Warming bag and warming bag container for blood processing circuit

Abstract

To provide a heating bag and the like capable of improving air-venting property or suppressing an increase in pressure loss while improving heating efficiency.SOLUTION: A heating bag 2 which is used for a blood processing circuit 1 and is for heating liquid flowing in the circuit 1 with a heater 303 includes a flat bag body 11 where a flow channel 10 is formed and a tube 12 connected to the bag body 11 and communicating with flow channel 10. The flow channel 10 has a flat flow channel cross section where a width dimension W in a width direction orthogonal to a flow direction of the liquid along a surface of the bag body 11 is larger than a thickness dimension T to be a dimension in the thickness direction vertical to the surface of the bag body 11. When an inner diameter of the tube 12 is Φ, the width dimension W satisfies 1.5Φ≤W≤4.0Φ, and the thickness dimension T satisfies 0.2Φ≤T≤0.6Φ.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a warming bag and a warming bag container used in a blood treatment circuit such as renal replacement therapy, simple plasma exchange therapy, and double filtration plasmapheresis therapy.

Background Art

[0002] As a treatment method for patients who have developed kidney disorders or the like, there is a blood treatment method called renal replacement therapy (RRT). RRT includes continuous renal replacement therapy (CRRT) and intermittent renal replacement therapy (IRRT). For example, in CRRT, blood taken out of the patient's body is passed through a filter (continuous slow blood filter), and dialysis and filtration are performed to perform water removal, electrolyte adjustment, waste removal, etc. on the blood over a long period of time. An example of a blood treatment circuit used for RRT including such CRRT is disclosed in Patent Document 1.

[0003] In addition, in order to perform treatment by RRT, it is necessary to appropriately control the temperature of the dialysate introduced into the filter and the replacement fluid introduced into the returned blood. Therefore, in order to warm each fluid to an appropriate temperature with a heater before it is introduced into the filter or the returned blood, the blood treatment circuit is provided with a warming bag in which a flow path through which each fluid flows is formed, in proximity to the heater.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, if air is present in the flow path of the heating bag, this air acts as an insulating medium, making it difficult for the heat from the heater to transfer to the liquid, and potentially preventing the liquid in the flow path from being properly heated. Possible causes of air being present in the flow path include residual air that was not completely expelled during priming before use, and vaporization of the liquid in the flow path that has been heated by the heater during use. Therefore, heating bags are required to have good air venting properties, meaning that air in the flow path can be easily expelled by the liquid flowing through it.

[0006] Furthermore, in CRRT, for example, two fluids are used: dialysate and replacement fluid. Therefore, it is necessary to efficiently heat these two fluids. Generally, the flow path of a heating bag is formed as a meandering flow path with multiple return sections in order to ensure a large heat transfer area from the heater and increase heating efficiency. However, the flow resistance of the fluid is large at the return sections, increasing pressure loss. Increased pressure loss reduces the amount of fluid supplied per unit time, which leads to longer overall treatment times or the need to increase the supply amount midway through, resulting in a burden on the patient. Therefore, there is a need for a heating bag that can improve heating efficiency while suppressing the increase in pressure loss.

[0007] Furthermore, unused heating bags are sterilized with a specific gas while packaged in a sterile bag, then vacuum-sealed to remove the gas, and stored as a heating bag container. During the vacuum-sealing process, the heating bag may deform along with the sterile bag as the gas inside is released. If the heating bag is stored in a deformed state with creases, these creases may remain even after it is removed from the sterile bag for use. If these creases form in the flow path, the air venting performance in that section of the flow path will be reduced. Therefore, it is necessary to house the heating bag in the sterile bag in a manner that minimizes the reduction in air venting performance due to creases.

[0008] Therefore, the present disclosure aims to provide a heating bag that can improve air release properties, or improve heating efficiency while suppressing an increase in pressure loss, and a heating bag container that can suppress a decrease in air release properties due to creases during storage. [Means for solving the problem]

[0009] A heating bag according to a first aspect of the present disclosure is a heating bag used in a blood processing circuit to heat a liquid flowing through the circuit with a heater, comprising: a flat bag body having a flow path formed therein for the liquid to flow through; and a tube connected to the bag body and communicating with the flow path, wherein the flow path has a flat flow path cross-section in which the width dimension W, which is the dimension in the width direction perpendicular to the direction of liquid flow in the direction along the surface of the bag body, is greater than the thickness dimension T, which is the dimension in the thickness direction perpendicular to the surface of the bag body, and when the inner diameter of the tube is Φ, the width dimension W satisfies 1.5Φ ≤ W ≤ 4.0Φ and the thickness dimension T satisfies 0.2Φ ≤ T ≤ 0.6Φ.

[0010] This design allows for a flattened flow path to increase the heater contact area, thereby improving heating efficiency while ensuring high air venting. Specifically, during the design process, it was confirmed that heating efficiency increased as the flow path was flattened and the width W increased, while the force pushing out bubbles weakened in areas far from the central axis of flow, resulting in more bubbles remaining. Poor heating efficiency leads to unstable liquid temperature settings, while a large number of bubbles raises concerns about adverse effects when delivering liquid to patients and reduced accuracy of flow control due to increased pressure loss as the effective flow cross-sectional area narrows. Therefore, after investigating the relationship between heating efficiency and air venting, it was found that this relationship could be improved by setting the ratio of the inner diameter Φ, width W, and thickness T within the above range.

[0011] Furthermore, in the first embodiment, the heating bag according to the second aspect of this disclosure may more preferably satisfy the width dimension W of the flow path 2.0Φ ≤ W ≤ 3.5Φ, and the thickness dimension T of the flow path 0.3Φ ≤ T ≤ 0.5Φ. This makes it possible to achieve a better balance between improved heating efficiency and improved air release.

[0012] A heating bag according to a third aspect of the present disclosure is a heating bag used in a blood processing circuit to heat a liquid flowing through the circuit with a heater, comprising a flat bag body having a first channel and a second channel through which liquid flows independently, wherein the first channel and the second channel have a plurality of straight channels that extend linearly in a first direction along the surface of the bag body and are aligned in a second direction perpendicular to the first direction, and a curved channel that connects the ends of two adjacent straight channels, wherein the straight channels and the curved channels form flat channels with a flat cross-section perpendicular to the direction of liquid flow, and both the first channel and the second channel have an elongated shape in which the dimension in the first direction is larger than the dimension in the second direction, and are arranged side by side in the second direction, and the bag body has a supported portion that, when heated by the heater, is supported in a position where the first direction is aligned horizontally and the second direction is aligned vertically.

[0013] In other words, the first and second flow channels are arranged vertically side by side, and the multiple straight flow channels within the first and second flow channels extend substantially horizontally. By making each flow channel a folded structure in this way, the contact area with the heater is increased, improving heating efficiency, while the number of curved flow channels that form the folded sections is reduced, thereby suppressing an increase in pressure loss. Specifically, in the heating bag of this disclosure, when supported, the straight flow channels are in a position that extends horizontally, so by arranging the first and second flow channels vertically, the length dimension of the straight flow channels can be increased compared to, for example, arranging them horizontally, and as a result, the number of folds can be reduced, thereby suppressing pressure loss. Furthermore, if flattened flow channels are adopted to improve heating efficiency, a problem of reduced accuracy in flow control due to pressure loss occurs, but by reducing the number of curved flow channels as described above, the occurrence of this problem can be suppressed.

[0014] Furthermore, in the third embodiment of the heating bag according to the fourth aspect of this disclosure, the flow path may satisfy the following condition: the length dimension L in the first direction from the curved flow path on one side to the curved flow path on the other side, and the dimension H of the flow path in the second direction, are 2.5H ≤ L ≤ 3.5H. This suppresses an increase in pressure loss of the flowing liquid and enables highly accurate flow rate control.

[0015] Furthermore, in the fourth embodiment, the heating bag according to the fifth aspect of this disclosure may more preferably satisfy the condition 2.8H ≤ L ≤ 3.2H for the dimension L. This makes it possible to further suppress the increase in pressure loss.

[0016] Furthermore, in the sixth aspect of the present disclosure, the heating bag further comprises, in the fifth aspect, an inlet tube connected to the bag body and communicating with the upstream ends of the first and second flow paths, and an outlet tube communicating with the downstream ends, wherein all of the inlet tube and the outlet tube are provided on the same side of the bag body, either one or the other side in the first direction. As a result, since each tube is provided on the same side of the bag body, the operation of attaching the heating bag to the heater of the blood processing circuit becomes easier.

[0017] A heated bag housing according to a seventh aspect of the present disclosure comprises a heated bag used in a blood processing circuit to heat a liquid flowing through the circuit with a heater, and a housing bag for housing the heated bag, wherein the heated bag comprises a flat bag body through which a liquid flows, and a tube connected to the bag body and communicating with the flow path, the flow path having a plurality of straight flow paths extending linearly in a first direction along the surface of the bag body and aligned in a second direction perpendicular to the first direction, and a curved flow path connecting the ends of two adjacent straight flow paths, the tube being connected to either one side of the bag body in the first direction and the other side, and the heated bag being housed in the housing bag in a state where it passes along the curved flow path on the side to which the tube is connected in the first direction and is folded along a fold line extending in the second direction.

[0018] In this way, by folding the bag body, it takes on a three-dimensional shape, which increases its resistance to external forces from the storage bag that shrinks during vacuum processing, making it less likely for creases to form. Therefore, a decrease in air release due to creases is less likely to occur. In fact, the inventors of this application devised various storage configurations, actually constructed heated bag storage units for each configuration, vacuum-processed them, and observed the heated bags after opening them from the perspective of air release. They found that the heated bag storage unit of the above configuration is compact when stored, while also having good air release properties when in use.

[0019] Furthermore, in the seventh embodiment, the heated bag containment according to the eighth aspect of this disclosure may have the tube fixed in a circular state and contained in the containment bag in a state where it is superimposed on the heated bag. As a result, the circular tube exhibits high resistance to external forces, thereby suppressing deformation of the bag body due to the force acting on the containment bag when vacuum processing is performed. Consequently, the formation of creases in the bag body can be suppressed, and the air venting of the flow path can be suitably ensured.

[0020] Further, in the heating bag container according to the ninth aspect of the present disclosure, in the eighth aspect, the tube may be wound around with a diameter equal to or greater than the dimension H in the second direction of the flow path. As a result, the force applied to the storage bag acts more easily on the tube than on the bag body, so that the deformation of the bag body can be further suppressed.

[0021] The heating bag container according to the tenth aspect of the present disclosure is a heating bag container including a heating bag for heating a liquid flowing through a blood treatment circuit using a heater and a storage bag for storing the heating bag, wherein the heating bag includes a flat bag body in which a flow path for the liquid to flow is formed, and the storage bag stores the bag body and a support for supporting the shape of the bag body in a stacked state.

[0022] This makes it difficult for creases to be formed in the bag body. That is, even when the storage bag contracts due to vacuum treatment, the support receives the contraction force, so that deformation due to the contraction force acting on the bag body is unlikely to occur. Therefore, it is difficult for creases to be formed in the bag body, and a decrease in air bleeding performance due to the creases can be suppressed.

Advantages of the Invention

[0023] According to the heating bag of the present disclosure, air bleeding performance can be improved, or an increase in pressure loss can be suppressed while improving heating efficiency. Further, according to the heating bag container of the present disclosure, a decrease in air bleeding performance due to creases during storage can be suppressed.

Brief Description of the Drawings

[0024] [Figure 1] FIG. 1 is a schematic diagram showing an overall configuration of a blood treatment circuit for RRT, which is an example of a blood circuit including a heating bag according to an embodiment. [Figure 2] FIG. 2 is a front view showing the configuration of the heating bag. [Figure 3]FIG. 3A is a perspective view showing the configuration of the mounting location of the warming bag in the blood treatment device. FIG. 3B is a perspective view showing the state of the warming bag mounted on the blood treatment device. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV of the flow path in FIG. 2. [Figure 5] FIG. 5 is a diagram showing the result of analysis using a computer regarding air bleeding performance. [Figure 6] FIG. 6 is a diagram substituting for a photograph showing the state of the warming bag before being housed in the housing bag in the warming bag housing body according to Example 1. [Figure 7] FIG. 7 are both diagrams substituting for a photograph regarding Example 1. The upper diagram shows the warming bag housing body after evacuation, and the lower diagram shows the deployed warming bag. [Figure 8] FIG. 8 is a diagram substituting for a photograph showing the state of the warming bag before being housed in the housing bag in the warming bag housing body according to Comparative Example 1. [Figure 9] FIG. 9 are both diagrams substituting for a photograph regarding Comparative Example 1. The upper diagram shows the warming bag housing body after evacuation, the middle diagram shows the warming bag taken out from the housing bag, and the lower diagram shows the deployed warming bag. [Figure 10] FIG. 10 is a diagram substituting for a photograph showing the state of the warming bag before being housed in the housing bag in the warming bag housing body according to Comparative Example 2. [Figure 11] FIG. 11 are both diagrams substituting for a photograph regarding Comparative Example 2. The upper diagram shows the warming bag housing body after evacuation, the middle diagram shows the warming bag taken out from the housing bag 4, and the lower diagram shows the deployed warming bag. [Figure 12] FIG. 12 is a diagram substituting for a photograph showing the state of the warming bag before being housed in the housing bag in the warming bag housing body according to Comparative Example 3. [Figure 13] FIG. 13 are both diagrams substituting for a photograph regarding Comparative Example 3. The upper diagram shows the warming bag taken out from the housing bag after evacuation, and the lower diagram shows the deployed warming bag.

MODE FOR CARRYING OUT THE INVENTION

[0025] The following description will explain the heating bag and heating bag housing for a blood processing circuit according to embodiments of the present disclosure, with reference to the drawings. The concept of direction used in the following description is for convenience of explanation and does not limit the orientation of each disclosed component to that direction. Furthermore, the heating bag and heating bag housing described below are merely one embodiment of the present disclosure. Therefore, the present disclosure is not limited to the following embodiments, and additions, deletions, and modifications to the configuration are possible without departing from the spirit of the disclosure.

[0026] (Embodiment 1) [1. Overall configuration of the blood processing circuit for RRT] This disclosure is applicable to heated bags and heated bag containers used in blood processing circuits for blood purification therapies such as renal replacement therapy (RRT), simple plasma exchange therapy (PE), or double filtration plasmapheresis (DEPP). Embodiments of this disclosure will be described below with an example of a blood circuit for RRT.

[0027] Figure 1 is a schematic diagram showing the overall configuration of a blood processing circuit for RRT, illustrating, as an example, blood processing circuit 1 used in HDF (hemodiafiltration). This blood processing circuit 1 generally consists of three sets: a blood set 100 on the right side of the figure, a processing fluid set 200 on the left side, and a heating set 300 in the center.

[0028] [1-1. Blood sample kit] The blood collection set 100 mainly comprises a blood withdrawal line 101, a filter 102, and a blood return line 103. The blood withdrawal line 101 has a flexible tube and connects the patient's blood vessel to the filter 102. A blood pump 110 is installed in the middle of the blood withdrawal line 101, and when this blood pump 110 is activated, the patient's blood is sent to the filter 102 through the blood withdrawal line 101.

[0029] In the blood withdrawal line 101, the saline line 111 joins the upstream portion (patient side portion) of the blood pump 110. A bag 112 containing physiological saline is connected to the saline line 111, and physiological saline is supplied to the blood withdrawal line 101 during priming. In the blood withdrawal line 101, the drug line 113 joins the upstream portion of the blood pump 101, upstream of the joining point of the saline line 111 (patient side portion). A syringe 114 containing drugs such as anticoagulants is connected to the drug line 113, and the anticoagulants are injected into the blood passing through the blood withdrawal line 101 via the drug line 113.

[0030] In the blood withdrawal line 101, an arterial pressure chamber 115, which consists of a drip chamber, is interposed downstream of the blood pump 110. By connecting a pressure monitor (not shown) via a patient protection filter 501A, which consists of a hydrophobic filter, to a pressure measurement line 501 extending from this arterial pressure chamber 115, the pressure of the blood in the blood withdrawal line 101 can be measured. In addition, a pre-dilution line 116 extends from the arterial pressure chamber 115, and by connecting a bag containing replacement fluid such as electrolyte solution to this line, the blood passing through the blood withdrawal line 101 can be pre-diluted with replacement fluid.

[0031] The filter 102 comprises a cylindrical case 120 and a filter 121 housed within the case 120. The filter 121 is constructed, for example, by bundling together multiple hollow fibers. The case 120 is provided with a blood inlet port 122 at one end, a blood outlet port 123 at the other end, a dialysate port 124 on the periphery near one end, and a drainage port 125 on the periphery near the other end. The downstream end of the blood withdrawal line 101 is connected to the blood inlet port 122.

[0032] The upstream end of the blood return line 103 is connected to the blood outlet port 123 of case 120. The blood return line 103 has a flexible tube and connects the filter 102 to the patient's blood vessel. A mixing chamber 130 is interposed in the middle of the blood return line 103, and the replacement fluid sent from the processing fluid set 200 (described later) can be supplied to the blood return through this mixing chamber 130. A pressure measurement line 502 extends from the mixing chamber 130 and is connected to a pressure monitor (not shown) via a patient protection filter 502A.

[0033] [1-2. Set for processing solution] The processing fluid set 200 mainly comprises a supply fluid line 201, a pump unit 202, and a drainage fluid line 203. The supply fluid line 201 has a storage bag 210 in which a common fluid for dialysate and replacement fluid is stored, a common line 211 with one end connected to the storage bag 210, and a first liquid bag 212 for measuring, which is connected to the other end of the common line 211 and in which liquid is temporarily stored.

[0034] Furthermore, the supply fluid line 201 also has a dialysate line 213 and a post-replenishment fluid line 214. That is, there are two branches in the middle of the common line 211, and the dialysate line 213 and the post-replenishment fluid line 214 extend from each branch. Of these, the post-replenishment fluid line 214 branches off from a position closer to the first fluid bag 212 along the common line 211 than the dialysate line 213.

[0035] The drainage line 203 includes a recovery line 230, one end of which is connected to the drainage port 125 of the filter 102, and a second liquid bag 231 for measuring, connected to the other end of the recovery line 230, where the drainage is temporarily stored. Furthermore, the drainage line 203 includes a waste line 232 extending from a branch in the middle of the recovery line 230, and a tank 233 located at the downstream end of the waste line 232.

[0036] Furthermore, each line 201, 203 (including the lines 211, 213, 214, 230, 232 that comprise them) of the processing fluid set 200 is made of flexible tubing. In addition, a pressure measurement line 503 extends from the middle of the recovery line 230 and is connected to a pressure monitor (not shown) via a patient protection filter 503A.

[0037] The pump unit 202, for example, comprises three finger pumps 221 to 223 and is installed on the side of the blood processing device 400, arranged vertically. The upper finger pump 221 is connected to an intermediate portion of the post-replacement fluid line 214, the middle finger pump 222 is connected to an intermediate portion of the dialysate line 213, and the lower finger pump 223 is connected to an intermediate portion of the recovery line 230.

[0038] [1-3. Heating Set] The heating set 300 includes a dialysate heating line 301 and a post-replenishment fluid heating line 302. The upstream end of the dialysate heating line 301 is connected to the downstream end of the dialysate line 213, and its downstream end is connected to the dialysate port 124 of the filter 102. The upstream end of the post-replenishment fluid heating line 302 is connected to the downstream end of the post-replenishment fluid line 214, and its downstream end is connected to the mixing chamber 130.

[0039] Furthermore, the heating set 300 is equipped with a heater 303. This heater 303 is installed in the blood processing device 400 and generates heat in proportion to the supplied power. The heating set 300 is equipped with a heating bag 2 that is positioned in contact with the heater 303. The heating bag 2 according to this embodiment has two flow paths 10. One flow path 10 is interposed in the middle of the dialysate heating line 301 and forms part of it, and the other flow path 10 is interposed in the middle of the post-replenishment fluid heating line 302 and forms part of it. Therefore, the liquid in each flow path 10 is heated by the heat generated by the heater 303. Details of the heating bag 2 will be described later.

[0040] [2. Operation of the blood processing circuit] Such a blood processing circuit 1 generally operates as follows: When the blood pump 110 is activated in the blood set 100, blood is drawn from the patient and sent to the filter 102 along the blood draw line 101, while replacement fluids and anticoagulants are injected. The blood sent to the filter 102 is filtered by the filter 121, and the resulting wastewater is collected in the tank 233 via the wastewater line 203 of the processing fluid set 200.

[0041] Meanwhile, some components of the blood sent to the filter 102 diffuse into the dialysate supplied from the processing fluid set 200 via the dialysate port 124, and this is also collected in the tank 233 by the drain line 203 of the processing fluid set 200. The blood that has undergone this filtration and diffusion in the filter 102 is then returned to the patient through the blood return line 103, with replacement fluid supplied in the mixing chamber 130 along the way.

[0042] Furthermore, in the circuit operation described above, the dialysate supplied from the dialysate port 124 to the filter 102 is preheated to an appropriate temperature by the warming set 300. In addition, the replacement fluid supplied for blood return in the mixing chamber 130 is also preheated to an appropriate temperature by the warming set 300. The warming bag 2 provided in this warming set 300 will be described in detail below.

[0043] [3. Heating bag] Figure 2 is a front view showing the configuration of the heating bag 2 according to this embodiment. The heating bag 2 comprises a flat bag body 11 through which a liquid flow channel 10 is formed, and a tube 12 connected to the bag body 11 and communicating with the flow channel 10. Here, the thickness direction of the bag body 11 is referred to as the "front-to-back direction," the horizontal direction intersecting the front-to-back direction is referred to as the "left-to-right direction" (or first direction), and the vertical direction intersecting the front-to-back direction is referred to as the "up-down direction" (or second direction).

[0044] The bag body 11 shown in Figure 2 has a rectangular shape when viewed from the front, and is particularly a horizontally elongated rectangle in which the left-right dimension is larger than the up-down dimension. This bag body 11 is formed by welding (for example, high-frequency welding) two sheets of flexible synthetic resin together, and two independent liquid channels 10, the first channel 10A and the second channel 10B, are formed inside. The first channel 10A and the second channel 10B have similar configurations and are arranged side by side in the vertical direction (second direction).

[0045] The first channel 10A is a meandering channel having straight channels 21 and curved channels 22. More specifically, the straight channels 21 are channels that extend linearly in the left-right direction (first direction) along the surface of the bag body 11, and multiple channels are arranged in a row in the up-down direction (second direction). In the example in Figure 2, six straight channels 21 are arranged in a row in the up-down direction. The curved channels 22 are channels that connect the ends of two adjacent straight channels 21, and are generally in the shape of a semicircular arc. In the example in Figure 2, the left ends of the two straight channels 21 from the bottom, the right ends of the second and third straight channels 21 from the bottom, the left ends of the third and fourth straight channels 21 from the bottom, the right ends of the fourth and fifth straight channels 21 from the bottom, and the left ends of the two straight channels 21 from the top are all connected by curved channels 22.

[0046] Furthermore, in the first channel 10A, the inner diameter edge 22c of the curved channel 22 forms a sideways teardrop shape. More specifically, the curved channel 22, which connects the vertically adjacent straight channels 21, has tapered portions 22a, 22a located at the end portions connected to each straight channel 21, and an arc-shaped portion 22b located between these tapered portions 22a, 22a. Of these, the arc-shaped portion 22b has a smaller width dimension (radial dimension) than the straight channels 21, and the tapered portions 22a, 22a, which change in width in a tapered manner, connect the straight channels 21 and the arc-shaped portion 22b, which have different width dimensions. As a result, the inner diameter edge 22c of the curved channel 2 forms a teardrop shape with the inner diameter edge 22c of the arc-shaped portion 22b and the edges of the subsequent tapered portions 22a, 22a.

[0047] In this first flow path 10A, a first connection port 23 is connected to the right end of the first straight flow path 21 from the bottom, and a second connection port 24 is connected to the right end of the first straight flow path 21 from the top. One end of a tube 12 is connected to each of the first connection port 23 and the second connection port 24, and the other end of the tube 12 is connected to a tube that constitutes the dialysate heating line 301.

[0048] Furthermore, as shown in Figure 2, the first connection port 23 of the first flow path 10A has a larger vertical dimension (width dimension) than the straight flow path 21. More specifically, the first connection port 23 has a tapered portion 23a close to the straight flow path 21 and an insertion portion 23b far from the straight flow path 21. Of these, the insertion portion 23b is straight with a certain width dimension, and its width dimension is larger than that of the straight flow path 21. Also, the tapered portion 23a has a straight edge portion 23c at its lower edge that extends in the first direction, while the upper edge portion 23d is an inclined edge portion 23d that extends at an angle with respect to the first direction.

[0049] As a result, the tapered portion 23a has a tapered shape in which the width dimension changes at a constant rate as it moves toward the first direction, the end connected to the straight channel 21 has the same width dimension as the straight channel 21, and the end connected to the insertion portion 23b has the same width dimension as the insertion portion 23b. Consequently, the lower edges of the first straight channel 21 from the bottom and the first connection port 23 form a single straight line that is parallel and continuous, while the upper edges are connected by the upper edge of the tapered portion 23a (i.e., the inclined edge 23d) to bridge the step between the upper edge of the straight channel 21 and the upper edge of the insertion portion 23b.

[0050] Thus, because the insertion portion 23b of the first connection port 23 has a larger width than the straight flow path 21, the tube 12 is easier to insert into the first connection port 23. In addition, because a tapered portion 23a is provided between the straight flow path 21 and the insertion portion 23b, air venting near the first connection port 23 is improved.

[0051] Furthermore, as described above, since one edge of the tapered portion 23a is a straight edge 23c and the other is an inclined edge 23d, the virtual centerline (centerline of the flow cross-section) 12L of the tube 12 connected thereto is offset upward with respect to the virtual centerline 21L of the straight flow path 21 following the first connection port 23. That is, in the second direction, the virtual centerline 12L of the tube 12 is positioned closer to the inner diameter edge 22c of the curved flow path 22 than to the outer diameter edge 22d. Consequently, the flow velocity near the inner diameter edge 22c, which forms a teardrop shape in the curved flow path 22, is increased, improving air release in this area.

[0052] Furthermore, the upper second connection port 24 of the first flow path 10A has a shape that is vertically symmetrical to the lower first connection port 23 described above. Therefore, the second connection port 24 has a tapered portion 24a, an insertion portion 24b, a special edge portion 24c, and an inclined edge portion 24d, which have the same configuration as the tapered portion 23a, insertion portion 23b, straight edge portion 23c, and inclined edge portion 23d of the first connection port 23. The ease of inserting the tube 12 into the second connection port 24, the improvement of air release near the second connection port 24, and the improvement of air release in the curved flow path 22 based on the offset arrangement of the tube 12 connected to the second connection port 24 are achieved in the same way as described above for the first connection port 23.

[0053] The second channel 10B, like the first channel 10A, is a meandering channel having straight channels 21 and curved channels 22. Specifically, the second channel 10B also has six straight channels 21 arranged vertically, and the ends of two adjacent straight channels 21 are connected by curved channels 22. In particular, in the example in Figure 2, the left ends of the two straight channels 21 from the bottom, the right ends of the second and third straight channels 21 from the bottom, the left ends of the third and fourth straight channels 21 from the bottom, the right ends of the fourth and fifth straight channels 21 from the bottom, and the left ends of the two straight channels 21 from the top are all connected by curved channels 22.

[0054] In this second flow path 10B, the right end of the first straight flow path 21 from the bottom forms the first connection port 23, and the right end of the first straight flow path 21 from the top forms the second connection port 24. One end of the tube 12 is connected to each of the first connection port 23 and the second connection port 24, and the other end of the tube 12 is connected to the tube that constitutes the post-replenishment fluid heating line 302.

[0055] Furthermore, the more specific configurations of the curved channel 22, first connection port 23, and second connection port 24 of the second channel 10B are the same as those of the curved channel 22, first connection port 23, and second connection port 24 described for the first channel 10A, and they produce the same effects. Therefore, a detailed explanation is omitted here.

[0056] In the example configuration of the blood circuit 1 shown in Figure 1, in the first flow path 10A of the heating bag 2, the lower first connection port 23 is located at the upstream end of the first flow path 10A (the upstream end in the direction of flow of the dialysate), and the upper second connection port 24 is located at the downstream end of the first flow path 10A. Therefore, in the first flow path 10A, the tube 12 communicating with the first connection port 23 forms the inlet tube 13, and the tube 12 communicating with the second connection port 24 forms the outlet tube 14.

[0057] Furthermore, in the second channel 10B, the lower first connection port 23 is located at the upstream end of the second channel 10B (the upstream end in the direction of flow of the post-replenishment fluid), and the upper second connection port 24 is located at the downstream end of the second channel 10B. Therefore, in the second channel 10B, the tube 12 communicating with the first connection port 23 forms the inlet tube 13, and the tube 12 communicating with the second connection port 24 forms the outlet tube 14.

[0058] Furthermore, whether the upper or lower connection ports 23 and 24 of each flow path 10A and 10B become the upstream end or the downstream end may vary depending on the configuration of the blood circuit 1. For example, contrary to the example described above, in both the first flow path 10A and the second flow path 10B, the first connection port 23 may be the downstream end and the second connection port 24 may be the upstream end. Also, for example, in the first flow path 10A, the first connection port 23 may be the upstream end and the second connection port 24 may be the downstream end, and in the second flow path 10B, the first connection port 23 may be the downstream end and the second connection port 24 may be the upstream end, and the opposite configuration may also occur.

[0059] However, in the heated bag 2 according to this embodiment, in all cases, the first connection port 23 and the second connection port 24 are located on the same side in the left-right direction of the bag body 11 (the right side in the example of Figure 2). Therefore, the tubes 12 (inlet tube 13 and outlet tube 14) are connected to the same side in the left-right direction of the bag body 11. By providing all the tubes 12 connected to the bag body 11 on the same side in this way, the process of attaching the heated bag 2 to the blood processing device 400 becomes easier.

[0060] Here, we will describe the configuration for attaching the heating bag 2 to the blood processing device 400.

[0061] Figure 3A is a perspective view showing the configuration of the attachment area for the heating bag 2 in the blood processing device 400. Figure 3B is a perspective view showing the blood processing device 400 with the heating bag 2 attached. As shown in Figure 3A, a door 403 is provided on the side wall 402 of the housing 401 of the blood processing device 400. The lower end of the door 403 is pivotally supported to the side wall 402 via a hinge 404, and it can be opened from a closed position by moving the upper end from front to bottom. When the door 403 is opened, the bag attachment area 405 is exposed.

[0062] The bag mounting section 405 has an inner wall 406 that is rectangular in shape and elongated in the left-right direction. This inner wall 406 has a vertical wall surface that has an area approximately the same as or larger than the area of ​​the bag body 1 of the heated bag 2 when viewed from the front. A heater 303 is built into this inner wall 406. The heater 303 is composed of a heating element that heats up when electricity is applied, and the heat is transferred to the outer surface of the inner wall 406 as it heats up. In addition, two hook-shaped support parts 407a and 407b are provided projecting from the upper end of the inner wall 406, spaced apart to the left and right. Furthermore, another boss-shaped support part 407c is provided projecting from the left end of the inner wall 406, at a position slightly below the center in the vertical direction.

[0063] On the other hand, as shown in Figure 2, the heating bag 2 is provided with support parts 25a to 25c for attachment to the bag mounting part 405. Of these, support parts 25a and 25b are located near the left and right ends of the upper end of the bag body 11, and support part 25c is located slightly below the center in the vertical direction at the left end. The upper support parts 25a and 25b are elongated oval openings that penetrate the bag body 11 in the front-to-back direction. The left support part 25c is an elongated oval opening that penetrates the bag body 11 in the front-to-back direction. Note that the dimension of support part 25c in the longitudinal direction is smaller than that of support parts 25a and 25b.

[0064] As shown in Figure 3B, the heating bag 2 is mounted so as to overlap the heater 303 built into the inner wall 406 of the bag mounting section 405. That is, the heating bag 2 is suspended by inserting its two upper support portions 25a and 25b into the support portions 407a and 407b of the bag mounting section 405. Furthermore, the heating bag 2 is positioned more appropriately by passing the support portion 407c through the remaining support portion 25c of the heating bag 2.

[0065] In this state, with the heating bag 2 attached to the bag mounting section 405, the flow path 10 of the heating bag 2 overlaps with the heater 303 in a front view. Therefore, when the heater 303 is energized and heated in this state, the liquid in the flow path 10 can be heated efficiently.

[0066] Furthermore, when the heated bag 2 is attached to the bag mounting section 405, the heated bag 2 is positioned so that its left-right direction (first direction) is aligned with the horizontal direction and its up-down direction (second direction) is aligned with the vertical direction. In other words, the bag body 11 of the heated bag 2 has supported sections 25a to 25c that are supported in a position where the first direction is aligned with the horizontal direction and the second direction is aligned with the vertical direction when heated by the heater 303.

[0067] In other words, in the heating bag 2 according to this embodiment, the first flow path 10A and the second flow path 10B are arranged side by side vertically, and the multiple straight flow paths 21 of the first flow path 10A and the second flow path 10B extend substantially horizontally. This configuration ensures a large contact area with the heater 303 by making each flow path a folded structure, thereby improving heating efficiency, while reducing the number of curved flow paths that form folded sections and suppressing an increase in pressure loss.

[0068] Furthermore, as shown in Figure 3A, the bag attachment section 405 of the blood processing device 400 has retaining sections 408a to 408d for holding the tube 12 on an edge 408 that extends vertically on one side (right side in Figure 3A). The edge 408 has a rectangular cross-section perpendicular to the vertical direction and a prismatic shape with a constant width in the horizontal direction. The retaining sections 408a to 408d are formed by cutting out the corner portion of the edge 408 on the side closer to the inner wall 406. More specifically, the retaining sections 408a to 408d are notches formed in the corner portion of the edge 408, opening forward and to the left, with a constant vertical width. Furthermore, the inner bottom surface, which is the surface located in the depth direction when the holding parts 408a to 408d are viewed from the front, is inclined so that it is located closer to the front (front side) as it moves from the part closer to the inner wall 406 (the left end of Figure 3A) to the part further away (the right end of Figure 3A). In addition, the vertical width dimension of the holding parts 408a to 408d is the same as, or slightly smaller than, the outer diameter of the tube 12.

[0069] These holding parts 408a to 408d are positioned to correspond to the base of the tube 12 extending from the bag body 11 (the portion near the connection point with the bag body 11) when the bag body 11 is supported by the supported parts 25a to 25c. When the heated bag 2 is attached to the bag mounting part 405, as described above, the supported parts 25a to 25c of the bag body 11 are supported by the supported parts 407a to 407c, and the tube 12 is fitted into the holding parts 408a to 408d and held in place by being sandwiched from above and below. This prevents kinking near the base of the tube 12 and prevents twisting of the bag body 11, thus maintaining its flatness.

[0070] Note that the configuration of the retaining parts 408a to 408d that hold the tube 12 is not limited to those exemplified above. The retaining parts 408a to 408d may be configured as grooves that penetrate the edge 408 from left to right, or other retaining structures may be employed.

[0071] Next, we will describe the detailed configuration of the flow path 10 of the heating bag 2.

[0072] The flow path 10 in the heating bag 2 shown in Figure 2 has a horizontally elongated shape in which the dimension L in the first direction (left-right direction) is larger than the dimension H in the second direction (up-down direction). Furthermore, the ratio of dimension L to dimension H is set to fall within a certain range. This will be explained in detail.

[0073] In other words, in one flow path 10 (first flow path 10A or second flow path 10B), the dimension in the first direction from one end of the curved flow path 22 on one side of the first direction to the other end of the curved flow path 22 on the other side of the first direction is defined as L. Also, in the same flow path 10, the dimension in the second direction from one end of the straight flow path 21 on one side of the second direction to the other end of the straight flow path 21 on the other side of the second direction is defined as H. In this case, the dimension L of the flow path 10 is configured to satisfy 2.5H ≤ L ≤ 3.5H.

[0074] This allows for the adoption of a folded structure in the flow path 10 to improve heating efficiency and reduce compactness, while suppressing an increase in the number of folded points and thus preventing an increase in liquid pressure loss. Furthermore, by suppressing pressure loss, the accuracy of liquid flow rate control by the pump unit 202 can be improved.

[0075] Furthermore, the dimension L in the flow path 10 may more preferably satisfy the condition 2.8H ≤ L ≤ 3.2H. In this case, the flow path 10 can further suppress the increase in pressure loss and improve the accuracy of flow rate control. In the heated bag 2 of Figure 2, both the first flow path 10A and the second flow path 10B are configured to satisfy 2.8H ≤ L ≤ 3.2H, but it is also possible to adopt a configuration that satisfies this relationship for only one of the flow paths 10.

[0076] On the other hand, the flow path 10 has a flattened cross-section with a straight flow path 21 and a curved flow path 22 perpendicular to the direction of liquid flow, and furthermore, the ratio of the width dimension W to the thickness dimension T in that cross-section is set to fall within a certain range. This will be explained in detail.

[0077] Specifically, as shown in Figure 4, in a straight channel 21 of one channel 10 (first channel 10A or second channel 10B), the width dimension W is defined as the dimension in the second direction perpendicular to the liquid flow direction, among the directions along the surface of the bag body 11. The thickness dimension T is defined as the dimension in the thickness direction (i.e., the front-to-back direction) perpendicular to the surface of the bag body 11. Furthermore, the inner diameter of the tube 12 connected to the channel 10 is defined as Φ. In this case, the width dimension W and thickness dimension T of the channel satisfy W > T, 1.5Φ ≤ W ≤ 4.0Φ, and 0.2Φ ≤ T ≤ 0.6Φ.

[0078] This improves heating efficiency by increasing the contact area between the heater 303 and the flow path 10, and also improves air venting. In other words, the flatter the flow path 10, the greater the contact area with the heater 303 and the better the heating efficiency. However, at the same time, the flow velocity decreases in areas far from the center of flow in the width direction, making it easier for bubbles to remain. Furthermore, if the flattening is increased too much, the flow velocity decreases in the areas at the edges in the width direction, which may actually decrease the heating efficiency. Therefore, by designing the width dimension W and thickness dimension T within the above range, it is possible to achieve a suitable balance between improved heating efficiency and improved air venting.

[0079] Furthermore, in the flow path 10 described above, the width dimension W may more preferably satisfy 2.0Φ ≤ W ≤ 3.5Φ, and the thickness dimension T may more preferably satisfy 0.3Φ ≤ T ≤ 0.5Φ. This makes it possible to achieve an even better balance between improved heating efficiency and improved air release.

[0080] Furthermore, the relationship between the width W, thickness T, and inner diameter Φ does not need to hold true for all parts of the flow path 10; it is sufficient if it holds true for only a part of the flow path 10. In that case, the effects described above will be exerted at least in that part. For example, the flow path 10 may be configured such that the above relationship holds true for all or part of the straight flow path 21, while the curved flow path 22 does not.

[0081] [Examples and Comparative Examples] The air venting performance when liquid is passed through the flow path 10 was analyzed using a computer, by changing the width dimension W of the flow path 10 relative to the inner diameter Φ of the tube 12. The results are shown in Figure 5. In Figure 5, six analysis results 5A to 5F are comparative examples, and three analysis results 5G to 5I are embodiments of the present disclosure.

[0082] The flow paths 10 used in analysis results 5A to 5I are configured as folded flow paths within the same area, and all have the same thickness dimension T. The connected tubes 12 have an inner diameter Φ of 3.3 mm. Of these, the flow path 10 used in analysis results 5A to 5C is configured by connecting two straight flow paths 21 with one curved flow path 22 (number of folds: 1), and the width dimension W of the straight flow path 21 is 36.5 mm (= approximately 11.06 Φ). The flow path 10 used in analysis results 5D to 5F is configured by connecting four straight flow paths 21 with three curved flow paths 22 (number of folds: 3), and the width dimension W of the straight flow paths 21 is 17.5 mm (= approximately 5.30 Φ). The flow path 10 used in analysis results 5G to 5I consists of six straight flow paths 21 connected by five curved flow paths 22 (number of turns: 5), and the width dimension W of the straight flow path 21 is 11.0 mm (= approximately 3.33 Φ).

[0083] In this analysis, each channel 10 was initially filled with air and no liquid, and then a predetermined liquid was passed through it at a predetermined flow rate. As a result, the areas where air remained, known as air retention areas 30, were extracted using predetermined analysis software and displayed as images. While any known analysis software can be used, here we used "HADI-S (version 1.7)" manufactured by 3D INDUSTRIAL IMAGING Co., Ltd. The conditions for the analysis can be set as appropriate, but in the case of Figure 5, as an example, RO water colored with food coloring was used as the liquid, the flow rate was set to 20 mL / min, and the flow was continued from the start of flow until the liquid flowed out from the outlet side. In addition, the straight channel 21 was set to be parallel to the horizontal direction when the liquid was flowing.

[0084] As a result, as shown in Figure 5, in analysis results 5A-5C and 5D-5F, relatively large air residue areas 30 were formed mainly near the edges of the flow path 10, whereas in analysis results 5G-5I, no such formation of air residue areas 30 was observed. Therefore, the flow path 10 used in analysis results 5G-5F is less prone to adiabatic phenomena due to residual air and is judged to be suitable from the viewpoint of improving heating efficiency. Furthermore, comparing analysis results 5A-5C with analysis results 5D-5F, the total area of ​​air residue areas 30 tended to be smaller in analysis results 5D-5F, where the width dimension W was smaller. Therefore, the smaller the width dimension W of the flow path 10, the greater the improvement in heating efficiency can be expected.

[0085] (Embodiment 2) For example, a heating bag as described in Embodiment 1 is sterilized with a specific gas while packaged in a sterile bag after manufacturing, then vacuum-treated to remove the gas, and stored as a heating bag container until use. However, external pressure is applied to the sterile bag during vacuum treatment, which may cause the heating bag to deform. In particular, if the bag body is constructed by overlapping two flexible resin sheets and bonding the parts other than the flow path (for example, by high-frequency welding), it has low rigidity and is easily deformed. Also, if the flow path has a flattened flow path where the width dimension is greater than the thickness dimension, it is more prone to deformation than a flow path with a circular cross-section, for example, because it has lower rigidity. When deformation occurs during vacuum treatment in this way, even if the heating bag is removed from the sterile bag before use, creases may remain on the heating bag. If these creases are formed in the flow path portion, air is more likely to be trapped in that portion of the flow path, reducing air release efficiency. Therefore, in this embodiment, a heating bag container is described in which the heating bag is housed in a sterile bag in a manner that minimizes the reduction in air release efficiency due to creases.

[0086] The heated bag housing according to this embodiment comprises a heated bag used in a blood processing circuit to heat the liquid flowing through the circuit with a heater, and a storage bag for housing the heated bag. The heated bag comprises a flat bag body through which a liquid flows, and a tube connected to the bag body and communicating with the flow path. The flow path has a plurality of straight flow paths that extend linearly in a first direction along the surface of the bag body and are arranged in a second direction perpendicular to the first direction, and a curved flow path that connects the ends of two adjacent straight flow paths. The tube is connected to either one side of the bag body in the first direction or the other side. The heated bag is housed in the storage bag in a state where it passes along the curved flow path on the side to which the tube is connected in the first direction, and is folded along a fold line extending in the second direction.

[0087] Furthermore, the heated bag housing according to this embodiment comprises a heated bag used in a blood processing circuit to heat the liquid flowing through the circuit with a heater, and a storage bag for housing the heated bag, wherein the heated bag comprises a flat bag body through which a liquid flows, and the storage bag houses the bag body and a support for supporting the shape of the bag body in a stacked state.

[0088] This makes it less likely for the air venting ability to decrease due to creases. Specifically, the inventors of this application devised various storage configurations, such as those described in Example 1 and Comparative Examples 1-3, and actually constructed heating bag containers for each configuration, subjected them to vacuum treatment, and observed the heating bags after opening them from the perspective of air venting ability. As a result, it was found that the heating bag containers of the above configurations are compact when stored, while also having good air venting ability when in use.

[0089] Here, the heating bag 2 according to Embodiment 1 described above comprises a flat bag body 11 through which a liquid flows 10, and a tube 12 connected to the bag body 11 and communicating with the flow path 10. The flow path 10 has a plurality of straight flow paths 21 that extend linearly in a first direction (left-right direction) along the surface of the bag body 11 and are arranged in a second direction (up-down direction) perpendicular to the first direction, and a curved flow path 22 that connects the ends of two adjacent straight flow paths 21. The tube 12 is connected to either one side or the other side of the bag body 11 in the first direction. Therefore, the heating bag 2 described in Embodiment 1 is suitably used as a heating bag constituting the heating bag housing according to this embodiment. As mentioned above, the bag body of the heating bag 2 according to Embodiment 1 is constructed by overlapping and welding two flexible resin sheets, and the flow path 10 is a flat flow path, which improves heating efficiency but is also a relatively deformable structure.

[0090] The following describes examples and comparative examples related to this embodiment, in which heated bag containers are constructed using heated bag 2 in various storage configurations.

[0091] [Example 1] Figure 6 is a photographic substitute diagram showing the configuration of the heating bag 2 before it is placed in the storage bag 4 in the heating bag housing 3 according to Example 1. In Example 1, the heating bag 2 was folded along the fold line F1. This fold line F1 passes over the curved channel 22 on one side in the first direction (left-right direction) and on the other side of the other side to which the tube 12 is connected, and extends in the second direction (up-down direction). The heating bag 2 was placed in the storage bag 4 while maintaining this configuration.

[0092] The upper part of Figure 7 is a photographic substitute showing the state after vacuuming, where the heating bag 2 is housed in the storage bag 4 and the gas inside the storage bag 4 is removed using a predetermined vacuum device. The lower part of Figure 7 is a photographic substitute showing the state of the heating bag 2 after the degassed heating bag storage body 3 has been opened, removed, and unfolded. As can be seen from the photograph in the upper part of Figure 7, the storage bag 4 has shrunk due to vacuuming. However, as shown in the photograph in the lower part of Figure 7, although fold marks are visible in the curved flow path 22 where the fold line F1 is set, no noticeable fold marks are visible in other parts of the heating bag 2. Therefore, the heating bag storage body 3 of Example 1 can suppress the decrease in air release performance caused by fold marks in the heating bag during use.

[0093] Incidentally, in the heating bag 2 of Example 1, as can be seen from the upper view of Figures 6 and 7, the tube 12 is fixed in a circular state by a fixing member 31 such as tape and is superimposed on the bag body 11 of the heating bag 2. In this case, the circular tube 12 exhibits high resistance to external forces. In other words, the circular and fixed tube 12 forms a support that supports (maintains) the shape of the bag body 11, and this support is housed in the storage bag 4 superimposed on the bag body 11. Therefore, deformation of the bag body 11 due to the force acting on the storage bag 4 when vacuum processing is performed is suppressed. Furthermore, in the heating bag 2 of Example 1, the tube 12 is circular with a diameter D that is greater than or equal to the dimension H in the second direction of the flow path 10. As a result, the force applied to the storage bag 4 is more likely to act on the tube 12 than on the bag body 11, thus further suppressing deformation of the bag body 11.

[0094] In the above-described Example 1, a tube 12 in a circular state is shown as the "support," but the form of the heated bag housing according to this disclosure is not limited to this. For example, a support sheet may be prepared as a separate component from the heated bag 2, having the same or substantially the same shape and area as the bag body 11 and made of a harder material than the bag body 11, and this support sheet may be placed on top of the bag body 11 and housed in the storage bag 4.

[0095] [Comparative Example 1] Figure 8 is a photographic substitute diagram showing the state of the heating bag 2 before being placed in the storage bag 4 in the heating bag housing 3A according to Comparative Example 1. In Comparative Example 1, the heating bag 2 is fixed by the fixing member 31 with the tube 12 wrapped around it. On the other hand, the bag body 11 is in an unfolded state and not folded. The heating bag 2 was placed in the storage bag 4 while maintaining this state. As is clear from Figure 8, in the case of Comparative Example 1, there is no support that supports the shape of the bag body 11.

[0096] The top image in Figure 9 is a substitute photograph showing the state after vacuuming, where the heating bag 2 is placed in the storage bag 4 and the gas inside the storage bag 4 has been removed using a predetermined vacuum device. The middle image in Figure 9 is a substitute photograph showing the state after the heating bag 2 has been removed from the storage bag 4. The bottom image in Figure 9 is a substitute photograph showing the state after the heating bag 2 has been unfolded after being removed from the storage bag 4.

[0097] In the case of the heated bag container 3A of Comparative Example 1, as shown in the upper part of Figure 9, the heated bag 2 deformed as the container bag 4 contracted due to vacuuming. In fact, as shown in the middle part of Figure 9, the bag body 11, which was in an unfolded state before storage, deformed significantly after vacuuming. When such a heated bag 2 was unfolded, as can be seen in the lower part of Figure 9, creases were formed in various places.

[0098] Thus, in Comparative Example 1, the heated bag container 3A forms creases in various places on the heated bag 2, and the deformation pattern due to vacuuming is difficult to predict, making it difficult to control the location of crease formation. Although not shown in the figures, several other examples were performed in which the bag body 11 was placed in the container bag 4 in its unfolded state and vacuumed, but different deformations occurred in the heated bag 2 each time, indicating that it is difficult to control the creases. Therefore, it can be seen that such a heated bag 2 has lower air release properties and lower individual performance stability compared to the case of Example 1.

[0099] [Comparative Example 2] Figure 10 is a photographic substitute diagram showing the configuration of the heating bag 2 before being placed in the storage bag 4 in the heating bag housing 3B according to Comparative Example 2. In Comparative Example 2, the heating bag 2 is fixed by a fixing member 31 with the tube 12 wrapped around it. On the other hand, the bag body 11 was folded into quarters. Specifically, the bag body 11 was folded in half along the fold line F2 (see the lower part of Figure 11) along the first direction, and then folded in half again along the fold line F3 (see the lower part of Figure 11) along the first direction. As a result, the bag body 11 took on a horizontally elongated configuration along the longitudinal direction (first direction) of the straight channel 21. The heating bag 2 was placed in the storage bag 4 while maintaining this configuration. As is clear from Figure 10, in the case of Comparative Example 2, there is no support to support the shape of the bag body 11.

[0100] The top image in Figure 11 is a photographic substitute showing the state after vacuuming, where the heating bag 2 is placed in the storage bag 4 and the gas inside the storage bag 4 has been removed using a predetermined vacuum device. The middle image in Figure 11 is a photographic substitute showing the state after the heating bag 2 has been removed from the storage bag 4. The bottom image in Figure 11 is a photographic substitute showing the state after the heating bag 2 has been unfolded after being removed from the storage bag 4.

[0101] In the case of the heating bag container 3B of Comparative Example 2, as shown in the upper part of Figure 11, the heating bag 2 deformed as the container bag 4 contracted due to vacuuming. Specifically, as shown in the middle part of Figure 11, the bag body 11, which is folded into quarters to form a horizontally elongated shape, was bent at two different points along its longitudinal direction. When such a heating bag 2 was unfolded, as can be seen in the lower part of Figure 11, creases were formed in various places.

[0102] Thus, in Comparative Example 2, the heated bag container 3B had creases formed in various places on the heated bag 2, and the degree of deformation of the bag body 11 at each crease was relatively large. Therefore, although such a heated bag 2 is compact and the container bag 4 can be made smaller, it is clear that it has lower air release properties compared to the case of Example 1.

[0103] [Comparative Example 3] Figure 12 is a photographic substitute diagram showing the configuration of the heating bag 2 before it is placed in the storage bag 4 in the heating bag housing according to Comparative Example 3. In Comparative Example 3, the heating bag 2 is fixed by a fixing member 31 with the tube 12 wrapped around it. On the other hand, the bag body 11 was not folded but rolled around an axis along the second direction. As a result, the bag body 11 became the most compact compared to the other examples. The heating bag 2 was then placed in the storage bag 4 while maintaining this configuration. As is clear from Figure 12, in the case of Comparative Example 3, there is no support that supports the shape of the bag body 11.

[0104] The upper part of Figure 13 is a photographic substitute showing the state of the heating bag 2 after it has been vacuumed while contained in the storage bag 4 and then removed from the storage bag 4. The lower part of Figure 13 is a photographic substitute showing the state of the heating bag 2 after it has been removed from the storage bag 4 and unfolded.

[0105] In the case of the heated bag container of Comparative Example 3, as shown in the upper part of Figure 13, the heated bag 2 deformed as the container bag 4 contracted due to vacuuming. Specifically, the bag body 11, which was rolled up lengthwise, was significantly bent in the middle of its longitudinal direction. When this heated bag 2 was unfolded, as can be seen in the lower part of Figure 13, creases were formed in many places throughout the bag body 11.

[0106] Thus, in Comparative Example 3, the heated bag container had creases formed in various places on the heated bag 2, and the degree of deformation of the bag body 11 at each crease was relatively large. Therefore, although such a heated bag 2 is compact and the container bag 4 can be made smaller, it is clear that it has lower air release properties compared to the case of Example 1.

[0107] It should be noted that this disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. [Industrial applicability]

[0108] This disclosure can be suitably applied to heated bags and heated bag containers used in blood processing circuits such as renal replacement therapy, simple plasma exchange therapy, and double filtration plasma exchange therapy. [Explanation of Symbols]

[0109] 1 Blood circuit 2. Heating bag 3. Heated bag container 4 storage bags 10 channels 10A First channel 10B Second channel 11 Bag body 12 Tubes (Supports) 13 Inlet tube 14 Outlet tube 21 Straight channel 22 Curved channel 25a Supported part 25b Supported part 25c Supported part

Claims

1. A heating bag used in a blood processing circuit to heat the liquid flowing through the circuit with a heater, It comprises a flat bag body through which a liquid flows, and a tube connected to the bag body and communicating with the flow path, The flow path includes a plurality of straight flow paths that extend linearly in a first direction along the surface of the bag body and are arranged in a second direction intersecting the first direction along the surface of the bag body, and a curved flow path that connects the ends of two adjacent straight flow paths, and the tube is connected to the end of the straight flow path that is not connected to the curved flow path. Of the multiple straight channels, the straight channel to which the curved channel and the tube are connected has a flat channel cross-section such that, when viewed along the first direction, the width dimension W, which is the width dimension parallel to the second direction, is greater than the thickness dimension T, which is the thickness dimension perpendicular to both the first and second directions. When the inner diameter of the tube is Φ, the width dimension W satisfies 2.0Φ ≤ W ≤ 3.5Φ, and the thickness dimension T satisfies 0.3Φ ≤ T ≤ 0.5Φ, Furthermore, the straight channel is connected to the tube via a connection port, and the connection port has a tapered portion whose width decreases as it moves away from the tube. Heated bag.

2. The flow path includes a first flow path and a second flow path through which liquid flows independently, The first channel and the second channel each have a straight channel and a curved channel, and both the first channel and the second channel have a horizontally elongated shape in which the dimension in the first direction is larger than the dimension in the second direction, and are arranged side by side in the second direction. The bag body has a supported portion which, when heated by the heater, is supported in a position where the first direction is aligned horizontally and the second direction is aligned vertically. The heating bag according to claim 1.

3. The flow path satisfies the following conditions: the length L in the first direction from the curved flow path on one side to the curved flow path on the other side, and the dimension H of the flow path in the second direction, are 2.5H ≤ L ≤ 3.5H. The heating bag according to claim 2.

4. The dimension L more preferably satisfies 2.8H ≤ L ≤ 3.2H. The heating bag according to claim 3.

5. The tube includes an inlet tube connected to the bag body and communicating with the upstream ends of the first and second flow paths, and an outlet tube communicating with the downstream ends, The inlet tube and outlet tube are all provided on the same side of the bag body, either one side or the other side in the first direction. The heating bag according to claim 4.

6. A heating bag housing comprising a heating bag according to Claim 1, and a housing bag for housing the heating bag, The tube of the heating bag is connected to either one of the first sides of the bag body, The heating bag is housed in the storage bag in a state where it passes along the curved channel on the side to which the tube is connected in the first direction, and is folded along a fold line extending in the second direction. Heated bag container.

7. The tube is fixed in a circular position and is placed in the storage bag while being stacked on top of the heating bag. The heated bag housing according to claim 6.

8. The tube is circumferentially arranged with a diameter greater than or equal to the second dimension H of the flow path. The heated bag container according to claim 7.

9. A heating bag container comprising a heating bag according to Claim 1 and a storage bag for housing the heating bag, The aforementioned storage bag contains the bag body of the heating bag and a support for supporting the shape of the bag body, stacked on top of each other. Heated bag container.

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