JP4493587B2 - Extracorporeal circulation device - Google Patents

Description

  The present invention relates to an extracorporeal circulation device for circulating a liquid, particularly a body fluid or a chemical solution, and more specifically, in an extracorporeal circuit in which a branch tube is connected to a circulation circuit made of a main tube, a circulation circuit made of a main tube. The body fluid in the branch tube is replaced by constantly flowing the fluid column of the body fluid or chemical liquid that is generated in the branch tube when the pressure is recovered after the inside becomes negative pressure for some reason, and replacing the liquid. Or it is related with the extracorporeal circulation apparatus which prevented that a chemical | medical solution stagnates and solidifies.

  In extracorporeal circulation therapy in which blood is removed from the patient's body, blood is treated outside the body using a blood treatment device, and the treated blood is returned to the body, a tube is usually placed on the main tube constituting the extracorporeal circuit. A tube-type liquid feed pump that feeds liquid is used. In the middle of the main tube on the upstream side or downstream side of the liquid feed pump, there are various types of tubes such as a branch tube for monitoring pressure, a branch tube for performing infusion, and a branch tube for changing the flow path. A branch tube is arranged, and often, a pressure measuring device, a clamp, a forceps, a three-way stopcock, a sampling port, a syringe or the like is provided at the end or in the middle of the branch tube, and the branch tube is thereby closed. ing.

  In these branch tubes, if the pressure in the main tube often recovers after being negative for some reason, for example, the tube-type liquid feed pump continues to operate while the main tube is bent. When the pressure becomes negative pressure and then the bend is resolved and the pressure recovers, the air in the branch tube is once drawn into the main tube by the negative pressure, and then when the pressure recovers, the same volume from the main tube A body fluid or a chemical solution may be drawn into the branch tube to form a liquid column.

  Since the length of the liquid column does not change unless there is a change in pressure, the bodily fluids and chemicals that form the liquid column may stagnate on the spot, particularly in the case of blood, which may coagulate as it is. is there.

  In the extracorporeal circuit, the liquid column in the branch tube is disturbed by the pulsation of the tube-type pump that continues to operate, so that the liquid in the branch tube is constantly replaced with the liquid in the main tube. In some cases, the above problem can be avoided.

  For example, when the position where the branch tube is closed by the closing device is a position close to the main tube, specifically, when the branch tube is closed immediately below the branch point with a clamp or forceps, the originally formed liquid column is Since there are many cases where the length is not so long, replacement is easily promoted by pulsation by the tube-type liquid feeding pump, and there is almost no problem.

  However, in the case where a circuit configuration in which the pressure measuring device is attached to the tip of the branch tube as shown in Non-Patent Document 1, body fluid or chemical solution is prevented from adhering to the pressure measuring device and being unable to be measured. Therefore, it is necessary to give a certain margin to the length of the branch tube. For this reason, the distance from the branch point of the main tube to the tip of the branch tube blocked by the pressure measuring device is increased, and the length of the liquid column formed thereby is also increased. The entire liquid column is not replaced by the effect of only the disturbance due to the turbulence, and there is a problem that the stagnation or coagulation of the body fluid or the chemical solution occurs in the branch tube.

  FIG. 4 is a schematic configuration diagram showing an example of a circuit configuration in which the closure device is attached to the tip of the branch tube in the conventional example described above. The circuit 4 of the extracorporeal circulation device is arranged at the main tube 10, the branch portion 40 disposed in the middle of the main tube 10, the branch tube 20 connected to the branch portion 40, and the end of the branch tube 20. The closure device 30 (for example, the closure device 30 is a pressure measuring device or the like).

  As described above, even after the inside of the main tube 10 becomes negative pressure for some reason, for example, as shown in FIG. When the operation continues (not shown), the air in the branch tube 20 is drawn into the main tube 10 in the direction indicated by the arrow 50 in FIG.

  When the pressure recovers again, the same amount of bodily fluid or chemical as the drawn-in air 51 is drawn into the branch tube 20 in the direction indicated by the arrow 53 in FIG. Is done. When the branch tube 20 is long, the formed liquid column 52 is also long. Therefore, the replacement cannot be promoted only by the influence of the turbulence in the branch tube 20 caused by the pulsation generated by the operation of the liquid feed pump. An arrow 54 shown in FIGS. 5A and 5B indicates the flow direction in the main tube 10.

  As an example of a blood circuit that solves such problems, Patent Document 1 describes a pressure measurement method using a drip chamber that is frequently used as a type of pressure monitoring in extracorporeal circulation therapy.

  FIG. 6A is a schematic configuration diagram showing an example of the circuit configuration of the drip chamber of the above-described conventional example. The drip chamber 5 is disposed in the middle of the main tube 10, and the branch tube 20 branched from the upper part of the drip chamber 5, the end of the branch tube 20 or the closing device 30 disposed in the middle thereof, And a pressure measuring device. In FIG. 6A, the same reference numerals are given to the constituent members having the same functions as the constituent members in FIG.

  In the drip chamber type pressure measurement method as shown in FIG. 6 (a), a certain amount of body fluid or chemical solution, for example, about half the volume is stored in the drip chamber 5, and the other half is extracorporeally circulated as an air layer. By performing the therapy, when the pressure is restored after the inside of the main tube 10 becomes negative pressure, there is a margin of the air layer, and therefore, body fluid or drug solution is rarely drawn into the branch tube 20.

  Patent Document 2 describes a pressure measurement method using a pillow, which is also frequently used in extracorporeal circulation therapy, as a pressure measurement method for avoiding contact with air. FIG. 6B is a schematic configuration diagram showing an example of the circuit configuration of the pillow 6 in the above-described conventional example. The pillow 6 is arranged in the middle of the main tube 10, and the pressure in the main tube 10 can be estimated from the deformation amount of the pillow 6. In FIG. 6B, constituent members that perform the same functions as those shown in FIG. 4 are given the same reference numerals.

Hygieia Plus "OPERATOR MANUAL" p.5-5 Load Screen 1 JP 2004-267672-A Japanese Patent Laid-Open No. 08-166301

  However, the drip chamber 5 described in the above-mentioned Patent Document 1 (see FIG. 6A) has a large contact area with air due to the size of its inner diameter, and further, the amount of body fluid or chemical solution to be stored is large. Therefore, it takes time until the entire stored liquid is replaced, and there is a possibility that the retention or coagulation of the body fluid or the chemical solution is induced.

  Further, in the example of the pillow type pressure detector described in Patent Document 2 (see FIG. 6B), it depends on a set position of the pillow 6, a difference in individual shape of each pillow 6, a difference in temperature, and a change with time. Even at the same pressure, there was a possibility that the measured value was not stable.

  Further, in the pressure measurement formats described in Patent Document 1 and Patent Document 2, since the priming volume is large, in extracorporeal circulation therapy, the burden on the patient is increased, and in addition, a blood circuit is installed at a specific site. In addition, it is necessary to provide a dedicated installation position for the extracorporeal treatment apparatus, which may lead to an increase in the size of the apparatus and a decrease in handleability.

  The present invention solves the above-mentioned problems. The object of the present invention is to reliably detect the pressure without increasing the priming volume, to cause coagulation of blood or plasma, and to have good handling properties. It is intended to provide an extracorporeal circulation device.

  As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by providing a throttle portion with a reduced flow path cross-sectional area at least at one location in the middle of the branch tube. The present invention has been completed.

That is, the first configuration of the extracorporeal circulation apparatus according to the present invention for achieving the above object is an extracorporeal circulation apparatus that monitors the pressure of the extracorporeal circulation circuit using a branch tube of the circuit, and the extracorporeal circulation circuit includes: A main tube for feeding at least a body fluid or a medicinal solution, a liquid feeding pump for feeding the main tube, a branching part disposed in the middle of the main tube, a branching tube connected to the branching part, And a pressure measuring means disposed so as to block the end of the branch tube or the middle thereof, and at least one throttle section with a reduced flow path cross-sectional area is provided in the middle of the branch tube. The liquid column in the branch tube between the throttle part of the branch tube and the pressure measuring means is disturbed by the pulsation at the time of liquid feeding .

The second configuration of the extracorporeal circulation apparatus according to the present invention is the first configuration, wherein the flow passage cross-sectional area of the non-throttle portion of the branch tube is 1.5 times the flow passage cross-sectional area of the throttling portion. It is the above.

Further, in the third configuration of the extracorporeal circulation device according to the present invention, in the first and second configurations, the cross-sectional area of the non-throttle portion of the branch tube is 7 mm ² or more and 51 mm ² or less, The flow path cross-sectional area of the throttle part is 3 mm ² or more and 30 mm ² or less, and the length of the throttle part in the longitudinal direction is 30 mm or less.

Further, a fourth configuration of the extracorporeal circulation apparatus according to the present invention is the first to third configurations, wherein there are a plurality of throttle portions in the middle of the branch tube, and the spacing between the throttle portions on the branch tube is different. It is characterized by being constant.

The fifth configuration of the extracorporeal circulation apparatus according to the present invention is characterized in that, in the fourth configuration, the spacing between the throttle portions on the branch tube is 10 mm or more and 50 mm or less.

According to a sixth configuration of the extracorporeal circulation apparatus according to the present invention, in the first to fifth configurations, the throttling portion includes a throttling portion tube having an inner diameter smaller than that of the branch tube. The diameter is increased at an inclination angle of not less than 60 ° and not more than 70 °, and communicates with the branch tube.

Further, in the seventh configuration of the extracorporeal circulation device according to the present invention, in the first to sixth configurations, at least one flow path cross-sectional area is reduced in the main tube upstream of the branch portion. A diaphragm is provided.

Further, an eighth configuration of the extracorporeal circulation device according to the present invention is the seventh configuration, wherein the flow passage cross-sectional area of the throttle portion of the main tube is 0.2 mm ² or more and 1.8 mm ² or less. It is characterized by.

  According to the extracorporeal circulation apparatus according to the present invention, there is a constricted portion with a reduced flow path cross-sectional area at least at one location in the middle of the branch tube, so that a liquid column is formed in the longitudinal direction of the branch tube by the pulsation of the liquid feed pump Since the flow is disturbed due to fluctuation and expansion of the flow path at the outlet of the throttle part, the replacement of liquid is facilitated compared to the branch tube without the throttle shown in FIG. Coagulation of is prevented. Moreover, since the overall shape is a simple branch tube branched from the main tube as shown in FIG. 4, the blood circuit is excellent in handleability.

  Furthermore, unlike the drip chamber 5 as shown in FIG. 6A and described above, there is no portion for storing liquid, so that the priming volume can be greatly reduced. Furthermore, unlike the pillow 6 as shown in FIG. 6B and described above, the pressure in the branch tube can be directly measured, so that the pressure in the extracorporeal circuit can be reliably measured.

  An embodiment of the circuit of the extracorporeal circulation apparatus according to the present invention will be specifically described with reference to the drawings. 1-3 is a figure which shows the structure of the 1st-3rd embodiment of the circuit of the extracorporeal circulation apparatus based on this invention. The present invention is not limited only to these embodiments.

  First, the configuration of the first embodiment of the circuit of the extracorporeal circulation apparatus according to the present invention will be described with reference to FIG. In FIG. 1, the circuit 1 of the extracorporeal circulation apparatus according to the first embodiment is connected to a main tube 10 for feeding a body fluid or a chemical solution, a branch portion 40 disposed in the middle of the main tube 10, and the branch portion 40. A branch tube 20, a closing device 30 disposed so as to close the end of the branch tube 20, and a narrowed portion 21 having a reduced flow path cross-sectional area provided in the middle of the branch tube 20. Configured.

  Here, the throttle portion 21 may be formed using a tube for a throttle portion having an inner diameter smaller than that of the branch tube 20, or if the branch tube 20 is a soft tube, the tube is pressed by pressing the tube. The channel cross-sectional area may be reduced. The closing device 30 may be arranged to close the middle of the branch tube 20.

  The body fluid or the chemical fluid flowing through the main tube 10 is fed by a rotating part of a liquid feeding pump (not shown) arranged on the main tube 10 squeezing a part of the main tube 10. The air in the branch tube 20 is drawn into the main tube 10 when the liquid feeding pump continues to operate when the pressure in the main tube 10 becomes negative, and the air drawn in when the pressure recovers again. The same amount of body fluid or chemical liquid column is formed in the branch tube 20.

  Thereafter, the liquid column has a certain width due to the pulsation generated on the upstream side and the downstream side of the tube pump when the rotating part of the liquid pump squeezes a part of the main tube 10. The inside of the tube fluctuates in the longitudinal direction. At that time, the presence of the throttle portion 21 causes disturbance due to the reduction and expansion of the flow, and the replacement is promoted in the main tube 10 and the branch tube 20, so that the body fluid or the chemical solution is It does not induce stagnation or clotting.

Here, if the difference between the flow passage cross-sectional area of the non-throttle portion of the branch tube 20 and the flow passage cross-sectional area of the narrow portion 21 is small, there is a possibility that flow disturbance due to shrinkage and expansion of the flow passage is difficult to occur. There is. In addition, if the flow path cross-sectional area of the branch tube 20 is too large, the fluctuation speed of the liquid column in the branch tube 20 due to pulsation becomes slow, so that it is difficult for disturbance to occur, and further, the operability is reduced. there is a possibility. Therefore, the flow passage cross-sectional area of the non-throttle portion of the branch tube 20 is preferably 1.5 times or more of the flow passage cross-sectional area of the throttling portion 21, and more specifically, the non-throttle portion of the branch tube 20 The cross-sectional area of the flow path is preferably 7 mm ² or more and 51 mm ² or less, and the cross-sectional area of the throttle portion 21 is preferably 3 mm ² or more and 30 mm ² or less.

More preferably, the cross-sectional area of the non-throttle portion of the branch tube 20 is 12 mm ² or more and 30 mm ² or less, and the cross-sectional area of the throttling portion 21 is 3 mm ² or more and 13 mm ² or less. The flow passage cross-sectional area of the non-throttle portion of the branch tube 20 is 12 mm ² or more and 20 mm ² or less, and the flow passage cross-sectional area of the throttle portion 21 is 3 mm ² or more and 7 mm ² or less.

  Furthermore, the length in the longitudinal direction of the narrowed portion 21 may be long or short, but the length in the longitudinal direction of the narrowed portion 21 is preferably 30 mm or less, more preferably 10 mm or less, and most preferably 5 mm or less.

  The branch tube 20 and the throttle portion 21 may be formed by forming tubes with different inner diameters as an integral tube or connecting them using different diameter connectors. When the communication part 22 is at an angle of 90 ° with respect to the inner wall surface of the branch tube 20, the circuit 1 of the extracorporeal circulation device of the present embodiment is installed only in the direction perpendicular to the ground. If the circuit 1 of the extracorporeal circulation apparatus is tilted with respect to the ground, the pressure in the main tube 10 becomes low, and when the liquid column fluctuates in the direction of shortening, the tip of the liquid column There is a possibility that the body fluid or the chemical solution present in the part remains on the tip side of the throttle part 21 and stay or solidify.

  Furthermore, when the communication portion 22 forms an angle of 90 ° with respect to the inner wall surface of the branch tube 20, liquid is entrained in the branch tube 20 by entraining air when the liquid column is formed. There is a possibility that the column is divided into a liquid layer and an air layer, and the body fluid or the chemical solution on the tip side of the air layer stays or solidifies. Therefore, it is preferable that the communicating portion 22 between the branch tube 20 and the throttle portion 21 is expanded in diameter at an inclination angle of 20 ° or more and 70 ° or less with respect to the inner wall surface of the branch tube 20 and communicates with the branch tube 20. More preferably, the communication part 22 is expanded in diameter at an inclination angle of 30 ° or more and 60 ° or less with respect to the inner wall surface of the branch tube 20 and communicates with the branch tube 20, most preferably. Is to expand the diameter at an inclination angle of 30 ° or more and 40 ° or less with respect to the inner wall surface of the branch tube 20 and communicate with the branch tube 20.

  Further, the shape of the communication portion 22 is not particularly limited as long as it has the same effect as the above shape. For example, the shape of the communication portion 22 is not limited to a linear shape as shown in FIG. is not.

  When a tube made of a soft material is used for the branch tube 20, the throttle portion 21 can be formed simply by sandwiching the tube with a clamp or a tube holder having a certain throttle. In this case, the communication part 22 may have a naturally formed shape.

  The branch portion 40 and the branch tube 20 disposed in the middle of the main tube 10 may be configured as an integral tube or connected using a connector. Any means can be used as long as the tube communicates with the branching portion 40, and the means is not particularly limited.

  The inner diameter of the main tube 10 may be selected according to each extracorporeal circulation therapy and is not particularly limited. For example, in blood purification therapy which is one of extracorporeal circulation therapy, a main tube 10 having an inner diameter of about 2 mm to 5 mm is generally selected. Here, the cross-sectional shapes of the main tube 10, the branch tube 20, and the throttle portion 21 do not have to be circular, and there is no problem even if they are non-circular cross sections including an ellipse, a quadrangle, and a hexagon.

  The entire length of the branch tube 20 may be set as appropriate in consideration of the operability of the blood processing apparatus used, and is not particularly limited. The liquid to be circulated in the circuit 1 of the extracorporeal circulation device may be any body fluid or chemical solution, and is not particularly limited. Examples of body fluids include blood, lymph, tissue fluid, mucus, hormones, cytokines, urine, etc. Examples of chemicals include physiological saline, anticoagulant, fresh frozen plasma, dialysate, albumin solution, filtration artificial Examples include kidney replacement fluid.

  The closing device 30 may be anything as long as it closes the end of the branch tube 20 or in the middle thereof, and examples thereof include a pressure measuring device, a clamp, forceps, a three-way stopcock, a sampling port, and a syringe, but are particularly limited. is not.

  The liquid feeding means for feeding the liquid disposed in the middle of the main tube 10 may be a pump, and may be any tube pump that feeds the liquid by squeezing the tube. For example, a rotary tube pump includes a rotating body to which a plurality of rollers are attached, and when the main tube 10 is set on the outer periphery of the rotating body, the rotating body is rotated, The roller is structured to feed liquid while squeezing the tube. The tube is regulated in a circular arc shape, and the center of the circular arc becomes the center of the rotating body, and the plurality of rollers rotate and revolve to rotate the tube and feed liquid.

  The material of the main tube 10 and the branch tube 20 is preferably a material having biocompatibility and biological safety because the patient's bodily fluids are directly or indirectly touched. The material may be any of synthetic resin, metal, glass and the like, but synthetic resin, particularly thermoplastic resin is preferable from the viewpoint of manufacturing cost, workability and operability.

  Thermoplastic resins include polyolefin resins, polyamide resins, polyester resins, polyurethane resins, fluorine resins, silicon resins, ABS (acrylonitrile-butadiene-styrene copolymer) resins, and polyvinyl chloride. Polycarbonate, polystyrene, polyacrylate, polyacetal and the like can be exemplified, and any of them can be suitably used. Among these, a soft material is preferable because it is resistant to bending and cracking and has excellent flexibility during operation, and soft vinyl chloride is particularly preferable for the reason of assembly.

  Next, the configuration of the second embodiment of the circuit of the extracorporeal circulation apparatus according to the present invention will be described with reference to FIG. FIG. 2 is a schematic view showing a second embodiment of the circuit of the extracorporeal circulation apparatus according to the present invention. In addition, about the part same as 1st Embodiment mentioned above and the part which has the same function, description is abbreviate | omitted using the same code | symbol.

  The length of the liquid column formed in the branch tube 20 changes in proportion to the differential pressure between the pressure when the pressure in the main tube 10 becomes negative and the pressure when the pressure recovers. When the pressure is large, the length of the liquid column formed becomes long. For this reason, as shown in FIG. 1, the influence of the flow turbulence generated in the branch tube 20 is limited only by one throttle part 21. Therefore, in the circuit 2 of the extracorporeal circulation device of the present embodiment, FIG. As shown in FIG. 2, this problem can be solved by providing a plurality of constricted portions 21 in the middle of the branch tube 20 and forming a stable disturbance in the branch tube 20.

  In FIG. 2, the circuit 2 of the extracorporeal circulation apparatus includes a main tube 10 for sending a body fluid or a chemical solution, a branch part 40 disposed in the middle of the main tube 10, and a branch tube 20 connected to the branch part 40. And a closing device 30 disposed so as to close the end of the branch tube 20 or in the middle thereof, and a narrowed portion 21 having a plurality of flow path cross-sectional areas provided in the middle of the branch tube 20 reduced. Composed.

  In the middle of the branch tube 20, by providing a plurality of constricted portions 21 with a reduced cross-sectional area of the flow path, turbulence was stably generated between the constricted portions 21, and the formed liquid column became longer. Even in this case, the replacement of the entire liquid column is promoted.

  Preferably, the narrowed portion 21 having a reduced flow path cross-sectional area can be formed more stably by making the distance between the narrowed portions 21 on the branch tube 20 constant, thereby facilitating stable replacement. Is possible. Furthermore, in the case of a low flow rate of 100 ml / min or less, it is preferable that the spacing between the throttle portions 21 be 10 mm or more and 50 mm or less, and more preferably the spacing interval of the throttle portions 21 is 20 mm or more and 40 mm. Most preferably, by setting the separation interval of the throttle part 21 to 20 mm or more and 30 mm or less, a stable turbulence is formed in the entire liquid column, and even when the flow rate is low, the entire liquid column is sufficiently Replacement can be facilitated.

  Next, the configuration of the third embodiment of the circuit of the extracorporeal circulation apparatus according to the present invention will be described with reference to FIG. FIG. 3 is a schematic diagram showing a third embodiment of the circuit of the extracorporeal circulation apparatus according to the present invention. In addition, about the part same as each embodiment mentioned above and the part which has the same function, description is abbreviate | omitted using the same code | symbol.

  In FIG. 3, the circuit 3 of the extracorporeal circulation apparatus according to the present embodiment is connected to the main tube 10 for feeding body fluid or chemical solution, the branching portion 40 disposed in the middle of the main tube 10, and the branching portion 40. A branch tube 20; a closing device 30 disposed at the end of the branch tube 20 or in the middle thereof; a plurality of narrowing portions 21 provided in the middle of the branch tube 20 having a smaller inner diameter; A throttle portion 11 having a reduced channel cross-sectional area at least at one location provided in the main tube 10 on the upstream side in the flow direction of the liquid in the tube 10 (the direction of arrow 54 shown in FIG. 3) Is done.

  Thus, by providing at least one throttle part 11 in the middle of the main tube 10 upstream of the branch part 40, the in-pipe friction of the main tube 10 can be increased. As a result, the energy of the pulsation generated by the operation of the liquid feeding pump can be concentrated in the branch tube 20, and as a result, the pulsation in the branch tube 20 becomes large, and the extracorporeal circulation of the first and second embodiments. Compared with the case of the circuits 1 and 2 of the apparatus, the replacement of the liquid column formed in the branch tube 20 can be further promoted.

  If the inner diameter of the narrowed portion 11 of the main tube 10 is too small, the friction in the duct becomes excessive, and an excessive load is applied to the main tube 10 to affect the treatment. On the other hand, when the inner diameter of the narrowed portion 11 of the main tube 10 is large, the influence of friction in the pipe line is reduced, and the pulsating energy cannot be sufficiently transmitted to the branch tube 20.

Therefore, the cross-sectional area of the throttle portion 11 of the main tube 10 is preferably set to 0.2 mm ² or more and 1.8 mm ² or less, more preferably 0.5 mm ² or more and 1.1 mm ² or less. Most preferably 0.5 mm ² or more and 0.8 mm ² or less to increase the pulsation of the liquid column formed on the branch tube 20 while minimizing the influence on the treatment. It is preferable to make it.

  Here, the number and length of the narrowed portions 11 of the main tube 10 are not particularly limited as long as the energy of pulsation is concentrated in the branch tube 20 as described above. Further, there is no problem in place of the throttle unit 11 instead of directly providing the throttle unit 11 to the main tube 10 by using a needle or a catheter having an equivalent size. In addition, the communication part 12 between the main tube 10 and the throttle part 11 forms an inclination at a certain angle, so that hemolysis can be prevented when the flow rate is large. Therefore, it is preferable that the communication portion 12 is formed so as to be expanded in diameter to some extent and communicate with the main tube 10, but the angle may be set according to the flow rate to be used. It is not intended to limit.

  Hereinafter, the effects of the present invention have been confirmed by examples, which will be described. Using the circuit 2 of the extracorporeal circulation apparatus according to the second embodiment shown in FIG. 2 and the circuit 4 of the conventional extracorporeal circulation apparatus shown in FIG. 4 (hereinafter referred to as “comparative example”), the liquid replacement efficiency can be improved by the following method. A comparative test was performed.

  First, (1) liquid is fed at a flow rate of 50 ml / min using a liquid feed pump as a first tap liquid through which the main tube 10 is circulated. (2) The upstream portion in the liquid flow direction in the main tube 10 is blocked from the branch portion 40. (3) The liquid feed pump is operated until it reaches −100 mmHg. (4) Release the blockage by the closure device 30 and form a liquid column in the branch tube 20. (5) The liquid feeding pump is operated again at a flow rate of 50 ml / min as tap water colored vermilion as the second liquid flowing through the main tube 10. (6) Measure the time until the entire liquid column becomes vermilion, that is, until the liquid column is replaced with vermilion tap water.

In the circuit 2 of the extracorporeal circulation apparatus shown in FIG. 2, the cross-sectional area of the main tube 10 is 8.5 mm ² , the cross-sectional area of the branch tube 20 is 17.3 mm ² , and the cross-sectional area of the throttle portion 21 of the branch tube 20 is 4.9 mm ² , the separation distance of the narrowed portion 21 of the branch tube 20 is 30 mm, and a test was performed using the circuit 2 of the extracorporeal circulation device. As a result, the liquid column in the branch tube 20 was replaced with vermilion tap water The time to be done was about 30 seconds.

On the other hand, as a comparative example, in the circuit 4 of the extracorporeal circulation apparatus shown in FIG. 4, the restriction of the branch tube 20 is achieved when the flow channel cross-sectional area of the main tube 10 is 8.5 mm ² and the flow tube cross-sectional area of the branch tube 20 is 17.3 mm ^2. As a result of performing a test using the circuit 4 of the extracorporeal circulation apparatus, only about half of the liquid column formed in the branch tube 20 became vermilion after 20 minutes, and was not completely replaced.

  From the above, it was shown that the provision of the narrowed portion 21 in the branch tube 20 promotes the replacement of the liquid column in the branch tube 20 and has a remarkable effect in preventing the liquid column from staying.

  As an example of use of the present invention, an extracorporeal circuit that circulates bodily fluids or drug solutions in extracorporeal circulation therapy that takes out blood from a patient's body, performs extracorporeal treatment of the blood using a blood treatment device, and returns the treated blood to the body Can be suitably used at the end or at the site where the instrument is connected in the middle.

It is a figure which shows the structure of 1st Embodiment of the circuit of the extracorporeal circulation apparatus which concerns on this invention. It is a figure which shows the structure of 2nd Embodiment of the circuit of the extracorporeal circulation apparatus which concerns on this invention. It is a figure which shows the structure of 3rd Embodiment of the circuit of the extracorporeal circulation apparatus which concerns on this invention. It is a schematic diagram which shows the circuit of the conventional extracorporeal circulation apparatus. It is a schematic diagram which shows the formation mechanism of a liquid column. It is a schematic diagram which shows the circuit of the conventional extracorporeal circulation apparatus.

1-3. Circuit of extracorporeal circulation device
10 ... Main tube
11 ... Main tube throttle
12 ... Communication with main tube throttle
20 ... Branch tube
21 ... Branch tube throttle
22 ... Communication part of branch tube and throttle part
30… Occlusion device
40 ... Branch
54 ... Flow direction of liquid in main tube

Claims (8)

An extracorporeal circulation device for monitoring the pressure of the extracorporeal circuit using a branch tube of the circuit,
The extracorporeal circuit includes at least a main tube for sending body fluid or chemical solution,
A liquid feed pump for feeding the main tube;
A branch portion disposed in the middle of the main tube;
A branch tube connected to the branch part;
Pressure measuring means arranged to block the end of the branch tube or the middle thereof;
Have
The narrowed portion in which a flow path cross-sectional area of at least one portion is reduced in the middle of the branch tube is provided, the pulsation in the liquid feed of the liquid feed pump, between the throttle portion of the branch tube the pressure measuring means An extracorporeal circulation device characterized by causing disturbance in a liquid column in a branch tube . The flow path cross-sectional area of the non-aperture portion of the branch tube, extracorporeal circulation apparatus according to claim 1, characterized in that at least 1.5 times the channel cross-sectional area of said throttle portion. The flow passage cross-sectional area of the non-throttle portion of the branch tube is 7 mm ² or more and 51 mm ² or less, the flow passage cross-sectional area of the throttle portion is 3 mm ² or more and 30 mm ² or less, and the longitudinal direction of the throttle portion extracorporeal circulation apparatus according to claim 1 or claim 2 the length of the is characterized in that it is 30mm or less. The extracorporeal circulation apparatus according to any one of claims 1 to 3 , wherein there are a plurality of throttle portions in the middle of the branch tube, and a spacing between the throttle portions on the branch tube is constant. The extracorporeal circulation apparatus according to claim 4 , wherein a spacing between the throttle portions on the branch tube is 10 mm or more and 50 mm or less. The throttle section is composed of a throttle section tube having an inner diameter smaller than that of the branch tube, and the throttle section tube is expanded in diameter at an inclination angle of 20 ° or more and 70 ° or less and communicates with the branch tube. The extracorporeal circulation apparatus according to any one of claims 1 to 5 . The extracorporeal circulation device according to any one of claims 1 to 6 , wherein the main tube on the upstream side of the branch portion is provided with a throttle portion having a reduced flow path cross-sectional area at least at one location. . The extracorporeal circulation apparatus according to claim 7 , wherein a flow passage cross-sectional area of the throttle portion of the main tube is 0.2 mm ² or more and 1.8 mm ² or less.

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