JP2013059771A - Welding method and medical equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding method that can more reliably ensure water-tightness while using pulsed irradiation of laser.SOLUTION: The welding method for forming, on an overlapping part of a first member 40 and a second member 50, a welded region 60 composed of a linear area formed by being irradiated with pulsed laser beams a plurality of times is characterized in that the welded region is formed such that a plurality of enclosed areas 64 surrounded by the linear area are annularly arrayed in series.

Description

  The present invention relates to a welding method, and more particularly, to a welding method using a pulse wave laser beam and a medical device including a casing joined by the welding method.

  Conventionally, as a group of medical devices, electrical stimulation is directly or indirectly applied to various biological tissues such as nerve tissues and muscles, such as nerve stimulation devices, pain relief devices, epilepsy treatment devices, and muscle stimulation devices. Stimulus generating devices to perform are known. These stimulation generators have a power source inside, and are usually implanted and used in a living body together with stimulation electrodes that transmit electrical stimulation.

  A medical device such as a stimulus generator includes a housing and various electric mechanisms housed in the housing. There are interstitial fluid and body fluid exuded from the tissue around the case implanted in the living body, and if these liquids enter the case, problems such as short circuit or corrosion of the electrical mechanism Therefore, the casing needs to be joined so as to ensure the watertightness of the internal space.

As a material for the housing, pure titanium, titanium alloy, stainless steel, etc., which have a good balance between robustness and biocompatibility are often used. As a method for joining casings made of such materials, for example, a laser welding method using a pulse wave laser beam is known.
As an example of a laser welding method using a pulsed laser beam, Patent Document 1 discloses that a pulsed laser beam is irradiated at a constant pitch in the first irradiation step, and the second irradiation step is the same as the first irradiation step. A method has been proposed in which a pulsed laser beam irradiated at a pitch is irradiated so that a new weld bead is formed between adjacent weld beads formed in a first irradiation step.

JP 2009-195948 A

  However, in the welding method described in Patent Document 1, since the laser is irradiated in a pulse shape, it is possible to completely prevent problems such as insufficient penetration of the weld bead overlap by simply adjusting the irradiation output and irradiation pitch. Since it is difficult to ensure watertightness, it is not easy.

  On the other hand, it is conceivable to increase the laser output or to irradiate a wide laser beam in a linear fashion, but because the medical device housing is often small and thin, In such a method, there are concerns about problems such as the internal electrical mechanism being adversely affected by the heat of the laser and the laser beam penetrating through the housing, which is not practical.

This invention is made | formed in view of the above situations, Comprising: It aims at providing the welding method which can take watertight more reliably, using the pulse irradiation of a laser.
Another object of the present invention is to provide a medical device provided with a casing having a good appearance while ensuring watertightness.

  A first aspect of the present invention is a welding method in which a welding region composed of a linear region formed by irradiating a pulse wave laser beam a plurality of times is formed in an overlapping portion of a first member and a second member. The welding region is formed by arranging a plurality of surrounding portions surrounded by the linear region so as to be continuous in an annular shape.

The welding region may include a first region composed of two annular regions formed in an annular shape and a plurality of second regions formed so as to intersect the annular region.
Further, a plurality of surrounding portions surrounded by the region may be formed so as to be continuously arranged side by side over the entire circumference of the peripheral wall portion.

  According to a second aspect of the present invention, there is provided a housing formed by welding a first member and a second member having peripheral walls facing each other so as to form an internal space, and joining the peripheral walls. In the medical device, the welding region that joins the peripheral wall portions includes a plurality of surrounding portions surrounded by a linear region formed by irradiating the pulse wave laser beam a plurality of times over the entire circumference of the peripheral wall portion. It is characterized by being formed so as to be continuous.

In the medical device of the present invention, the first member and the second member may be welded in a state in which a part of the peripheral wall portion of the first member is fitted to the peripheral wall portion of the second member.
The welding region may include a first region composed of two annular regions formed in an annular shape and a plurality of second regions formed so as to intersect the annular region. Further, a plurality of surrounding portions surrounded by the region may be formed so as to be continuously arranged side by side over the entire circumference of the peripheral wall portion.

According to the defibrillation electrode of the present invention, it can be attached without thoracotomy, and defibrillation can be performed with smaller energy.
Moreover, according to the implantable defibrillation system of the present invention, it is possible to perform an attachment procedure without opening the chest, and to perform defibrillation with smaller energy.

It is a figure which shows the structure of the defibrillator which concerns on 1st embodiment of this invention. It is a perspective view which shows the housing | casing of the defibrillator. It is sectional drawing in the thickness direction of the housing | casing. It is an expansion perspective view which shows the welding area | region formed in the housing | casing. It is a schematic diagram which shows the shape of the welding area | region. It is a schematic diagram which shows the modification of the welding area | region. It is a schematic diagram which shows the modification of the welding area | region. It is a schematic diagram which shows the modification of the welding area | region. It is a schematic diagram which shows the shape of the welding area | region in 2nd embodiment of this invention. It is a schematic diagram which shows the modification of the welding area | region. It is a disassembled perspective view of the housing | casing in 3rd embodiment of this invention. It is sectional drawing in the thickness direction of the housing | casing. It is an expansion perspective view which shows the welding area | region formed in the housing | casing.

A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram showing a defibrillator (medical device) 1 of the present embodiment. As shown in FIG. 1, a defibrillator 1 includes a defibrillator 10 that is implanted in a living body such as under the skin and generates electrical energy for defibrillation, and an electrode unit 20 attached to the heart 100. And a lead 30 that connects the defibrillator 10 and the electrode unit 20.

  The defibrillator 10 includes a battery as a power source, a capacitor that stores electrical energy, a detection circuit that detects an electrocardiogram, a determination circuit that determines the state of the heart based on the electrocardiogram, and a defibrillation drive circuit that releases energy from the capacitor Various electrical mechanisms (not shown) such as these are accommodated in a metal casing 11. Since the main feature of the defibrillator 1 is the structure of the housing 11, the structure of the housing 11 will be described in detail later.

  The electrode unit 20 includes a first electrode 21 and a second electrode 22 having the same structure. As shown in FIG. 1, the first electrode 21 is placed on the pericardial membrane 101 on the right ventricular side, and the second electrode 22 is on the left ventricular side so as to face the first electrode 21 across the heart 100. Placed on the pericardial membrane 101.

  The configuration of the lead 30 is not particularly limited as long as it can transmit electrical energy from the defibrillator 10 to the electrode unit 20 while maintaining electrical insulation. In this embodiment, for example, an MP35N alloy wire having a core wire containing 41% silver at the center is wound in a coil shape in a polyurethane tube having an outer diameter φ of about 2 mm.

  FIG. 2 is a perspective view of the housing 11, and FIG. 3 is a cross-sectional view in the thickness direction of the housing 11. The housing 11 has a substantially D-shape with a curved lower part when viewed from the front, and includes a first member 40 that forms the front side and a second member 50 that forms the back side. Although the dimension of the housing | casing 11 can be set suitably, for example, the front longitudinal direction can be 100 millimeters (mm), the width direction can be 70 mm, and thickness can be 10 mm, and the thickness of the 1st member 40 and the 2nd member 50 is sufficient. Can be 0.3 to 1.0 mm.

  The materials of the first member 40 and the second member 50 are not particularly limited as long as they have a certain level of rigidity (fastness) and biocompatibility, and may be different materials. However, it is a matter of course that the same material can be welded better as described later. In the present embodiment, the first member 40 and the second member 50 are made of pure titanium.

  The first member 40 includes a substantially D-shaped front portion 41 that is the front surface of the housing 11, and a peripheral wall portion 42 that rises from the periphery of the front portion 41 in the thickness direction of the front portion 41. Similarly, the second member 50 includes a substantially D-shaped rear surface portion 51 that is the rear surface of the housing 11, and a peripheral wall portion 52 that rises from the periphery of the rear surface portion 51 in the thickness direction of the rear surface portion 51. The upper end portion (the end portion farther from the front portion 41) of the peripheral wall portion 42 is a fitting portion 43 whose outer peripheral side is cut away and thinner than the other portions, and the upper end portion (rear surface) of the peripheral wall portion 52. The end part farther from the part 51 is a fitted part 53 whose inner peripheral side is cut and thinned. The first member 40 and the second member 50 are electrically connected to each other by being welded in a state in which the fitting portion 43 is fitted in the fitting portion 53 and the peripheral wall portion 42 is fitted to the peripheral wall portion 52. They are joined in a state of facing each other so as to form an accommodation space for accommodating the mechanism.

  The first member 40 and the second member 50 are welded by laser welding using a pulsed laser beam (hereinafter referred to as “pulse laser”). In the welding method of the present invention, a welding region 60 is formed by providing a linear region formed by irradiating each pulse laser several times so as to partially overlap the surface of the housing 11 in a predetermined shape. And the site | part with which the 1st member 40 and the 2nd member 50 were piled up is welded and joined.

  The output value, speed, beam width, pitch, etc. of the pulse laser can be set as appropriate, but it is necessary not to penetrate the fitting portion 43 and the fitting portion 53 (overlapping portion) overlapped in the thickness direction, and it is burnt It is preferable to set it to such an extent that discoloration of the welded part due to the above does not occur, or a welding mark having a bad appearance does not occur. As an example of the setting in this embodiment, for example, when the thickness of the fitting part and the fitted part is about 0.15 to 0.5 mm, which is half of the other part, the output is 5 V, the speed is 15 Hz, and the beam width is 0.3 mm. The pitch can be 0.2 mm.

  FIG. 4 is a partially enlarged view of the housing 11, and FIG. 5 is a schematic diagram illustrating the shape of the welding region 60 formed in the housing 11. As shown in FIG. 4 and FIG. 5, the welding region 60 intersects the first region 61 and the first region 61 formed in an annular shape closed on the outer surface of the fitted portion 53 over the entire circumference of the peripheral wall portion 52. And a second region 62 formed in such a manner.

  The first region 61 includes two annular linear regions (hereinafter referred to as “annular regions”) that are separated from each other in a direction in which the first member 40 and the second member 50 are brought close to each other (a fitting direction). It consists of 61A and 61B. The second region 62 includes a plurality of linear regions 63 formed at intervals in the circumferential direction of the peripheral wall portion 52 so as to be orthogonal to the two annular regions 61A and 61B of the first region 61. It is sufficient that at least two second regions 63 are formed, and the number can be set as appropriate.

  Since the welding region 60 includes the first region 61 and the second region 62, the band-shaped portion formed between the annular regions 61A and 61B is divided into a plurality of surrounding portions 64 surrounded by the linear region. . The plurality of surrounding portions 64 are arranged side by side so as to be annularly continuous over the entire circumference of the peripheral wall portion 52.

  When manufacturing the defibrillator 10 of the present embodiment, the first member is accommodated in the space formed in the first member 40 or the second member 50 with the electrical mechanism accommodated in the housing 11. 40 and the 2nd member 50 are made to approach in a fitting direction, and the fitting part 43 is fitted to the to-be-fitted part 53. FIG. When the welding region 60 is formed on the fitted portion 53 using the pulse laser, the first member 40 and the second member 50 are melted and joined together in the welding region 60 to keep the internal space watertight. The defibrillator 10 is completed. In addition, at the time of joining the first member 40 and the second member 50, a part of the electrical mechanism is arranged so as to be exposed to the outside of the housing 11 so that it can be connected to the lead 30. Details are omitted because they are not particularly different from known procedures.

The effects of the housing 11 of the present embodiment configured as described above will be described.
When the defibrillator 10 is implanted subcutaneously or the like, the housing 11 is exposed to interstitial fluid of surrounding tissues, various body fluids exuded from the tissues, and the like. These living body-derived liquids permeate through the joint L (see FIG. 4) between the first member 40 and the second member 50 exposed on the outer surface of the casing 11, and enter the internal space in which the electrical mechanism is accommodated. Try to advance.

  Here, if the first member 40 and the second member 50 are sufficiently melted in all the welding regions 60, the water tightness of the internal space is secured, so that the liquid that has entered from the joint L enters the internal space. Never do. On the other hand, if there is a poor penetration due to fluctuations in the output of the pulse laser or a disturbance in the pitch, etc., since the water tightness is not secured in the defective part, the liquid passes through the defective part. Move towards the interior space.

When this is considered in view of each region of the welding region 60, the following is obtained.
First, out of the two annular regions of the first region 61, if the annular region 61A closer to the joint L is suitably welded throughout, there is a defective portion in the other annular region 61B and the second region 62. Even if it does, the liquid does not enter the internal space.
If defective portions exist in both the annular regions 61A and 61B, the liquid can pass through these defective portions and enter the internal space. However, in the welding region 60 of the present embodiment, the second region Since the plurality of surrounding portions 64 are formed by 62, the liquid can enter the internal space when the defective portions formed in the annular regions 61A and 61B exist in the same surrounding portion 64. Limited. When the defective portions formed in the annular regions 61A and 61B exist in different surrounding portions, all of the second regions 62 that pass through from one surrounding portion to the other surrounding portion are passed. This is only when there is a defective part in the linear region 63, and as the number of linear regions to pass through increases, the possibility decreases substantially to a negligible level.

  As described above, according to the welding method of the present embodiment, in the overlapping portion where the first member 40 and the second member 50 are joined together, a plurality of the surrounding portions 64 are arranged side by side so that the surrounding portions 64 are annularly connected. Since 60 is formed, the case where watertightness is broken is limited to the case where two or more defective portions exist in a certain enclosing portion. Therefore, while welding is performed using a pulse laser, when only one defective portion is present, it is possible to reliably ensure water tightness and to significantly reduce the possibility of water tightness being broken, thereby realizing stable water tightness.

  Moreover, since the 1st area | region 61 and the 2nd area | region 62 which comprise the welding area | region 60 are all linear, a welding area | region can be easily formed with the conventional general welding equipment.

  Further, according to the defibrillator 1 of the present embodiment, since the welded region 60 as described above is formed at the joint portion of the casing 11 implanted in the living body, the liquid can be accommodated during the period of use. The possibility of entering the body 11 can be further reduced, and it can be used more safely.

  The welding region in the present embodiment is not limited to the one provided with the first region and the second region as described above, and various modes can be used as long as a plurality of surrounding portions are annularly continued. .

The modification examples of the welding region shown in FIGS. 6 and 7 are examples in which the welding region is configured only by the first region. In the welding region 60A shown in FIG. 6, one annular region is a linear annular region 61A and the other annular region 61C is formed in a sine curve shape, so that a part of the annular region 61A and a part of the annular region 61C are formed. The surrounding portion 64A surrounded by is continuous in the circumferential direction. In this way, even in a welding region that does not include the second region, a case where watertightness is broken by arranging a plurality of surrounding portions 64A so as to be continuous in an annular shape can be detected in two or more defective portions in a certain surrounding portion. It can be limited to the case where it exists, and stable watertightness can be realized.
In the welding region 60B shown in FIG. 6, the two annular regions 61C and 61D are both formed in a sine curve shape, and a plurality of surrounding portions 64B are arranged in an annular shape by overlapping each other while shifting the phase. Even if it does in this way, the same effect as the above-mentioned welding field 60A can be acquired.

  In the welding region 60C shown in FIG. 8, a closed, substantially circular linear region 65 is formed by a plurality of pulse lasers, and is formed continuously in the circumferential direction while overlapping a part thereof, thereby enclosing two types of shapes. The portions 64C and 64D are alternately arranged so that the plurality of surrounding portions are annularly continued. As described above, the shapes of the surrounding portions do not have to be the same, and there may be several types. In any case, the same effect can be obtained by arranging a plurality of surrounding portions so as to be continuous in an annular shape, and the effect increases as the number of surrounding portions to be arranged increases.

  Next, a second embodiment of the present invention will be described with reference to FIG. 9 and FIG. The difference between this embodiment and the first embodiment is the arrangement of the second region in the welding region. In the following description, the same components as those already described are denoted by the same reference numerals and redundant description is omitted.

  FIG. 9 is a diagram showing the shape of the welding region 70 in the present embodiment. The 1st field 61 is constituted by two annular fields 61A and 61B like a 1st embodiment. The second region 72 is formed in a zigzag shape so as to reciprocate between the annular regions 61A and 61B. As a result, the triangular enclosure 74A having a part of the annular region 61A as a base and the triangular enclosure 74B having a part of the annular region 61B as a base are alternately arranged in the circumferential direction of the casing. A welded region 70 is formed side by side.

  In this embodiment, since all the surrounding parts are formed in a triangle, the second region 72 exists between the two annular regions 61A and 61B at any position over the entire circumference of the welding region 70. . For this reason, when a defective part exists only in one surrounding part, even if a defective part exists on all three sides of the surrounding part, the watertightness is not broken, and the surrounding part adjacent to the surrounding part does not break. The possibility that the watertightness is broken only occurs when there is a defective part at the bottom. That is, it is not until there is a defective portion in each of the bottom sides of the surrounding portions 74A and 74B adjacent to each other so that at least a part thereof overlaps in the fitting direction, and all of the second regions shared by the adjacent surrounding portions. Watertightness is broken. For this reason, although the density of the linear region constituting the welding region is not significantly different from that of the first embodiment, the stability of watertightness can be dramatically improved as compared with the welding region of the first embodiment. it can.

  In the above-described embodiment, the example in which the surrounding portion is a right triangle has been described, but the same effect can be obtained even if the surrounding portion is an acute triangle or an obtuse triangle. Further, if the second region always exists between the two annular regions over the entire circumference of the first region, a part of the second region 72A or the like, for example, a welding region 70A of the modification shown in FIG. All may be formed in a curved shape. In this modification, the two annular regions 71A and 71B are also formed in a curved shape, but a part or all of the annular region in the first region may be formed in a curved shape in this way.

  Next, a third embodiment of the present invention will be described with reference to FIGS. The difference between the present embodiment and each of the above-described embodiments is the joining mode between the first member and the second member and the shape of the welding region.

  FIG. 11 is an exploded view of the housing 81 in the present embodiment. The shapes of the first member 82 and the second member 83 are substantially the same as those of the first member 40 and the second member 50, respectively. However, the peripheral wall portions 82A and 83A have no thin portion, and the fitting portion and the mated portion are fitted. There is no section.

  FIG. 12 is a cross-sectional view of the casing 81 in the thickness direction. As shown in FIGS. 11 and 12, the first member 82 and the second member 83 are joined together with an annular joining member 84 disposed therein. The joining member 84 is formed such that a belt-like member made of the same material as that of the first member 82 and the second member 83 is formed in an annular shape having a size and shape that is in contact with the inside of the peripheral wall portions 82A and 83A. The inner wall 82A and the inner wall 83A are disposed so as not to rattle.

  The peripheral wall portions 82A and 83A are abutted on the surface of the joining member 84, and welding by a pulse laser is performed along the abutting line L1 between the first member 82, the second member 83, and the joining member 84. Be joined. Furthermore, in order to ensure watertightness, a linear region having a predetermined shape is formed in the overlapping portion of the peripheral wall portions 82A and 83A and the joining member 84, and a welding region described later is formed. The conditions of the pulse laser at the time of welding are appropriately set depending on the thicknesses of the peripheral wall portions 82A and 83A and the joining member 84, but are generally the same as those in the first embodiment.

  FIG. 13 is an enlarged perspective view showing a welding region 90 in the housing 81. The first region 91 of the welding region has a total of three annular regions, an annular region 91A along the butt line, and annular regions 91B and 91C formed on the peripheral wall portions 82A and 83A so as to sandwich the annular region. ing. The second region 92 has a plurality of linear regions 92A formed so as to intersect with all the annular regions 91A to 91C of the first region 91.

In the casing 81, the watertightness is not broken unless there is a defective portion in the annular region 91A. When a defective portion exists in the annular region 91A, the liquid or the like that has entered from the defective portion may go to both the first member 82 side and the second member 83 side and enter the internal space. Since the intrusion is inhibited by the annular regions 91B and 91C, the watertightness is not easily broken. Furthermore, because the second region 92 forms the welded region 90 side by side on both sides of the annular region 91A so that a plurality of surrounding portions 95 are continuous over the circumferential direction of the peripheral wall portion, the annular region 91A, Even when defective portions exist in the annular region 91B or 91C, the watertightness is not broken unless the defective portions are present in the same surrounding portion.
Therefore, as in each of the above-described embodiments, even when welding is performed using a pulse laser, when there is only one defective portion, the water tightness is surely secured, and the possibility of the water tightness being broken is significantly reduced, so that stable water tightness is achieved. Can be realized.

  In the present embodiment, an example in which one of the annular regions of the first region is formed along the butt line L1 has been described. Instead, two annular regions are provided on both sides of the butt line L1. It may be formed. Even in this case, by combining with the second region 92, a plurality of surrounding portions 95 can be formed into a welding region formed so as to be continuously arranged in a ring shape in the circumferential direction.

  The embodiments of the present invention have been described above. However, the technical scope of the present invention is not limited to the above-described embodiments, and the combinations of the components or the components may be changed without departing from the spirit of the present invention. It is possible to make various changes to or delete them.

For example, in each of the above-described embodiments, the example in which the first region and the second region, or each annular region of the first region is formed separately, may be formed at a time.
The welding region 70A of the modified example shown in FIG. 10 described above includes two annular regions 71A and 71B constituting the first region, and a second region 72A formed between the annular regions 71A and 71B. . This welding region 70A can be formed in one step by irradiating a pulse laser so as to draw a plurality of substantially circular shapes while gradually shifting in the circumferential direction. Therefore, a welding area can be formed more efficiently.

  Further, in each of the above-described embodiments, the example in which the welding region is formed in the circumferential direction of the casing has been described, but the welding method of the present invention is not limited to this. For example, even if the welded region is formed so that the encircling part continues in an annular shape on a certain plane, the watertightness of the part surrounded by the welded region can be more reliably maintained.

  In addition, the housing structure of the present invention is not limited to the above-described defibrillator, but can be suitably applied to other medical devices implanted in a living body such as a pacemaker.

DESCRIPTION OF SYMBOLS 1 Defibrillator 10 Defibrillator 11, 81 Case 40, 82 1st member 50, 83 2nd member 42, 52, 82A, 83A Peripheral wall part 60, 60A, 60B, 70, 70A, 90 Welding area 61 91 First region 61A, 61B, 61C, 61D, 71A, 71B, 91A, 91B, 91C Annular region 62, 72, 72A, 92 Second region 63, 65, 92A Linear region 64, 64A, 64B, 74A, 74B, 95 Box

Claims (7)

A welding method for forming a welded region consisting of a linear region formed by irradiating a pulse wave laser beam a plurality of times in an overlapping portion of a first member and a second member,
The welding method, wherein the welding region is formed by arranging a plurality of surrounding portions surrounded by the linear region so as to be continuous in an annular shape.   The weld region includes a first region composed of two annular regions formed in an annular shape and a plurality of second regions formed so as to intersect the annular region. The welding method described.   The welding method according to claim 2, wherein the second region is formed so as to be positioned between the two annular regions over the entire circumference of the annular shape of the first region. The first member and the second member having a peripheral wall portion are welded so as to face each other so as to form an internal space, and a medical device including a housing formed by joining the peripheral wall portions,
The welding region that joins the peripheral wall portions is formed such that a plurality of surrounding portions surrounded by a linear region formed by irradiating the pulse wave laser beam a plurality of times are arranged side by side over the entire circumference of the peripheral wall portion. Medical device characterized by that.   The first member and the second member are welded in a state in which a part of the peripheral wall portion of the first member is fitted to the peripheral wall portion of the second member. Medical equipment.   5. The welding region according to claim 4, wherein the welding region includes a first region composed of two annular regions formed in an annular shape and a plurality of second regions formed so as to intersect the annular region. 5. A medical device according to 5.   The medical device according to claim 6, wherein the second region is formed between the two annular regions over the entire circumference of the annular shape of the first region.

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