Solution emptiness detection device, transfusion device, and solution emptiness detection method

Abstract

To provide a solution emptiness detection device which detects emptiness of a medical solution out of a transfusion bag while keeping the medical solution remaining in a drip tube and a tube on the downstream side of the drip tube, and a transfusion device, and a solution emptiness detection method.SOLUTION: A solution emptiness detection device 10 which is attached to a downstream side tube connected to the downstream side of a drip tube and detects emptiness of a solution out of a transfusion bag in which a medical solution to feed from the upstream side of the drip tube is reserved comprises: a pressure measurement unit 13 which measures the internal pressure of the downstream side tube; a reporting unit 14 which reports abnormality; and a control unit 11 which determines whether or not the medical solution is emptied based on the variation of a sensor value measured by the pressure measurement unit 13, and controls the reporting unit 14 when it is determined that the medical solution is emptied.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an empty liquid detection device, an infusion device, and an empty liquid detection method. [Background technology]

[0002] 2. Description of the Related Art In medical settings, when it is necessary to accurately deliver liquids such as medicinal solutions, nutrients, blood, etc. to patients at a predetermined speed and amount, infusion devices equipped with pumps are used. When administering fluid to a patient, an infusion stand is used to hold the infusion device, infusion bag, etc. The infusion device is fixedly placed in the middle of the infusion stand, the infusion bag is suspended above the infusion stand, and the drip tube is placed between the infusion device and the infusion bag via a tube. This infusion device is easy to carry and can be used in various places such as hospital rooms, ICUs, etc. It also has a function that notifies medical staff with an alarm if any abnormality occurs.

[0003] Some infusion devices have a drip sensor attached to the drip tube to monitor flow rate abnormalities (for example, Patent Document 1). Infusion devices with a drip sensor attached to the drip tube, such as that described in Patent Document 1, if it becomes unable to detect drops falling from the drip tube during infusion, it determines that the medicinal liquid in the infusion bag has run out, stops the pump, and stops the infusion, leaving the medicinal liquid in the drip tube and in the tube downstream of the drip tube. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-177131 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the drip sensor is not attached to the drip tube, the infusion device cannot monitor the drip status of the drip tube, so the pump continues to operate and infuse even when the drip stops. This infusion continues, for example, until the medicinal solution in the tube downstream of the drip tube is empty and the air bubble sensor in the pump detects air bubbles. Therefore, when replacing the infusion bag, the infusion set must be primed, which is time-consuming.

[0006] Therefore, the present invention aims to provide an empty liquid detection device, an infusion device, and an empty liquid detection method that detect when the medicinal liquid in an infusion bag has been emptied while leaving the medicinal liquid in the drip tube and in the tube downstream of the drip tube. [Means for solving the problem]

[0007] The present invention relates to an empty liquid detection device that is attached to a tube connected to the downstream side of an infusion tube and detects empty liquid in an infusion supply member that stores a medicinal liquid to be delivered from the upstream side of the infusion tube, and that includes a pressure measurement unit that measures the internal pressure of the tube, a notification unit that notifies of abnormalities, and a control unit that determines whether the liquid is empty based on changes in the measurement value measured by the pressure measurement unit and controls the notification unit when it is determined to be empty.

[0008] It is also preferable that the pressure measurement unit acquires the measured value by A / D converting the internal pressure of the tube at predetermined time intervals.

[0009] Furthermore, it is preferable that the control unit calculates an approximate straight line using a predetermined number of the measurement values ​​measured by the pressure measurement unit, calculates a predicted value using the calculated approximate straight line, and determines that the liquid is empty when a difference between the calculated predicted value and the measurement values ​​measured by the pressure measurement unit is equal to or greater than a first threshold value.

[0010] Furthermore, it is preferable that the control unit calculates a latest approximate line, which is the approximate line, using a predetermined number of the measurement values ​​including the most recent measurement value measured by the pressure measurement unit, repeats the process of calculating the latest approximate line until the difference between the slope of the calculated latest approximate line and the slope of the previous approximate line, which is the approximate line calculated one time before, becomes equal to or less than a certain value, and calculates the predicted value using the latest approximate line when the difference becomes equal to or less than the certain value.

[0011] The present invention also relates to an infusion device comprising the empty liquid detection device and a pump unit that presses the tube to deliver the liquid.

[0012] Furthermore, it is preferable that the control unit determines that there is a blockage when the difference between the current measurement value, which is the measurement value measured by the pressure measurement unit, and the previous measurement value, which is the measurement value measured one time before, is equal to or greater than a second threshold value, and when it determines that there is a blockage, it controls the alarm unit to issue an alarm different from that issued when it determines that there is an empty liquid.

[0013] The present invention also relates to an empty liquid detection method using an empty liquid detection device that is attached to a tube connected to the downstream side of a drip cylinder and detects empty liquid in an infusion supply member that stores a medicinal liquid to be delivered from the upstream side of the drip cylinder, the empty liquid detection method including a step in which the empty liquid detection device determines whether the empty liquid is empty based on a change in a measurement value measured by a pressure measurement unit that measures the internal pressure of the tube, and a step in which, when it is determined that the empty liquid is empty, the empty liquid detection method controls a notification unit that notifies of an abnormality. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide an empty liquid detection device, an infusion device, and an empty liquid detection method that detect when the medicinal liquid in an infusion bag has been emptied while leaving the medicinal liquid in the drip tube and in the tube downstream of the drip tube. [Brief explanation of the drawings]

[0015] [Figure 1]1 is a diagram showing the state in which an infusion device in an infusion line system according to this embodiment is used. [Figure 2] 1A and 1B are diagrams illustrating the structure of an infusion device according to an embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing the functional blocks of the infusion device according to the present embodiment. [Figure 4] 1 is a diagram showing the progression of a medicinal liquid during infusion in an infusion line system according to this embodiment. FIG. [Figure 5] FIG. 10 is a diagram showing the transition of the sensor value during infusion according to the present embodiment. [Figure 6] 10A and 10B are diagrams for explaining causes of abnormalities during infusion according to the present embodiment and graphs of sensor values ​​at the time of abnormalities. [Figure 7] 4 is a flowchart showing the infusion process of the infusion device according to the present embodiment. [Figure 8] 10 is a flowchart showing an empty liquid detection process of the infusion device according to the present embodiment. [Figure 9] 10 is a flowchart showing a calculation process of the infusion device according to the present embodiment. [Figure 10] 10A and 10B are diagrams for explaining a method for detecting empty liquid using a sensor value according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that this is merely an example, and the technical scope of the present invention is not limited to this example. (Embodiment) FIG. 1 is a diagram showing a state in which an infusion device 1 in an infusion line system 100 according to this embodiment is used. The infusion line system 100 comprises an infusion device 1 and an infusion set 30. The infusion device 1 includes an empty liquid detection device 10, and an infusion set 30 is attached to the infusion device 1. The empty liquid detection device 10 is a device that detects and notifies when an infusion bag 31 containing a medicinal liquid, such as a medicinal liquid or a nutrient (hereinafter referred to as a medicinal liquid), becomes empty when the medicinal liquid is administered to a patient at a predetermined rate and amount. In this embodiment, the empty liquid detection device 10 is incorporated into the infusion device 1. The infusion device 1 is used to monitor the infusion status and is used together with the infusion set 30. The infusion device 1 is fixed to a stand 42 provided on an infusion stand 41.

[0017] Before describing the structure of the infusion device 1 of this embodiment, the infusion set 30 will be described. The infusion set 30 includes an infusion bag 31, an upstream tube 32, a drip tube 33, a downstream tube 34, and a puncture needle 35. The infusion bag 31 is a sealed bag-shaped member that stores a medicinal solution and is made of a transparent and flexible material such as polyethylene.

[0018] The upstream tube 32 is a hollow member configured to be able to deliver the medicinal solution, extending from the infusion bag 31 to the drip tube 33. The downstream tube 34 is a hollow member configured to be able to deliver the medicinal solution, extending from the drip tube 33 to the puncture needle 35. The upstream tube 32 and the downstream tube 34 are made of a transparent and flexible material such as polyvinyl chloride. The drip tube 33 is made of a transparent material such as polypropylene. With this drip tube 33, droplets grow in the upper part of the interior of the drip tube 33, and when the droplets reach a predetermined size, they fall downward and collect in the lower part of the drip tube 33, and the collected medicinal liquid is administered to the patient. The puncture needle 35 is a needle member that is inserted into the body of a patient to administer a medicinal liquid to the patient.

[0019] Next, the structure of the infusion device 1 will be described. FIG. 2 is a diagram illustrating the structure of the infusion device 1 according to this embodiment. The infusion device 1 includes an upper occlusion sensor 2 (pressure measuring unit), an infusion pump 3 (pump unit), a lower occlusion sensor 4, an air bubble sensor 5, and a touch panel liquid crystal display 6. The upper occlusion sensor 2 is provided at the upper part of the infusion device 1 and is a device for measuring the internal pressure of the downstream tube . The infusion pump 3 is a device that delivers a liquid by pressing the downstream tube 34. As the infusion pump 3, for example, a well-known finger pump type pump can be used.

[0020] The lower occlusion sensor 4 is provided at the bottom of the infusion device 1 and is a device that measures the internal pressure of the downstream tube 34. The sensor value measured by the lower occlusion sensor 4 is used to detect occlusion downstream of the infusion pump 3. The air bubble sensor 5 is provided below the lower occlusion sensor 4 of the infusion device 1, and is a device for detecting air bubbles contained in the downstream tube . The touch panel LCD 6 is an input / output unit that sets the amount and time of infusion and displays the infusion status. The touch panel LCD 6 also serves as a notification unit that notifies the user when an abnormality is detected, for example.

[0021] Next, the functional blocks of the infusion device 1 will be described. FIG. 3 is a diagram showing functional blocks of the infusion device 1 according to this embodiment. The infusion device 1 includes an empty liquid detection device 10 and a pump unit 21. The empty liquid detection device 10 includes a control unit 11, a storage unit 12, a pressure measurement unit 13, and a notification unit 14. The control unit 11 is a central processing unit (CPU) that controls the entire infusion device 1, including the empty liquid detection device 10. The control unit 11 cooperates with the above-mentioned hardware to perform various functions by appropriately reading and executing the operating system (OS) and application programs stored in the storage unit 12.

[0022] The control unit 11 performs general infusion-related control, for example, by controlling the pump unit 21 to send a medicinal liquid in the downstream direction so that the medicinal liquid is administered to a patient. The control unit 11 also determines whether the infusion bag 31 is empty based on changes in the sensor values ​​measured by the pressure measurement unit 13, and if it is determined that the infusion bag 31 is empty, controls the notification unit 14 to issue a notification. More specifically, the control unit 11 calculates an approximate line using a predetermined number of sensor values ​​measured by the pressure measurement unit 13, calculates a predicted value using the calculated approximate line, and determines that the infusion bag 31 is empty when the difference between the calculated predicted value and the sensor value measured by the pressure measurement unit 13 is equal to or greater than a first threshold. In this case, the control unit 11 calculates a latest approximate line, which is an approximate line, using a predetermined number of sensor values ​​including the most recent sensor value measured by the pressure measurement unit 13, and repeats the process of calculating the latest approximate line until the difference between the slope of the calculated latest approximate line and the slope of the previous approximate line, which is the approximate line calculated one time previously, becomes equal to or less than a certain value. When the difference becomes equal to or less than the certain value, the control unit 11 calculates the predicted value using the latest approximate line.

[0023] Furthermore, the control unit 11 determines that the downstream tube 34 is blocked when the difference between the current value (current measurement value), which is the sensor value measured by the pressure measurement unit 13, and the previous value (previous measurement value), which is the sensor value measured immediately before that, reaches a second threshold value. If it is determined that the downstream tube 34 is blocked, the control unit 11 controls the notification unit 14 to issue a notification different from that issued when it is determined that the downstream tube 34 is empty.

[0024] The storage unit 12 is a storage area such as a semiconductor memory element for storing programs, data, etc. required for the control unit 11 to execute various processes. The storage unit 12 stores control programs for executing various functions of the control unit 11. The pressure measurement unit 13 is configured with an upper occlusion sensor 2 and measures the internal pressure of the downstream tube 34 at predetermined time intervals. Then, the pressure measurement unit 13 A / D converts the internal pressure of the downstream tube 34 measured at predetermined time intervals to obtain a sensor value (measured value). The sensor value obtained by the pressure measurement unit 13 is used to detect empty liquid in the infusion bag 31. The sensor value measured by the pressure measurement unit 13 is also used to detect an occlusion upstream of the infusion pump 3.

[0025] The notification unit 14 is configured with a touch panel LCD 6 and notifies of abnormalities in infusion. It is desirable that the notification unit 14 notifies the user of the abnormality. The notification unit 14 may notify the user by displaying a message, by using a lamp, or by using both. The pump unit 21 is configured by an infusion pump 3, and is controlled so that the flow rate per unit time becomes a predetermined value. Although not shown, the infusion device 1 has functional parts corresponding to the lower occlusion sensor 4 and the air bubble sensor 5, as well as various other functional parts for functioning as the infusion device 1.

[0026] 3, in this embodiment, the control unit 11, memory unit 12, pressure measurement unit 13, and notification unit 14 provided in the empty liquid detection device 10 are provided in the infusion device 1. This allows the pressure measurement unit 13 provided in the infusion device 1 to be used not only to detect blockage of the downstream tube 34 but also to detect empty liquid. As a modification of this embodiment, the empty liquid detection device 10 may be provided as a separate device from the infusion device 1. In this case, the pressure measurement unit 13 of the empty liquid detection device 10 may be provided at a position where the pressure of the downstream tube 34 can be measured.

[0027] Next, the transition of the sensor value during infusion will be described. FIG. 4 is a diagram showing the progression of the medicinal liquid during infusion in the infusion line system 100 according to this embodiment. FIG. 5 is a diagram showing the transition of the sensor value during infusion according to this embodiment. During infusion in the infusion line system 100, the transition from FIG. 4(A) to FIG. 4(F) is sequentially followed.

[0028] As shown in FIG. 4(A), when the infusion bag 31 is empty of medicinal liquid, the amount of medicinal liquid in the upstream tube 32 decreases downstream as shown in FIG. 4(B). Then, as shown in FIG. 4(C), the upstream tube 32 becomes emptied of medicinal liquid, and the amount of medicinal liquid remaining in the drip tube 33 decreases. Then, as shown in FIG. 4(D), the drip tube 33 becomes emptied of medicinal liquid, and the amount of medicinal liquid in the downstream tube 34 decreases downstream. As shown in FIG. 4(E), when the medicinal liquid falls below line L2, which indicates the position of the upper occlusion sensor 2, the control unit 11 can also report an occlusion. Furthermore, as shown in FIG. 4(F), when the medicinal liquid falls below line L5, which indicates the position of the air bubble sensor 5, the control unit 11 reports an air bubble.

[0029] Fig. 5(A) corresponds to the transition in Fig. 4 and shows the transition of the sensor value measured by the pressure measuring unit 13 during infusion in the form of a graph 51. Fig. 5(B) shows the transition of the graph 51 in section 60 of Fig. 5(A). Graph 51 shows a rising state with large pressure fluctuations immediately after the start of infusion. After that, when the pressure fluctuations stabilize, the sensor value shows a linear progression, and graph 51 approximates a straight line with a constant slope. Graph 51 in the portion excluding section 60 in FIG. 5(A) and the period 61 in FIG. 5(B) corresponds to the state of the infusion line system 100 shown in FIG. 4(A). Thereafter, when the state shown in FIG. 4(B) is reached, that is, when the medicinal liquid in the infusion bag 31 is depleted, the sensor value increases. Therefore, as shown in period 62 in FIG. 5(B), the slope of the graph 51 increases. This is because when the infusion bag 31 is empty, the downstream tube 34 collapses, and the internal pressure of the downstream tube 34 decreases. In other words, the graph 51 during period 62 in FIG. 5(B) corresponds to the state of the infusion line system 100 shown in FIG. 4(B). Graph 51 for period 63 corresponds to the state of the infusion line system 100 shown in Figure 4(C), and graphs 51 for periods 64 to 66 correspond to the states of the infusion line system 100 shown in Figures 4(D) to 4(F), respectively. In this embodiment, the rise in the graph 51 during the period 62 is considered to be an empty liquid detection.

[0030] Here, the change in the graph when the infusion bag 31 becomes empty will be explained in comparison with the change in the graph when the bag is blocked. FIG. 6 is a diagram for explaining causes of abnormalities during infusion according to this embodiment and graphs of sensor values ​​at the time of abnormalities. Graph 51 shows the change in the graph when the infusion bag 31 becomes empty, while graph 52 shows the change in the graph when the bag is blocked. 5, graph 51 detects empty liquid from a change in the range of width W1. On the other hand, graph 52 detects blockage only when there is a change in width W2 up to the upstream blockage detection line Lu. As described above, the change in graph 51 when the infusion bag 31 becomes empty is very small compared to the change in graph 52 when the infusion bag 31 is blocked.

[0031] Next, a process for detecting and reporting a change in the graph when the infusion bag 31 becomes empty will be described. FIG. 7 is a flowchart showing the infusion process of the infusion device according to this embodiment. FIG. 8 is a flowchart showing the empty space detection process of the infusion device according to this embodiment. FIG. 9 is a flowchart showing the calculation process of the infusion device according to this embodiment. FIG. 10 is a diagram for explaining a method of detecting empty liquid using a sensor value according to this embodiment.

[0032] When administering infusion to a patient, the infusion line system 100 is set to the state shown in FIG. 1 and the infusion device 1 is powered on. Then, a medical professional or the like sets various parameters such as the flow rate and planned volume using the touch panel LCD 6 of the infusion device 1. Thereafter, in step S11 of FIG. 7 (hereinafter, "step S" will be simply referred to as "S"), the control unit 11 of the infusion device 1 sets initial values. As an example of setting initial values, the control unit 11 turns off the start flag for empty liquid detection.

[0033] Thereafter, the pump unit 21 of the infusion device 1 is operated, and the control unit 11 starts infusion in S12. In S13, the control unit 11 acquires from the pressure measurement unit 13 the sensor value that the pressure measurement unit 13 acquires by measuring the internal pressure of the downstream tube . In S14, the control unit 11 determines whether or not a blockage has been detected. Since a sudden increase in the sensor value is observed during a blockage (see FIG. 6), the control unit 11 can determine that a blockage has occurred when the difference between the current value, which is the sensor value measured by the pressure measurement unit 13, and the previous value, which is the sensor value measured immediately before, is equal to or greater than the second threshold value (equal to or greater than the width W2 in FIG. 6). If a blockage has been detected (S14: YES), the control unit 11 proceeds to S17. On the other hand, if a blockage has not been detected (S14: NO), the control unit 11 proceeds to S15. In S15, the control unit 11 performs empty liquid detection processing.

[0034] Here, the empty liquid detection process will be described with reference to FIG. In S31 of FIG. 8, the control unit 11 determines whether the empty liquid detection start flag is ON. Here, since the empty liquid detection start flag is set to OFF in the initial value setting, S31 becomes NO immediately after the start of infusion. If the empty liquid detection start flag is ON (S31: YES), the control unit 11 proceeds to S32. On the other hand, if the empty liquid detection start flag is not ON (S31: NO), the control unit 11 proceeds to S35. In S32, the control unit 11 performs empty liquid determination processing, which will be described later.

[0035] In S33, the control unit 11 determines whether the infusion bag 31 is empty as a result of the determination. If the determination result indicates that the infusion bag 31 is empty (S33: YES), the control unit 11 proceeds to S34. On the other hand, if the determination result indicates that the infusion bag 31 is not empty (S33: NO), the control unit 11 proceeds to S35. In S34, the control unit 11 performs a first notification process, and then the process proceeds to S16 in Fig. 7. Here, the first notification process refers to a process for notifying that the liquid is empty. On the other hand, in S35, the control unit 11 performs a calculation process.

[0036] Here, the calculation process will be described with reference to FIG. In S41 of FIG. 9, it is determined whether the number of sensor values ​​measured after the start of infusion has reached a predetermined number. The predetermined number is, for example, 100 for the first infusion and 25 for the second infusion and thereafter. By doing so, the first through 100th sensor values ​​can be obtained for the first infusion, the 26th through 125th sensor values ​​can be obtained for the second infusion, and 100 sensor values ​​offset by 25 for the third infusion and thereafter. If the number of sensor values ​​has reached the predetermined number (S41: YES), the control unit 11 proceeds to S42. On the other hand, if the number of sensor values ​​has not reached the predetermined number (S41: NO), the control unit 11 proceeds to S16 of FIG. 7. In S42, the control unit 11 calculates an approximate straight line.

[0037] Here, calculation of the approximation line will be described with reference to FIG. 10(A) shows the initial approximate straight line 71. The approximate straight line 71 is calculated by arranging the first to 100th sensor values ​​Sv in a two-dimensional matrix with the X axis representing the number of cycles and the Y axis representing the sensor value, and can be expressed as y = a1x + b1. In S43 of Fig. 9, the control unit 11 determines whether an approximate line has already been stored. When the first approximate line is calculated, no other approximate lines are stored. Therefore, the control unit 11 determines NO in S43 and moves the process to S47. On the other hand, when the second or subsequent approximate line is calculated, the previous approximate line will be stored in the subsequent process, so the control unit 11 determines YES in S43 and moves the process to S44.

[0038] In S44, the control unit 11 determines whether the difference in slope between the previous approximate line (previous approximate line) and the current approximate line (latest approximate line) is equal to or smaller than a certain value. FIG. 10(B) shows the first approximate line 71 and the second approximate line 72 when the second approximate line is calculated. The first approximate line corresponds to the previous time, and the second approximate line corresponds to the current time. The second approximate line 72 is obtained from the 26th to 125th sensor values. Here, the first approximate line 71 is expressed as y = a1x + b1, and the second approximate line 72 is expressed as y = a2x + b2. The control unit 11 can determine whether the difference in slope is equal to or smaller than a certain value, for example, by determining whether the absolute value of the slope ratio (|a1x / a2x|) is close to 1. If the difference in the slope of the approximate line between the previous and current times is equal to or less than a certain value (S44: YES), the control unit 11 proceeds to S45. On the other hand, if the difference in the slope of the approximate line between the previous and current times is not equal to or less than a certain value (S44: NO), the control unit 11 proceeds to S46.

[0039] In S45, the control unit 11 sets the empty liquid detection start flag to ON. In S46, the control unit 11 calculates a predicted value. 10C shows the current approximate line 72 and a line 72a obtained by extending the approximate line 72 to the next cycle. In this example, the sensor values ​​from the 126th to the 150th sensor values ​​after the 125th sensor value are predicted by the line 72a. 9, the control unit 11 stores the calculated approximate straight line. After that, the control unit 11 moves the process to S16 in FIG.

[0040] In S16 of Fig. 7, the control unit 11 determines whether or not a notification has been made. If the process of S34 of Fig. 8 has been performed, this process becomes YES; otherwise, this process becomes NO. If a notification has been made (S16: YES), the control unit 11 shifts the process to S18. On the other hand, if a notification has not been made (S16: NO), the control unit 11 shifts the process to S13 and repeats the process of acquiring the sensor value and subsequent processes.

[0041] Here, the empty liquid determination process will be described. If it is determined that there is no obstruction based on the sensor value acquired in S13 of Fig. 7 (NO in S14), the process proceeds to S31 of Fig. 8. If the empty fluid detection start flag is ON (YES in S31), the sensor value at the start of the infusion is removed, and the graph is in a stable state. In this case, empty fluid determination processing is performed in S32 of Fig. 8.

[0042] 10(D) shows the sensor value Sva at the 130th cycle. At this time, the control unit 11 can determine whether the liquid is empty by determining the extent of the difference Wx between the acquired sensor value Sva and the straight line 72a, which is the predicted value. If the acquired sensor value Sva is at approximately the same position as the straight line 72a, which is the predicted value, the control unit 11 determines that the liquid is not empty, assuming that the difference Wx between the acquired sensor value Sva and the predicted value is almost zero. On the other hand, if the acquired sensor value Sva is at a position that deviates from the straight line 72a, which is the predicted value, the control unit 11 determines that the liquid is empty, assuming that the difference Wx between the acquired sensor value Sva and the predicted value is equal to or greater than the first threshold value.

[0043] 7, in S17, the control unit 11 performs a second notification process. The second notification process is a notification that is performed when a blockage occurs. In S18, the control unit 11 stops the infusion when a predetermined state is reached, and ends this process.

[0044] An embodiment of the present invention has been described above. The present invention is not limited to the present embodiment, and includes modifications and improvements within the scope of achieving the object of the present invention. In this embodiment, the number of sensor values ​​used to calculate the approximate line is 100, and the approximate line is calculated by shifting the sensor values ​​by 25. Specifically, the first time, the first to 100th sensor values ​​are used, the second time, the 26th to 125th sensor values ​​are used, and the third time, the 51st to 150th sensor values ​​are used, but the present invention is not limited to this. The number of sensor values ​​used to calculate the approximate line and the number of sensor values ​​shifted to calculate the approximate line are merely examples.

[0045] In the present embodiment, the sensor values ​​are acquired at a predetermined cycle, but this is not limiting. The sensor values ​​may be acquired at predetermined time intervals, or may be acquired in accordance with the operation of the pump unit. Furthermore, the timing for calculating the approximate line may be at predetermined time intervals, rather than at predetermined intervals.

[0046] In this embodiment, when the difference in slope between the most recent approximate line and the previous approximate line is equal to or less than a certain value, the most recent approximate line is used to calculate the predicted value. However, this is not limiting. For example, the calculation of the approximate line may not be performed from the start of infusion until the sensor value stabilizes, and the approximate line may be calculated and the predicted value may be calculated when the sensor value stabilizes. Note that the period until the sensor value stabilizes may be specified in advance as a time based on empirical rules, etc.

[0047] In the present embodiment, a finger pump type pump is used as the pump unit, but the present invention is not limited to this. For example, a roller pump type pump in which a roller rotates and squeezes a tube to send liquid may be used. The present invention may also be applied to a flow rate control type infusion device that controls the flow rate of infusion by the rotation speed of the roller pump, etc., and the process of measuring the internal pressure of the downstream tube 34 and acquiring the sensor value may be performed for each rotation.

[0048] As described above, the infusion device 1 according to this embodiment has the following advantages. (1) An empty liquid detection device 10 is attached to a downstream tube 34 connected to the downstream side of an infusion tube 33 and detects empty liquid in an infusion bag 31 that stores medicinal liquid delivered from the upstream side of the infusion tube 33. The empty liquid detection device 10 includes a pressure measurement unit 13 that measures the internal pressure of the downstream tube 34, an alarm unit 14 that notifies of abnormalities, and a control unit 11 that determines whether the liquid is empty based on changes in the sensor value measured by the pressure measurement unit 13 and controls the alarm unit 14 when it determines that the liquid is empty. This makes it possible to determine whether the infusion bag 31 is empty based on a change in the sensor value measured by the pressure measuring unit 13, which measures the internal pressure of the downstream tube 34, and therefore it is possible to determine that the infusion bag 31 is empty while leaving the medicinal solution in the drip tube 33 and the downstream tube 34. In addition, since an alarm can be issued when it is determined that the infusion bag 31 is empty, medical personnel can be notified, and when replacing the infusion bag 31, infusion can be started without priming the infusion set 30, which is convenient.

[0049] (2) In the empty liquid detection device 10 described in (1), the pressure measurement unit 13 performs A / D conversion on the internal pressure of the downstream tube 34 at predetermined time intervals to obtain a sensor value. This allows the sensor value obtained by measuring the internal pressure of the downstream tube 34 to be obtained periodically.

[0050] (3) In the empty liquid detection device 10 described in (1) or (2), the control unit 11 calculates an approximate straight line using a predetermined number of sensor values ​​measured by the pressure measurement unit 13, calculates a predicted value using the calculated approximate straight line, and determines that the liquid is empty when the difference between the calculated predicted value and the sensor value measured by the pressure measurement unit 13 is equal to or greater than a first threshold value. This makes it possible to determine whether the downstream tube 34 is empty by detecting the change in the sensor value based on the empirical rule that the internal pressure of the downstream tube 34 changes when the tube becomes empty.

[0051] (4) In the empty liquid detection device 10 described in (3), the control unit 11 calculates a latest approximate line, which is an approximate line, using a predetermined number of sensor values ​​including the most recent sensor value measured by the pressure measurement unit 13, and repeats the process of calculating the latest approximate line until the difference between the slope of the calculated latest approximate line and the slope of the previous approximate line, which is the approximate line calculated one time before, becomes equal to or less than a certain value.When the difference becomes equal to or less than a certain value, the control unit 11 calculates the sensor value using the latest approximate line. This allows the state immediately after the start of infusion to be excluded, and the empty infusion status to be determined using values ​​when the medicinal solution is stable, allowing for more precise predictions.

[0052] (5) The infusion device 1 includes the empty liquid detection device 10 according to any one of (1) to (4) and a pump unit 21 that presses the downstream tube 34 to deliver the liquid. This allows the empty infusion bag 31 to be detected simply by using the infusion device 1.

[0053] (6) In the infusion device 1 described in (5), when the difference between the current value, which is the sensor value measured by the pressure measuring unit 13, and the previous value, which is the sensor value measured one time before, becomes equal to or greater than a second threshold value, the control unit 11 determines that there is an obstruction and controls the alarm unit 14 to issue an alarm different from that issued when it is determined that there is an empty liquid. This allows for the determination of blockage in addition to the determination of empty liquid using the upper blockage sensor 2 provided in the infusion device 1. The infusion device 1 can provide multiple functions such as empty liquid detection and blockage detection. [Explanation of symbols]

[0054] 1 Infusion device 2 Upper occlusion sensor 3. Infusion pump 6 Touch panel LCD 10 Empty liquid detector 11 Control section 12 Storage section 13 Pressure measurement section 14. Information Department 21 Pump section 30 infusion sets 31 Infusion bag 32 Upstream tube 33 Drip tube 34 Downstream tube 41 Infusion stand 42 Mounting stand 100 Infusion Line System

Claims

1. An empty liquid detection device that is attached to a tube connected to the downstream side of an infusion tube and detects empty liquid in an infusion supply member that stores a medicinal liquid to be delivered from the upstream side of the infusion tube, a pressure measuring unit for measuring the internal pressure of the tube; a notification unit that notifies of an abnormality; a control unit that determines whether or not the liquid is empty based on a change in the measurement value measured by the pressure measurement unit, and controls the notification unit when it determines that the liquid is empty; An empty liquid detection device comprising:

2. The empty liquid detection device according to claim 1, The pressure measuring unit performs A / D conversion on the internal pressure of the tube at predetermined time intervals to obtain the measured value.

3. 3. The empty liquid detection device according to claim 2, The control unit calculating an approximate straight line using a predetermined number of the measured values ​​measured by the pressure measuring unit; Calculating a predicted value using the calculated approximation line; The empty liquid detection device determines that the liquid is empty when a difference between the calculated predicted value and the measured value measured by the pressure measurement unit is equal to or greater than a first threshold value.

4. 4. The empty liquid detection device according to claim 3, The control unit calculating a latest approximate line, which is the approximate line, using a predetermined number of the measurement values ​​including the most recent measurement value measured by the pressure measurement unit, and repeating the process of calculating the latest approximate line until a difference between a slope of the calculated latest approximate line and a slope of a previous approximate line, which is the approximate line calculated immediately before, becomes equal to or less than a certain value; When the difference becomes equal to or smaller than a certain value, the empty liquid detection device calculates the predicted value using the latest approximate straight line.

5. The empty liquid detection device according to any one of claims 1 to 4, a pump unit that presses the tube to send a liquid; An infusion device comprising:

6. 6. The infusion device according to claim 5, The control unit When a difference between a current measurement value, which is the measurement value measured by the pressure measurement unit, and a previous measurement value, which is the measurement value measured immediately before, is equal to or greater than a second threshold value, it is determined that there is a blockage; The infusion device controls the notification unit when it is determined that the blockage has occurred, and issues a notification different from that when it is determined that the empty solution has occurred.

7. An empty liquid detection method using an empty liquid detection device that is attached to a tube connected to the downstream side of an infusion tube and detects empty liquid in an infusion supply member that stores a medicinal liquid to be delivered from the upstream side of the infusion tube, The empty liquid detection device is a step of determining whether or not the liquid is empty based on a change in a measurement value measured by a pressure measuring unit that measures the internal pressure of the tube; a step of controlling a notification unit that notifies an abnormality when it is determined that the liquid is empty; An empty liquid detection method comprising:

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