oscillating unit 681. Detects the presence of bubbles.

The vein side clamp receiving portion 692 is arranged to face the vein side movable clamp portion 691 arranged in the unit main body 61 when the lid portion 62 is closed. The vein side clamp receiving portion 692 and the vein side movable clamp portion 691 form the vein side clamp portion 69, and hold the tube forming the vein side line 22 by sandwiching the tube.

As shown in FIGS. 3 and 7, the vein side clamp part 69 includes a vein side movable clamp part 691 arranged in the unit main body 61, and a solenoid 693 arranged in the unit main body 61 and driving the vein side movable clamp part 691. , And a vein-side clamp receiving portion 692 arranged on the lid portion 62. The vein side clamp receiving portion 692 is formed to project from the inner surface of the lid portion 62 and extends in the width direction H.

The venous side movable clamp portion 691 has a tip end formed in a flat shape extending in the width direction H and a trapezoid shape having a narrow width on the tip end side in a cross section cut in the direction in which the tube placement portion extends. An output shaft 693a of a solenoid 693 is connected to the rear end of the vein side movable clamp portion 691 so as to be able to move forward and backward. The vein side movable clamp section 691 clamps the tube forming the vein side line 22 by sandwiching the tube forming the vein side line 22 between the tip of the vein side movable clamp section 691 and the tip of the vein side clamp receiving section 692 by advancing and retracting the output shaft 693a of the solenoid 693. Alternatively, the vein side line 22 is opened and closed.

The vein side clamp part 69 configured as described above is disposed between the unit main body 61 and the lid part 62 by the vein side movable clamp part 691 and the vein side clamp receiving part 692 during the normal operation of the hemodialysis apparatus 1. The tube forming the venous line 22 is clamped.
Further, the vein side clamp section 69 is controlled according to the detection result of the bubble by the vein side bubble sensor 68 or the artery side bubble sensor 67. The venous side clamp portion 69 configures the venous side line 22 by advancing the venous side movable clamp portion 691 when the venous side bubble sensor 68 or the arterial side bubble sensor 67 detects more bubbles than a predetermined amount. By crushing the tube and closing the flow path of the venous line 22, the liquid supply flowing through the inside of the tube is stopped on the upstream side of the venous bubble sensor 68.

The pressing convex portion 604b of the vein side downstream tube pressing portion 604 is arranged so as to face the accommodation concave portion 604a arranged in the unit main body 61 when the lid portion 62 is closed, and circulates through the vein side line 22 in the clamp unit 60. On the downstream side (lower side in FIG. 3) of the liquid, the tube forming the vein side line 22 is pressed.

The clamp unit 60 configured as described above is configured such that the tube forming the artery side line 21 and the tube forming the vein side line 22 are arranged in the unit main body 61, and the lid portion 62 is simply closed. The tube can be securely clamped at 60.

The control device 50 is composed of an information processing device (computer), and controls the operation of the dialysis device 1 by executing a control program. The control device 50 controls the operation of the hemodialysis device 1 to operate by executing control programs for various processes. Specifically, the control device 50 controls the operations of various pumps and clamps arranged in the blood circuit 20 and the dialysate circuit 30, the heater 40, and the like to perform various steps (priming) performed by the hemodialysis device 1. Process, blood removal process, dialysis process, fluid replacement process, blood return process, etc.). In the various steps of the hemodialysis apparatus 1 of the present embodiment, for example, a priming step, a blood removal step, a dialysis step, and a blood return step are executed in this order, and the execution time of all these steps requires about 4 to 5 hours. .

The priming process is a preparatory process for cleaning and cleaning the blood circuit 20 and the dialyzer 10.
The blood removal step is a step of filling the blood circuit 20 with blood of the patient after the puncture and circulating the blood extracorporeally.
The dialysis step is a step performed after the blood removal step and dialyzes and purifies blood.
The fluid replacement step is a step of performing rapid fluid replacement performed when the blood pressure decreases during dialysis treatment.
The blood returning step is a step of returning the blood in the blood circuit 20 into the body of the patient.

Here, in the present embodiment, the control device 50 performs an operation of determining whether the tube is closed, an operation of correcting a reference voltage (reference value) according to the elapsed time of use of the tube, and a hardness of the tube is a clamp unit. The operation of issuing an alarm when the hardness of the tube used for 60 is not met is realized.

In order to realize the above functions, the control device 50 includes a control unit 51 and a storage unit 52, as shown in FIG. The control unit 51 includes a blockage determination unit 511, a correction control unit 512, and a notification control unit 513.

The storage unit 52 stores in advance a reference voltage (reference value) serving as a reference for determining the blockage of the tube according to the elapsed time of the liquid flowing through the tube. The reference voltage serves as a reference for determining the blockage of the tube, and is an output voltage of the load detection unit 66 in a state where no pressure is applied to the tube (a state in which the blood pump 212 is stopped). , Output voltage when the tube is not blocked. For example, a value obtained by subtracting a constant voltage from the reference voltage is set as a threshold value of the output voltage of the load detection unit 66 when the tube has a negative pressure, and a value obtained by adding the constant voltage causes the tube to have a positive pressure. In this case, the threshold value of the output voltage of the load detection unit 66 can be set. Alternatively, in consideration of the negative pressure and the positive pressure, the value in a range in which the absolute value of the constant voltage is adjusted may be used as the threshold value in each process (for example, the negative pressure determination threshold value Va and the positive pressure determination threshold value shown in FIG. 12). Vb). As a result, even when the tube becomes familiar with the liquid or the temperature change with the passage of time, the correction control unit 512 described later can update the reference voltage stored in the storage unit 52. The reference voltage stored in the storage unit 52 is obtained in advance from experimental results and the like.
The storage unit 52 may store in advance a reference voltage (reference value) serving as a reference for determining the blockage of the tube according to the difference in outer size of the tube, the temperature change, or the like.

The blockage determination unit 511 determines the blockage of the tube by comparing the detection value detected by the load detection unit 66 with a blockage threshold value set based on a reference voltage serving as a reference for determining the blockage of the tube. To do.

The correction control unit 512 updates and corrects the reference voltage according to the elapsed time, based on the reference voltage that is stored in the storage unit 52 and serves as a reference for determining the blockage of the tube. The correction timing by the correction control unit 512 is, for example, real-time timing, timing at predetermined time intervals, or predetermined timing for dialysis treatment.

The notification control unit 513, when the blockage determination unit 511 determines that the tube is blocked, issues a warning in a notification unit such as a display screen, an indicator lamp, or a speaker.

In addition, when the notification control unit 513 determines that the detection value detected by the load detection unit 66 when the lid 62 is closed falls outside the preset range, the notification control unit 513 notifies, for example, a display screen, an indicator lamp, or a speaker. The department issues an alarm. As a result, when the hardness, diameter, or wall thickness of the tube is not appropriate, or when the tube is deformed, an alarm is issued, so that the tube in an appropriate state can be used and the detection detected by the load detection unit 66. The value can be obtained accurately.

Here, in the load receiving portion 662 of the present embodiment, the guide cylinder 72 is arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the axial movement of the load shaft 71, and the guide cylinder 72 is The reason why the structure is connected to the ground via the connecting member 73 will be described.

Conventionally, in the clamp unit 60, static electricity is charged on the load shaft 71 due to the forward / backward movement of the load shaft 71, so that the output voltage of the load detection unit 66 becomes an abnormal value due to the influence of static electricity, and the force sensor 665 makes a false detection. There was an occasion.

For example, as shown in FIG. 12, although the output voltage Vs of the load detection unit 66 is an output value within the range of the negative pressure determination threshold value Va, the negative pressure determination threshold value is affected by the static electricity charged on the load shaft 71, as shown in FIG. An output below the range of Va may occur, and an output abnormality may occur due to the influence of static electricity. In this case, the force sensor 665 has erroneously detected.
Although the output voltage Vs of the load detection unit 66 is an output value within the range of the positive pressure determination threshold value Vb, the positive pressure determination threshold value is affected by the static electricity charged on the load shaft 71 as shown in FIG. An output exceeding the range of Vb may be generated, and an output abnormality may occur due to the influence of static electricity. In this case, the force sensor 665 has erroneously detected.

On the other hand, in the present invention, in the load receiving portion 662, the guide cylinder 72 is arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the axial movement of the load shaft 71, and the guide cylinder 72 is also provided. Is connected to the ground via the connecting member 73, so that the static electricity generated in the load shaft 71 is released to the ground. As a result, erroneous detection of the force sensor 665 due to static electricity is prevented while the movement of the load shaft 71 in the axial direction is not hindered, and the force sensor 665 accurately detects both the negative pressure and the positive pressure of the tube. can do.

In particular, in the case of single-needle dialysis, in which a single needle is punctured in the patient to continuously perform blood removal and blood return, the clamp operation and the unclamp operation are performed every few seconds. In the case of the single-needle dialysis, static electricity is easily generated because the clamping operation is performed every few seconds. However, according to the present invention, erroneous detection due to the influence of static electricity can be preferably prevented even in the case where there is the influence of static electricity generated by frequent clamping operations.

Furthermore, the load detection unit 66 in the present invention has a precise structure so that the force sensor 665 can accurately detect both the negative pressure and the positive pressure of the tube. Specifically, the guide cylinder 72 is arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the axial movement of the load shaft 71. The load shaft 71 housed in the guide cylinder 72 can move back and forth in the axial direction along the guide cylinder 72. The force sensor 665 facing the tip of the load shaft 71 detects both the load due to the pressure of the tube and the load due to the negative pressure and the positive pressure of the tube.

Here, for example, in the case of a configuration in which wiring is attached to the load shaft 71 to release static electricity to the ground, resistance is applied to the load shaft 71 due to the influence of the wiring attached to the load shaft 71, and the force sensor 665 uses a tube There is a possibility that both the negative pressure and the positive pressure of the mouse may not be accurately detected. On the other hand, according to the configuration of the present invention, the force sensor 665 can detect both the negative pressure and the positive pressure of the tube more accurately than the configuration in which the wiring is attached to the load shaft 71 to release the static electricity to the ground.

Further, for example, if the copper foil is sandwiched between the load shaft 71 and the force sensor 665 and the static electricity is released to the ground through the copper foil, the copper foil is stacked in the moving direction of the load shaft 71. Since they are sandwiched and sandwiched, the force sensor 665 may not be able to accurately detect both the negative pressure and the positive pressure of the tube. It is also possible that the thickness of the copper foil changes due to deterioration over time, and it is not possible to accurately detect both the negative pressure and the positive pressure of the tube. On the other hand, according to the configuration of the present invention, the force sensor 665 can accurately detect both negative pressure and positive pressure, and since the deterioration over time is less than that of copper foil, durability can be improved and long-term Performance can be maintained even when used.

Further, for example, in the case of a configuration in which a metal brush is brought into contact with the outer peripheral surface of the load shaft 71 to prevent electrostatic charging, the brush shaft of the metal brush is brought into contact with the outer peripheral surface of the load shaft 71 due to the influence. 71 may be subject to resistance, the metal brush may deteriorate over time, and it is necessary to secure a space for disposing the metal brush on the outer side in the radial direction of the load shaft 71. On the other hand, according to the configuration of the present invention, the force sensor 665 is more accurate in both the negative pressure and the positive pressure than the configuration in which the metal brush is brought into contact with the outer peripheral surface of the load shaft 71 to prevent electrostatic charge. It is possible to detect it well and stably, and it is possible to improve durability because it is less deteriorated with time than a metal brush, and because the metal brush can be arranged in a space smaller than that on the outer side in the radial direction of the load shaft 71, it is possible to clamp the clamp. The unit 60 can be formed compactly.

According to the load detection unit 66 of the present embodiment described above, the following effects are obtained.

(1) The load detection unit 66 is configured to include a unit body 61 and a lid portion 62 that opens and closes the unit body 61, and is arranged between the unit body 61 and the lid portion 62 when the lid portion 62 is closed. A load detection unit 66 for detecting a load due to the pressure from the tube, which is capable of advancing and retracting in the axial direction by the pressure from the tube, and a load shaft 71 that is disposed so as to face the tip of the load shaft 71. The force sensor 665 for detecting the load, the guide cylinder 72 arranged in contact with the outer peripheral surface of the load shaft 71 so as not to hinder the axial movement of the load shaft 71, the guide cylinder 72 and the ground metal plate 610 are electrically connected. And a load detecting unit 66 having a connecting member 73 that is electrically connected to each other. Accordingly, the force sensor 665 can accurately detect both the negative pressure and the positive pressure of the tube without impeding the movement of the load shaft 71 in the axial direction, and the force sensor 665 can be erroneously detected due to static electricity. It can be prevented. Further, for example, since deterioration over time is less than when copper foil is used or when a metal brush is used, the detection performance of the force sensor 665 can be maintained even when used for a long period of time.

(2) The guide cylinder 72 is formed in a cylindrical shape. Therefore, since the guide cylinder 72 is arranged so as to surround the entire circumference of the load shaft 71, the load shaft 71 is likely to come into contact with any part of the inner peripheral surface of the guide cylinder 72. Thereby, the load shaft 71 can be stably brought into contact with the guide cylinder 72. Therefore, it is possible to further prevent the force sensor 665 from making an erroneous detection due to the influence of static electricity.

(3) A guide groove 713 and a guide protrusion 724 for preventing the rotation of the load shaft 71 are further provided. As a result, the rotation of the load shaft 71 is prevented, so that the load shaft 71 and the force sensor 665 can always be in contact with each other at the same position in the circumferential direction. Therefore, for example, even if the contact point is not the center in the longitudinal direction of the load shaft 71 and the length of the load shaft 71 may vary at each contact position in the circumferential direction, the force of the load shaft 71 and the force may be different. Since the sensor 665 contacts at the same position in the circumferential direction, a stable load can be continuously applied and the performance can be maintained.

(4) The clamp unit 60 is configured to include the load detection unit 66, and the tube arranged between the unit body 61 and the lid unit 62 can be clamped when the lid unit 62 is closed. Thus, for example, in the case of single-needle dialysis, even when there is an influence of static electricity generated by a frequent clamping operation, it is possible to preferably prevent erroneous detection of the force sensor 665 due to the influence of static electricity.

Although the preferred embodiments of the load detection unit 66 and the clamp unit 60 of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate.
For example, although the load shaft 71 is formed in a cylindrical shape in the above-described embodiment, the present invention is not limited to this. For example, the shaft body 711A of the load shaft 71A may be formed of a quadrangular prism as in the first modification shown in FIG. 13, or the shaft body 711B of the load shaft 71B as in the second modification shown in FIG. It may be formed of a triangular prism.

Further, in the above-mentioned embodiment, the contact portion is formed by the cylindrical guide cylinder 72, but the invention is not limited to this. For example, the contact portion may be formed in a C-shape that does not surround the entire circumference of the load shaft 71 like the contact portion main body 721A of the contact portion 72A of the third modified embodiment shown in FIG. You may form in a rod shape like the contact part 72B of 4 modifications. When the contact portion is formed by the rod-shaped contact portion 72B, a straight line extending along the axial direction of the load shaft 71 with the end portion of the contact portion 72B arranged in the guide groove 713 as shown in FIG. It is preferably formed into a shape.

Further, the connecting member 73 is formed by a plate member extending in a crank shape in a plan view, but the shape is not limited as long as it can be grounded (grounded), and may be a flat member or wiring, and can be freely formed. .

Further, in the above embodiment, the case where the load detection unit (load detector) is applied to the clamp unit has been described, but the present invention is not limited to this and may be used for other purposes. For example, the load detection unit (load detector) is preferably used when used in an environment where static electricity is generated.

60 Clamp unit 61 Unit body (body)
62 lid part 66 load detecting part (load detector)
71 load shaft (load part)
72 Guide tube (contact part)
73 Connection member (connection part)
610 Ground sheet metal (ground section)
665 Force sensor (load detection sensor)
713 Guide groove (rotation prevention part)
724 Guide protrusion (rotation prevention part)

Claims

A load detector that includes a main body and a lid portion that opens and closes the main body, and detects a load due to pressure from a measurement target portion that is arranged between the main body and the lid portion when the lid portion is closed. There
A load portion that can be moved back and forth in the axial direction by the pressure from the measurement target portion,
A load detection sensor arranged to face the tip of the load portion to detect a load from the load portion,
A contact portion arranged in contact with the outer peripheral surface of the load portion so as not to hinder the axial movement of the load portion,
A load detector comprising: a connecting portion that electrically connects the contact portion and the ground portion.
The load detector according to claim 1, wherein the contact portion is formed in a tubular shape.
The load detector according to claim 1 or 2, further comprising a rotation preventing portion that prevents rotation of the load portion.
A load detector according to any one of claims 1 to 3,
The measurement target part is a tube through which a liquid flows,
The clamp unit further comprising a clamp part capable of clamping the tube arranged between the main body and the lid part when the lid part is closed.