Blood purification device
Through load detection and benchmark update mechanisms, the blood purification device can accurately determine tube occlusion under different conditions, solving the problem of inaccurate detection in existing technologies and improving the safety and reliability of treatment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JMS CO LTD
- Filing Date
- 2020-08-21
- Publication Date
- 2026-05-26
Smart Images
Figure CN114423467B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a blood purification apparatus having an occlusion determination section for determining the occlusion of a tube. Background Technology
[0002] Blood purification therapies such as dialysis include pre-flushing, blood removal, treatment, and blood return procedures. In order to carry out these procedures smoothly, a blood circuit is used, and it is necessary to check whether the tubes that make up the blood circuit are blocked.
[0003] Causes of occlusion include, for example, connecting the blood circuit to the patient during the devascularization process, forgetting to remove the forceps or release the clamps during the treatment process; poor devascularization due to insufficient blood flow caused by the puncture needle adhering to the blood vessel wall or poor blood vessel condition during the devascularization and treatment processes; and thrombus blocking the puncture needle during the blood return process.
[0004] To detect such blockage, a blood purification device is known in the past, which includes: a tube for the flow of liquid; a load detection unit for detecting the load received from the tube; and a blockage determination unit for determining the blockage of the tube based on the detection value detected by the load detection unit (see, for example, Patent Document 1).
[0005] Existing technical documents
[0006] Patent documents
[0007] Patent Document 1: Japanese Patent No. 5587958 Summary of the Invention
[0008] In the blood purification device described in Patent Document 1, during blood purification treatments such as dialysis, the tube's state changes due to fluid flow and sometimes deformation caused by changes in the fluid or temperature. Therefore, variations in usage conditions, such as prolonged treatment sessions, and changes in the usage environment, such as room temperature, make it impossible to accurately determine tube occlusion. Thus, even during prolonged treatments, accurate determination of tube occlusion is desirable.
[0009] Therefore, the object of the present invention is to provide a blood purification device that can determine tube occlusion with high accuracy regardless of the usage conditions or environment.
[0010] This invention relates to a blood purification device comprising: a blood purifier; an arterial side tubing connected upstream of the blood purifier; and a pump for transporting liquid disposed in the arterial side tubing. The blood purification device further comprises: a load detection unit that detects a load acting on a tube constituting the arterial side tubing; a reference value generation unit that generates a measured reference value based on a detection value detected by the load detection unit when the pump is stopped at a predetermined time; a reference value updating unit that updates the reference value based on the change in the detection value over time and the measured reference value; and a occlusion determination unit that determines the tube to be occluded if the detection value deviates from a predetermined determination range set according to the reference value for determining whether the tube is occluded.
[0011] Alternatively, preferably, the reference value updating unit repeatedly updates the reference value at predetermined intervals, and updates the reference value based on the most recently updated reference value and the most recent change in the detected value over the predetermined time.
[0012] Alternatively, preferably, the reference value updating unit updates the reference value based on the most recently updated reference value and the predetermined set change amount when the most recent change amount of the detected value deviates from the set change range.
[0013] Alternatively, preferably, the set change amount is set to decrease over time or decrease as the reference value decreases.
[0014] Alternatively, preferably, the reference value updating unit sets the most recent reference value as the reference value when the pump stops at a time other than the predetermined time.
[0015] Alternatively, preferably, the reference value updating unit sets the most recent reference value as the reference value when the pump is driven to deliver fluid to the upstream side of the arterial side tubing.
[0016] Alternatively, preferably, the size of the determination range is set to decrease over time or decrease as the reference value decreases.
[0017] Additionally, preferably, the blood purification device further comprises: a unit body; and a cover that opens and closes the unit body, wherein the load detection unit has a force sensor disposed on the unit body, and when the cover is closed, the cover presses the tube against the force sensor, thereby the force sensor detects the load received from the tube; and further comprises a notification control unit that, when it determines that the detection value detected by the load detection unit deviates from a preset range when the cover is closed, notifies the determination result.
[0018] According to the present invention, the reference value is updated based on the measured reference value generated at a predetermined time and the change in the detection value caused by the compliant deformation of the tube, thus ensuring the accuracy of tube blockage determination regardless of the usage conditions or environment. Attached Figure Description
[0019] Figure 1 This is a diagram showing the overall structure of the blood purification device according to an embodiment of the present invention.
[0020] Figure 2 This is a front view showing the structure of the clamping unit.
[0021] Figure 3 This is a diagram showing the open state of the clamping unit.
[0022] Figure 4 This is a perspective view showing the closed state of the clamping unit.
[0023] Figure 5 yes Figure 4 The AA line cross-section diagram.
[0024] Figure 6 yes Figure 4 BB line cross-section diagram.
[0025] Figure 7 This is a block diagram showing the structure of the control panel.
[0026] Figure 8 It is a graph showing the changes in the reference value, detection value, and occlusion determination value over time in Example 1.
[0027] Figure 9 It is a graph showing the changes in the reference value, detection value, and occlusion determination value over time in Example 2.
[0028] Figure 10 It is a graph showing the relationship between the changes in the measured reference value and the detected value in Example 3.
[0029] Figure 11 It is a graph used to compare the changes in the occlusion determination value in Example 1 and Example 4. Detailed Implementation
[0030] Hereinafter, preferred embodiments of the blood purification device of the present invention will be described with reference to the accompanying drawings. The blood purification device of the present invention purifies the blood of patients with renal insufficiency and drug poisoning, removes excess water from the blood, and replenishes the blood with water (fluid replacement) as needed.
[0031] First, refer to Figure 1The overall structure of the blood purification apparatus 1 according to this embodiment is described below. The blood purification apparatus 1 includes a dialyzer 10 as a blood purifier, a blood circuit 20, a dialysate circuit 30, a replenishment fluid line 38, and a control panel 100. The control panel 100 is equipped with an operation panel 70, a clamping unit 60, a portion of the blood circuit 20, a portion of the dialysate circuit 30, a heater 40 as a temperature control unit, a drug pump 231, a replenishment fluid pump 39, and a control device 50.
[0032] The dialyzer 10 includes a cylindrical container body 11 and a dialysis membrane (not shown) housed inside the container body 11. The interior of the container body 11 is divided into a blood-side flow path and a dialysate-side flow path (both not shown) by the dialysis membrane. A blood inlet 111 and a blood outlet 112 connected to the blood-side flow path, and a dialysate inlet 113 and a dialysate outlet 114 connected to the dialysate-side flow path are formed on the container body 11.
[0033] The blood circuit 20 includes an arterial side line 21, a venous side line 22, a drug line 23, and an overflow line 24. The arterial side line 21, the venous side line 22, the drug line 23, and the overflow line 24 are all mainly composed of flexible tubes that allow fluid flow.
[0034] In this embodiment, the tubes constituting the arterial side tubing 21, the venous side tubing 22, the drug tubing 23, and the overflow tubing 24 are formed of flexible tubes such as polyvinyl chloride (PVC) or silicone (Si). For example, tubes with an outer diameter of 5.5 mm and an inner diameter of 3.3 mm are used. The tube hardness is, for example, around 50 to 85 (JIS K7215).
[0035] One end of the arterial side tubing 21 is connected to the artery of the recipient (dialysis patient), and the other end is connected to the blood inlet 111 of the dialyzer 10. A control panel 100 is disposed midway through the arterial side tubing 21. A clamping unit 60 and a blood pump 212 are disposed in the portion of the control panel 100 through which the arterial side tubing 21 passes. An arterial side clamping part (clamping part) 65, a load detection part 66, and an arterial side bubble sensor (bubble detection part) 67 are disposed in the portion of the clamping unit 60 through which the arterial side tubing 21 passes. The clamping unit 60 will be described in detail later.
[0036] The blood pump 212 is positioned downstream of the clamping unit 60 in the arterial side tubing 21. The blood pump 212 uses rollers to squeeze the tubing that forms the arterial side tubing 21, thereby delivering blood, pre-flushing fluid, and other liquids from inside the arterial side tubing 21.
[0037] One end of the venous side tubing 22 is connected to the blood outlet 112 of the dialyzer 10, and the other end is connected to the vein of the recipient (dialysis patient). A venous side lumen 222 and a control panel 100 are disposed along the middle of the venous side tubing 22. A clamping unit 60 is disposed in the portion of the control panel 100 through which the venous side tubing 22 passes. A venous side clamping part 69 and a venous side bubble sensor 68 are disposed in the portion of the clamping unit 60 through which the venous side tubing 22 passes. The clamping unit 60 will be described in detail later.
[0038] The venous side lumen 222 is disposed between the dialyzer 10 and the control panel 100 in the venous side tubing 22. The venous side lumen 222 holds a predetermined amount (e.g., 20 ml) of blood.
[0039] The drug line 23 supplies the drugs required for hemodialysis to the arterial side line 21. One end (base end) of the drug line 23 is connected to the drug delivery pump 231, and the other end (front end) is connected between the blood pump 212 in the arterial side line 21 and the dialyzer 10.
[0040] One end (base end) of the overflow line 24 is connected to the venous lumen 222. The overflow line 24 discharges saline, air, etc., that have flowed through the venous line 22 during the pre-flushing process to the outside. An overflow clamp 241 is provided in the overflow line 24. The overflow clamp 241 opens and closes the flow path of the overflow line 24.
[0041] According to the blood circuit 20, blood drawn from the artery of the patient undergoing dialysis is pumped by blood pump 212 through the arterial side tubing 21 and introduced into the blood side flow path of the dialyzer 10. The blood introduced into the dialyzer 10 is purified by dialysate flowing through the dialysate circuit 30 (described later) via the dialysis membrane. The purified blood in the dialyzer 10 flows through the venous side tubing 22 and returns to the patient's vein.
[0042] In this embodiment, the dialysate circuit 30 is configured as a dialysate circuit 30 with a so-called closed-loop capacity control method. The dialysate circuit 30 includes a dialysate chamber 31, a dialysate supply line 32, a dialysate inlet line 33, a dialysate outlet line 34, a drain line 35, a bypass line 36, and a dewatering / reverse filtration pump 37.
[0043] The dialysate chamber 31 includes a rigid container 311 capable of holding a certain volume (e.g., 300ml to 500ml) of dialysate and a soft diaphragm 312 dividing the interior of the container 311. The interior of the dialysate chamber 31 is divided by the diaphragm 312 into a delivery receiving section 313 and a discharge receiving section 314.
[0044] The base end of the dialysate supply line 32 is connected to the dialysate supply device (not shown), and the front end is connected to the dialysate chamber 31. The dialysate supply line 32 supplies dialysate to the liquid delivery and receiving section 313 of the dialysate chamber 31.
[0045] The dialysate inlet line 33 connects the dialysate chamber 31 to the dialysate inlet 113 of the dialyzer 10, and introduces the dialysate contained in the liquid delivery receiving part 313 of the dialysate chamber 31 into the dialysate side flow path of the dialyzer 10.
[0046] The dialysate outlet 34 connects the dialysate outlet 114 of the dialyzer 10 to the dialysate chamber 31, and exports the dialysate discharged from the dialyzer 10 to the drain receiving section 314 of the dialysate chamber 31.
[0047] The base end of the drain line 35 is connected to the dialysate chamber 31 to drain the dialysate contained in the drain receiving part 314.
[0048] The bypass line 36 connects the dialysate outlet line 34 to the drain line 35.
[0049] A dewatering / reverse filtration pump 37 is disposed in the bypass line 36. The dewatering / reverse filtration pump 37 is a pump capable of being driven to deliver liquid in the following directions: the direction in which the dialysate inside the bypass line 36 flows toward the drain line 35 (dewatering direction) and the direction in which the dialysate inside the bypass line 36 flows toward the dialysate outlet line 34 (reverse filtration direction).
[0050] The heater 40 heats the dialysate flowing through the dialysate circuit 30 to a specified temperature.
[0051] The supplemental fluid line 38 is used to directly supply dialysate to the blood circuit 20. For example... Figure 1 As shown, the upstream side of the replenishment fluid line 38 is connected between the dialysate chamber 31 in the dialysate inlet line 33 of the dialysate circuit 30 and the dialysate inlet 113 of the dialyzer 10. A replenishment fluid clamp 381 is provided in the replenishment fluid line 38. (As shown...) Figure 1 As shown by the solid line, when the blood pump 212 in the arterial side line 21 is connected to the dialyzer 10 on the downstream side of the replenishment fluid line 38, it becomes a pre-dilution hemofiltration dialysis. Additionally, as... Figure 1 As shown by the dashed line, when the downstream side of the supplemental fluid line 38 is connected to the venous side lumen 222 in the venous side line 22, it becomes a post-dilution hemofiltration dialysis.
[0052] Description of clamping unit 60.
[0053] like Figure 1As shown, the clamping unit 60 is modularly configured and mounted on the control panel 100. The clamping unit 60 clamps and holds the tube constituting the arterial side conduit 21 and the tube constituting the venous side conduit 22. In the clamping unit 60, the tube constituting the arterial side conduit 21 is arranged vertically along one side of the width direction H, and the tube constituting the venous side conduit 22 is arranged vertically along the other side of the width direction H.
[0054] like Figures 2 to 4 As shown, the clamping unit 60 includes a unit body 61, a cover 62 for opening and closing the unit body 61, a hinge 63, an opening and closing lever 641, and an opening and closing engaging part 642. With the tube constituting the arterial side conduit 21 and the tube constituting the venous side conduit 22 arranged on the inner surface of the unit body 61, the clamping unit 60 presses the inner surface of the cover 62 against the inner surface of the unit body 61, thereby fixing the tube constituting the arterial side conduit 21 and the tube constituting the venous side conduit 22.
[0055] The inner surface of the cap 62 forms a tube fixing part, which fixes the tube constituting the arterial side conduit 21 and the tube constituting the venous side conduit 22 with a certain force. Among the components constituting the inner surface of the cap 62, at least the material used for pressing the tube can be a resin material, such as ABS resin (acrylonitrile-butadiene-styrene copolymer), ASA resin (butadiene replacing ABS resin, obtained by polymerizing acrylic rubber), polypropylene, or other synthetic resins. Therefore, the inner surface of the cap 62 can fix the tube constituting the arterial side conduit 21 and the tube constituting the venous side conduit 22 with a suitable holding force that is sufficient to hold them in place without excessive flattening.
[0056] like Figure 2 As shown, the hinge portion 63 is disposed at the end of the clamping unit 60 on the other side of the width direction H when the cover portion 62 is closed, and rotatably connects the cover portion 62 relative to the unit body 61.
[0057] The opening / closing lever 641 is located at one end of the cover 62 in the width direction H when the cover 62 is closed. For example... Figure 3 As shown, the opening / closing engagement part 642 is provided at one end of the inner surface of the unit body 61 in the width direction H, so as to engage with the opening / closing lever 641 when the cover 62 is closed. By operating the opening / closing lever 641, the unit body 61 and the cover 62 are opened and closed.
[0058] like Figure 3As shown, a main body-side arterial tube configuration portion 611 (tube configuration portion) and a main body-side venous tube configuration portion 612 (tube configuration portion) are formed on the inner surface of the unit body 61. The main body-side arterial tube configuration portion 611 and the main body-side venous tube configuration portion 612 are separately configured on the inner surface of the unit body 61 in the width direction H of the unit body 61 and extend in a straight line. The main body-side venous tube configuration portion 612 is disposed on the hinge portion 63 side in the width direction H, which is closer to the main body-side arterial tube configuration portion 611.
[0059] In addition, such as Figure 3 As shown, a cover-side arterial tube configuration portion 621 and a cover-side venous tube configuration portion 622 are formed on the inner surface of the cover portion 62, which are positioned opposite to the main body-side arterial tube configuration portion 611 when the cover portion 62 is closed. The cover-side arterial tube configuration portion 621 and the cover-side venous tube configuration portion 622 are separately positioned on the inner surface of the cover portion 62 in the width direction H of the cover portion 62 and extend in a straight line. The cover-side venous tube configuration portion 622 is positioned on the hinge portion 63 side, which is further in the width direction H than the cover-side arterial tube configuration portion 621.
[0060] When the cover 62 is closed, a tube constituting an arterial side tube 21 is disposed between the main body side arterial side tube disposal section 611 and the cover side arterial side tube disposal section 621, and a tube constituting a venous side tube 22 is disposed between the main body side venous side tube disposal section 612 and the cover side venous side tube disposal section 622.
[0061] Here, the structure of the arterial side tube configuration section 611 on the main body side and the arterial side tube configuration section 621 on the cover side will be described first.
[0062] like Figure 3 and Figure 5 As shown, when the cover 62 is closed, an upstream arterial tube pressing part 601, an arterial clamping part 65, a load detection part 66, an arterial bubble sensor 67, and a downstream arterial tube pressing part 602 are arranged along the main body-side arterial tube arrangement part 611 and the cover-side arterial tube arrangement part 621. In this embodiment, the upstream arterial tube pressing part 601, the arterial clamping part 65, the load detection part 66, the arterial bubble sensor 67, and the downstream arterial tube pressing part 602 are arranged from the upstream side to the downstream side in the clamping unit 60. Figure 1 and Figure 3 They are arranged side by side in order from bottom to top.
[0063] like Figure 3 As shown, the main body-side arterial side tube arrangement section 611 is disposed on the inner surface of the unit body 61. In the main body-side arterial side tube arrangement section 611, the fluid flowing in the tube constituting the arterial side conduit 21 flows from the upstream side to the downstream side (from...) Figure 3The following components are arranged side by side (from the lower side to the upper side): the receiving recess 601a of the upstream arterial tube pressing part 601, the arterial movable clamping part 651 of the arterial clamping part 65, the load receiving part 662 of the shaft 661 (the force sensor itself is not shown, but is referred to as the force sensor 661) that transmits the load to the force sensor of the load detection part 66, the arterial bubble sensor receiving member 672 that internally houses the ultrasonic oscillation part 671 of the arterial bubble sensor 67, and the receiving recess 602a of the downstream arterial tube pressing part 602.
[0064] The cover-side arterial side tube arrangement 621 is disposed on the inner surface of the cover 62, and is disposed opposite to the main body-side arterial side tube arrangement 611 when the cover 62 is closed. In the cover-side arterial side tube arrangement 621, fluid flows from the upstream side to the downstream side of the tube constituting the arterial side conduit 21. Figure 3 The following components are arranged side by side (from the lower side to the upper side): the pressing protrusion 601b of the upstream artery pressing part 601, the artery side clamping receiving part 652 of the artery side clamping part 65, the load pressing part 663 of the load detection part 66, the artery side bubble sensor pressing member 674 which internally houses the ultrasonic receiving part 673 of the artery side bubble sensor 67, and the pressing protrusion 602b of the downstream artery pressing part 602.
[0065] The pressing protrusion 601b of the upstream arterial tube pressing part 601 is positioned opposite to the receiving recess 601a disposed in the unit body 61 when the cover 62 is closed, on the upstream side of the liquid flowing through the arterial tube 21 in the clamping unit 60. Figure 3 (On the lower side of the middle), press the tube that forms the arterial side channel 21.
[0066] When the cover 62 is closed, the arterial side clamping receiving part 652 is positioned opposite to the arterial side movable clamping part 651 disposed on the unit body 61. The arterial side clamping receiving part 652 and the arterial side movable clamping part 651 constitute the arterial side clamping part 65, which clamps and holds the tube constituting the arterial side conduit 21.
[0067] like Figure 3 and Figure 5 As shown, the arterial side clamping portion 65 includes an arterial side movable clamping portion 651 disposed on the unit body 61, a solenoid 653 disposed on the unit body 61 and driving the arterial side movable clamping portion 651, and an arterial side clamping receiving portion 652 disposed on the cover portion 62. The arterial side clamping receiving portion 652 is formed protruding from the inner surface of the cover portion 62 and extends in the width direction H.
[0068] like Figure 5As shown, the arterial-side movable clamping part 651 is formed as a planar shape with its front end extending in the width direction H, and is also formed as a trapezoidal shape with a narrower front end in a cross-section cut in the direction in which the tube arrangement part extends. The output shaft 653a of the solenoid 653 is retractably connected to the rear end of the arterial-side movable clamping part 651. By moving the output shaft 653a of the solenoid 653 forward and backward, the arterial-side movable clamping part 651 clamps and holds the tube constituting the arterial-side tube 21 or opens and closes the arterial-side tube 21.
[0069] When the blood purification device 1 is operating normally, the arterial side clamping part 65 with the above structure clamps the tube that constitutes the arterial side pipeline 21 disposed between the unit body 61 and the cover part 62 through the arterial side movable clamping part 651 and the arterial side clamping receiving part 652.
[0070] In addition, the arterial side clamping part 65 is opened and closed during the pre-rinsing and blood return processes using dialysis fluid and reverse-filtered dialysis fluid as pre-rinsing fluid. The arterial side clamping part 65 moves the arterial side movable clamping part 651 forward and backward, and flattens the tube constituting the arterial side pipeline 21 to close it or opens it to open it, thereby opening and closing the flow path of the arterial side pipeline 21, thereby allowing the flow / stopping of the liquid flowing inside the tube at a position upstream of the arterial side bubble sensor 67.
[0071] like Figure 3 , Figure 5 as well as Figure 6 As shown, the load pressing part 663 is positioned opposite the load receiving part 662 disposed on the unit body 61 when the cover part 62 is closed, and presses the tube constituting the arterial side conduit 21. A load detection part 66 is disposed inside the load receiving part 662 disposed on the unit body 61. It should be noted that, in order to obtain the same voltage value output from the load detection part 66 when the tube diameter is changed, the load pressing part 663 can be configured to be height-adjustable, or it can be configured to be replaceable with load pressing parts of different heights.
[0072] The load detection unit 66 detects the load received from the tube constituting the arterial side conduit 21 and outputs it as a voltage value. The load detection unit 66 includes a load receiving unit 662 and a force sensor 661. Here, the voltage value, as the detected value, is detected once every 100 milliseconds, and a moving average of 10 values is calculated over 1 second.
[0073] When the cover 62 is closed, the load receiving part 662 receives the pressure from the tube constituting the arterial side conduit 21 that is pressed by the load pressing part 663.
[0074] Force sensor 661 is disposed inside load-bearing portion 662 in unit body 61. Force sensor 661 detects the load pressure load from the tube by moving load-bearing portion 662 radially in the tube through load-bearing portion 662, which in turn moves the load load from the tube. Thus, force sensor 661 outputs the load of the tube pressure constituting arterial side conduit 21 as a voltage.
[0075] The load detection unit 66, having the above structure, presses the tube constituting the arterial side conduit 21 towards the force sensor 661 when the cover 62 is closed. The force sensor 661 detects the load from the pressure of the tube and outputs the load as a voltage value. The detection value detected by the load detection unit 66 is sent to the occlusion determination unit 513 of the control device 50 (described later), which determines whether the tube is occluded. Examples of tube occlusion include forgetting to remove the forceps or release the clamps when connecting the blood circuit to the patient and entering the treatment process; insufficient blood flow due to poor blood removal caused by the puncture needle adhering to the blood vessel wall or poor blood vessel condition during the blood removal and treatment processes; and puncture needle blockage by thrombus during the blood return process.
[0076] When the cover 62 is closed, the arterial bubble sensor pressing member 674 is positioned opposite the arterial bubble sensor receiving member 672 disposed on the unit body 61, pressing the tube constituting the arterial conduit 21. An ultrasonic receiver 673 is disposed inside the arterial bubble sensor pressing member 674. An ultrasonic oscillator 671 is disposed inside the arterial bubble sensor receiving member 672. The ultrasonic receiver 673 and the ultrasonic oscillator 671 constitute the arterial bubble sensor 67. The arterial bubble sensor 67 is a sensor that detects the presence of air bubbles in the liquid flowing inside the arterial conduit 21. It should be noted that it is also possible to configure the ultrasonic receiver 673 to be disposed inside the arterial bubble sensor receiving member 672 and the ultrasonic oscillator 671 to be disposed inside the arterial bubble sensor pressing member 674.
[0077] like Figure 4 As shown, when the cover 62 is closed, the arterial side bubble sensor presses the member 674 (refer to...). Figure 3 The tube constituting the arterial side conduit 21 is pressed towards the arterial side bubble sensor receiving member 672. The ultrasonic oscillation unit 671 detects the presence of bubbles by irradiating the liquid flowing through the tube constituting the arterial side conduit 21 with ultrasonic waves generated from the ultrasonic receiving unit 673, and detecting the difference in transmittance between the liquid and the bubble.
[0078] The pressing protrusion 602b of the downstream arterial tube pressing part 602 is positioned opposite to the receiving recess 602a disposed in the unit body 61 when the cover 62 is closed, downstream of the liquid flowing through the arterial tube 21 in the clamping unit 60. Figure 3 (Above the middle side), press the tube that forms the arterial side channel 21.
[0079] Next, the structure of the vein side tube configuration part 612 on the main body side and the vein side tube configuration part 622 on the cover side when the cover part 62 is closed will be described.
[0080] like Figure 3 As shown, when the cover 62 is closed, an upstream vein-side pressing part 603, a vein-side air bubble sensor 68, a vein-side clamping part 69, and a downstream vein-side pressing part 604 are arranged along the vein-side tube arrangement part 612 on the main body side and the vein-side tube arrangement part 622 on the cover side. In this embodiment, the upstream vein-side pressing part 603, the vein-side air bubble sensor 68, the vein-side clamping part 69, and the downstream vein-side pressing part 604 are arranged from the upstream side to the downstream side in the clamping unit 60. Figure 1 and Figure 3 The two structures are arranged side by side in order from top to bottom.
[0081] like Figure 3 As shown, the main body-side vein-side tube arrangement section 612 is disposed on the inner surface of the unit body 61. In the main body-side vein-side tube arrangement section 612, the liquid flowing through the tube constituting the vein-side conduit 22 flows from the upstream side to the downstream side (from...) Figure 3 The following components are arranged side by side from top to bottom: the receiving recess 603a of the upstream vein pressing part 603, the vein-side bubble sensor receiving member 682 that houses the ultrasonic oscillation part 681 of the vein-side bubble sensor 68, the vein-side movable clamping part 691 of the vein-side clamping part 69, and the receiving recess 604a of the downstream vein pressing part 604.
[0082] A venous side tube arrangement 622 is disposed on the inner surface of the cover 62 and is positioned opposite to the main body side venous side tube arrangement 612 when the cover 62 is closed. In the venous side tube arrangement 622, fluid flows from upstream to downstream of the tube constituting the venous side conduit 22. Figure 3 The pressing protrusion 603b of the upstream pressing part 603 of the vein side, the vein side bubble sensor pressing member 684 which internally houses the ultrasonic receiving part 683 of the vein side bubble sensor 68, the vein side clamping receiving part 692 of the vein side clamping part 69, and the pressing protrusion 604b of the downstream pressing part 604 of the vein side are arranged side by side from the upper side to the lower side.
[0083] The pressing protrusion 603b of the upstream pressing part 603 on the vein side is positioned opposite to the receiving recess 603a disposed on the unit body 61 when the cover 62 is closed, on the upstream side of the liquid flowing through the vein side conduit 22 in the clamping unit 60. Figure 3 (On the upper side of the middle), press the tube that forms the venous side channel 22.
[0084] When the cover 62 is closed, the vein-side bubble sensor pressing member 684 is positioned opposite to the vein-side bubble sensor receiving member 682 disposed on the unit body 61, pressing the tube constituting the vein-side conduit 22. An ultrasonic receiver 683 is disposed inside the vein-side bubble sensor pressing member 684. An ultrasonic oscillating member 681 is disposed inside the vein-side bubble sensor receiving member 682. The ultrasonic receiver 683 and the ultrasonic oscillating member 681 constitute the vein-side bubble sensor 68. The vein-side bubble sensor 68 is a sensor that detects the presence of bubbles in the liquid flowing inside the vein-side conduit 22. It should be noted that it is also possible to configure the ultrasonic receiver 683 to be disposed inside the vein-side bubble sensor receiving member 682 and the ultrasonic oscillating member 681 to be disposed inside the vein-side bubble sensor receiving member 684.
[0085] like Figure 4 As shown, when the cover 62 is closed, the vein-side bubble sensor presses the member 684 (refer to...). Figure 3 The tube constituting the vein-side conduit 22 is pressed towards the vein-side bubble sensor receiving member 682. The ultrasonic oscillation unit 681 detects the presence of bubbles by irradiating the liquid flowing through the tube constituting the vein-side conduit 22 with ultrasonic waves generated from the ultrasonic receiving unit 683, and detecting the difference in transmittance between the liquid and the bubble.
[0086] When the cover 62 is closed, the vein-side clamping receiving part 692 is positioned opposite to the vein-side movable clamping part 691 disposed on the unit body 61. The vein-side clamping receiving part 692 and the vein-side movable clamping part 691 constitute the vein-side clamping part 69, which clamps and holds the tube constituting the vein-side conduit 22.
[0087] like Figure 3 and Figure 6 As shown, the vein-side clamping portion 69 includes a vein-side movable clamping portion 691 disposed on the unit body 61, a solenoid 693 disposed on the unit body 61 and driving the vein-side movable clamping portion 691, and a vein-side clamping receiving portion 692 disposed on the cover portion 62. The vein-side clamping receiving portion 692 is formed protruding from the inner surface of the cover portion 62 and extends in the width direction H.
[0088] The movable clamping part 691 on the vein side is formed as a planar shape with its front end extending in the width direction H, and is also formed as a trapezoidal shape with its width narrowing at the front end in a cross-section cut in the direction in which the tube arrangement part extends. The output shaft 693a of the solenoid 693 is retractably connected to the rear end of the movable clamping part 691 on the vein side. By moving the output shaft 693a of the solenoid 693 forward and backward, the movable clamping part 691 on the vein side clamps and holds the tube constituting the vein side conduit 22, or opens and closes the vein side conduit 22, through the front end of the movable clamping part 691 and the front end of the vein side clamping receiving part 692.
[0089] When the blood purification device 1 is operating normally, the vein-side clamping part 69 with the above structure clamps the tube that constitutes the vein-side pipeline 22 disposed between the unit body 61 and the cover part 62 through the vein-side movable clamping part 691 and the vein-side clamping receiving part 692.
[0090] Furthermore, the vein-side clamping part 69 is controlled based on the detection results of bubbles by the vein-side bubble sensor 68 or the arterial-side bubble sensor 67. When the vein-side bubble sensor 68 or the arterial-side bubble sensor 67 detects that the number of bubbles is greater than a predetermined amount, the vein-side clamping part 69 moves the vein-side movable clamping part 691 in and out, flattening the tube constituting the vein-side conduit 22, thereby closing the flow path of the vein-side conduit 22. This stops the delivery of liquid flowing inside the tube at a position upstream of the vein-side bubble sensor 68.
[0091] The pressing protrusion 604b of the downstream vein-side tube pressing part 604 is positioned opposite to the receiving recess 604a disposed in the unit body 61 when the cover 62 is closed, downstream of the liquid flowing through the vein-side tube 22 in the clamping unit 60. Figure 3 (On the lower side of the middle), press the tube that forms the vein side channel 22.
[0092] With the above-described clamping unit 60 having the cap 62 closed while the tube constituting the arterial side conduit 21 and the tube constituting the venous side conduit 22 are arranged in the unit body 61, the clamping unit 60 can reliably clamp the tubes in the clamping unit 60.
[0093] The control device 50, comprised of an information processing unit (computer), controls the operation of the blood purification device 1 by executing a control program. The control device 50 controls the operation and runs the blood purification device 1 by executing control programs for each step described below. Specifically, the control device 50 controls the operation of various pumps, clamps, and heaters 40 located in the blood circuit 20 and dialysate circuit 30, executing various steps performed by the blood purification device 1 (pre-flushing step, blood removal step, treatment step, fluid replacement step, blood return step, etc.). In the various steps of the blood purification device 1 of this embodiment, for example, the pre-flushing step, blood removal step, treatment step, and blood return step are executed sequentially, and the execution time for all these steps is approximately 4 to 5 hours. Furthermore, in long-term dialysis or overnight dialysis treatment performed during sleep at night, the execution time for all steps is approximately 7 to 8 hours.
[0094] The pre-flushing process is a preparatory process to clean the blood circuit 20 and dialyzer 10.
[0095] The blood removal procedure is a process of filling the blood circuit 20 with the patient's blood after puncture to perform extracorporeal circulation.
[0096] The treatment process follows the blood removal process and involves dialysis to purify the blood.
[0097] The fluid resuscitation procedure is a process of rapidly replenishing fluids when blood pressure drops during dialysis treatment.
[0098] The blood return process is the process of returning the blood in the blood circuit 20 to the patient's body.
[0099] In this embodiment, the control device 50 has the following structure: it updates the reference voltage (reference value) according to the elapsed time of tube use; it expands the tube when the pressure inside the tube becomes positive due to blockage and contracts the tube when it becomes negative; and it issues an alarm when the detected value deviates from the predetermined judgment range used to determine whether a blockage has occurred.
[0100] To achieve the above functions, such as Figure 7 As shown, the control device 50 includes a control unit 51 and a storage unit 52. The control unit 51 includes a reference value generation unit 511, a reference value updating unit 512, an occlusion determination unit 513, and a notification control unit 514. The storage unit 52 stores various control programs for the blood purification device 1.
[0101] The reference value generation unit 511 generates a measured reference value as the voltage detected by the load detection unit 66, which is the voltage of a state where the tube is not blocked, when the blood pump 212 is stopped at a predetermined time. In this case, the detected value and the measured reference value become equal. Specifically, the predetermined time refers to the time elapsed after the arterial side tube 21 is assembled, at the start of the pre-flushing process, at the end of the pre-flushing process, at the start of the blood removal process, at the start of the treatment process, or every predetermined time elapsed from the start of the treatment process, such as every hour. More specifically, assembling the arterial side tube 21 means when the arterial side tube 21 is placed in the clamping unit 60 and the cover 62 is changed from the open state to the closed state. The measured reference value is the value used to calculate the reference value for determining tube occlusion. The reference value refers to, for example, the voltage (detected value) at which no pressure is applied to the tube when the blood pump 212 is rotating (presumably obtained when the blood pump 212 is stopped at this time), and is the voltage of a state where the tube is presumed to be unblocked. This is because, when the blood pump 212 is rotating, the pressure inside the tube varies depending on the patient's vascular condition, the diameter of the puncture needle, and the flow rate setting of the blood pump 212. Therefore, it is impossible to set the voltage during the rotation of the blood pump 212 as a measured reference value for determining occlusion. However, it is difficult to frequently measure the measured reference value by stopping the blood pump 212 during the various processes of the blood purification device 1. Therefore, in this embodiment, the blood pump 212 is stopped at a predetermined time or the measured reference value is generated at the time of stopping. In addition, the time for stopping the blood pump 212 to generate the measured reference value is only about a few seconds, so the measured reference value can be generated with almost no impact during the various processes of the blood purification device 1. Furthermore, the control of stopping the blood pump 212 at a predetermined time can be performed automatically by the control device 50 or by the user operating the operation panel 70.
[0102] The reference value updating unit 512 calculates and updates the reference value based on the change in voltage over time detected by the load detection unit 66 and the measured reference value. More specifically, the reference value is repeatedly calculated and updated at predetermined intervals, such as every minute. Specifically, in the case where a measured reference value is generated every hour and updated every minute during the treatment process, 59 reference values are calculated and updated until the reference value generation unit 511 generates the next measured reference value. For example, periodic processing at predetermined intervals is implemented using the timing function of the control device 50.
[0103] When each reference value is set as reference value (0), reference value (1), ..., reference value (N) and the detected value detected when calculating reference value (N) is set as the detection value (N), the change of the most recent detection value after 1 minute becomes {detection value (N) - detection value (N-1)}, and the reference value (N) can be expressed using the following formula 1.
[0104] Reference value (N) = Reference value (N-1) + {Detected value (N) - Detected value (N-1)} ... Equation 1
[0105] In this way, the reference value update unit 512 sets the reference value based on actual measurements, and calculates the change in the reference value caused by the conformal deformation of the tube based on the change in the detected value, thereby enabling high-precision updating of the reference value. Here, if the blood pump 212 is stopped during the treatment process, the treatment efficiency decreases. Therefore, even if it decreases by a few seconds per hour, it is best not to stop the blood pump 212 during the treatment process to generate the measured reference value. That is, the reference value generation unit 511 generates the measured reference value at the beginning of the treatment process, and the reference value update unit 512 updates the reference value until the end of the treatment process.
[0106] Alternatively, the measured baseline value can be generated every 30 minutes, every 2 hours, etc., and updated every 30 seconds, every 2 minutes, every 3 minutes, etc., allowing for appropriate changes.
[0107] Furthermore, when calculating and updating the reference value (N), if the blood pump 212 stops for some reason, such as issuing an alarm for a purpose other than the purpose of measuring the reference value (other than the specified timing), immediately after the blood pump 212 starts running; or if an obstruction occurs, and the change in the detected value = {detected value (N) - detected value (N-1)} in Equation 1 deviates from the preset range, a predetermined set change amount (a positive value when the change in the detected value is positive, and a negative value when the change in the detected value is negative) can be used instead of the change in the detected value to calculate and update the reference value (N) (see Equation 2). Here, the set change amount refers to a quantity assumed to change due to the compliance deformation of the tube. An appropriate value can be calculated based on tests of the tube used. This value can be preset and stored in the storage unit 52, or the change in the most recent detected value can be used as the set change amount. As a result, the situation where the reference value is updated to an inaccurate value due to reasons other than the compliance deformation of the tube can be reduced.
[0108] Baseline value (N) = Baseline value (N-1) + Set change amount... Equation 2
[0109] Furthermore, when the blood pump 212 is stopped outside of the specified timing period, the most recent reference value (N-1) can be set as the reference value (N), meaning the reference value is not updated. Alternatively, the timing function can be temporarily stopped without updating, and then restarted when the blood pump 212 operates. Additionally, during the blood return process, even when the blood pump 212 is reverse-driven to deliver fluid (blood) upstream of the arterial side tubing 21, the reference value can also be left unupdated. This reduces the likelihood of the reference value being updated to an inaccurate value due to reasons other than tubing conformal deformation (see Equation 3).
[0110] Reference value (N) = Reference value (N-1) ... Equation 3
[0111] Here, the following trend was confirmed: the tube conforms to deformation over time, thereby gradually decreasing the reference value and the amount of change in the detected value (see the embodiment described later). Therefore, the set change amount is preferably set to decrease over time or as the reference value decreases. This allows for more accurate updates to the reference value.
[0112] The occlusion determination unit 513 sets a predetermined determination range for determining whether a tube is occluded based on a reference value (N) updated by the reference value update unit 512. If the detection value detected by the load detection unit 66 deviates from the predetermined determination range, the tube is determined to be occluded. Specific examples are given below. If the determination range is fixed at reference value (N) ± 0.5V, then in the case of occlusion determination during the blood removal process and treatment process, for example, when the reference value (N) is 2.0V, the lower limit of the determination range (occlusion determination value) is 1.5V. Therefore, if the detection value is appropriately set to 1.5V for 1 to 10 seconds (for example, 3 seconds), and remains below this value for more than that time, tube occlusion is determined. Furthermore, in the case of occlusion determination during the blood return process, when the reference value (N) is 2.0V, the upper limit of the determination range (occlusion determination value) is 2.5V. Therefore, if the detection value is appropriately set to 2.5V (e.g., 1 second) for 1 to 3 seconds and remains above this value for more than that time, it is determined that the tube is blocked. When the blockage determination value is greater than the reference value (positive pressure inside the tube), the detection value changes drastically compared to when it is lower than the reference value (negative pressure inside the tube). Therefore, as shown in the specific example, it is preferable to set the determination time to be shorter when the tube is under positive pressure than when it is under negative pressure. Alternatively, the determination range can be set to reference value (N) + 0.6V or reference value (N) - 0.3V. The specified determination range can be appropriately set through experiments (e.g., referring to Example 3 described later) based on the voltage level used, the operating conditions of the tube, etc.
[0113] Here, as described above, the following trend was confirmed: the tube conforms to deformation over time, thereby gradually decreasing the reference value and the amount of change in the detected value (see Embodiment 3 described later). Therefore, the size of the determination range is preferably set to decrease over time or as the reference value decreases. This allows for more accurate determination of occlusion.
[0114] The notification control unit 514 performs the following control: when the blockage determination unit 513 determines that the pipe is blocked, for example, the notification unit such as the display screen, indicator light, and speaker is activated to notify the determination result.
[0115] Furthermore, the notification control unit 514 performs the following control: if, when the cover 62 is closed, it determines that the detection value detected by the load detection unit 66 deviates from a preset range, it activates notification units such as the display screen, indicator lights, and speaker to notify the determination result. Thus, the determination result is not only notified when a blockage is determined, but also when there is an abnormality in the tube (such as when the tube's hardness, diameter, or wall thickness is unsuitable, when the tube is deformed, or when the cover 62 fails to close properly). Therefore, a tube in an appropriate condition can be used, and the detection value detected by the load detection unit 66 can be obtained with high accuracy.
[0116] Next, the advantages of using the clamping unit 60 to clamp the tube constituting the arterial side conduit 21 and for detection by the load detection unit 66 and the arterial side bubble sensor 67 will be explained.
[0117] In this embodiment, in the portion clamped by the main body-side arterial tube configuration section 611 and the cover-side arterial tube configuration section 621 in the clamping unit 60, the arterial side clamping section 65, the load detection section 66, and the arterial side bubble sensor 67 are arranged side-by-side in the section through which the arterial side tube 21 passes. When the medical personnel clamp the tube with the clamping unit 60, the tube can be fixed in the arterial side clamping section 65 simply by closing the cover 62. Therefore, the medical personnel can easily set up settings for detecting the presence of bubbles using the arterial side bubble sensor 67 and detecting the load on the tube using the load detection section 66. In addition, since the arterial side clamping section 65, the load detection section 66, and the arterial side bubble sensor 67 are arranged side-by-side, the load on the tube using the load detection section 66 and the detection of the presence of bubbles using the arterial side bubble sensor 67 can be performed with high precision near the tube being fixed in the arterial side clamping section 65.
[0118] As mentioned above, the softer the tube, the shorter the time it takes for the output voltage detected by the load detection unit 66 to reach stability. Therefore, the tube used in detecting the load on the tube by the load detection unit 66 is preferably made of a soft material to speed up the time until the output voltage stabilizes.
[0119] On the other hand, in this embodiment, the load detection unit 66 and the arterial side bubble sensor 67 are arranged side by side in the clamping unit 60, and the distance between the load detection unit 66 and the arterial side bubble sensor 67 is easily shortened. Here, it was confirmed that because the load detection unit 66 and the arterial side bubble sensor 67 are arranged side by side, when the tube is too soft and becomes blocked, it is flattened. Before the load detection unit 66 detects the load on the tube and determines the blockage, the arterial side bubble sensor 67 may incorrectly detect the presence of bubbles even when there are no bubbles in the tube. More specifically, when the tube has low rigidity, when blood at 36°C or the like flows through it during dialysis treatment, the tube becomes softer due to the high temperature of the blood flowing through it. It was confirmed that when the tube becomes blocked at this time, it is flattened when there is negative pressure inside the tube. Here, the ultrasonic bubble sensor has the part that transmits the sensor signal in close contact with the tube and transmits and receives ultrasonic waves through the tube. Therefore, if the tube is flattened, a gap is created between the bubble sensor and the tube, and ultrasonic waves cannot be received. This state is the same as the state where no voltage can be received when a bubble enters, therefore the arterial bubble sensor 67 makes an incorrect detection. Therefore, the tube used for detecting the presence of bubbles using the arterial bubble sensor 67 is preferably made of a rigid material that is not easily flattened, so that incorrect detections will not occur during prolonged dialysis treatment.
[0120] Therefore, in this embodiment, when the clamping unit 60 is configured with the load detection unit 66 and the arterial side bubble sensor 67 arranged side by side, it is necessary to select the hardness of the tube to ensure high-precision and stable detection using the load detection unit 66 and the arterial side bubble sensor 67. Here, different tube materials can be used in the part that detects the presence of bubbles using the arterial side bubble sensor 67 and the part that detects the load on the tube using the load detection unit 66; however, using different tube materials increases costs and is not practical.
[0121] Therefore, in this embodiment, when using the clamping unit 60 with the arterial side bubble sensor 67 and the load detection unit 66 arranged side by side, in order to perform high-precision detection of the load on the tube by the load detection unit 66 and the detection of bubbles by the arterial side bubble sensor 67, considering that it is preferable for the tube to have low hardness when the load detection unit 66 detects the load, and that the detection of bubbles by the arterial side bubble sensor 67 may be erroneous when the tube hardness is too low, the hardness of the tube is increased to a certain extent. Thus, even when the arterial side bubble sensor 67 and the load detection unit 66 are arranged side by side and close to each other, the load detection unit 66 can detect the load with high precision, and the arterial side bubble sensor 67 can also detect bubbles with high precision.
[0122] For example, when selecting the pipe's hardness based on this viewpoint, and using polyvinyl chloride (PVC) as the pipe material, experiments have shown that, for example, the inner diameter of the pipe is preferably 3.3 to 4.7 mm, the wall thickness is preferably 0.9 to 1.3 mm, and the JIS hardness is preferably 67 to 73. In this embodiment, polyvinyl chloride (PVC) is used as the pipe, and a pipe with an inner diameter of 3.3 mm, a JIS hardness of approximately 70, and a wall thickness of 1.1 mm is used.
[0123] The blood purification device 1 of this embodiment, as described above, achieves the following effects.
[0124] (1) The blood purification device 1 is configured to include: a load detection unit 66, which is disposed upstream of the blood pump 212 in the arterial side conduit 21 and detects the load received by the tube constituting the arterial side conduit 21; a reference value generation unit 511, which generates a measured reference value based on the detection value detected by the load detection unit 66 when the blood pump 212 is stopped at a predetermined time; a reference value updating unit 512, which updates the reference value based on the change in the detection value detected by the load detection unit 66 over time and the measured reference value; and a occlusion determination unit 513, which determines that the tube is occluded when the detection value detected by the load detection unit 66 deviates from a predetermined determination range set according to the reference value for determining whether the tube is occluded. Therefore, even if the output voltage value detected by the load detection unit 66 changes due to the tube's conformal deformation caused by changes in liquid or temperature over time, tube occlusion can be determined with high accuracy. Thus, even during prolonged dialysis treatment, tube occlusion can be determined with high accuracy. By generating and updating measured baseline values at specified intervals, baseline values can be set to correspond to usage conditions and environment, thus ensuring accuracy. Furthermore, the change in baseline values is calculated based on the change in detected values caused by the compliant deformation of the tube, allowing for high-precision updates. Therefore, even when the treatment process lasts for a long time, the baseline values can be set according to changes in detected values regardless of the temperature of the blood purification device's operating environment, thereby improving the accuracy of occlusion determination.
[0125] (2) The reference value updating unit 512 repeatedly updates the reference value at predetermined intervals, and updates the reference value (N) based on the most recently updated reference value (N-1) and the most recent change in the detected value over the predetermined time. Therefore, the change in the reference value is calculated based on the most recent change in the detected value caused by the compliant deformation of the pipe, so the reference value can be updated with high precision, thereby improving the accuracy of the blockage determination.
[0126] (3) When the most recent change in the detected value deviates from the set change range, the reference value update unit 512 updates the reference value based on the most recently updated reference value and the set change. As a result, the situation where the reference value is updated to an inaccurate value due to reasons other than the conformal deformation of the pipe can be reduced, thereby improving the accuracy of the blockage determination.
[0127] (4) In the reference value update unit 512, the set change amount is set to decrease as time passes or as the reference value decreases. As a result, the reference value can be updated with higher precision, thereby improving the accuracy of the blockage determination.
[0128] (5) When the timed blood pump 212 stops outside of a predetermined time, the reference value update unit 512 sets the most recent reference value as the reference value. This reduces the possibility of the reference value being updated to an inaccurate value due to reasons other than tube conformal deformation, thereby improving the accuracy of occlusion determination.
[0129] (6) When the blood pump 212 is driven to deliver fluid to the upstream side of the arterial side tubing 21, the reference value update unit 512 sets the most recent reference value (N-1) as the reference value (N). This reduces the possibility of the reference value being updated to an inaccurate value due to reasons other than tubing compliance deformation, thereby improving the accuracy of occlusion determination.
[0130] (7) The notification control unit 514 is configured to notify the determination result when the detection value detected by the load detection unit 66 deviates from a preset range when the cover 62 is determined to be closed. As a result, a notification is made when the pipe is abnormal, so a pipe in an appropriate state can be used, thereby obtaining the detection value detected by the load detection unit 66 with high accuracy and improving the accuracy of the blockage determination.
[0131] (8) The size of the determination range in the blockage determination unit 513 is set to decrease as time passes or as the reference value decreases. This can further improve the accuracy of blockage determination.
[0132] Example
[0133] (Example 1)
[0134] Next, the results of confirming the changes over time of the reference value calculated and updated by the reference value update unit 512, the detection value detected by the load detection unit 66, and the occlusion determination value that becomes the lower limit of the determination range used by the occlusion determination unit 513 using the blood purification device 1 of the present invention in Embodiment 1 will be explained.
[0135] The blood circuit 20 is assembled and the load detection unit 66 is positioned upstream of the arterial side tubing 21. Immediately after positioning the arterial side tubing 21 with the load detection unit 66, a pre-flushing process is performed. Then, the puncture needle 18G is inserted into the upstream end of the arterial side tubing 21, and the treatment process begins (by rotating the blood pump 212) with water flowing at 250 mL / min at 37°C for 4 hours. Figure 8 The changes in the baseline value, detection value, and occlusion determination value over time are shown in this case. In Example 1, the blood pump 212 is stopped for a few seconds after 1 hour, 2 hours, and 3 hours from the start of the treatment procedure. Here, in this embodiment, only the measured baseline value is generated at the start of the treatment procedure, and no measured baseline value is generated for updating the baseline value after 1 hour, 2 hours, and 3 hours, for example, 4 hours prior.
[0136] Within one minute of the start of the treatment procedure, the set flow rate of blood pump 212 is gradually increased to 250 mL / min, thus increasing the change (decrease) in the detected value. In Example 1, when such a change in the detected value deviates from the assumed range, a predetermined set change is used instead of the change in the detected value to calculate and update the baseline value. Subsequently, the baseline value is repeatedly calculated and updated based on the most recent baseline value and the most recent change in the detected value. Figure 8 The baseline value changed smoothly after approximately 60 minutes (1 hour), and the baseline value after 60 minutes was approximately the same as the value detected when the blood pump 212 was stopped. Therefore, it was confirmed that the baseline value at the initial stage of water infusion, using the measured baseline value at the start of the treatment procedure, could be updated to an appropriate value. Furthermore, it was confirmed that the baseline value also changed smoothly around 120 minutes and 180 minutes, and could be appropriately updated without generating a measured baseline value midway through the 4-hour period. Thus, it was confirmed that the baseline value can be updated with high accuracy over a 4-hour period based on the measured baseline value at the start of the treatment procedure, eliminating the need for prior testing and storage of baseline values, even during prolonged blood purification treatments. It should be noted that... Figure 8 The blockage situation is not illustrated, but the detected value is much lower than the blockage determination value (a value less than the reference value), so the blockage can be properly determined.
[0137] Furthermore, it was confirmed that the baseline value is updated every minute, so changes in the detection value caused by the blood pump 212 stopping for a few seconds have almost no impact on the baseline value update. In Example 1, the occlusion determination value (a value lower than the baseline value) is the value obtained by subtracting a certain value from the baseline value. It should be noted that the case where occlusion occurs during the blood return process when the blood pump 212 is driven to rotate in the opposite direction to deliver fluid (blood) to the upstream side of the arterial side tubing 21 is not illustrated, but since the detection value becomes a value much larger than the occlusion determination value (a value greater than the baseline value) and the baseline value in the blood return process is set not to be updated, occlusion can be appropriately determined.
[0138] (Example 2)
[0139] In Example 2, the results of confirming the changes over time of the reference value, the detected value, and the occlusion determination value that becomes the lower limit of the determination range are described in the same way as in Example 1.
[0140] The blood circuit 20 was assembled and the load detection unit 66 was placed upstream of the arterial side pipe 21. Twelve hours after the arterial side pipe 21 was placed on the load detection unit 66, water at 37°C was passed through for 4 hours under the same conditions as in Example 1. Figure 9 The changes in the baseline value, detected value, and occlusion determination value over time under this condition are shown. Furthermore, it was confirmed that, similar to Example 1, the detected values at 1 hour, 2 hours, and 3 hours after the start of the dialysis procedure, when the blood pump 212 is stopped for a few seconds, are compared with the baseline value, and the baseline value is updated appropriately. Here, in this embodiment, the measured baseline value is only generated at the start of the treatment procedure; no measured baseline value is generated for updating the baseline value until 4 hours have elapsed.
[0141] Approximately one hour after the start of the treatment procedure, the value showing the smallest change in the detected quantity compared to Example 1 was confirmed. It was found that even under these circumstances, the baseline value was calculated and updated based on the change in the detected value per minute. Therefore, the baseline value changed smoothly and was updated appropriately over the 4-hour period.
[0142] Thus, according to the present invention, it is confirmed that even under different usage conditions, such as different compliant deformation states of the tube, the reference value can be updated appropriately.
[0143] (Example 3)
[0144] Example 3 illustrates the experimental results of studying the relationship between the changes in the measured reference value and the detected value.
[0145] Figure 10The results show the measured values (actual reference values) detected by the load detection unit 66 that detects the load on the pipe. The changes in the measured values before and after the blockage are measured according to the degree of pipe's compliance deformation, etc., while changing from a small output state to a large output state. The results are plotted to show the relationship between the measured reference values and the changes in the measured values under the blockage condition.
[0146] With the tube closed, the pressure gauge is connected to the tube and the pressure is changed as follows: starting from 0 mmHg (measured reference value) before the closure is implemented with the blood pump 212 stopped, the pressure in the tube is reduced by 100 mmHg each time while the blood pump 212 is rotating, so that the pressure in the tube becomes negative until -600 mmHg.
[0147] Assemble the blood circuit 20 and place the load detection unit 66 on the upstream side of the arterial side tubing 21. After pre-flushing, under various detection values (actual reference values), measure the changes in detection values from the state of passing water at 37°C to 0 mmHg (actual reference value) before the occlusion is implemented by stopping the blood pump 212, and after the occlusion is implemented with the blood pump 212 rotating at 200 mL / min (each pressure).
[0148] The following was confirmed: a linear approximation (R0) was performed at various pressures. 2 The range was 0.515 to 0.772. The results showed that even under the same pressure inside the pipe, a larger measured reference value resulted in a greater change in the detected value in the case of pipe closure, while a smaller measured reference value resulted in a smaller change in the detected value. Therefore, it was confirmed that the change in the detected value decreased as the reference value decreased. Thus, it was confirmed that setting the range for determining closure to decrease over time or as the reference value decreases improves the accuracy of closure determination.
[0149] (Example 4)
[0150] Based on the results obtained in Example 3, Example 4 is a case in which the lower limit of the judgment range, i.e., the occlusion judgment value, is taken as the case where the reference value is subtracted from the linear approximation of the change in pressure at -400 mmHg in the pipe. Figure 11 The changes over time of the baseline value, the detected value, and the occlusion determination value of Example 4 are shown under the same conditions as in Example 1. Additionally, in... Figure 11 The document also shows an example 1 in which the occlusion determination value is set to constant for comparison (that is, the amount of change relative to the reference value is constant).
[0151] When comparing Example 4 with Example 1, the occlusion determination values were approximately the same at the start of the treatment process. In contrast, from the middle to the later stages of the treatment process, the difference between the occlusion determination value and the reference value in Example 4 decreased, while the difference between the occlusion determination value and the reference value in Example 1 remained constant. Therefore, in the case of Example 4, occlusion determination could be performed with high sensitivity and high accuracy. Thus, it was confirmed that setting the determination range (the absolute value of the difference between the reference value and the occlusion determination value) to decrease as time passes or as the reference value decreases can improve the accuracy of occlusion determination.
[0152] The preferred embodiments of the blood purification device of the present invention have been described above. However, the present invention is not limited to the described embodiments and can be appropriately modified.
[0153] Explanation of reference numerals in the attached figures
[0154] 1: Blood purification device; 10: Blood purifier; 21: Arterial side tubing; 22: Venous side tubing; 61: Unit body; 62: Cover; 66: Load detection unit; 212: Blood pump; 511: Reference value generation unit; 512: Reference value update unit; 513: Occlusion determination unit; 514: Notification control unit; 661: Force sensor.
Claims
1. Blood purification device, equipped with: Blood purifier; An arterial side tubing, connected upstream of the blood purifier; and A pump for delivering fluid is installed in the arterial side tubing. The blood purification device includes: A load detection unit that detects the load received from the tube constituting the arterial side conduit; The reference value generation unit generates a measured reference value by taking the detection value detected by the load detection unit when the pump is stopped at a predetermined time. The reference value update unit updates the reference value based on the change in the detected value over time while the pump is rotating and the measured reference value. as well as The blockage determination unit determines that the pipe is blocked if the detected value deviates from a predetermined determination range set according to the reference value for determining whether the pipe is blocked. The reference value updating unit sets a reference value based on the measured reference value detected by the load detection unit when the pump is stopped, and calculates the change in the reference value over time based on the change in the detected value when the pump is rotating, thereby updating the reference value. When the most recent change in the detected value deviates from a preset range, the reference value update unit updates the reference value based on the most recently updated reference value and a predetermined set change, instead of the change in the detected value over time.
2. The blood purification device according to claim 1, wherein, The benchmark value updating unit repeatedly updates the benchmark value at predetermined intervals, and updates the benchmark value based on the most recently updated benchmark value and the most recent change in the detected value over the predetermined time.
3. The blood purification device according to claim 1, wherein, The set change amount is set to decrease over time or decrease as the reference value decreases.
4. The blood purification device according to any one of claims 1 to 3, wherein, When the pump stops at a time other than the specified time, the reference value update unit sets the most recent reference value as the reference value.
5. The blood purification device according to any one of claims 1 to 4, wherein, When the pump is driven to deliver fluid to the upstream side of the arterial side tubing, the reference value update unit sets the most recent reference value as the reference value.
6. The blood purification device according to any one of claims 1 to 5, wherein, The size of the determination range is set to decrease over time or as the reference value decreases.
7. The blood purification device according to any one of claims 1 to 6, further comprising: Unit body; and The cover allows the unit body to be opened and closed. The load detection unit has a force sensor disposed on the main body of the unit. When the cover is closed, the cover presses the tube against the force sensor, thereby the force sensor detects the load received from the tube. The blood purification device also includes a notification control unit, which notifies the determination result when the load detection unit detects a value that deviates from a preset range when the cover is closed.