Medical Fluid Warming Device

Abstract

To provide a transfusion device capable of grasping the maximum flow of a blood product for allowing the blood product to reach a target temperature in a warming part.SOLUTION: A transfusion device 1 includes passages 50, 25-29 through which a blood product flows, a warming part 21 for warming the blood product in a warming passage 50 by a heater 51, a first pump 23 and a second pump 24 for sending the blood product in the passages 50, 25-29, a wattmeter 32 for detecting actual power fed to the heater 51, and a flow amount calculation part for calculating the maximum flow of the blood product in the warming part 21, for allowing the blood product at a passage outlet 61 of the warming part 21 to reach a target temperature by heating by the heater 51, based on the actual power detected by the wattmeter 32.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a medical fluid warming device. [Background technology]

[0002] In hospitals, blood products are stored in a refrigerator to maintain the quality of the blood products that are infused into patients. When infusing blood products into patients, the blood products must be warmed to an appropriate temperature before infusion to reduce the burden on the patient. In particular, in cases of massive or critical bleeding, it is necessary to infuse a large amount of blood products in a short period of time, and in such cases, it is necessary to rapidly warm the blood products to the patient's body temperature to prevent hypothermia.

[0003] Conventionally, infusion devices that infuse a heated blood product into a patient have been used to treat patients who have experienced the above-mentioned massive or critical bleeding. The infusion device has a heating section that uses a heater to heat the blood product flowing through a heating flow path of a specified length, and heats the blood product to a target temperature (a temperature equivalent to body temperature) by setting the flow rate of the blood product according to the heat generation capacity of the heater (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-187606 A Summary of the Invention [Problem to be solved by the invention]

[0005] In some cases, the infusion device is powered by a commercial power source, and in this case, wiring is used to connect the commercial power source to the infusion device's power supply, and from the power supply to the heater. The power supply is also connected to a number of other devices, such as a pump, by wiring to supply power to each device.

[0006] However, if the infusion device has complicated wiring such as multiple power strips, a large current may flow through the wiring, causing a voltage drop. In this case, sufficient power may not be supplied to the heater in the heating flow path of the heating unit of the infusion device, and the blood product may not reach the target temperature (corresponding to body temperature).

[0007] In such cases, in order to bring the blood product up to the target temperature with less power supply, it is necessary to reduce and adjust the flow rate of the blood product in the heating flow path of the heating unit, but the user does not know how to adjust the flow rate of the blood product in the heating unit.

[0008] The present application has been made in consideration of such points, and one of its objectives is to provide a medical liquid warming device, such as an infusion device, that is capable of grasping the maximum flow rate of liquid for causing liquid, such as blood products, to reach a target temperature in the heating section. [Means for solving the problem]

[0009] After much investigation, the inventors discovered that the above problems could be solved by providing a medical liquid heating device with an actual power detection unit that detects the actual power supplied to the heater, and a flow rate calculation unit that calculates the maximum flow rate of liquid in the flow path of the heating section so that the liquid at the flow path outlet of the heating section reaches the target temperature through the heat generated by the heater, and thus completed the present invention.

[0010] That is, the present invention includes the following aspects. (1) A medical liquid warming device comprising: a flow path through which a liquid flows; a heating unit having a heater that generates heat when powered, and which heats the liquid in the flow path using the heater; a liquid delivery unit that delivers the liquid in the flow path; an effective power detection unit that detects the effective power supplied to the heater; and a flow rate calculation unit that calculates, based on the effective power detected by the effective power detection unit, a maximum flow rate of liquid in the flow path of the heating unit, for liquid at a flow path outlet of the heating unit to reach a target temperature through the heat generated by the heater. (2) The medical liquid warming device according to (1), wherein the effective power detection unit is a power meter. (3) A medical liquid warming device as described in (2), comprising a power supply unit connected to the heater and supplying power to the heater, and the actual power detection unit is provided in the wiring between the power supply unit and the heater. (4) A medical liquid warming device as described in (2) or (3), further comprising a temperature estimation unit that estimates the temperature of the liquid at the flow path outlet of the heating unit based on the actual power detected by the actual power detection unit, and an alarm unit that issues a warning when the temperature estimated by the temperature estimation unit is lower than a predetermined threshold value. (5) The medical liquid heating device described in (1), wherein the effective power detection unit has a temperature sensor for detecting the temperature difference between the liquid at the flow path outlet and the flow path inlet of the heating unit, and an effective power calculation unit for calculating the effective power based on the temperature difference between the liquid at the flow path outlet and the flow path inlet of the heating unit detected by the temperature sensor and the flow rate of the liquid in the flow path of the heating unit. (6) A medical liquid warming device as described in any one of (1) to (3) and (5), further comprising a temperature sensor that measures the temperature of the liquid at the flow path outlet of the heating unit, and an alarm unit that issues a warning when the temperature measured by the temperature sensor is lower than a predetermined threshold value. (7) A medical liquid warming device as described in any one of (1) to (3) or (5), further comprising a low voltage detection circuit in a power supply unit that supplies power to the heater, which detects a low voltage at which the temperature of the liquid at the flow path outlet of the heating unit falls below a predetermined threshold, and an alarm unit that issues a warning when low voltage is detected by the low voltage detection circuit. (8) The medical liquid warming device according to any one of (1) to (7), further comprising a display unit that displays the maximum flow rate calculated by the flow rate calculation unit. (9) The medical liquid warming device according to any one of (1) to (8), further comprising a selection unit for selecting whether or not to change the set flow rate of the liquid in the flow path of the heating unit to the maximum flow rate. (10) The medical liquid warming device according to any one of (1) to (9), further comprising a control unit that controls the liquid delivery unit so that the flow rate of liquid in the flow path of the heating unit becomes the maximum flow rate. Effect of the Invention

[0011] According to the present invention, it is possible to provide a medical liquid warming device that is capable of grasping the maximum flow rate of liquid for making the liquid reach a target temperature in the heating section. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an infusion device according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram of a control unit. [Diagram 3] FIG. 2 is an explanatory diagram showing a display example of a display. [Figure 4] FIG. 2 is a block diagram of a control unit. [Diagram 5] 11 is an explanatory diagram showing an example of a display on a display when a warning is issued; FIG. [Figure 6] FIG. 1 is a schematic diagram showing the configuration of an infusion device having a temperature sensor. [Figure 7] FIG. 11 is a schematic diagram showing the configuration of an infusion device according to a second embodiment. [Figure 8] 1 is a schematic diagram showing the configuration of an infusion device having a low-voltage detection circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The same elements are given the same reference numerals, and duplicated descriptions will be omitted. Furthermore, unless otherwise specified, the positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of the drawings are not limited to the illustrated ratios. Furthermore, the following embodiments are examples for explaining the present invention, and the present invention is not limited to these embodiments.

[0014] <First embodiment> 1 is a schematic diagram showing an example of the outline of the configuration of an infusion device 1 as a medical liquid warming device according to the present embodiment. The infusion device 1 has, for example, a liquid storage section 20 for storing a blood product as a liquid, a heating section 21, a drip chamber 22, a first pump 23 as a liquid delivery section, a second pump 24, a first flow path 25, a second flow path 26, a third flow path 27, a fourth flow path 28, a fifth flow path 29, a power supply section 30, wiring 31, a power meter 32 as an effective power detection section, and a control section 33.

[0015] The liquid storage portion 20 is made of, for example, a soft resin, and has a capacity of, for example, 0.5 L or more. The soft material of the liquid storage portion 20 may be, for example, polyvinyl chloride (PCV), polycarbonate (PC), ABS resin, or the like.

[0016] The heating unit 21 has a heating flow path 50 through which the blood product flows, and a heater 51 that heats the heating flow path 50 by coming into contact with it. The heating flow path 50 has a flow path inlet 60 and a flow path outlet 61, and meanders from the flow path inlet 60 to the flow path outlet 61. The heater 51 is, for example, an electric heating wire that generates heat when power is supplied, and is arranged in a predetermined pattern within the heating plate surface.

[0017] The first flow path 25 is for connecting the blood product bag 70 and the liquid storage section 20, and is connectable to the blood product bag 70 on the upstream side and connected to the liquid storage section 20 on the downstream side.

[0018] The second flow path 26 connects the liquid storage section 20 and the heating section 21, with its upstream side connected to the lower part of the liquid storage section 20 and its downstream side connected to the flow path inlet 60 of the heating flow path 50 of the heating section 21.

[0019] The third flow path 27 connects the heating section 21 and the drip chamber 22, and is connected on the upstream side to the flow path outlet 61 of the heating flow path 50 of the heating section 21 and on the downstream side to the upper part of the drip chamber 22.

[0020] The fourth flow path 28 is for connecting the drip chamber 22 to a patient, and is connected at its upstream side to the lower part of the drip chamber 22 and at its downstream side to a puncture part 80 for connection to the patient.

[0021] The fifth flow path 29 connects the drip chamber 22 and the liquid storage portion 20, and is connected to the upper part of the drip chamber 22 on the upstream side and to the upper part of the liquid storage portion 20 on the downstream side.

[0022] The first to fifth flow paths 25 to 29 are soft tubes.

[0023] The first pump 23 is provided in the second flow path 26. The first pump 23 is, for example, a tube pump that pumps the liquid in the tube by manipulating the tube of the second flow path 26. The first pump 23 can adjust the flow rate of the blood product flowing through the heating flow path 50 connected to the second flow path 26.

[0024] The second pump 24 is provided in the fourth flow path 28. The second pump 24 is, for example, a tube pump that pumps the liquid in the tube by manipulating the tube of the fourth flow path 28. The second pump 24 can adjust the flow rate of the blood product supplied to the patient.

[0025] The power supply unit 30 supplies power to various devices of the infusion device 1, for example, the heater 51 of the heating unit 21, the first pump 23, and the second pump 24 through wiring 31. The power supply unit 30 can be connected to, for example, a commercial power source and can obtain power from the commercial power source.

[0026] The wiring 31 is connected from the power supply unit 30 to the heater 51 of the heating unit 21, the first pump 23, the second pump 24, and the like.

[0027] The power meter 32 is connected, for example, between the power supply unit 30 of the wiring 31 and the heater 51 of the heating unit 21. The power meter 32 can measure the effective power (actual power) supplied to the heater 51.

[0028] The control unit 33 is, for example, a general-purpose computer, and can execute a program recorded in the memory with a CPU to control the power supply unit 30, the power meter 32, the heater 51 of the heating unit 21, the first pump 23, the second pump 24, etc., to execute the infusion process in the infusion device 1. The control unit 33 can heat a predetermined flow rate of the blood product flowing through the heating flow path 50 of the heating unit 21 to a predetermined target temperature, for example, by controlling the power supply unit 30 to supply a predetermined amount of power from the power supply unit 30 to the heater 51 and cause the heater 51 to generate heat at a predetermined amount.

[0029] As shown in FIG. 2, the control unit 33 further includes a flow rate calculation unit 100 that calculates a maximum flow rate Qm of the blood product in the heating flow path 50 for the blood product at the flow path outlet 61 of the heating unit 21 to reach a target temperature through the heat generated by the heater 51, based on the effective power detected by the power meter 32, a display unit 101 that displays the maximum flow rate Qm of the blood product calculated by the flow rate calculation unit 100, and a selection unit 102 that selects whether or not to change the set flow rate of the blood product in the heating flow path 50 of the heating unit 21 to the maximum flow rate Qm.

[0030] The flow rate calculation unit 100 has a function of calculating the maximum flow rate Qm of the blood product based on the effective power Pd detected by the power meter 32 using a general formula, for example, the following formula 1. (Tout-Tin)×(Qm / 60)×D=Pd...(Formula 1) Tout is the target temperature of the blood product at the flow path outlet 61 of the heating unit 21, Tin is the temperature of the blood product at the flow path inlet 60 of the heating unit 21 (the temperature of the blood product before heating), and D is the specific heat of the blood product.

[0031] The display unit 101 has a function of displaying the target temperature Tout and the maximum flow rate Qm of the blood product at which the target temperature Tout can be achieved using the available power Pd on a display 110 of the control unit 33 as shown in FIG.

[0032] The selection unit 102 has a function of displaying, for example, on the display 110 of the control unit 33, a selection button 111 for selecting whether or not to change the set flow rate Q of the blood product in the heating flow path 50 of the heating unit 21 to the maximum flow rate Qm.

[0033] Next, a description will be given of the operation of the infusion device 1 configured as above. When infusion is performed, for example, the temperature of the prepared blood product (e.g., about 4°C), the target temperature of the heated blood product to be supplied to the patient (e.g., 37°C equivalent to body temperature), and the set flow rates Q of the first pump 23 and the second pump 24 are input and set in the control unit 33.

[0034] 1, a blood product bag 70 containing a prepared blood product is connected to the first flow path 25, and the blood product in the blood product bag 70 falls by gravity through the first flow path 25 and is contained in the liquid storage unit 20. When infusion is started, the first pump 23 and the second pump 24 are operated, and the blood product in the liquid storage unit 20 is sent by the first pump 23 through the second flow path 26 to the heating unit 21. In the heating unit 21, the blood product passes through the heating flow path 50, and during the passage, the blood product is heated by the heater 51 to a target temperature equivalent to body temperature.

[0035] The blood product heated to the target temperature in the heating unit 21 passes through the third flow path 27 and flows into the drip chamber 22. The blood product is then pumped by the second pump 24 through the fourth flow path 28 and supplied to the patient through the puncture unit 80.

[0036] Additionally, air bubbles generated in the blood product in heating unit 21 are captured in drip chamber 22. A portion of the blood product and gas in drip chamber 22 is returned to liquid storage unit 20 through fifth flow path 29.

[0037] Then, the power meter 32 measures the effective power Pd supplied from the power supply unit 30 to the heater 51, and outputs the effective power Pd to the control unit 33. This measurement and output of the effective power Pd may be performed continuously at all times, may be performed intermittently multiple times, or may be performed once during the infusion process. Next, the flow rate calculation unit 100 calculates the maximum flow rate Qm of the blood product at the flow path outlet 61 of the heating unit 21 for the blood product to reach the target temperature by the heat generated by the heater 51 based on the effective power Pd detected by the power meter 32.

[0038] 3, the maximum flow rate Qm of the blood product calculated by the flow rate calculation unit 100 is displayed on the display 110 of the control unit 33 by the function of the display unit 101. Furthermore, a selection button 111 for selecting whether or not to change the set flow rate Q of the blood product in the heating flow path 50 to the maximum flow rate Qm is displayed on the display 110 of the control unit 33 by the function of the selection unit 102. If the user selects "change", the set flow rate Q of the blood product in the control unit 33 is changed to the maximum flow rate Qm, and then the control unit 33 controls the first pump 23 so that the flow rate of the blood product in the heating flow path 50 becomes the maximum flow rate Qm.

[0039] According to this embodiment, the infusion device 1 includes a power meter 32, which is an effective power detection unit that detects the effective power supplied to the heater 51, and a flow rate calculation unit 100 that calculates the maximum flow rate Qm of the blood product at the flow path outlet 61 of the heating unit 21 to reach the target temperature based on the effective power detected by the power meter 32. This makes it possible to grasp the maximum flow rate of the blood product to make the blood product reach the target temperature in the heating unit 21. As a result, even if a large current flows through the wiring leading to the heater 51 in the infusion device 1 and a voltage drop occurs in the heater 51, for example, the user can reduce the flow rate of the blood product in the heating unit 21 to make the blood product reach the target temperature. As a result, it is possible to prevent the patient from suffering from hypothermia.

[0040] Since the effective power detection unit is the power meter 32, the effective power supplied to the heater 51 can be reliably and accurately grasped.

[0041] Since the power meter 32 is provided on the wiring 31 between the power supply unit 30 and the heater 51, the effective power can be detected at a position close to the heater 51, and as a result, the effective power supplied to the heater 51 can be accurately grasped.

[0042] Since the infusion device 1 includes the display unit 101 that displays the maximum flow rate Qm calculated by the flow rate calculation unit 100, the user can easily and quickly grasp the maximum flow rate Qm.

[0043] Since the infusion device 1 includes a selection unit 102 for selecting whether or not to change the set flow rate Q of the heating flow path 50 of the heating unit 21 to the maximum flow rate Qm, the user can easily change the set flow rate.

[0044] In this embodiment, the infusion device 1 may further include a temperature estimation unit 120 that estimates the temperature of the blood product at the flow path outlet 61 of the heating unit 21 based on the effective power Pd detected by the power meter 32, and an alarm unit 121 that issues a warning when the temperature estimated by the temperature estimation unit 120 is lower than a predetermined threshold value, as shown in, for example, Fig. 4. The temperature estimation unit 120 and the alarm unit 121 are realized by, for example, the control unit 33.

[0045] The temperature estimation unit 120 has a function of estimating the temperature (outlet temperature) Td(out) of the blood product at the flow path outlet 61 of the heating unit 21, for example, by the following equation 2. (Td(out)-Tin) × (Q / 60) × D = Pd (Equation 2) Tin is the temperature of the blood product at the flow channel inlet 60 of the heating unit 21 (the temperature of the blood product before heating), D is the specific heat of the blood product, and Q is the set flow rate of the heating flow channel 50 of the heating unit 21. Note that Tin at the flow channel inlet 60 may be detected by a temperature sensor.

[0046] When the outlet temperature Td(out) is lower than a predetermined threshold value E (Td(out) < E), the notification unit 121 has functions such as displaying the outlet temperature Td(out) and a warning on the display 110 of the control unit 33 as shown in FIG. 5, for example, and outputting a warning sound using a speaker (not shown) of the control unit 33. The predetermined threshold value E is not particularly limited, but a target temperature Tout or a temperature lower than the target temperature Tout is set.

[0047] According to such an example, it is possible to surely notify the user that the outlet temperature Td(out) of the blood preparation in the heating unit 21 does not reach the target temperature Tout.

[0048] Further, in the above example, the infusion device 1 may have a temperature sensor 130 that measures the temperature Td(out) of the blood preparation at the flow path outlet 61 of the heating unit 21 as shown in FIG. 6, for example. When the outlet temperature Td(out) measured by the temperature sensor 130 is lower than a predetermined threshold value E, the notification unit 121 may notify a warning as shown in FIG. 5, for example. In this case, it is possible to accurately and surely notify the user that the outlet temperature Td(out) of the blood preparation in the heating unit 21 does not reach the target temperature Tout, and hypothermia of the patient can be prevented.

[0049] In the present embodiment, the power meter 32 may be provided in the wiring between the power supply unit 30 and the commercial power supply. The power meter 32 may be provided in the heating unit 21 or may be provided in the housing of the power supply unit 30. Further, for example, the display unit 101 and the selection unit 102 may not be provided.

[0050] <Second Embodiment> In the first embodiment, the power meter 32 is used as the available power detection unit, but as shown in FIG. 7, the available power detection unit 150 may have temperature sensors 151, 152 for detecting the temperature difference between the blood product at the flow path outlet 61 and the flow path inlet 60 of the heating unit 21, and an available power calculation unit 153 for calculating the available power based on the temperature difference between the blood product at the flow path outlet 61 and the flow path inlet 60 of the heating unit 21 detected by the temperature sensors 151, 152 and the flow rate Q of the blood product in the heating flow path 50 of the heating unit 21. The temperature sensor 151 is provided at the flow path inlet 60 of the heating unit 21, and the temperature sensor 152 is provided at the flow path outlet 61 of the heating unit 21. The available power calculation unit 153 is realized by, for example, the control unit 33. The other configurations of the infusion device 1 are the same as those of the first embodiment, and will not be described.

[0051] The available power calculation unit 153 has a function of calculating the available power Pd supplied from the power supply unit 30 to the heater 51, for example, by the following equation 3. (Td(out)-Td(in))×(Q / 60)×D=Pd...(Formula 3) Td(in) is the temperature of the blood product at the flow path inlet 60 of the heating unit 21 detected by the temperature sensor 151, Td(out) is the temperature of the blood product at the flow path outlet 61 of the heating unit 21 detected by the temperature sensor 152, D is the specific heat of the blood product, and Q is the set flow rate of the heating flow path 50 of the heating unit 21.

[0052] When the infusion process is performed by the infusion device 1, the temperature sensors 151, 152 detect the temperature difference between the blood product at the flow path outlet 61 and the flow path inlet 60 of the heating unit 21, and the available power calculation unit 153 calculates the available power Pd to be supplied from the power supply unit 30 to the heater 51 based on the temperature difference. This calculation of the available power Pd may be performed continuously at all times, intermittently multiple times, or once during the infusion process.

[0053] Next, similarly to the first embodiment, the flow rate calculation unit 100 calculates the maximum flow rate Qm of the blood product in the heating flow path 50 for the blood product at the flow path outlet 61 of the heating unit 21 to reach the target temperature by heat generation by the heater 51 based on the effective power Pd. That is, the maximum flow rate Qm of the blood product is calculated by the following formula 1. At this time, Td(in) detected by the temperature sensor 151 may be used for Tin. (Tout-Tin)×(Qm / 60)×D=Pd...(Formula 1) Tout is the target temperature of the blood product at the flow path outlet 61 of the heating unit 21, Tin is the temperature of the blood product at the flow path inlet 60 of the heating unit 21 (the temperature of the blood product before heating), and D is the specific heat of the blood product.

[0054] 3, the maximum flow rate Qm of the blood product calculated by the flow rate calculation unit 100 is displayed on the display 110 of the control unit 33 by the function of the display unit 101. Furthermore, a selection button 111 for selecting whether or not to change the set flow rate Q of the blood product in the heating flow path 50 of the heating unit 21 to the maximum flow rate Qm is displayed on the display 110 of the control unit 33 by the function of the selection unit 102. Then, when the user selects "change", the set flow rate Q of the blood product in the control unit 33 is changed to the maximum flow rate Qm, and thereafter, the control unit 33 controls the first pump 23 so that the flow rate of the blood product in the heating flow path 50 becomes the maximum flow rate Qm.

[0055] According to this embodiment, it is possible to grasp the maximum flow rate Qm of the blood product for making the blood product reach a target temperature in the heating unit 21. In addition, the actual power detection unit 150 has temperature sensors 151, 152 and the actual power calculation unit 153, and the actual power supplied to the heater 51 can be easily calculated.

[0056] In this embodiment, the flow rate Q of the blood product in the heating flow path 50 of the heating unit 21 may be a set flow rate or may be measured by a flow meter. Also, for example, the display unit 101 and the selection unit 102 may be omitted. Furthermore, the temperature sensor may be of another type as long as it can detect the temperature difference between the blood product at the flow path outlet 61 and the flow path inlet 60 of the heating unit 21.

[0057] In this embodiment, similarly to the first embodiment, the infusion device 1 may have a notification unit 121 in addition to the temperature sensor 152 for detecting the outlet temperature Td(out) of the blood product of the heating unit 21, and the notification unit 121 may notify the outlet temperature Td(out) and a warning, for example, as shown in FIG. 5, when the outlet temperature Td(out) measured by the temperature sensor 152 is lower than a predetermined threshold E. In this case, the user can be accurately and reliably notified that the outlet temperature Td(out) of the blood product of the heating unit 21 does not reach the target temperature Tout. As a result, the patient can be prevented from suffering from hypothermia.

[0058] In the first and second embodiments described above, after the maximum flow rate Qm is calculated, the control unit 33 may automatically control the first pump 23 so that the flow rate Q of the blood product in the heating flow path 50 of the heating unit 21 becomes the maximum flow rate Qm.

[0059] Furthermore, in the first and second embodiments, the infusion device 1 may have a low voltage detection circuit 180 for detecting a low voltage at which the temperature Td(out) of the blood product at the flow outlet 61 of the heating unit 21 becomes lower than a predetermined threshold value E in the power supply unit 30 that supplies power to the heater 51, as shown in FIG. 8, and the notification unit 121 may issue a warning when the low voltage detection circuit 180 detects the low voltage. In this case, the low voltage detection circuit 180 monitors the voltage of the power supply unit 30 and detects a low voltage at which the temperature Td(out) of the blood product at the flow outlet 61 of the heating unit 21 becomes lower than the predetermined threshold value E. Here, the power value required for the temperature Td(out) of the blood product to reach the predetermined threshold value E can be known from the above-mentioned formula 1, and if the power value is known, the required voltage value can be known because the resistance value of the heater 51, etc., is already known. This voltage value is preset as a low voltage in the low voltage detection circuit 180, and the low voltage detection circuit 180 detects that the voltage value of the power supply unit 30 has become a low voltage. Specifically, the AC component of the normal voltage is made full-wave or half-wave, and it is divided by a voltage dividing resistor or the like, and the divided voltage is compared with a preset threshold value (low voltage), and if the divided voltage is greater than the threshold value, "1" is output, and if not, "0" is output. For example, if this is realized using a comparator IC, the input voltage value of the IC may be divided so as to be within the maximum rated voltage. If the output is always "0", low voltage is detected, and the notification unit 121 issues a warning. In this case, too, it is possible to accurately and reliably notify the user that the outlet temperature Td(out) of the blood product of the heating unit 21 does not reach the target temperature Tout, and hypothermia of the patient can be prevented.

[0060] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modified or altered examples within the scope of the ideas described in the claims, and it is understood that such examples also naturally belong to the technical scope of the present invention.

[0061] For example, the configuration of the flow path of the infusion device 1 and the configuration of the heating unit 21 in the above embodiment are not limited to those in the present embodiment. In addition, the infusion liquid delivered by the infusion device 1 is a blood product, but is not limited to this and may be, for example, fresh frozen plasma (FFP), albumin, or extracellular fluid. The present invention can also be applied to other medical liquid warming devices such as dialysis devices, blood purification devices, extracorporeal circulation devices, and body temperature management devices other than infusion devices. [Industrial Applicability]

[0062] INDUSTRIAL APPLICABILITY The present invention is useful in providing a medical liquid warming device that is capable of grasping the maximum flow rate of liquid for making the liquid reach a target temperature in the heating section. [Explanation of symbols]

[0063] 1 Infusion device 21 Heating section 23 First Pump 24 Second Pump 25 First Channel 26 Second Channel 27 The Third Stream 28 The Fourth Stream 29 The fifth stream 30 Power supply section 31 Wiring 32 Power meter 33 Control Unit 50 Heating channel 51 Heater 60 Flow Channel Inlet 61 Flow passage outlet

Claims

1. A flow path through which a liquid flows; a heating unit having a heater that generates heat when powered and that heats the liquid in the flow path by the heater; A liquid delivery section that delivers liquid through the flow path; an effective power detection unit that detects an effective power supplied to the heater; a flow rate calculation unit that calculates a maximum flow rate of liquid in the flow path of the heating unit, based on the actual power detected by the actual power detection unit, for the liquid at the flow path outlet of the heating unit to reach a target temperature through the heat generated by the heater.

2. The medical liquid warming device according to claim 1 , wherein the actual power detection unit is a power meter.

3. a power supply unit connected to the heater and supplying power to the heater; 3. The medical liquid warming device according to claim 2, wherein the effective power detection unit is provided on a wiring between the power supply unit and the heater.

4. a temperature estimation unit that estimates a temperature of the liquid at the flow path outlet of the heating unit based on the effective power detected by the effective power detection unit, the liquid temperature at the flow path inlet of the heating unit, the set flow rate of the liquid in the flow path of the heating unit, and the specific heat of the liquid flowing through the flow path; The medical liquid warming device according to claim 2 or 3, further comprising a notification unit that issues a warning when the temperature estimated by the temperature estimation unit is lower than a predetermined threshold value.

5. The effective power detection unit is a temperature sensor for detecting a temperature difference between the liquid at the flow passage outlet and the flow passage inlet of the heating unit; 2. The medical liquid heating device according to claim 1, further comprising an effective power calculation unit that calculates effective power based on the temperature difference between the liquid at the flow path outlet and the flow path inlet of the heating unit detected by the temperature sensor and the flow rate of the liquid in the flow path of the heating unit.

6. A temperature sensor for measuring the temperature of the liquid at the flow path outlet of the heating unit; The medical liquid warming device according to any one of claims 1 to 3 and 5, further comprising an alarm unit that issues a warning when the temperature measured by the temperature sensor is lower than a predetermined threshold value.

7. a low voltage detection circuit configured to detect a low voltage that is preset as a voltage at which the temperature of the liquid at the outlet of the flow path of the heating unit becomes lower than a predetermined threshold value in a power supply unit that supplies power to the heater; The medical liquid warming device according to claim 1, further comprising an alarm unit that issues a warning when a low voltage is detected by the low voltage detection circuit.

8. The medical liquid warming device according to any one of claims 1 to 7, further comprising a display unit that displays the maximum flow rate calculated by the flow rate calculation unit.

9. The medical liquid warming device according to any one of claims 1 to 8, further comprising a selection unit for selecting whether or not to change the set flow rate of the liquid in the flow path of the heating unit to the maximum flow rate.

10. The medical liquid warming device according to any one of claims 1 to 9, further comprising a control unit that controls the liquid delivery unit so that the flow rate of liquid in the flow path of the heating unit becomes the maximum flow rate.

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