JPS6311965Y2 - - Google Patents

Description

[Detailed Description of the Invention] Background Technical Field of the Invention The present invention relates to an extracorporeal blood circulation circuit such as an artificial heart-lung machine, that is, circulation piping, or an oxygenator, a blood storage tank, a pump, and a heat pump provided in the middle of the circulation piping. The present invention relates to a temperature sensor that can measure blood temperature in an extracorporeal blood circulation circuit configured by each circulation device such as an exchanger. Prior Art In extracorporeal circulation using an artificial heart-lung machine, various body temperature controls are carried out according to hypothermia, normal temperature circulation, etc., but in this case, it is necessary to measure the blood temperature during extracorporeal circulation. FIG. 1 is a sectional view showing a conventional blood temperature measuring device. This blood temperature measuring device has a cylindrical body 1 made of synthetic resin and an open end of a metal sheath 2 integrally molded in a liquid-tight manner. The cylindrical body 1 is bonded to the wall of the container 3 with an adhesive so that the cylindrical body 1 and A temperature sensing element 4 is removably attached to the inside of the bottomed tube 2. According to this blood temperature measuring device, by arranging the temperature sensing body 4 inside the blood flow path, it is possible to measure blood temperature with high accuracy without being affected by the outside temperature. However, in this blood temperature measuring device, since the bottomed tube 2 is arranged to protrude greatly inside the blood flow path, turbulence of blood flow occurs around the bottomed tube 2. It may promote the formation of blood aggregates in the surrounding area or damage blood cells. FIG. 2 is a sectional view showing another conventional blood temperature measuring device. This blood temperature measuring device has a temperature sensing element 7 fixedly arranged on the inner surface of a connecting pipe 6 of a circulation line 5. In this blood temperature measuring device, in order to reduce the amount of protrusion of the temperature sensor 7 into the blood flow path, if the temperature sensor 7 is buried shallowly within the wall of the connecting tube 6, The influence of outside air temperature becomes large, making it impossible to measure blood temperature with high precision. Therefore, even in this blood temperature measuring device, it is necessary to dispose the temperature sensitive body 7 in a large protruding manner inside the blood flow path, which causes disturbance of blood flow around the temperature sensitive body 7, and the temperature sensitive body There is a risk of promoting the formation of blood aggregates around 7 or damaging blood cells. Purpose of the invention The purpose of the invention is to provide a temperature sensor for an extracorporeal blood circulation circuit that is capable of measuring blood temperature with high precision without the temperature-sensing part protruding significantly into the blood flow path. . Structure of the invention In order to achieve the above object, the temperature sensor for an extracorporeal blood circulation circuit according to the invention includes a ring-shaped metal heat collector that can be placed around the blood flow path of the extracorporeal blood circulation circuit, and a temperature sensor for an extracorporeal blood circulation circuit. a temperature detection element joined to the back side of the heat collector with respect to the blood flow path; and a heat insulator disposed on the back side of the heat collector and the temperature detection element with respect to the blood flow path and covering the temperature detection element. , and a connector electrically connected to the temperature detection element, wherein the thickness of the heat collector is
The diameter of the heat collecting body is approximately equal to the inner diameter of the blood flow path. Further, in a preferred embodiment of the temperature sensor for an extracorporeal blood circulation circuit according to the present invention, the connector is fixed to a heat insulator that covers and holds the heat collector and the temperature detection element. It is. Specific Description of the Invention Hereinafter, embodiments of the invention will be described with reference to the drawings. FIG. 3 is a sectional view showing the first embodiment of the present invention. This embodiment is an example in which the present invention is applied to a connecting pipe 12 interposed in the middle of a circulation pipe 11 forming an extracorporeal blood circulation circuit of an artificial heart-lung machine or the like. The connecting tube 12 defines a blood flow path 14 by a tube body 13 that forms a heat insulator in the present invention.
The tube body 13 as a heat insulator is connected to the blood flow path 14.
An annular metal heat collector 1 that can be placed around the
5 and the thermistor 16 as a temperature detection element, which is electrically connected to the back side of the heat collector 15 with respect to the blood flow path 14 by soldering or using adhesive, etc., to insulate it from the outside temperature. Covered and maintained in condition. Lead wires 17A, 17B connected to the electrodes of the thermistor 16 are connected to pins 18A, 18 of the connector 18 fixed to the tube body 13.
It is electrically connected to B. The connecting tube 12 transfers the temperature of the blood flowing through the blood flow path 14 to the thermistor 16 via the heat collector 15 with good thermal conductivity, and uses the thermistor 16 as a heat insulator to transfer the temperature of the outside air to the thermistor 16. By insulating the temperature from the blood, the thermistor 16 can detect the temperature of the blood without attenuation. The tube body 13 must be made of a material that is inert to living organisms and has high heat insulation properties, and vinyl chloride, urethane, polycarbonate, polyacetal, polypropylene, Teflon, etc. are used. The heat collector 15 needs to be inert to living organisms and a good thermal conductor, and gold, silver, platinum, titanium, and stainless steel are used. Also, empirically, the thickness of the heat collector 15 is preferably 0.01 mm to 3 mm; anything less than this thickness has no elasticity as a metal foil, and if it is thick, the heat dissipation area will be larger than the heat sensitive area, and the outside temperature will affect the heat collector 15. becomes impossible to ignore. Further, the temperature detection element of the present invention is not limited to the above-mentioned thermistor, but may be a platinum resistor, a thermocouple, or the like. Further, the inner diameter of the heat collector 15 and the inner diameter of the blood flow path 14 formed by the tube body 13 are formed to be approximately equal. Specific Effects of the Invention The connecting tube 12 is disposed closer to the human body 22 in the middle of an arterial line connecting the oxygenator 21 and the aorta of the human body 22 in the artificial heart-lung machine shown in FIG. 4, for example, and flows into the human body 22. It is possible to measure the blood temperature immediately before the test. In addition, in FIG. 4, 23 is a blood storage tank, 24 is a pump, and 25 is a heat exchanger. Therefore, in the case of the connecting pipe 12, the blood temperature comes into wide contact with the blood flow, and the heat collector 15 has good thermal conductivity.
Since the thermistor 16 is insulated from the outside air temperature due to the presence of the tube body 13 as a heat insulator, the blood flow passes through the temperature sensing section consisting of the heat collector 15 and thermistor 16. A state in which there is no significant protrusion into the interior of the tract 14, that is, turbulence of blood flow around the temperature sensing part,
It becomes possible to measure blood temperature with high precision without promoting the generation of blood aggregates or damaging blood cells. Note that, since the inner diameter of the heat collector 15 and the inner diameter of the blood flow path 14 formed by the tube body 13 are approximately equal, the temperature sensing portion consisting of the heat collector 15 and thermistor 16 is located in the blood flow path 14. The above-mentioned state in which no protrusion into the interior occurs is ensured. Further, since the connector 18 is fixed to the tube body 13, no tension is applied to the lead wires 17A, 17B, and it is possible to prevent the lead wires 17A, 17B from being damaged. The results of experiments conducted using the connecting pipe 12 according to the above embodiment will be explained as follows. That is, in this experiment, the total length was 70
mm, in the center of the polycarbonate connecting pipe 12 with an outer diameter of 10 mm, an inner diameter of 6 mm, and a wall thickness of 20 mm at the joint with the circulation pipe 11, a width of 5 mm, a thickness of 1 mm, and an outer diameter of 6 mm.
Heat collector 1 made of stainless steel pipes
5, fix the square thermistor 16 with 3 mm on each side on the back side of the heat collector 15 with adhesive, and connect the lead wire 1.
It was connected to an external thermometer through 7A and 17B. A circulation pipe 11 made of vinyl chloride was connected to this connecting pipe 12, and hot water was circulated using a pump. First, Table 1 was obtained as a result of comparing the measurement results according to the conventional method in which the detection probe was largely protruded into the inside of the blood flow path 14 and the measurement results according to the present invention. According to Table 1, it is recognized that the present invention makes it possible to measure blood temperature with extremely high accuracy without the temperature sensing portion protruding significantly into the blood flow path 14.

[Table] Next, the connecting tube 12 was used in an animal experiment, and the presence or absence of thrombus formation and the internal pressure on the primary side in front of the temperature detection part were measured, and Table 2 was obtained.

[Table] According to Table 2, it is recognized that the present invention makes it possible to measure blood temperature without the occurrence of thrombi and without increasing blood flow resistance. Next, in the connecting pipe 12, the detected temperature difference with respect to the reference water temperature when the wall thickness of the stainless steel pipe serving as the heat collector is varied from 0.01 mm to 5 mm is shown in Figure 5. . That is, according to this FIG. 5, as mentioned above, when the thickness of the heat collector is set to 0.01 to 3 mm, it is recognized that the blood temperature can be measured with extremely high accuracy. FIG. 6 is a partially cutaway side view of a second embodiment of the present invention, and FIG. 7 is a sectional view showing the main parts thereof. In this example, a hollow fiber oxygenator 30
This is an example of applying the present invention to. Hollow fiber oxygenator 3
0 includes a housing 31, a large number of hollow fiber membranes 32 housed inside the housing 31, and a hollow fiber membrane 3.
A partition wall 33 liquid-tightly holds both ends of 2 to the housing 31, and a partition wall 33 provided on the outside of the partition wall 33,
Blood inflow section 3 communicating with the internal space of the hollow fiber membrane 32
4 and a blood outflow section 35, a gas chamber 36 composed of a partition wall 33, an inner wall of the housing 31, and an outer wall of the hollow fiber membrane 32, and a gas inflow section 37 and a gas outflow section 38 communicating with the gas chamber 36. , hollow fiber membrane 3
Blood and gas are brought into contact via 2, making it possible to perform gas exchange. Here, in this embodiment, an annular metal heat collector is attached to the inner peripheral part of the cylindrical part 40A of the header 40 defining the blood flow path 39 of the blood outflow part 35 in the hollow fiber oxygenator 30. 41 are arranged. A thermistor 42 is bonded to the back surface of the heat collector 41 with respect to the blood flow path 39 . That is, the heat collector 4
1 and the thermistor 42 are connected to a cylindrical portion 4 made of a heat insulator.
0A, it is covered and maintained insulated from outside temperature. Lead wires 43A and 43B connected to the electrodes of the thermistor 42 are connected to the cylindrical portion 4.
Pin 44 of connector 44 fixed at 0A
A, 44B. Further, the inner diameter of the heat collector 41 and the inner diameter of the blood flow path 39 formed by the blood outflow portion 35 are formed to be approximately equal. According to the hollow fiber oxygenator 30 according to the second embodiment, as in the connecting pipe 12 of the first embodiment, the blood temperature is brought into wide contact with the blood flow, and the heat collector 41 with good thermal conductivity is used. The thermistor 42 is connected to the header 40 as a heat insulator.
The heat collector 41 and the thermistor 42 are insulated from the outside air by the cylindrical portion 40A.
It becomes possible to measure the blood temperature with high precision without the temperature sensing part consisting of the blood flow path 39 protruding significantly into the inside of the blood flow path 39. Note that, since the inner diameter of the heat collector 41 and the inner diameter of the blood flow path 39 formed by the blood outflow portion 35 are approximately equal, the heat collector 41 and the thermistor 4
The above-mentioned state in which the temperature-sensing section consisting of 2 does not protrude into the blood flow path 39 is ensured. Effects of the Invention As described above, the temperature sensor for an extracorporeal blood circulation circuit according to the present invention includes a ring-shaped metal heat collector that can be placed around the blood flow path of the extracorporeal blood circulation circuit, and the heat collector. a temperature detection element bonded to the back surface of the blood flow channel, a heat insulator disposed on the back surface of the heat collector and the temperature detection element with respect to the blood flow channel, and covering the temperature detection element; In a temperature sensor comprising a connector electrically connected to a detection element, the thickness of the heat collector is 0.01 mm to 3 mm, and the diameter of the heat collector and the inner diameter of the blood flow path are approximately equal. This is how it works. Therefore, since the blood temperature comes into contact with the blood flow and is transmitted to the temperature detection element via a heat collector with good thermal conductivity, and the temperature detection element is insulated from the outside air by the presence of the heat insulator, , a state in which the temperature sensing part consisting of a heat collector and a temperature detection element does not protrude significantly into the blood flow path, that is, it does not cause turbulence in blood flow around the temperature sensing part and promote the generation of blood aggregates. It becomes possible to set the state in a state where there is no risk of damaging blood cells and to measure blood temperature with high accuracy. In addition, the temperature-sensing part consisting of the heat collector and temperature detection element does not protrude into the blood flow path, and the diameter of the heat-collecting body and the inner diameter of the blood flow path are made almost equal, thereby preventing turbulence in blood flow around the temperature-sensing part. As a result, it becomes possible to measure blood temperature with high precision without any fear of promoting the generation of blood aggregates or damaging blood cells. Further, in a preferred embodiment of the temperature sensor for an extracorporeal blood circulation circuit according to the present invention, the connector is fixed to a heat insulator that covers and holds a heat collector and a temperature detection element. . As a result, no tension is applied to the lead wires that connect the connector and the temperature detection element, making it possible to prevent damage to the lead wires.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional blood temperature measuring device, FIG. 2 is a sectional view showing another conventional blood temperature measuring device, and FIG. 3 is a sectional view showing a first embodiment of the present invention. Figure 4 is a circuit diagram showing an extracorporeal circulation circuit using the temperature sensor for extracorporeal blood circulation circuit according to the first embodiment, and Figure 5 shows the influence of the thickness of the heat collector on temperature detection accuracy. FIG. 6 is a partially cutaway side view of the second embodiment of the present invention, and FIG. 7 is a cross-sectional view of the main part of FIG. 6. 12... Connection pipe, 13... Pipe body, 14... Blood flow path, 15... Heat collector, 16... Thermistor,
17A, 17B... Lead wire, 18... Connector, 30... Hollow fiber oxygenator, 39... Blood flow path, 40A... Cylindrical part, 41... Heat collector, 42...
...Thermistor, 43A, 43B...Lead wire, 4
4...Connector.

Claims (1)

[Claims for Utility Model Registration] (1) An annular metal heat collector that can be placed around the blood flow path of an extracorporeal blood circulation circuit, and a heat collector that is bonded to the back surface of the heat collector with respect to the blood flow path. a temperature detecting element, a heat insulator disposed on the back side of the heat collector and the temperature detecting element with respect to the blood flow path and covering the temperature detecting element, and a connector electrically connected to the temperature detecting element. Extracorporeal blood circulation, characterized in that the heat collector has a thickness of 0.01 mm to 3 mm, and the diameter of the heat collector is approximately equal to the inner diameter of the blood flow path. Temperature sensor for circuit. (2) The extracorporeal blood circulation circuit according to claim 1, wherein the connector is fixed to a heat insulator that covers and holds the heat collector and the temperature detection element. Temperature sensor.