Heat supplying system, computer program, and heat supplying system control method

Abstract

Provided are a heat supplying system, a computer program, and a heat supplying system control method which make it possible to maintain the temperature of circulating blood during transportation of a patient.　This heat supplying system comprises: a first circulation path through which a medium that supplies heat to blood circulating in a medical device circulates; a circulation pump which is for circulating the medium in the first circulation path; a flow path branching unit which is provided along the first circulation path; a second circulation path which branches from the flow path branching unit and through which a medium flows; a heating unit which heats the medium in the second circulation path; a mixing unit which mixes the medium that has been heated in the second circulation path with the medium that has circulated only in the first circulation path; and a control unit which controls the mixing ratio between media to be mixed in the mixing unit.

Description

Heat supply system, computer program, and method for controlling a heat supply system

[0001] The present disclosure relates to a heat supply system, a computer program, and a method for controlling a heat supply system.

[0002] Extracorporeal circulation systems have been widely used to temporarily maintain life during open-heart surgery for cardiac disease, or in the event of circulatory failure or cardiac arrest, by assisting a patient's blood circulation and breathing and substituting for the patient's cardiopulmonary function. For example, an extracorporeal membrane oxygenator (ECMO) is a medical device used to assist the heart and lungs when they are unable to function properly. It extracts blood from the patient's body (bleeding), exchanges the extracted blood with oxygenators (which substitute for the gas exchange function of the living lungs) within the ECMO, and then returns the gas-exchanged blood to the patient (blood reinfusion). The ECMO can be transported with the patient.

[0003] Patent Document 1 discloses an extracorporeal circulation device used in cardiac surgery and the like, which includes an artificial lung, performs extracorporeal circulation and auxiliary circulation of blood, and performs gas exchange with the blood.

[0004] Japanese Patent Application Laid-Open No. 2007-236564

[0005] When using ECMO, especially in extracorporeal circulation systems used in operating rooms, oxygenators with integrated heat exchangers have been proposed to prevent the circulating blood from dropping in temperature due to exposure to the outside air. However, unlike normal use in operating rooms, when the patient is transported with an emergency patient, the circulating blood is exposed to the outside air for a longer period of time than when used in a normal operating room. In this case, there is a problem in that an extracorporeal circulation system equipped with a heating device, which is larger and requires a larger amount of power, is required to prevent the blood temperature from dropping.

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a heat supply system, a computer program, and a method for controlling a heat supply system that can maintain the temperature of circulating blood during patient transport.

[0007] (1) A heat supply system according to the present disclosure includes a first circulation path through which a medium circulates to supply heat to blood circulating within a medical device, a circulation pump for circulating the medium within the first circulation path, a flow path branching section provided within the first circulation path, a second circulation path branching from the flow path branching section through which the medium flows, a heating section for heating the medium within the second circulation path, a mixing section for mixing the medium heated in the second circulation path with the medium circulated only through the first circulation path, and a control unit for controlling the mixing ratio of the media mixed in the mixing section. Here, an embodiment of the present disclosure includes: (2) The heat supply system of (1) above includes a flow rate adjusting section for adjusting the flow rate of the medium from the flow path branching section on the first circulation path to the second circulation path. (3) In the heat supply system of (1) or (2) above, the control unit heats the temperature of the medium within the second circulation path to a predetermined temperature and controls the heating section to adjust the temperature of the medium supplied to the medical device to a target temperature. (4) In the heat supply system of any one of (1) to (3) above, the control unit controls the mixing ratio of the media mixed in the mixer by adjusting the flow rate ratio of the medium in the first circulation path and the medium in the second circulation path. (5) In the heat supply system of any one of (1) to (4) above, the control unit includes a first temperature detection unit that detects the temperature of the medium flowing into the first circulation path from the medical device, and the control unit adjusts the flow rate of at least the medium in the second circulation path out of the medium in the first circulation path and the medium in the second circulation path based on the temperature detected by the first temperature detection unit. (6) Any one of the heat supply systems (1) to (4) above includes a first temperature detection unit that detects the temperature of the medium flowing from the medical device into the first circulation path and a second temperature detection unit that detects the temperature of the medium flowing out from the outlet of the second circulation path, and the control unit adjusts the flow rate of at least the medium in the second circulation path out of the medium in the first circulation path and the medium in the second circulation path based on the temperatures detected by the first temperature detection unit and the second temperature detection unit, respectively.(7) The heat supply system of any one of (1) to (4) above includes a third temperature detection unit that detects the temperature of the medium flowing from the first circulation path to the medical device, and the control unit adjusts the flow rate of at least the medium in the second circulation path out of the medium in the first circulation path and the medium in the second circulation path based on the temperature detected by the third temperature detection unit. (8) The heat supply system of any one of (1) to (7) above includes a heating unit that includes a latent heat storage material. (9) The heat supply system of (8) above includes a latent heat storage material that maintains the predetermined temperature during a phase change process when heating the temperature of the medium in the second circulation path to the predetermined temperature. (10) The heat supply system of any one of (1) to (9) above includes a mixing unit that mixes the mixed medium. (11) The heat supply system of (2) above includes a control unit that controls the flow rate adjustment unit to block the flow of the medium in the second circulation path when the temperature of the medium reaches a predetermined reference value. (12) In the heat supply system of (2) above, the control unit controls the flow rate adjustment unit to cut off the flow rate of the medium from the flow path branch when the temperature of the medium in the second circulation path reaches an upper limit value. (13) In the heat supply system of any one of (1) to (12) above, the medical device includes an oxygenator having a heat exchanger, and the medium is water. (14) The heat supply system includes: a first circulation path through which a first medium circulates to supply heat to blood circulating in the medical device; a circulation pump for circulating the first medium in the first circulation path; a second circulation path communicating with the first circulation path via an inlet and an outlet and through which a second medium flows; a heating unit for heating the second medium in the second circulation path; a mixing unit for mixing the second medium heated in the second circulation path and flowing out from the outlet with the first medium circulating in the first circulation path; and a control unit for controlling the mixing ratio of the first medium and the second medium mixed in the mixing unit. (15) In the heat supply system of (14) above, the second medium is the first medium adjusted to a different temperature and flows through the second circulation path.(16) A computer program according to the present disclosure is a computer program for controlling the operation of a heat supply system including: a first circulation path through which a medium circulates to supply heat to blood circulating within a medical device; a circulation pump for circulating the medium within the first circulation path; a flow path branching section provided within the first circulation path; a second circulation path branching from the flow path branching section through which the medium flows; a heating section for heating the medium within the second circulation path; a mixing section for mixing the medium heated within the second circulation path with the medium circulated only through the first circulation path; and a control section for controlling the mixing ratio of the media mixed in the mixing section, and causes a computer to execute a process for controlling the mixing ratio of the medium within the first circulation path and the medium within the second circulation path mixed in the mixing section. (17) A control method for a heat supply system according to the present disclosure is a control method for a heat supply system including a first circulation path through which a medium circulates to supply heat to blood circulating within a medical device, a circulation pump for circulating the medium within the first circulation path, a flow path branching section provided within the first circulation path, a second circulation path branching from the flow path branching section through which the medium flows, a heating section for heating the medium within the second circulation path, a mixing section for mixing the medium heated within the second circulation path with the medium circulated only through the first circulation path, and a control section for controlling the mixing ratio of the media mixed in the mixing section, wherein the control section controls the mixing ratio of the medium within the first circulation path and the medium within the second circulation path that are mixed in the mixing section. (18) In the control method of the heat supply system of (17) above, the control unit adjusts the flow rate of the medium circulating only within the first circulation path and the medium in the second circulation path, based on the temperature detected by a first temperature detection unit that detects the temperature of the medium flowing from the medical device into the first circulation path.

[0008] According to the present disclosure, the temperature of circulating blood can be maintained during patient transport.

[0009] FIG. 1 is a diagram illustrating an example of the configuration of a heat supply system of the present embodiment; FIG. 2 is a diagram illustrating a first example of a method for adjusting a flow rate ratio between a first medium and a second medium; FIG. 3 is a diagram illustrating a second example of a method for adjusting a flow rate ratio between a first medium and a second medium; FIG. 4 is a diagram illustrating a third example of a method for adjusting a flow rate ratio between a first medium and a second medium; FIG. 5 is a diagram illustrating a first example of a method for controlling a heat supply system; FIG. 6 is a diagram illustrating a second example of a method for controlling a heat supply system; and FIG. 7 is a diagram illustrating a third example of a method for controlling a heat supply system.

[0010] An embodiment of the present disclosure will be described below. Fig. 1 is a diagram showing an example of the configuration of a heat supply system 100 of this embodiment. The heat supply system 100 includes a first circulation path 10 through which a first medium circulates to supply heat to blood circulating in a medical device such as an ECMO, a circulation pump 30 for circulating the medium circulating in the first circulation path 10 (hereinafter, the medium circulating only in the first circulation path 10 will be referred to as the first medium), a second circulation path 20 that communicates with the first circulation path 10 via an inlet 21 and an outlet 22 and through which a medium branched from the first circulation path 10 (hereinafter, referred to as the second medium) flows, and a second circulation path 21 that communicates with the first circulation path 10 via an inlet 21 and an outlet 22. The device includes a flow rate adjusting unit 40 that adjusts the flow rate of the first medium from the circulation path 10 to the inlet 21 of the second circulation path 20, a heating unit 50 that heats the second medium in the second circulation path 20, a mixing unit 60 that mixes the second medium that has been heated in the second circulation path 20 and flows out from the outlet 22 with the first medium circulating in the first circulation path 10, a control unit 70 that controls the mixing ratio of the first medium and the second medium mixed in the mixing unit 60, and a chamber 90 interposed in the first circulation path 10. The flow paths of the inlet 21 and the outlet 22 are also called flow path branch paths.

[0011] The outlet 101 of the heat supply system 100 can be connected to the inlet of the oxygenator 200 in the medical device via a pipe, and the inlet 102 of the heat supply system 100 can be connected to the outlet of the oxygenator 200 via a pipe.

[0012] The heat supply system 100 supplies a medium (a mixture of a first medium and a second medium) heated to a target temperature T (e.g., 37°C) to the oxygenator 200 through the outlet 101. The first medium and the second medium are, for example, water. The first medium is a medium that has not been heated by the heating unit 50, and the second medium is a medium that has been heated by the heating unit 50. In other words, the second medium is the first medium adjusted to a different temperature that flows through the second circulation path 20. Furthermore, the heat supply system 100 circulates the medium discharged from the outlet of the oxygenator 200 to the first circulation path 10 through the inlet 102. The flow rate of the medium supplied to the oxygenator 200 through the outlet 101 is, for example, 1.0 L / min, but is not limited to this.

[0013] The medical equipment includes an oxygenator 200, a pump 300, and the like. The oxygenator 200 includes a heat exchanger 210. A tube through which blood removed from the patient's body flows is connected to the pump 300. A tube through which the blood that has undergone gas exchange in the oxygenator 200 is returned (transported) into the patient's body is connected to the oxygenator 200. The pump 300 is, for example, a centrifugal pump, and performs blood removal and blood transport using centrifugal force.

[0014] Because the blood removed from the patient's body is exposed to the outside air as it flows through the tubes, the temperature of the blood drops below body temperature. The removed blood, which is at a relatively low temperature, is sent to the heat exchanger 210 of the oxygenator 200 via the pump 300. In the heat exchanger 210, heat is exchanged between the heated medium supplied from the heat supply system 100 and the blood, and the temperature of the removed blood is warmed to body temperature before being sent to the patient.

[0015] A temperature sensor 81 serving as a first temperature detector for detecting the temperature of the first medium flowing from the medical device into the first circulation path 10 is provided in the first circulation path 10 near the inlet 102. A temperature sensor 82 serving as a second temperature detector for detecting the temperature of the second medium flowing from the outlet 22 of the second circulation path 20 is provided in the first circulation path 10 near the outlet 22. A temperature sensor 83 serving as a third temperature detector for detecting the temperature of the first medium flowing from the first circulation path 10 to the medical device is provided in the first circulation path 10 near the outlet 101. All or some of the temperature sensors 81, 82, and 83 may be provided.

[0016] The circulation pump 30 can adjust the flow rate of the first medium in the first circulation path 10. The circulation pump 30 can also stably discharge a constant amount of the first medium. The circulation pump 30 can be, for example, a diaphragm pump, a plunger pump, or a tube pump, but is not limited to these.

[0017] The flow rate adjustment unit 40 can be configured, for example, by a valve, and can adjust the flow rate of the second medium flowing through the second circulation path 20 by controlling the opening and closing of the valve. Furthermore, the flow rate adjustment unit 40 may be any means capable of adjusting the flow rate, and may be configured, for example, by a pump of the same type as the circulation pump 30.

[0018] The heating unit 50 includes a latent heat storage material 51. The latent heat storage material 51 is a heat source that utilizes latent heat generated when a substance undergoes a phase change. During a phase change, the substance absorbs surrounding heat and conversely releases heat, so heat is absorbed and released through the phase change. When the temperature of the second medium is heated to a predetermined temperature (e.g., 70°C to 80°C), the latent heat storage material 51 can maintain the predetermined temperature during the phase change process. For example, materials such as paraffin, fatty acid, and vanadium dioxide can be used as the latent heat storage material 51.

[0019] The second circulation path 20 passing through the heating unit 50 is arranged, for example, in a coil shape, a flat spiral shape, or a crank structure, and can increase the contact area with the latent heat storage material 51. The heating unit 50 includes an electric heating wire heater and a high-frequency power source, and can heat the second circulation path 20 and the latent heat storage material 51.

[0020] The mixing section 60 mixes the first medium circulating through the first circulation path 10 and flowing into the mixing section 60 with the second medium flowing from the outlet 22 of the second circulation path 20 through the first circulation path 10 into the mixing section 60. The mixing section 60 includes a stirring section that stirs the first medium and the second medium. The stirring section can be configured with, for example, an impeller, a spiral groove, a spiral tubular structure, or the like.

[0021] The chamber 90 can remove air that has entered the first circulation path 10 or the second circulation path 20, and can create a stable flow of the medium.

[0022] The control unit 70 includes a processor, a memory, an interface, and the like, and acquires temperatures detected by the temperature sensors 81, 82, and 83. The control unit 70 outputs control signals to perform operations such as controlling the operation of the circulation pump 30, controlling the flow rate of the flow rate adjustment unit 40, and controlling the heating of the heating unit 50. The control unit 70 stores a computer program (program product) 71, and can execute the functions of the control unit 70 by executing the computer program 71 with a processor. The computer program 71 can be stored in the control unit 70 by reading it from a recording medium (for example, an optically readable disk storage medium such as a CD-ROM) M using a recording medium reading unit (not shown).

[0023] The control unit 70 heats the temperature of the second medium flowing out from the outlet 22 of the second circulation path 20 to a predetermined temperature (e.g., 70°C to 80°C), and controls the heating unit 50 to heat the temperature of the first medium supplied to the medical device from the outlet 101 to a target temperature T (e.g., 37°C).

[0024] Furthermore, the control unit 70 controls the flow rate adjustment unit 40 to adjust the flow rate ratio between the first medium flowing through the first circulation path 10 and the second medium flowing through the second circulation path 20. Here, the first medium flowing through the first circulation path 10 is a medium that flows out from the output side of the circulation pump 30 and flows through the first circulation path 10 without flowing through the second circulation path 20. The flow rate ratio can be adjusted by adjusting at least the flow rate of the second medium. That is, the control unit 70 may adjust the flow rate of the second medium, or may adjust the flow rates of the second medium and the first medium.

[0025] The control unit 70 controls the flow rate adjustment unit 40, thereby controlling the mixing ratio of the first medium and the second medium mixed in the mixing unit 60. The first medium and the second medium mixed in the mixing unit 60 are the first medium that flows into the mixing unit 60 through the first circulation path 10, and the second medium that flows out from the outlet 22 of the second circulation path 20 and flows into the mixing unit 60.

[0026] Next, a method for adjusting the flow rate ratio between the first medium and the second medium will be described.

[0027] Let f1 be the flow rate of the first medium and T1 be its temperature. Let f2 be the flow rate of the second medium and T2 be its temperature. The flow rate is the mass of the medium flowing per unit time. If m1 and m2 are the masses of the first medium and second medium flowing per unit time, then f1 = m1 and f2 = m2. If T is the temperature after mixing the first medium with a flow rate of f1 and a temperature of T1 with the second medium with a flow rate of f2 and a temperature of T2, then temperature T can be expressed by equation (1). If the ratio (flow rate ratio) of the flow rate f2 of the second medium to the flow rate f1 of the first medium is R (= f1 / f2), then equation (2) can be derived from equation (1).

[0028]

[0029] The temperature T after mixing the first medium and the second medium can be set as a target temperature T.

[0030] FIG. 2 illustrates a first example of a method for adjusting the flow rate ratio of the first medium to the second medium. This first example is an example of feedback control. As shown in FIG. 2, the temperature of the first medium detected by a temperature sensor 81 provided near the inlet 102 of the first circulation path 10 is designated as T1. The control unit 70 outputs a control signal to the flow rate adjustment unit 40 based on the difference (error) between the standard temperature and temperature T1. The standard temperature is the standard temperature of the medium flowing into the inlet from the medical device. The standard temperature can be the temperature of the medium discharged from the oxygenator 200 when a medium at a target temperature T (e.g., 37°C) is introduced into the oxygenator 200. The flow rate adjustment unit 40 adjusts the flow rate ratio based on the input control signal. Note that the control signal may be output to the flow rate adjustment unit 40 based on the difference between the target temperature and temperature T1.

[0031] 2, the temperature of the first medium detected by the temperature sensor 81 when the flow rate ratio R is R1 is defined as T1. To bring the temperature T1 closer to the standard temperature, the control unit 70 can adjust the flow rate ratio from R1 to R2. The same applies when the temperature T1 is lower than the standard temperature.

[0032] As described above, the control unit 70 can adjust the flow rate of at least one of the first medium and the second medium based on the temperature T detected by the temperature sensor 81 (first temperature detection unit).

[0033] FIG. 3 illustrates a second example of a method for adjusting the flow rate ratio of the first medium to the second medium. This second example is an example of feedback control. As shown in FIG. 3, the temperature of the first medium detected by the temperature sensor 81 provided near the inlet 102 of the first circulation path 10 is defined as T1. The temperature of the second medium detected by the temperature sensor 82 provided near the outlet 22 of the second circulation path 20 is defined as T2. The control unit 70 outputs a control signal to the flow rate adjustment unit 40 based on the difference (error) between the standard temperature and temperature T1 and the difference (error) between a predetermined temperature (e.g., 70°C to 80°C) and temperature T2. The predetermined temperature is the temperature of the second medium heated by the heating unit 50. The flow rate adjustment unit 40 adjusts the flow rate ratio based on the input control signal.

[0034] Since it is sufficient that the temperature of the medium obtained after mixing the first medium at temperature T1 and the second medium at temperature T2 becomes the target temperature T, the flow rate ratio R can be calculated using the above-mentioned formula (2) as follows: R = (target temperature T - temperature T1) / (temperature T2 - target temperature T).

[0035] As described above, the control unit 70 can adjust the flow rate of at least one of the first medium and the second medium based on the temperatures detected by the temperature sensor 81 (first temperature detection unit) and the temperature sensor 82 (second temperature detection unit), respectively.

[0036] FIG. 4 is a diagram showing a third example of a method for adjusting the flow rate ratio of the first medium and the second medium. The third example is an example of feedforward control. As shown in FIG. 4, the temperature of the first medium detected by the temperature sensor 83 provided near the outlet 101 of the first circulation path 10 is defined as T3. The control unit 70 outputs a control signal to the flow rate adjustment unit 40 based on the detected temperature T3. The output control signal is determined in advance according to the temperature T3. The flow rate adjustment unit 40 adjusts the flow rate ratio based on the input control signal.

[0037] 4, the temperature of the first medium detected by the temperature sensor 83 when the flow rate ratio R is R3 is set to T3. The control unit 70 can adjust the flow rate ratio from R3 to R4 by increasing or decreasing the flow rate ratio determined in accordance with the temperature T3 (in the example of FIG. 4, the flow rate ratio R is increased).

[0038] As described above, the control unit 70 can adjust the flow rate of at least one of the first medium and the second medium based on the temperature detected by the temperature sensor 83 (third temperature detection unit).

[0039] It is not necessary to provide all of the temperature sensors 81, 82, and 83. It is possible to provide only a temperature sensor according to the configuration of any one of the first to third examples illustrated in Figures 2 to 4. It is also possible to provide all of the temperature sensors 81, 82, and 83.

[0040] In the case of ECMO, which is transported together with an emergency patient, the circulating blood temperature drops due to prolonged exposure to the outside air. In particular, in the case of children, whose body surface area is large relative to the circulating blood volume, the circulating blood temperature drops even during a short transport.

[0041] On the other hand, the power capacity of emergency vehicles transporting patients is limited, for example, to 1000 to 1500 W, and extracorporeal circulation devices used in hospitals, etc., consume a lot of power, making them difficult to use in emergency vehicles. However, the heat supply system 100 of this embodiment, using the latent heat storage material 51, enables efficient heat exchange with a small size and low power consumption (for example, 170 W or less).

[0042] Furthermore, the circulating water (second medium) intended to heat the heat exchanger cannot be set to a temperature significantly higher than body temperature because it comes into contact with blood via the heat exchanger 210 in the oxygenator 200. However, the heat supply system 100 of this embodiment produces high-temperature circulating water for heating (second medium) separately from the circulating water (first medium), and can maintain a target circulating water temperature by mixing the circulating water for heating (high-temperature water) with the circulating water. The heat supply system 100 of this embodiment uses a latent heat storage material 51, allowing the temperature of the circulating water intended to heat the heat exchanger to be set to a predetermined temperature (e.g., 70°C to 80°C).

[0043] Furthermore, even if the power supply in the heat supply system 100 is lost, the second medium can be heated by using the latent heat storage material 51, and the time during which the blood can be maintained at the target temperature can be extended.

[0044] Fig. 5 is a diagram showing a first example of a control method for the heat supply system 100. Fig. 5 corresponds to the method for adjusting the flow rate ratio shown in Fig. 2. The control unit 70 detects the temperature T1 of the first medium flowing from the medical device into the first circulation path 10 (S11), and determines whether the detected temperature T1 is higher than the standard temperature (S12).

[0045] If the detected temperature T1 is higher than the standard temperature (or the set temperature) (YES in S12), the control unit 70 adjusts the flow rate ratio by reducing the flow rate of the first medium or increasing the flow rate of the second medium (S13), and then ends the process.

[0046] If the detected temperature T1 is not higher than the standard temperature (or the set temperature) (NO in S12), the control unit 70 adjusts the flow rate ratio by increasing the flow rate of the first medium or decreasing the flow rate of the second medium (S14), and ends the process.

[0047] Fig. 6 is a diagram showing a second example of a control method for the heat supply system 100. Fig. 6 corresponds to the method of adjusting the flow rate ratio shown in Fig. 3. The control unit 70 detects a temperature T1 of the first medium flowing from the medical device into the first circulation path 10 (S21), and detects a temperature T2 of the second medium flowing out from the outlet 22 of the second circulation path 20 (S22).

[0048] The control unit 70 calculates the flow rate ratio based on the detected temperatures T1, T2 and the target temperature T, adjusts the flow rate ratio between the first medium and the second medium (S23), and ends the process.

[0049] Fig. 7 is a diagram showing a third example of a control method for the heat supply system 100. Fig. 7 corresponds to the method for adjusting the flow rate ratio shown in Fig. 4. The control unit 70 detects the temperature T3 of the first medium flowing from the first circulation path 10 to the medical device (S31), and determines whether the detected temperature T3 is higher than the target temperature T (S32).

[0050] If the detected temperature T3 is higher than the target temperature T (YES in S32), the control unit 70 adjusts the flow rate ratio by increasing the flow rate of the first medium or decreasing the flow rate of the second medium (S33), and then ends the processing.

[0051] If the detected temperature T3 is not higher than the target temperature T (NO in S32), the control unit 70 adjusts the flow rate ratio by reducing the flow rate of the first medium or increasing the flow rate of the second medium (S34), and terminates the process.

[0052] In the above-described configuration, when the temperature of the first medium detected by the temperature sensor 83 reaches a predetermined reference value (for example, a temperature equivalent to body temperature that is lower than the mutation point of the protein, taking into account a safety margin), the control unit 70 can control the flow rate adjustment unit 40 to block the flow of the second medium in the second circulation path 20. This prevents the temperature of the first medium from exceeding the reference value, thereby ensuring the safety of the patient.

[0053] In addition, when the temperature of the second medium detected by the temperature sensor 82 reaches an upper limit value, the control unit 70 may control the flow rate adjustment unit 40 to cut off the flow rate of the first medium from the first circulation path 10 to the inlet 21 of the second circulation path 20.

[0054] According to this embodiment, compact and efficient heating (blood temperature management and maintenance) can be achieved while reducing power consumption without requiring a large-capacity power source, and blood heating can be maintained even in the event of a sudden power loss. This makes it possible to heat circulating blood with a limited power source capacity when urgently transporting a patient by ambulance.

[0055] In this embodiment, the heating unit 50 may be provided with a cooling function to adjust the temperature of the second medium. Also, a battery for supplying power to the control unit 70 may be provided.

[0056] REFERENCE SIGNS LIST 10 First circulation path 20 Second circulation path 21 Inlet 22 Outlet 30 Circulation pump 40 Flow rate adjustment section 50 Heating section 51 Latent heat storage material 60 Mixing section 70 Control section 71 Computer program 81, 82, 83 Temperature sensor 90 Chamber 100 Heat supply system 101 Outlet 102 Inlet 200 Oxygenator 210 Heat exchanger 300 Pump

Claims

1. A heat supply system comprising: a first circulation path through which a medium circulates to supply heat to blood circulating within a medical device; a circulation pump for circulating the medium within the first circulation path; a flow path branching section provided within the first circulation path; a second circulation path branching from the flow path branching section and through which the medium flows; a heating section for heating the medium within the second circulation path; a mixing section for mixing the medium heated in the second circulation path with the medium circulated only through the first circulation path; and a control section for controlling the mixing ratio of the media mixed in the mixing section.

2. The heat supply system according to claim 1, further comprising a flow rate adjusting unit that adjusts the flow rate of the medium from a flow path branch on the first circulation path to the second circulation path.

3. The heat supply system according to claim 1, wherein the control unit heats the temperature of the medium in the second circulation path to a predetermined temperature and controls the heating unit to bring the temperature of the medium supplied to the medical device to a target temperature.

4. The heat supply system according to claim 1, wherein the control unit adjusts the flow rate ratio of the medium in the first circulation path and the medium in the second circulation path to control the mixing ratio of the media mixed in the mixing unit.

5. A heat supply system as described in claim 1, further comprising a first temperature detection unit that detects the temperature of a medium flowing from the medical device into the first circulation path, and wherein the control unit adjusts the flow rate of the medium in the first circulation path and the medium in the second circulation path, at least, based on the temperature detected by the first temperature detection unit.

6. A heat supply system as described in claim 1, comprising a first temperature detection unit that detects the temperature of the medium flowing from the medical device into the first circulation path, and a second temperature detection unit that detects the temperature of the medium flowing out from the outlet of the second circulation path, wherein the control unit adjusts the flow rate of at least the medium in the second circulation path out of the medium in the first circulation path and the medium in the second circulation path based on the temperatures detected by the first temperature detection unit and the second temperature detection unit, respectively.

7. A heat supply system as described in claim 1, further comprising a third temperature detection unit that detects the temperature of the medium flowing from the first circulation path to the medical device, and the control unit adjusts the flow rate of at least the medium in the second circulation path out of the medium in the first circulation path and the medium in the second circulation path based on the temperature detected by the third temperature detection unit.

8. The heat supply system according to any one of claims 1 to 7, wherein the heating section includes a latent heat storage material.

9. The heat supply system according to claim 8, wherein the latent heat storage material maintains the predetermined temperature during a phase change process when the temperature of the medium in the second circulation path is heated to the predetermined temperature.

10. A heat supply system according to any one of claims 1 to 7, wherein the mixing section includes a stirring section that stirs the mixed medium.

11. The heat supply system of claim 2, wherein the control unit controls the flow rate adjustment unit to cut off the flow of the medium in the second circulation path when the temperature of the medium reaches a predetermined reference value.

12. The heat supply system according to claim 2, wherein the control unit controls the flow rate adjustment unit to cut off the flow rate of the medium from the flow path branching section when the temperature of the medium in the second circulation path reaches an upper limit value.

13. The heat supply system according to any one of claims 1 to 7, wherein the medical device includes an oxygenator having a heat exchanger, and the medium is water.

14. A heat supply system comprising: a first circulation path through which a first medium circulates to supply heat to blood circulating within a medical device; a circulation pump for circulating the first medium within said first circulation path; a second circulation path that communicates with said first circulation path via an inlet and an outlet and through which a second medium flows; a heating unit that heats the second medium within said second circulation path; a mixing unit that mixes the second medium heated within said second circulation path and flowing out from said outlet with the first medium circulating within said first circulation path; and a control unit that controls the mixing ratio of the first medium and second medium mixed in said mixing unit.

15. The heat supply system according to claim 14, wherein the second medium is the first medium regulated to a different temperature and flows through the second circulation path.

16. A computer program for controlling the operation of a heat supply system comprising: a first circulation path through which a medium circulates to supply heat to blood circulating within a medical device; a circulation pump for circulating the medium within the first circulation path; a flow path branching section provided within the first circulation path; a second circulation path branching from the flow path branching section and through which the medium flows; a heating section for heating the medium within the second circulation path; a mixing section for mixing the medium heated within the second circulation path with the medium circulated only through the first circulation path; and a control section for controlling the mixing ratio of the media mixed in the mixing section, the computer program causing a computer to execute a process for controlling the mixing ratio of the medium within the first circulation path and the medium within the second circulation path mixed in the mixing section.

17. A control method for a heat supply system comprising: a first circulation path through which a medium circulates to supply heat to blood circulating within a medical device; a circulation pump for circulating the medium within the first circulation path; a flow path branching section provided within the first circulation path; a second circulation path branching from the flow path branching section and through which the medium flows; a heating section for heating the medium within the second circulation path; a mixing section for mixing the medium heated in the second circulation path with the medium circulated only through the first circulation path; and a control section for controlling the mixing ratio of the media mixed in the mixing section, wherein the control section controls the mixing ratio of the medium within the first circulation path and the medium within the second circulation path that are mixed in the mixing section.

18. A control method for a heat supply system as described in claim 17, wherein the control unit adjusts the flow rate of the medium circulating only within the first circulation path and the medium within the second circulation path, based on the temperature detected by a first temperature detection unit that detects the temperature of the medium flowing into the first circulation path from the medical device.

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