US20090235686A1

US20090235686A1 - Fluid temperature regulator

Info

Publication number: US20090235686A1
Application number: US12/406,070
Authority: US
Inventors: Yoshiharu Kikuchi
Original assignee: Nihon Kohden Corp
Current assignee: Nihon Kohden Corp
Priority date: 2008-03-18
Filing date: 2009-03-17
Publication date: 2009-09-24
Also published as: JP2009254795A

Abstract

A fluid temperature regulator includes: a case, containing a refrigerant; a cooling/warming device, configured to cool/warm the case; and a storage, including an opening through which a circuit for transfusing fluid is to be inserted/removed. The storage is configured to house the circuit inserted through the opening and be in contact with the circuit. The storage is surrounded by the refrigerant and watertight for the refrigerant in the case.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a fluid temperature regulator which cools/warms fluid such as blood to a desired temperature.
As a related-art fluid temperature regulator of this kind, there is a regulator (a first related-art regulator) in which, as indicated by the schematic plan and side configurations shown in FIGS. 7A and 7B, an extracorporeal circulation blood circuit 41 is sandwiched between a metallic plate 42 and a heat insulating material 43, and blood in the extracorporeal circulation blood circuit 41 is cooled/warmed through the metallic plate 42 by a cooling/warming apparatus 44 (see JP-A-09-602).
In the first related-art regulator, however, the heat capacity must be increased by enlarging (thickening) the metallic plate 42 so that blood in the extracorporeal circulation blood circuit 41 is prevented from being broken by a sudden drop or rise in temperature, and the performance must be improved by using a higher-power cooling/warming apparatus 44. Therefore, the shape and weight of the regulator are increased, and furthermore the production cost is raised. The cooling/warming is performed from one face of the extracorporeal circulation blood circuit 41, and hence there is a problem in that the heat transfer efficiency is poor.
There is another related-art fluid temperature regulator (a second related-art regulator) in which, as shown in schematic plan and side views of FIGS. 8A and 8B, an extracorporeal circulation blood circuit 41 is sandwiched between metallic plates 42-1, 42-2, and blood in the extracorporeal circulation blood circuit 41 is cooled/warmed through the metallic plates 42-1, 42-2 by two cooling/warming apparatuses 44-1, 44-2 (see JP-A-2004-148027).
In the second related-art regulator, the heat transfer efficiency is superior to the first related-art regulator, but it is required to use the two cooling/warming apparatuses 44-1, 44-2, thereby producing a problem in that the configuration grows in size and the production cost is raised.
In both the first and second related-art regulators, as the metallic plate 42 and the blood in the extracorporeal circulation blood circuit 41 are further separated from the portions where they are in contact with the cooling/warming apparatus 44, they are less thermally affected by the cooling/warming apparatus 44. Therefore, a temperature bias is caused and the heat transfer efficiency is reduced.
There is a related-art fluid temperature regulator (a third related-art regulator) in which, as indicated by the schematic plan configuration shown in FIG. 9, an extracorporeal circulation blood circuit 41 is immersed in a circulation medium 46 in a refrigerant tank 47 the temperature of which is regulated by a thermal regulator 45, thereby cooling/warming blood in the extracorporeal circulation blood circuit 41 (see JP-A-2002-119586 and JP-A-2007-151696) A third related-art regulator corresponding to one of the related-art fluid temperature regulators is disclosed in JP-A-2002-119586. A fourth related-art regulator corresponding to the other is disclosed in JP-A-2007-151696.
In the third related-art regulator, when a damage occurs in a portion of the extracorporeal circulation blood circuit 41 where the extracorporeal circulation blood circuit 41 is in direct contact with the circulation medium 46, there is a fear that the circulation medium 46 flows into the extracorporeal circulation blood circuit 41, In a related art disclosed in JP-A-2002-119586, the thermal regulator 45 and the refrigerant tank 47 must be disposed, and hence there is a problem in that the regulator grows in size. In a related art disclosed in JP-A-2007-151696, the refrigerant is not stirred, and hence a thermal gradient is produced in the refrigerant tank 47, thereby producing a problem in that the heat transfer efficiency with the blood is poor.

SUMMARY

It is therefore an object of the invention to provide a fluid temperature regulator in which the size and cost of the configuration are not increased, the heat transfer efficiency is high, and, even when a damage occurs in a transfusion circuit, a medium does not flow into the transfusion circuit so that the safety level is high.
In order to achieve the object, according to the invention, there is provided a fluid temperature regulator, comprising:

- a case, containing a refrigerant;
- a cooling/warming device, configured to cool/warm the case; and
- a storage, including an opening through which a circuit for transfusing fluid is to be inserted/removed, the storage configured to house the circuit inserted through the opening and be in contact with the circuit, the storage being surrounded by the refrigerant and watertight for the refrigerant in the case.

The fluid temperature regulator may further include: a stirrer, configured to stir the refrigerant is provided in the case.
The fluid temperature regulator may further include: a guide, configured to guide the refrigerant to a face of the storage, the refrigerant being in contact with the face of the storage.
The guide may include a flow path through which the refrigerant spirally flows around the storage.
The stirrer may guide the refrigerant to the guide.
The storage nay be comprised of a heat-conducting material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a first embodiment of the fluid temperature regulator of the invention.

FIG. 2 is a section view taken along line A-A in a state where a transfusion circuit in FIG. 1 is housed in a storage.

FIG. 3 is a view showing a combination of a section view taken along line B-B in the state where the transfusion circuit in FIG. 1 is housed in the storage, and a functional block diagram of temperature adjustment.

FIG. 4 is a section view taken along line B-B in the state where the transfusion circuit in FIG. 1 is housed in the storage, showing the temperature difference between fluid in the transfusion circuit and a refrigerant by means of the size of an arrow.

FIG. 5 s a section view of a second embodiment of the fluid temperature regulator of the invention, taken along a line segment which is identical with line A-A in FIG. 1.

FIG. 6 s a section view of the second embodiment of the fluid temperature regulator of the invention, taken along a line segment which is identical with line B-B in FIG. 1.

FIG. 7A is a schematic view showing a plan configuration of the first related-art regulator, and FIG. 7B is a schematic view showing a side configuration.

FIG. 8A is a schematic view showing a plan configuration of the second related-art regulator, and FIG. 8B is a schematic view showing a side configuration.

FIG. 9 is a schematic view showing a plan configuration of the third related-art regulator.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter embodiments of the fluid temperature regulator of the present invention will be described with reference to the accompanying drawings. In the figures, the identical components are denoted by the same reference numerals, and duplicated description will be omitted. FIG. 1 is a perspective view showing a first embodiment of the fluid temperature regulator. In the fluid temperature regulator, for example, a refrigerant 11 shown in FIG. 2 and the like is filled in a refrigerant case 10 made from a metal which is a good heat-conducting material, such as copper or stainless steel. As the refrigerant 11, water, antifreezing fluid, or the like may be used.
An opening 12 which is for example laterally elongated is formed in one wall face of the refrigerant case 10 so that a transfusion circuit 21 for transfusing fluid such as blood is insertable/removable. A cooling/warming unit 31 which is configured by Peltier element is bonded to, for example, the lower wall of the refrigerant case 10 which stands as shown in FIG. 1, and configured so that the refrigerant 11 in the refrigerant case 10 is cooled/warmed by the cooling/warming unit 31.
FIG. 2 is a section view taken along line A-A of FIG. 1, and FIG. 3 is a section view taken along line B-B. Both FIGS. 2 and 3 show a state where the transfusion circuit 21 is inserted into a storage 13 through the opening 12. The storage 13 which communicates with the opening 12 is made from a metal or metal alloy which is a good heat-conducting material, and watertight for the refrigerant 11.
The storage 13 is disposed at a point substantially intermediate of the height of the refrigerant case 10, and has a size which can house a required portion of the transfusion circuit 21. The required portion means a portion where a tube 22 constituting the transfusion circuit 21 is meanderingly bent, or that corresponding to the bag member in JP-A-09-602 above. Preferably, the transfusion circuit 21 is in contact with all of the walls of the storage 13 so that heat exchange between the refrigerant 11 surrounding the storage 13 and the fluid in the transfusion circuit 21 is performed.
A stirring unit 14 for stirring the refrigerant 11 is disposed in the refrigerant case 10. The stirring unit is configured by, for example, a pump. In the embodiment, the stirring unit 14 is placed on the bottom face in the lower end of the wall face opposed to that where the opening 12 is formed, so that all of the refrigerant 11 including portions which are above and below the storage 13 can be satisfactorily stirred.
The fluid in the transfusion circuit 21 is sent by, for example, an infusion pump which is not shown, and flows in the directions of the arrows S1, S2 in FIG. 2. In order to perform temperature adjustment by the cooling/warming unit 31, temperature sensors 32 are disposed on the tube 22 in the vicinity of the opening 12. In the embodiment, the temperature sensors 32 are disposed on a portion of the tube 22 where the fluid flows into the storage 13, and that of the tube 22 where the fluid flows out from the storage 13, respectively.
Signals from the temperature sensors 32 are supplied to a control portion 40 to be used as temperature data. Preset temperature information is given to the control portion 40. The control portion 40 performs an electric power control in accordance with the difference between the preset temperature information and the temperature data which are obtained as described above, on the cooling/warming unit 31, thereby adjusting the temperature.
In the thus configured fluid temperature regulator, the temperature adjustment is performed by the cooling/warming unit 31 in the state where the transfusion circuit 21 is inserted through the opening 12 and housed in the storage 13. Furthermore, all of the refrigerant 11 is stirred by the stirring unit 14, and the temperature of the refrigerant 11 in the refrigerant case 10 is equalized. The heat of the refrigerant 11 is transmitted to the fluid in the transfusion circuit 21 through the walls of the storage 13. Therefore, highly efficient heat exchange occurs, so that the temperature of the whole refrigerant 11 and that of the fluid in the transfusion circuit 21 are rapidly equalized.
Therefore, it is possible to realize highly efficient heat exchange which is similar to that in the configuration of the related art shown in FIG. 8 where the transfusion circuit is sandwiched by the two metallic plates and the temperature is adjusted by using the two cooling/warming apparatuses. Moreover, only one cooling/warming apparatus is required, and hence the space saving can be achieved together with the cost reduction.
Furthermore, uniformalization of the temperature of the refrigerant 11 in the refrigerant case 10 can be realized, and the heat exchange is performed through the walls of the storage 13. As indicated by the sizes of the arrows in FIG. 4, therefore, the temperature difference between the fluid in the transfusion circuit 21 and the refrigerant 11 is uniform irrespective of positional differences. Consequently, it is possible to prevent a risk that the fluid (for example, blood) is locally cooled/warmed to apply extra stress to the fluid of the portion, from occurring.
Next, FIGS. 5 and 6 show a second embodiment of the fluid temperature regulator of the invention. The fluid temperature regulator of the embodiment has a configuration where a continuous partition plate 50 is disposed to partition the space between the inner wall face 10 a of the refrigerant case 10 and the outer wall face 13 a of the storage 13. For example, the partition plate 50 is made from the same good heat-conducting material (such as copper or stainless steel) as the storage 13, whereby the heat transfer efficiency can be improved. The form obtained by connecting together portions where the inner wall face 10 a of the refrigerant case 10 and the outer wall face 13 a of the storage 13 are joined to the partition plate 50 has a spiral shape centered at the storage.
The region which is surrounded by the inner wall face 10 a of the refrigerant case 10, the outer wall face 13 a of the storage 13, and the partition plate 50 forms a passage 51 which is continuous from the side of the opening 12 to the face opposite to the opening 12, thereby forming a flow path. The start end 52 and the terminal end 53 of the passage 51 are communication with each other by a pipe 54, The pipe 54 is passed through the partition plate 50, and the passed portions are sealed. The stirring unit 14 is disposed in the terminal end 53 of the passage 51, and configured so as to send the refrigerant 11 which comes through the passage 51, into the pipe 54. Namely, the stirring unit 14 is configured so as to guide the refrigerant 11 from the terminal end 53 of the passage 51 to the start end 52 of the passage 51 which is formed by the partition plate 50. Furthermore, the partition plate 50 corresponds to a guiding unit for guiding the refrigerant 11 to the face of said storage 13 which is on the side of the refrigerant 11 and with which the refrigerant 11 is in contact.
Also in the embodiment, the signals detected by the temperature sensors 32 are supplied to the control portion 40 to he used as temperature data, to be given to the control portion 40. Also in the embodiment, the control portion 40 performs an electric power control in accordance with the difference between the preset temperature information and the temperature data which are obtained as described above, on the cooling/warming unit 31, thereby adjusting the temperature.
In the thus configured fluid temperature regulator, the refrigerant 21 which is fed into the pipe 54 with stirring by the stirring unit 14 reaches the start end 52 of the passage 51 through the pipe 54, and further flows through the pipe 54 to reach the terminal end 53. Then, the refrigerant 11 is sent into the pipe 54 with stirring by the stirring unit 14, and circulates through a path similar to that described above.
In the circulation process, in the passage 51, the refrigerant 11 flows in a state where the refrigerant is always in contact with the outer wall face 13 a of the storage 13 to perform heat exchange. Furthermore, the refrigerant 11 receives cooling/warming by the cooling/warming unit 31. Namely, the refrigerant 11 always performs heat exchange with the transfusion circuit 21 through the outer wall face 13 a of the storage 13, while receiving cooling/warning by the cooling/warming unit 31. The fluid in the transfusion circuit 21 can be efficiently cooled/warmed by the refrigerant 11 the temperature of which is uniformalized by the flow. The temperature adjustment can be performed very adequately.
In the above, the configuration where the pipe 54 and the stirring unit 14 are disposed inside the refrigerant case 10 is employed. Alternatively, a configuration where the pipe 54 and/or the stirring unit 14 are disposed outside the refrigerant case 10 may be employed. The shape of the passage 51 is not restricted to a spiral shape. For example, the space between the inner wall face 10 a of the refrigerant case 10 and the outer wall face 13 a of the storage 13 may be partitioned by a plurality of annular partition plates, and communication ports are formed in the partition plates to configure a passage which is continuous from the side of the opening 12 to the face opposite to the opening 12.
Also in the configuration of the modification, it is possible to achieve the effect that the temperature of the fluid in the transfusion circuit 21 can be adjusted very adequately by the refrigerant 11 the temperature of which is uniformalized by the flow in the passage.
According to an aspect of the invention, the fluid temperature regulator includes a storage that has an opening through which a transfusion circuit for transfusing fluid is to be inserted/removed, that houses the transfusion circuit inserted through the opening, while being in contact with the transfusion circuit, that is surrounded by a refrigerant, and that is watertight for the refrigerant. Even when a damage occurs in the transfusion circuit, since the transfusion circuit exists in the storage that is watertight for the refrigerant, there is no fear that the medium flows into the transfusion circuit. The storage is surrounded by the refrigerant, and a refrigerant case which contains the refrigerant is cooled/warmed. Therefore, heat is gradually transferred, so that, in the case where the fluid is blood, the blood is not exposed to a temperature which is so high or low that the blood may be damaged, and a high safety level can be ensured. Heat is uniformly transferred from the refrigerant to the whole storage. Therefore, the temperature of the fluid can be efficiently adjusted.
According to an aspect of the invention, a thermal gradient is not produced in the refrigerant of the refrigerant case, and the heat transfer efficiency with the blood can be improved.
According to an aspect of the invention, the refrigerant is guided to the face of the storage on the side of the refrigerant by the guiding unit, so that a flow is produced in the refrigerant. Consequently, the refrigerant in the refrigerant case can be maintained more efficiently to a uniform temperature, and the heat transfer efficiency with the blood can be improved.
According to an aspect of the invention, the refrigerant is guided to a flow path through which the refrigerant can spirally flow around the storages so that a flow is produced in the refrigerant. Consequently, the refrigerant in the refrigerant case can be maintained more efficiently to a uniform temperature, and the heat transfer efficiency with the blood can be improved.
According to an aspect of the invention, a flow passing through the stirring unit and the guiding unit is produced in the refrigerant. Consequently, the refrigerant in the refrigerant case can be maintained more efficiently to a uniform temperature, and the heat transfer efficiency with the blood can be improved.
According to an aspect of the invention, the refrigerant and the transfusion in the transfusion circuit can perform highly efficient heat exchange with each other through the storage which is configured by a good heat-conducting material.

Claims

1. A fluid temperature regulator, comprising:

a case, containing a refrigerant;

a cooling/warming device, configured to cool/warm the case; and

a storage, including an opening through which a circuit for transfusing fluid is to be inserted/removed, the storage configured to house the circuit inserted through the opening and be in contact with the circuit, the storage being surrounded by the refrigerant and watertight for the refrigerant in the case.

2. The fluid temperature regulator according to claim 1, further comprising:

a stirrer, configured to stir the refrigerant is provided in the case.

3. The fluid temperature regulator according to claim 2, further comprising:

a guide, configured to guide the refrigerant to a face of the storage, the refrigerant being in contact with the face of the storage.

4. The fluid temperature regulator according to claim 3,

the guide includes a flow path through which the refrigerant spirally flows around the storage.

5. The fluid temperature regulator according to claim 3, wherein

the stirrer guides the refrigerant to the guide.

6. The fluid temperature regulator according to claim 4, wherein

the stirrer guides the refrigerant to the guide.

7. The fluid temperature regulator according to claim 1, wherein

the storage is comprised of a heat-conducting material.