Method for manufacturing a medical assembly, and blood pump

Abstract

This prevents laser light that has passed through the area to be welded from irradiating other areas. [Solution] A method for manufacturing a medical assembly 100 comprising a first member 20 and a second member 30 formed of a light-transmitting resin, the first member 20 having a first welded portion 26, a groove portion 27 located radially inward from the first welded portion 26, and a bottom portion 25 located radially inward from the groove portion 27, and the second member 30 having a second welded portion 34 to be welded to the first welded portion 26, wherein the light-shielding portion 65 of the jig 60 is inserted into the groove portion 27 so that the light-shielding portion 65 of the jig 60 is positioned between the interface between the first welded portion 26 and the second welded portion 34 and the bottom portion 25, the first member 20 and the second member 30 are fitted together so that the first welded portion 26 and the second welded portion 34 come into contact, and the interface is irradiated with laser light LB to weld the first welded portion 26 and the second welded portion 34.

Description

【Technical Field】 【0001】 The present invention relates to a manufacturing method for manufacturing a medical assembly by laser welding and a blood pump. 【Background Art】 【0002】 Patent Document 1 discloses a method for manufacturing a blood pump including a pump housing and an impeller housed inside the pump housing. The pump housing is configured by assembling a top case and a base case formed of a transparent thermoplastic resin. Specifically, the pump housing is assembled by irradiating a laser beam to the interface between the thin-walled portion of the top case and the raised portion of the base case and welding them. Further, the impeller is rotatably housed in the internal space of the pump housing formed by assembling the top case and the base case. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2021-177884 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 In the pump housing in Patent Document 1, the thin-walled portion and the raised portion where welding is performed are formed of a transparent thermoplastic resin. However, when the portion where welding is performed has light transmissivity, the irradiated laser beam passes through the portion where welding is performed. Therefore, it is conceivable that the irradiated laser beam is irradiated to other portions than the portion where welding is performed. Thus, means for suppressing the irradiated laser beam from being irradiated to other portions is required. 【Means for Solving the Problems】 【0005】 A method for manufacturing a medical assembly according to one embodiment is a method for manufacturing a medical assembly comprising a first member and a second member formed of a light-transmitting resin, the first member having a first welded portion, a groove portion located radially inward from the first welded portion, and a bottom portion located radially inward from the groove portion, and the second member having a second welded portion that is welded to the first welded portion, The light-shielding portion of the jig is inserted into the groove portion so that it is positioned between the interface between the first welded portion and the second welded portion and the bottom portion. The first member and the second member are fitted together so that the first welded portion and the second welded portion come into contact with each other. The interface is irradiated with laser light to weld the first welding portion and the second welding portion together. 【0006】 A blood pump according to another embodiment comprises a bottom case and a top case formed of a light-transmitting resin, The system comprises an impeller housed in a housing space defined by the bottom case and the top case, The bottom case has a first welded portion, a groove portion located radially inward from the first welded portion, and a bottom portion located radially inward from the groove portion. The top case has a second welded portion which is welded to the first welded portion, At least a portion of the groove is interposed between the first welded portion and the second welded portion and the bottom portion. [Brief explanation of the drawing] 【0007】 [Figure 1] This is a schematic perspective view of a blood pump. [Figure 2] This is a schematic exploded perspective view of a blood pump. [Figure 3] This is a schematic plan view of a blood pump. [Figure 4] This is a schematic cross-sectional view of a blood pump. [Figure 5] This is a schematic perspective view of the jig. [Figure 6] This is a schematic cross-sectional view of the blood pump in combination with a jig. [Figure 7] This is an explanatory diagram showing the blood pump during welding. [Figure 8] This is a flowchart showing the manufacturing process of blood pumps. [Figure 9] This is a schematic perspective view of the jig related to the modified form. [Modes for carrying out the invention] 【0008】 Hereinafter, exemplary embodiments for carrying out the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of components described in the following embodiments can be arbitrarily set and modified according to the configuration of the apparatus or method to which the present invention is applied, or according to various conditions. Furthermore, unless otherwise specified, the scope of the present invention is not limited to the embodiments specifically described below. 【0009】 In this specification, the side that is placed on the jig 60 (Figure 6) corresponds to the lower side of the blood pump 100, and the opposite side corresponds to the upper side. However, when using the blood pump 100, it may be used upside down or tilted at an arbitrary angle (for example, 90 degrees) in a desired direction. 【0010】 [Blood pump] First, referring to Figures 1 to 4, we will describe a blood pump 100, which is an example of a medical assembly. The blood pump 100 is a single-use centrifugal pump used in an extracorporeal circulation circuit and is driven by a drive unit (not shown). A medical assembly is an item composed of multiple components assembled together. Other examples of medical assemblies include artificial lungs, heat exchangers, arterial filters, and blood reservoirs. In the following, we will describe the blood pump 100 as an example of a medical assembly. 【0011】 As an example, an extracorporeal circulation circuit using a blood pump 100 includes a flow sensor, a blood reservoir, and an artificial lung. Upstream of the blood reservoir, a blood withdrawal circuit, a suction circuit, a negative pressure suction assist circuit, and a fluid replacement circuit are connected. Downstream of the artificial lung, a blood delivery circuit equipped with an arterial filter is connected. The artificial lung is connected to a gas supply circuit for supplying oxygen exchange gas. Furthermore, the artificial lung and the blood reservoir are connected by a blood collection circuit equipped with a stopcock. The blood delivery circuit is connected via a blood withdrawal circuit and a recirculation circuit, but the recirculation circuit is closed during extracorporeal circulation. When starting extracorporeal circulation, blood is injected into the blood reservoir, and the blood stored in the reservoir is guided to the blood pump 100. 【0012】 The blood pump 100 includes a hollow pump housing 10. The pump housing 10 has a bottom case 20 and a top case 30, which are examples of first and second members formed of a light-transmitting resin. The top case 30 has an inlet port 31 connected to the downstream side of the blood reservoir and an outlet port 32 connected to the upstream side of the artificial lung. 【0013】 The light-transmitting resin is, for example, a thermoplastic resin that is transparent to the wavelength range of laser light. As an example, the bottom case 20 and the top case 30 are formed from polycarbonate. In this embodiment, the absorption rate of laser light in the near-infrared region of the light-transmitting resin is, for example, 60 percent or less. In other examples, the absorption rate of laser light in the near-infrared region of the light-transmitting resin is 40 percent or less, or 30 percent or less and 20 percent or more. Furthermore, the light-transmitting resin may also be transparent to the wavelength range of visible light. This allows the inside of the blood pump 100 to be seen. 【0014】 As shown in FIG. 2, the blood pump 100 includes a pump housing 10 having a bottom case 20 and a top case 30, and an impeller 50 housed inside the pump housing 10. In the center of the bottom case 20, a hollow bottom convex portion 22 having a substantially cylindrical shape protruding toward the top case 30 side is formed. And in the center of the top surface of the bottom convex portion 22, a central convex portion 23 is formed. Further, a plurality of substantially spiral dynamic pressure grooves 24 for realizing dynamic pressure bearings are formed on the outer peripheral surface of the bottom convex portion 22. Furthermore, the bottom case 20 has a bottom portion 25 formed in a substantially donut shape so as to surround the bottom convex portion 22. And a raised portion 26 as an example of the first welded portion protrudes from between the outer peripheral edge portion of the bottom case 20 and the bottom portion 25. 【0015】 The top case 30 has a substantially cylindrical shape that opens at an annular opening 33. And the top case 30 is fitted with the bottom case 20 so as to cover the bottom case 20. Thereby, an accommodation space for accommodating the impeller 50 is formed between the top case 30 and the bottom case 20. 【0016】 The impeller 50 is rotatably accommodated in an accommodation space defined by the bottom case 20 and the top case 30. And in the center of the impeller 50, an introduction flow path 54 through which blood is introduced via an inlet port 31 is formed. Further, the introduction flow path 54 communicates with a plurality of flow paths 57 extending toward the outer side in the radial direction of the impeller 50. Thereby, the blood flowing in from the inlet port 31 is guided to the flow paths 57 through the introduction flow path 54. And when the impeller 50 rotates, the blood guided to the flow paths 57 is transferred to the outer peripheral side of the impeller 50 by centrifugal force. The blood transferred to the outer peripheral side of the impeller 50 flows along the inner peripheral surface of the pump housing 10 and is sequentially sent out from the outlet port 32. 【0017】 Also, a through-hole 56 communicating with the inlet port 31 via the introduction flow path 54 is formed in the center of the impeller 50. In the state where the blood pump 100 is combined, the central convex portion 23 of the bottom case 20 penetrates through the through-hole 56. Further, a plurality of dynamic pressure grooves (not shown) for realizing a dynamic pressure bearing are formed on the impeller top surface 58 of the impeller 50. 【0018】 FIG. 3 is a schematic plan view of the blood pump 100 as viewed from the inlet port 31 side. The portion surrounded by a circle in FIG. 4 is shown as a partially enlarged view in the upper left of FIG. 4. As shown in FIG. 3, the bottom case 20 has a substantially circular outer shape when viewed from the inlet port 31 side. The inlet port 31 is formed at the center of the top surface of the top case 30. The outlet port 32 is formed so as to protrude from the outer peripheral surface of the top case 30. 【0019】 FIG. 4 is a schematic cross-sectional view showing a VI-VI cross-section along the dashed-dotted line in FIG. 3 passing through the center of the blood pump 100. As shown in FIG. 4, the top case 30 is arranged to cover the bottom case 20. The top case 30 has a thin portion 34 as an example of a second welding portion welded to the raised portion 26. The thin portion 34 is formed in an annular shape at the end of the top case 30 on the bottom case 20 side. The thin portion 34 has a thinner wall thickness compared to other portions of the top case 30. 【0020】 The inlet port 31 is formed on the top surface of the top case 30 so as to extend coaxially with the rotation axis CL of the impeller 50. The inlet port 31 is connected to a tube (not shown) forming a part of the upstream flow path with respect to the blood pump 100. The tip opening of the inlet port 31 functions as a blood suction port. 【0021】 Furthermore, a donut-shaped fluid passage 11 is formed between the bottom case 20 and the top case 30, surrounding the impeller 50. An outlet port 32 is connected to the fluid passage 11. The outlet port 32 is formed to extend approximately tangentially with respect to the rotational direction of the impeller 50. The outlet port 32 is also connected to a tube (not shown) that forms part of the downstream flow path to the blood pump 100. The tip opening of the outlet port 32 functions as a blood discharge port. 【0022】 The impeller 50 has an impeller recess 51 that opens downward. The impeller 50 is combined with the bottom case 20 such that a bottom protrusion 22 is inserted into the impeller recess 51. A liquid-tight, donut-shaped sealed space 52 is formed outside the impeller recess 51. Inside the sealed space 52 are multiple driven magnetic elements 53 arranged in a circumferentially dispersed manner. The driven magnetic elements 53 attract the drive magnetic elements of the drive unit described later, thereby rotating the impeller 50 around the rotation axis CL in accordance with the rotation of the drive unit. As an example, the driven magnetic elements 53 are permanent magnets. Alternatively, iron pieces may be housed in the sealed space 52 as driven magnetic elements 53. Dynamic pressure grooves for realizing a dynamic pressure bearing are formed on the upper surface 51A of the recess 51 and the bottom surface 59 of the impeller recess 51. 【0023】 The bottom protrusion 22 has a substantially cylindrical shape formed to constitute a recess that opens downward. The drive unit (not shown) of the drive unit, which will be described later, is arranged in the internal space of the bottom protrusion 22. A central protrusion 23, which has a substantially conical shape, protrudes from the top surface of the bottom protrusion 22. The central protrusion 23 penetrates the through hole 56 of the impeller 50 when the bottom case 20 and the impeller 50 are assembled. 【0024】 The bottom case 20 also has a raised portion 26, a grooved portion 27 located radially inward from the raised portion 26, and a bottom portion 25 located radially inward from the grooved portion 27. The raised portion 26 is formed in an annular shape so as to surround the entire circumference of the bottom portion 25. The outer circumferential surface of the raised portion 26 of the bottom case 20 in the radial direction faces the inner circumferential surface of the thin-walled portion 34 of the top case 30 in the radial direction. Laser light is irradiated from the radial outside of the blood pump 100 to this interface between the raised portion 26 and the thin-walled portion 34, thereby welding the raised portion 26 and the thin-walled portion 34 together. By laser welding the raised portion 26 and the thin-walled portion 34 around their entire circumference, the bottom case 20 and the top case 30 are joined in a liquid-tight manner. 【0025】 Furthermore, the raised portion 26 is not limited to annular shape; it may also be formed with a portion interrupted in the circumferential direction. However, forming it annular has the advantage of ensuring a secure bond between the bottom case 20 and the top case 30. Also, the thickness D1 from the interface between the raised portion 26 and the thin-walled portion 34 to the groove portion 27 is thinner than the thickness D2 in the height direction perpendicular to the radial direction in the bottom portion 25. As a result, the heat capacity of the bottom portion 25 is larger compared to the thin-walled portion 34, and the bottom portion 25 is less affected by the heat generated in the raised portion 26 and the thin-walled portion 34 by laser irradiation. Therefore, deformation of the bottom portion 25 due to heat can be suppressed. 【0026】 Furthermore, the welded portions of the raised portion 26 and the thin-walled portion 34 are integrated after being melted by laser welding. Therefore, the welded portions of the raised portion 26 and the thin-walled portion 34 in the welded blood pump 100 may exist as a single joined portion after melting. However, in Figure 4, the raised portion 26 and the thin-walled portion 34 are shown separately. 【0027】 The groove portion 27 is formed between the bottom portion 25 and the raised portion 26, opening toward the side opposite to the top case 30. At least a portion of the groove portion 27 is interposed between the interface between the raised portion 26 and the thin-walled portion 34 and the bottom portion 25. The groove portion 27 is also formed in an annular shape so as to surround the bottom portion 25. In this embodiment, the groove portion 27 has a substantially triangular shape in cross-section. Alternatively, the groove portion 27 may be formed to have a substantially rectangular or substantially semicircular shape in cross-section. 【0028】 A drive unit (not shown) of the drive unit is arranged in the internal space formed in the bottom protrusion 22. This drive unit rotates the impeller 50 via the driven magnetic elements 53. For example, the drive unit has a motor. The drive unit, which is attached to the output shaft connected to the motor, rotates together with the output shaft. The output shaft of the motor is set coaxially with the rotation axis CL of the impeller 50. The drive unit has the same number of drive magnetic elements as the number of driven magnetic elements 53 of the impeller 50, arranged at a constant interval in the circumferential direction. Furthermore, the orientation of these drive magnetic elements is adjusted so that they attract each other with respect to the driven magnetic elements 53. As a result, the drive unit attracts the driven magnetic elements 53 by magnetic force. When the motor is driven and the output shaft rotates, the drive unit fixed to the output shaft rotates. Furthermore, when the drive unit rotates, the impeller 50 rotates together with the driven magnetic elements 53. 【0029】 [Hydraulic bearing] A relatively narrow gap is formed between the top surface 58 of the impeller 50 and the inner surface of the top case 30 to form a first thrust bearing TB1 that rotatably supports the impeller 50. A relatively narrow gap is also formed between the bottom surface 59 of the impeller 50 and the bottom portion 25 of the bottom case 20 to form a second thrust bearing TB2 that rotatably supports the impeller 50. Furthermore, a relatively narrow gap is formed between the upper surface 51A of the recess 51 of the impeller recess 50 and the top surface of the bottom protrusion 22 of the bottom case 20 to form a third thrust bearing TB3 that rotatably supports the impeller 50. As an example, the relatively narrow gap for forming the first thrust bearing TB1 is 1.0 mm or less. The relatively narrow gaps for forming the second thrust bearing TB2 and the third thrust bearing TB3 are, as an example, 0.5 mm or less. 【0030】 Furthermore, a relatively narrow gap is formed between the inner circumferential surface of the impeller recess 51 of the impeller 50 and the outer circumferential surface of the bottom protrusion 22 of the bottom case 20, for forming a radial bearing RB that rotatably supports the impeller 50. As an example, the relatively narrow gap for forming the radial bearing RB is 0.5 mm or less. In the following, the first thrust bearing TB1, the second thrust bearing TB2, the third thrust bearing TB3, and the radial bearing RB may be collectively referred to as a dynamic pressure bearing. 【0031】 When blood is introduced into the pump housing 10, some of the introduced blood flows into the hydrodynamic bearing. This causes the blood introduced into the pump housing 10 to flow into the gap between the pump housing 10 and the impeller 50. When the impeller 50 rotates with the blood flowing in, the pressure of the blood in the hydrodynamic bearing increases. This creates a support action in the hydrodynamic bearing, supporting the impeller 50 so that it can rotate. In other words, the pressure of the liquid (dynamic pressure) generated as the impeller 50 rotates without contacting the pump housing 10. The blood introduced into the pump housing 10 can move between the introduction passage 54 and passage 57, the second thrust bearing TB2, the third thrust bearing TB3, and the radial bearing RB through the through hole 56 of the impeller 50. 【0032】 [jig] Next, the jig 60 used in the manufacture of the blood pump 100 will be described with reference to Figures 5 and 6. Figure 5 shows the jig 60 viewed from diagonally above. Figure 6 is a schematic cross-sectional view showing the jig 60 in a holding state combined with the blood pump 100, corresponding to the cross-section shown in Figure 3. 【0033】 As shown in Figure 5, the jig 60 has a jig projection 61 that protrudes from the center of the jig 60. A shaft hole 62 is formed in the center of the jig projection 61, passing through the jig 60. A roughly donut-shaped jig recess 63 is formed around the jig projection 61, surrounding it. Multiple magnet holes 64 are formed in the jig recess 63, passing through the jig recess 63 in the vertical direction of the jig 60. Fixing holes 66 are formed on the outer edge of the jig 60, passing through the jig 60. Furthermore, a light-shielding portion 65 protrudes from between the outer edge of the jig 60 and the jig recess 63. That is, the light-shielding portion 65 is formed on the outside of the jig recess 63 in the radial direction of the jig 60. 【0034】 As shown in Figure 6, the jig projection 61 is inserted into the internal space of the bottom projection 22 when the blood pump 100 is held in place. The shaft hole 62 of the jig projection 61 is positioned coaxially with the rotation axis CL of the impeller 50. The shaft hole 62 penetrates the jig 60 in the vertical direction along the rotation axis CL. The upper corner of the jig projection 61 is chamfered. 【0035】 The jig recess 63 contacts the bottom portion 25 of the bottom case 20 when the blood pump 100 is held. The magnet holes 64 are formed at positions corresponding to the driven magnetic elements 53 via the bottom portion 25 and the impeller bottom surface 59. That is, when the blood pump 100 is held, the driven magnetic elements 53 and the magnet holes 64 are aligned in the vertical direction. As an example, the jig recess 63 has the same number of magnet holes 64 as the number of driven magnetic elements 53. Alternatively, the jig recess 63 may have fewer magnet holes 64 than the number of driven magnetic elements 53. 【0036】 The light-shielding portion 65 has an outer shape that is complementary to the inner shape of the groove portion 27. The light-shielding portion 65 is inserted into the groove portion 27 of the bottom case 20 when held. Here, the groove portion 27 is formed such that at least a part of it is interposed between the raised portion 26 and the thin-walled portion 34 and the bottom portion 25. More specifically, at least a part of the groove portion 27 is interposed between the welded portion of the raised portion 26 and the thin-walled portion 34 and the bottom portion 25. Therefore, by inserting the light-shielding portion 65 into the groove portion 27, the light-shielding portion 65 is interposed between the interface between the raised portion 26 and the thin-walled portion 34 and the bottom portion 25. By performing laser welding with the light-shielding portion 65 interposed between this interface and the bottom portion 25, the light-shielding portion 65 blocks the laser light that has passed through the raised portion 26 and the thin-walled portion 34. This suppresses the irradiation of the bottom portion 25 with laser light. 【0037】 Furthermore, the light-shielding portion 65 is formed in an annular shape so as to surround the jig recess 63. The bottom portion 25 of the bottom case 20 is surrounded by a groove portion 27. This allows the light-shielding portion 65 to be inserted into the groove portion 27 so as to surround the bottom portion 25. Therefore, the laser light can be shielded around the entire circumference of the bottom portion 25. The light-shielding portion 65 may have other shapes as long as it can be inserted into the groove portion 27 so as to be interposed between the interface between the raised portion 26 and the thin-walled portion 34 and the bottom portion 25. For example, the light-shielding portion 65 may have a roughly rectangular or roughly semicircular shape in cross-sectional view. In this case as well, the groove portion 27 has an inner shape that is complementary to the outer shape of the light-shielding portion 65. 【0038】 Furthermore, in the jig 60, at least the light-shielding portion 65 is formed of a light-shielding material that blocks laser light. Moreover, this light-shielding material may have a higher thermal conductivity than the light-transmitting resin that constitutes the bottom case 20 and the top case 30. This allows heat generated by laser irradiation to be efficiently dissipated through the jig 60. Therefore, deformation due to heat transfer to the bottom portion 25 can be suppressed. For example, the jig 60 can be formed from a metal material such as aluminum, stainless steel, or copper. Alternatively, the jig 60 may be formed from a silicon resin mixed with a material that absorbs laser light, such as carbon black. In addition, in the jig 60, the light-shielding portion 65 may be formed from a different material than the other parts. 【0039】 [Manufacturing method for medical assemblies] Next, with reference to Figures 7 and 8, a method for manufacturing a blood pump 100 as an example of a medical assembly will be described. Figure 7 is an explanatory diagram showing the state of welding the bottom case 20 and the top case 30 together. In Figure 7, for explanatory purposes, the impeller 50 is represented by a dashed line and detailed illustration is omitted. Figure 8 is a flowchart showing the process of manufacturing the blood pump 100 by assembling the prepared components. 【0040】 As shown in Figure 7, the jig 60 is positioned on the rotating stage 72. A laser oscillator 71 is positioned opposite the blood pump 100, which is combined with the jig 60. The laser oscillator 71 emits laser light LB to weld the raised portion 26 and the thin-walled portion 34. For example, the laser oscillator 71 has a known laser light source such as a semiconductor laser, a solid-state laser, or a gas laser. The laser light LB emitted by the laser oscillator 71 has a wavelength range, for example, in the near-infrared region. As an example, the laser light LB has a wavelength range of 800 nm or more and 2500 nm or less, and preferably has a central wavelength of 1940 nm. 【0041】 The rotary stage 72 supports the jig 60 and rotates the jig 60 around the stage rotation axis, which is coaxial with the rotation axis CL. Therefore, the rotary stage 72 has a motor (not shown) and a shaft 73 that is rotated by the motor. When welding is performed, the jig 60 is set on the rotary stage 72 so that the shaft 73 is inserted into the shaft hole 62. Fixing bolts 74 are inserted into the fixing holes 66 of the jig 60, and the jig 60 is fixed to the rotary stage 72. Then, by driving the motor, the jig 60 can be rotated around the stage rotation axis. 【0042】 Furthermore, a magnet 64a is placed in the magnet hole 64 of the jig 60, which is positioned on the rotating stage 72, and is magnetically coupled to the driven magnetic element 53 via the bottom portion 25. The magnet 64a is magnetically coupled to the driven magnetic element 53 via the bottom portion 25. This restricts the movement of the impeller 50 in the rotational direction when the jig 60 and the blood pump 100 are rotated by the rotating stage 72. 【0043】 Referring to Figure 8, the flow for manufacturing the blood pump 100 will be described. First, the bottom case 20, the top case 30, and the impeller 50 are prepared. As an example, the bottom case 20 and the top case 30 can be molded by injection molding of a thermoplastic light-transmitting resin. Alternatively, the bottom case 20 and the top case 30 may be formed by other methods such as casting and 3D printing. The impeller 50 can be formed by a known method. Note that the bottom case 20 and the top case 30 may be formed from different light-transmitting resins. Furthermore, the bottom case 20 and the top case 30 may be formed using light-transmitting resins with different transmittances to laser light LB. 【0044】 Next, the jig 60 is set on the rotary stage 72 (step S101). Specifically, the jig 60 is set on the rotary stage 72 so that the shaft 73 is inserted into the shaft hole 62 of the jig 60. Then, the magnet 64a is placed in the magnet hole 64 of the jig 60. However, the magnet hole 64 may be formed as a bottomed hole and the magnet 64a may be placed in the magnet hole 64 in advance. Then, the fixing bolt 74 is inserted into the fixing hole 66 of the jig 60 to fix the jig 60 to the rotary stage 72. Alternatively, instead of inserting the fixing bolt 74, the jig 60 may be set on the rotary stage 72 so that a fixing key, which is pre-fixed to the rotary stage 72, is inserted into the fixing hole 66. 【0045】 Next, the light-shielding portion 65 of the jig 60 is inserted into the groove portion 27 so that it is positioned between the interface between the raised portion 26 and the thin-walled portion 34 and the bottom portion 25 (step S102). For example, the bottom case 20 and the jig 60 are combined so that the jig protrusion 61 is inserted into the internal space of the bottom protrusion 22. This inserts the light-shielding portion 65 into the groove portion 27. After that, the impeller 50 is placed on top of the bottom case 20 (step S103). Specifically, the impeller 50 is placed on top of the bottom case 20 so that the bottom protrusion 22 of the bottom case 20 is inserted into the impeller recess 51 of the impeller 50. Alternatively, the bottom case 20 and the jig 60 may be combined after the impeller 50 has been placed on top of the bottom case 20. 【0046】 Next, the thin-walled portion 34 of the top case 30 is heated to expand it (step S104). Before heating, the inner diameter of the thin-walled portion 34 is smaller than the outer diameter of the raised portion 26. Therefore, by heating and expanding the thin-walled portion 34, the inner diameter of the thin-walled portion 34 is made larger than the outer diameter of the raised portion 26. For example, the thin-walled portion 34 can be heated by placing the top case 30 in a high-temperature bath. Alternatively, the thin-walled portion 34 may be heated by bringing a heating device into contact with it, or by blowing a high-temperature fluid onto it. Note that the heating of the thin-walled portion 34 may be performed before or simultaneously with the placement of the impeller 50. 【0047】 Next, the bottom case 20 and the heated top case 30 are fitted together, and the impeller 50 is housed in the accommodation space defined by the bottom case 20 and the top case 30 (step S105). At this time, the inner diameter of the thin-walled portion 34 is larger than the outer diameter of the raised portion 26 due to heating. Then, the lower end of the thin-walled portion 34 of the top case 30 is abutted against the plane between the outer peripheral edge of the bottom case 20 and the raised portion 26. This allows the thin-walled portion 34 to be positioned in the vertical direction. 【0048】 Subsequently, the thin-walled portion 34 is cooled (step S106). For example, the thin-walled portion 34 can be cooled by exposing the bottom case 20 and top case 30 to an ambient air atmosphere. Alternatively, the thin-walled portion 34 may be cooled by spraying it with a low-temperature fluid. This causes the thin-walled portion 34 to contract, bringing it into contact with the fitted raised portion 26. Furthermore, the contracted thin-walled portion 34 pressurizes the raised portion 26 inward, causing the thin-walled portion 34 and the raised portion 26 to adhere tightly. This suppresses a decrease in the heat conduction efficiency generated by laser irradiation. Therefore, it suppresses a decrease in the strength of the bond between the raised portion 26 and the thin-walled portion 34. 【0049】 Furthermore, when cooling the thin-walled portion 34, the light-shielding portion 65 is inserted into the groove portion 27 while the thin-walled portion 34 is cooled. As a result, even if the contracted thin-walled portion 34 pressurizes the raised portion 26 inward, the displacement of the raised portion 26 is restricted by the light-shielding portion 65. Therefore, deformation of the outer edge of the bottom case 20 in the direction indicated by arrow A1 in Figure 7 can be suppressed. In addition, deformation of the bottom portion 25 of the bottom case 20 in the upward direction indicated by arrow A2 in Figure 7 can be suppressed. As a result, a relatively narrow gap can be maintained between the bottom portion 25 and the impeller bottom surface 59. 【0050】 Next, the interface between the raised portion 26 and the thin portion 34 is irradiated with laser light LB to weld the raised portion 26 and the thin portion 34 together (step S107). The laser light LB is irradiated from the outer surface side of the thin portion 34, focusing on the interface between the raised portion 26 and the thin portion 34. This generates heat in at least one of the raised portion 26 and the thin portion 34, causing the resin to melt. The melted resin then re-solidifies when the irradiation of the laser light LB is stopped. This welds the raised portion 26 and the thin portion 34 together. 【0051】 Furthermore, a portion of the irradiated laser light LB passes through the raised portion 26 and the thin-walled portion 34 formed from the light-transmitting resin. The laser light LB that has passed through the raised portion 26 and the thin-walled portion 34 is then blocked by the light-shielding portion 65. This prevents the laser light LB that has passed through the raised portion 26 and the thin-walled portion 34 from irradiating the bottom portion 25. Therefore, it is possible to prevent the bottom portion 25 from overheating and deforming. In other words, it is possible to prevent the bottom portion 25 from deforming in the direction indicated by arrow A2 in Figure 7. This prevents the bottom portion 25 from being displaced in the direction of approaching the impeller bottom surface 59. This also prevents a decrease in the accuracy of forming a relatively narrow gap between the bottom portion 25 and the impeller bottom surface 59. Furthermore, it is possible to prevent the gap from narrowing and causing hemolysis. 【0052】 Furthermore, the heat generated by the irradiation of the laser beam LB is efficiently dissipated through the light-shielding portion 65. This prevents heat from being transferred to the bottom portion 25 and causing deformation. It also prevents heat from being transferred to the impeller 50 and causing deformation of the impeller 50. In particular, if the jig 60 is made of a material with a higher thermal conductivity than the light-transmitting resin, heat can be dissipated more efficiently. 【0053】 Simultaneously, with the laser beam LB irradiated, the blood pump 100 is rotated at a constant speed around the rotation axis CL. Specifically, the rotation stage 72 is rotated to rotate the jig 60 together with the blood pump 100. This allows the entire circumference of the blood pump 100 to be welded. The laser beam LB may be irradiated intermittently or continuously. However, continuous irradiation can suppress the occurrence of strain in the area to be welded. When the laser beam LB is irradiated intermittently, it is sufficient that the light-shielding portion 65 is inserted into the groove portion 27 so as to be interposed between the portion to which the laser beam LB is irradiated and the bottom portion 25. Alternatively, the laser oscillator 71 may be rotated around the blood pump 100 to weld the entire circumference of the blood pump 100. 【0054】 According to the manufacturing method of the blood pump 100 described above, the laser light LB that passes through the raised portion 26 and the thin-walled portion 34 is blocked by the light-shielding portion 65. Therefore, it is possible to suppress the irradiation of other parts with the laser light LB that has passed through the part to be welded. This prevents deformation of other parts (for example, the bottom portion 25) by the laser light LB. In other words, it is possible to suppress the irradiation of the bottom portion 25 with the laser light LB that has passed through the raised portion 26 and the thin-walled portion 34. Furthermore, by suppressing the deformation of the bottom portion 25, the accuracy of the relatively narrow gap that forms the second thrust bearing TB2 can be maintained. Therefore, hemolysis can be prevented. 【0055】 [Differentiation] In the embodiment described above, the jig 60 is formed such that a jig projection 61 and a light-shielding portion 65 protrude from a substantially disc-shaped body. However, the jig 60 may have other shapes as long as it has a light-shielding portion 65. For example, it may have a substantially cylindrical shape, as shown in the modified jig 260 in Figure 9. As an example, the jig 260 has a substantially cylindrical cylindrical portion 267. A light-shielding portion 265 is formed at one end of the cylindrical portion 267 in the vertical direction of the jig 260. The light-shielding portion 265 is inserted into the groove portion 27 when laser welding is performed, thereby shielding the laser light LB that has passed through the interface between the raised portion 26 and the thin-walled portion 34. Even with such a jig 260, it is possible to suppress the irradiation of the bottom portion 25 by the laser light LB that has passed through the raised portion 26 and the thin-walled portion 34. 【0056】 When using the jig 260, for example, a shaft 73 whose outer diameter has been enlarged to approximately match the inner diameter of the recess of the bottom protrusion 22 is inserted into the internal space of the bottom protrusion 22. This allows the bottom case 20 to be set on the rotating stage 72. As an example, such enlargement can be achieved by placing a cylindrical body having an outer diameter approximately matching the inner diameter of the recess of the bottom protrusion 22 over the shaft 73. 【0057】 Although the present invention has been described above with reference to the embodiments described, the present invention is not limited to the embodiments described above. Inventions modified within the scope that does not contradict the present invention, and inventions equivalent to the present invention are also included in the present invention. Furthermore, each embodiment and each variation can be appropriately combined within the scope that does not contradict the present invention. 【0058】 For example, the steps of heating the thin-walled portion 34 (step S104) and cooling the thin-walled portion 34 (step S106) may be omitted. In this case, the bottom case 20 and the top case 30 may be fitted together by press-fitting the bottom case 20 into the top case 30. Alternatively, the top case 30 may have a thin-walled portion 34 having an inner diameter approximately the same as the outer diameter of the raised portion 26. In this case, the bottom case 20 and the top case 30 are fitted together so that the raised portion 26 and the thin-walled portion 34 are in contact. Even in this case, the heat generated by laser irradiation can be conducted. Furthermore, if the raised portion 26 and the thin-walled portion 34 can be brought into contact during welding, there may be a small gap between the raised portion 26 and the thin-walled portion 34 after fitting. 【0059】 Furthermore, the light-shielding portion 65 only needs to be formed so as to be interposed between the portion to be laser-welded and the bottom portion 25. For example, if laser welding is performed only on a portion of the circumferential direction at the interface between the raised portion 26 and the thin-walled portion 34, the light-shielding portion 65 only needs to be formed so as to be interposed between the portion to be laser-welded and the bottom portion 25 when the piece is held. This suppresses the irradiation of the bottom portion 25 by the laser light LB that has passed through the portion to be laser-welded. For example, the light-shielding portion 65 may have a shape that is interrupted in the portion where laser welding is not performed. As an example, the light-shielding portion 65 may include a portion that has a substantially semicircular shape or a substantially arc shape in a plan view. In this case, the light-shielding portion 65 may be composed of a combination of multiple portions that have a semicircular shape or an arc shape. Also, the groove portion 27 only needs to be formed so as to be interposed between the portion to be laser-welded and the bottom portion 25, as long as the light-shielding portion 65 can be inserted into it. This allows the light-shielding portion 65 of the jig 60 to be inserted between the laser welding portion and the bottom portion 25. 【0060】 Alternatively, welding may be performed with the rotation axis of the rotating stage 72 horizontal and the blood pump 100 and jig 60 tilted sideways. When welding is performed with the rotation axis of the rotating stage 72 horizontal, the magnet 64a placed in the magnet hole 64 of the jig 60 magnetically couples with the driven magnetic element 53 of the impeller 50, thereby holding the blood pump 100 on the rotating stage 72. 【0061】 Some or all of the above embodiments may also be described as follows, but are not limited to the following: 【0062】 (Note 1) A method for manufacturing a medical assembly comprising a first member and a second member formed of a light-transmitting resin, the first member having a first welded portion, a groove portion located radially inward from the first welded portion, and a bottom portion located radially inward from the groove portion, and the second member having a second welded portion that is welded to the first welded portion, The light-shielding portion of the jig is inserted into the groove portion so that it is positioned between the interface between the first welded portion and the second welded portion and the bottom portion. The first member and the second member are fitted together so that the first welded portion and the second welded portion come into contact with each other. A method for manufacturing a medical assembly, comprising irradiating the interface with laser light to weld the first weld portion and the second weld portion together. 【0063】 (Note 2) The method for manufacturing a medical assembly according to Appendix 1, wherein at least the light-shielding portion of the jig is formed of a light-shielding material that blocks the laser light. 【0064】 (Note 3) The method for manufacturing a medical assembly as described in Appendix 2, wherein the light-shielding material has a higher thermal conductivity than the light-transmitting resin. 【0065】 (Note 4) The second welded portion is heated to expand it, A method for manufacturing a medical assembly according to any one of the appendices 1 to 3, wherein the light-shielding portion is inserted into the groove portion and the second welded portion is cooled to bring the first welded portion and the second welded portion into contact. 【0066】 (Note 5) The method for manufacturing a medical assembly according to any one of the appendices 1 to 4, wherein the bottom portion is surrounded by the groove portion. 【0067】 (Note 6) A method for manufacturing a medical assembly according to any one of the appendices 1 to 5, wherein the thickness from the interface to the groove portion is thinner than the thickness in the height direction perpendicular to the radial direction at the bottom portion. 【0068】 (Note 7) An impeller is prepared having multiple driven magnetic elements arranged in a circumferential direction, A magnet that magnetically couples with the driven magnetic element via the bottom portion is placed in the jig. A method for manufacturing a medical assembly according to any one of the appendices 1 to 6, wherein the impeller is housed in a housing space defined by the first member and the second member. 【0069】 (Note 8) A bottom case and a top case formed from a light-transmitting resin, The system comprises an impeller housed in a housing space defined by the bottom case and the top case, The bottom case has a first welded portion, a groove portion located radially inward from the first welded portion, and a bottom portion located radially inward from the groove portion. The top case has a second welded portion which is welded to the first welded portion, A blood pump in which at least a portion of the groove is interposed between the first welded portion and the second welded portion and the bottom portion. [Explanation of Symbols] 【0070】 100: Blood pump (medical assembly) 20: Bottom case (first component) 25: Bottom part 26: Raised part (first welded part) 27:Groove part 30: Top case (second component) 34: Thin wall part (second welding part) 50: Impeller 53: Driven magnetic element 60: Jig 64a: Magnet 65: Light shielding part LB: Laser light

Claims

[Claim 1] A method for manufacturing a medical assembly comprising a first member and a second member formed of a light-transmitting resin, the first member having a first welded portion, a groove portion located radially inward from the first welded portion, and a bottom portion located radially inward from the groove portion, and the second member having a second welded portion that is welded to the first welded portion, The light-shielding portion of the jig is inserted into the groove portion so that it is positioned between the interface between the first welded portion and the second welded portion and the bottom portion. The first member and the second member are fitted together so that the first welded portion and the second welded portion come into contact with each other. A method for manufacturing a medical assembly, comprising irradiating the interface with laser light to weld the first welding portion and the second welding portion together. [Claim 2] The method for manufacturing a medical assembly according to claim 1, wherein at least the light-shielding portion of the jig is made of a light-shielding material that blocks the laser light. [Claim 3] The method for manufacturing a medical assembly according to claim 2, wherein the light-shielding material has a higher thermal conductivity than the light-transmitting resin. [Claim 4] The second welded portion is heated to expand it, A method for manufacturing a medical assembly according to any one of claims 1 to 3, wherein the light-shielding portion is inserted into the groove portion and the second welded portion is cooled to bring the first welded portion and the second welded portion into contact. [Claim 5] The method for manufacturing a medical assembly according to any one of claims 1 to 3, wherein the bottom portion is surrounded by the groove portion. [Claim 6] A method for manufacturing a medical assembly according to any one of claims 1 to 3, wherein the thickness from the interface to the groove portion is thinner than the thickness in the height direction perpendicular to the radial direction in the bottom portion. [Claim 7] An impeller is prepared having multiple driven magnetic elements arranged in a circumferential direction, A magnet that magnetically couples with the driven magnetic element via the bottom portion is placed in the jig. A method for manufacturing a medical assembly according to any one of claims 1 to 3, wherein the impeller is housed in a housing space defined by the first member and the second member. [Claim 8] A bottom case and a top case formed from a light-transmitting resin, The system comprises an impeller housed in a housing space defined by the bottom case and the top case, The bottom case has a first welded portion, a groove portion located radially inward from the first welded portion, and a bottom portion located radially inward from the groove portion. The top case has a second welded portion which is welded to the first welded portion, A blood pump in which at least a portion of the groove is interposed between the first welded portion and the second welded portion and the bottom portion.

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