The disclosure relates to methods of welding for components of medical devices, particularly thermally welding polymeric medical device components.
Laser welding may be used to produce welds for items such as medical devices and related components. In some examples, laser welding may provide hermetic seals for medical devices enclosures and associated components for the medical devices.
The disclosure is directed to systems and techniques for thermally welding of a first polymeric member with a second polymeric member at a joint region using a compression sleeve to provide a smooth, e.g., tapered, joint and a strong, hermetic bond between the first and second polymeric members. The thermally welding is controlled to selectively heat the joint region between the first polymeric member and the second polymeric member.
In one aspect, the disclosure is directed to a system for forming a medical device. The system includes a first tubular member comprising a first polymer and a second tubular member comprising a second polymer. The first tubular member defines a lumen configured to receive at least a portion of the second tubular member therein to define a joint region. The system further includes a tubular compression sleeve configured to receive at least a portion of the first tubular member at the joint region and an energy source comprising a fiber laser configured to deliver energy to the joint region to thermally weld the first tubular member to the second tubular member. In some examples, the energy includes a wavelength of radiation transmittable through the compression sleeve and the first tubular member, and absorbable by the first tubular member and the second tubular member.
In another aspect, the disclosure is directed to a method of forming a medical device. The method includes preparing a joint region by introducing at least a portion of a second tubular member into a lumen of a first tubular member. The first tubular member comprising a first polymer and the second tubular member comprising a second polymer. The method includes positioning a tubular compression sleeve over at least a portion of the first tubular member at the joint region. The method further includes directing, by a fiber laser, an energy beam to the joint region to thermally weld the first tubular member to the second tubular member and removing the compression sleeve from the joint region after welding. In some examples, the energy beam comprises a wavelength of radiation transmittable through the tubular compression sleeve and the first tubular member, and absorbable by the first tubular member and the second tubular member.
In another aspect, the disclosure is directed to a method of thermal welding that includes preparing a joint region by positioning at least a portion of a first member adjacent to at least a portion of a second member to define a joint region. The first member includes a first polymer and the second member includes a second, different polymer. The method also includes positioning a compression sleeve over at least a portion of the joint region. The method also includes directing, by a fiber laser, an energy beam to the joint region to thermally weld the first member to the second member. The energy beam includes a wavelength of radiation. The wavelength of radiation is transmittable through the compression sleeve and the first member. The wavelength of radiation also is absorbable by the first member and the second member. The method also includes removing the compression sleeve from the joint region.
The details of one or more examples of the disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.
The disclosure is directed to systems and technique for welding of a first polymeric member to a second polymeric member at a joint region using a compression sleeve to providing a smooth joint region and a strong, hermetic bond between the two tubular members, e.g., to couple the first member and the second member via fiber laser welding. The disclosure also describes methods for forming medical devices. The described systems and technique may, during a welding process, reduce expansion and distortion of the neck of a medical balloon with high equator to neck ratio welded to a catheter body.
System 10 may be used to weld first tubular member 18 to second tubular member 20 at a joint region 24. In particular, system 10 may be used to form a smooth joint region 24 to couple first tubular member 18 and second tubular member 20.
In some examples, first tubular member 18 is a component of a medical device 50. For example, first tubular member 18 may be a medical balloon of medical device 50, such as a medical balloon with a high equator-to-neck ratio. In another example, the first tubular member 18 may be medical tubing, or a portion thereof, used to transport a fluid in a medical procedure or a medical device. Suitable fluid-transporting medical tubing can include, for example, a catheter or an extension tube or connector that overlies at least a portion of the catheter. In another example, the first tubular member may be a medical device component with an opening such as an orifice, a slot, or a luer configured to accept medical tubing.
In some examples, first tubular member 18 may include a first polymer, such as an elastic polymer that expands under pressure. Examples of the first polymer include, but not limited to, polyethylene, polyethylene terephthalate (PET), polyamide, polyether block amide elastomer, polyether ester elastomer, polytetrafluorethylene (PTFE), polyurethane, polyester, silicone, polyvinyl chloride, polypropylene, polyurethanes, polyamides, latex, natural rubber, synthetic rubber, or the like. In some examples, the first polymer may be selected to substantially transmit radiation having a selected range of wavelengths. For example, the first polymer may be selected to substantially transmit radiation having a wavelength within a range from about 800 nanometers (nm) to about 3000 nm, such as within a range from about 1500 nm to about 2200 nm. Substantially transmit may include transmission of about 30% to about 70% of incident radiation, such as 60% of incident radiation or 70% of incident radiation.
In some examples, second tubular member 20 is a component of a medical device. For example, second tubular member 20 may be medical tubing such as a catheter body, an extension tube or connector overlying at least a portion of the catheter body, a rigid hub, or a luer of the medical device. In some examples, second tubular member 20 may include a second polymer, which may be the same material as, or a different material from, first tubular member 18.
Examples of the second polymer include, but are not limited to, polyethylene, polyethylene terephthalate (PET), polyamide, polyether block amide elastomer, polyether ester elastomer, polytetrafluorethylene (PTFE), polyurethane, polyester, silicone, polyvinyl chloride, polypropylene, polyurethanes, polyamides, latex, natural rubber, synthetic rubber, or the like. In some examples, the second polymer may be selected to substantially absorb radiation having a selected range of wavelengths. For example, the second polymer may be selected to substantially absorb radiation having a wavelength within a range from about 800 nanometers (nm) to about 3000 nm, such as within a range from about 1500 nm to about 2200 nm. Substantially absorb may include absorption of about 30% to about 70% of incident radiation, such as 60% of incident radiation or 70% of incident radiation. Absorptivity of second tubular member 20 may be adjusted by the incorporation of different additives, such as carbon black, indium tin oxide, or other materials selected to absorb a selected wavelength of radiation.
Compression sleeve 22 is configured to, during a welding process, compress at least a portion of first tubular member 18 against at least a portion of second tubular member 20. By compressing at least a portion of first tubular member 18, compression sleeve 22 may aid in connecting of first tubular member 18 with second tubular member 20. In some examples, compression sleeve 22 may be configured to compress the parts to be welded to constrain first tubular member 18 and second tubular member 20 in a substantially fixed position. In some examples, compression sleeve 22 may include a heat-shrinkable sleeve. In other examples, compression sleeve 22 may include a non-shrinkable tube with a tight fit to joint region 24.
In some examples, compression sleeve 22 may be heated to the desired pre-shrunk dimension using a fixture. The diameter of the fixture may be selected based on the diameter of second tubular member 20 such that compression sleeve 22 may be shrink down to about the diameter of second tubular member 20. After shrinking compression sleeve 22, compression sleeve 22 may be fitted to second tubular member 20 to connect second tubular member 20 to first tubular member 18. Pre-shrinking compression sleeve 22 protects first tubular member 18 and/or second tubular member 20 from the heat, and thereby potential distortion of first tubular member 18 and/or second tubular member 20, during heat shrinking of compression sleeve 22.
In some examples, compression sleeve 22 may be directly apply to second tubular member 20 and may be configured to, when heated to a selected temperature, shrink around the parts to be welded to constrain first tubular member 18 and second tubular member 20 in a substantially fixed position as a bonding aid.
In some examples, compression sleeve 22 is removable after the welding process. For example, compression sleeve 22 may be removed by any suitable means, such as, for example, cutting, peeling, laser etching, or other material removal techniques. In some examples, compression sleeve 40 may include other compression sleeves or compression devices, such as a cold-shrink sleeve, a compression wrap, or a clamp.
Compression sleeve 22 may include any suitable polymer. For example, compression sleeve 22 may include fluorinated ethylene propylene (FEP), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), polyethylene terephthalate (PET), polyolefin, polyether block amide, silicone or other suitable material.
While not wishing to be bound by any theory, presently available evidence indicates that FEP materials with lower shrink temperatures are preferred to reduce or eliminate deformation of the first and the second tubular members during the welding process. In one example, suitable polymers for the compression sleeve 22 include FEP materials available from Optinova, Mariehamn, Finland, that have a shrink temperature of less than about 100° C., or less than about 90° C., or less than about 85° C.
In some examples, compression sleeve 22 may have a thickness within a range from about 0.02 inches to about 0.05 inches, such as within a range from about 0.02 inches to about 0.03 inches.
As shown in
In some examples, the materials of the first tubular member 18, the second tubular member 20, or both, may be sufficiently dimensionally stable that the compression sleeve 22 is not needed to maintain the relative positions of the tubular members during the bonding process. For example, if the second tubular member 20 fits tightly in the lumen of the first tubular member such that there is minimal (or no) relative movement between the first tubular member 18 and the second tubular member 20 during a bonding procedure, the compression sleeve 22 may not be required over the first tubular member 18 to form a bond. In another example, if the polymeric material from which the first tubular member 18 is formed is sufficiently rigid, the compression member 22 may not apply sufficient compressive force against the first tubular member to cause deformation of the first tubular member, and the compression member 22 may not be required during a bonding procedure.
System 10 includes energy source 12, which emits energy beam 16. Energy source 12 may include, for example, a laser source. In some examples, energy source 12 may include a fiber laser such as a thulium fiber laser. Energy beam 16 may provide energy to thermally weld first tubular member 18 to second tubular member 20 of the medical device at a joint region 24.
System 10 may include at least one optical component that directs and/or focuses energy beam 16 to joint region 24. For example, the system 10 may include lens 14, which is positioned to directed energy beam 16 to joint region 24. In some examples, system 10 may include other optical components (e.g., lenses, collimators, or the like) and/or a fiber-optic beam delivery (FOBD) system. A FOBD system uses an optical cable to deliver energy beam 16 to joint region 24, enabling energy source 12 to be located remotely from first tubular member 18 and second tubular member 20 of the medical device during welding, if desired. FOBD systems may be configured to permit the output of one laser source to supply the laser energy to be used for several welding processes located in different locations.
System 10 may be configured to operate in a direct welding mode or a transmission welding mode to thermally weld first tubular member 18 to second tubular member 20 of the medical device.
In some examples, system 10 may be configured to operate in a transmission welding mode to thermally weld first tubular member 18 to second tubular member 20 of the medical device. When operating in the transmission welding mode, energy source 12 may be configured to generate energy beam 16 with a selected wavelength of radiation transmittable through compression sleeve 22 and first tubular member 18, and absorbable by first tubular member 18 and second tubular member 20. In this way, energy beam 16 with the selected wavelength may be directed to joint region 24, e.g., interface 26 between first tubular member 18 and second tubular member 20. By directing energy beam 16 to interface 26, system 10 may be configured to weld both relatively thicker first tubular member 18 and/or relatively thicker second tubular member 20 compared to other thermal welding techniques, such as, for example, direct welding techniques or welding techniques using carbon dioxide lasers. Absorption of energy beam 16 at interface 26 heats portions of first tubular member 18 and/or second tubular member 20 to a softened state or molten state. Upon cooling, the softened or the molten portions of first tubular member 18 and/or second tubular member 20 solidify. The resulting joint region 24 provides mechanical coupling between first tubular member 18 and second tubular member 20.
In accordance with aspects of this disclosure, energy source 12 may be configured to generate an energy beam 16 with a wavelength within a selected range to thermally weld both relatively thick parts and relatively thin parts of first tubular member 18 and second tubular member 20 together. In examples in which energy source 12 includes a fiber laser, the wavelength of energy beam 16 is within a range from about 1500 nm to about 2200 nm. In some examples, which are not intended to be limiting, the thulium fiber laser has an output wavelength of about 1940 nm to provide optimal heating with an FEP compression member 22.
In some examples, energy beam 16 may be directed through lens 14. Lens 14 may include any suitable type of lens, such as, for example, a collimating lens, a plano-convex lens, an aspheric lens, a cylinder lens, a laser generator lens, or the like. Lens 14 may be configured to direct energy beam 16 toward joint region 24 to weld first tubular member 18 and second tubular member 20 together. In some examples, lens 14 may be configured to focus energy beam 16 at or near interface 26, e.g., within tolerances of laser optics and/or thermal welding techniques. In some examples, as needed to form bonds between various tubular members 18, 20 with different thicknesses, shapes, beam absorption, and the like, the optical components may be used to shape the beam profile of the energy beam 16 to provide more concentrated heating in a small area, or less concentrated heating over a larger area.
Although direct welding may be used to weld first tubular member 18 to second tubular member 20, direct welding may result in a relatively thin weld joint at joint region 24, which may result in a relatively weak bond when welding relatively thick members. For instance, welding a relatively thick first tubular member 18 to a relatively thick second tubular member 20 may result in joint region 24 having a thickness less than first tubular member 18 and second tubular member 20. Additionally, direct welding requires a protective layer to be disposed over first tubular member 18 to protect first tubular member 18 and second tubular member 20.
The techniques of this disclosure may improve the welding process of medical devices. According to aspects of this disclosure, system 10 may be operated in transmission welding mode to weld first tubular member 18 and second tubular member 20 having both thick and thin parts, such as welding a catheter body with a medical balloon with high equator-to-neck ratio. Using transmission welding, system 10 may weld first tubular member 18 with second tubular member 20 while providing a smooth joint region 24 and a strong, hermetic joint between the two tubular members, e.g., to couple the first member and the second member via transmission welding. Additionally, transmission welding may eliminate the need to use a protective layer.
Catheter 38 includes catheter body 40. Catheter body 40 extends from a proximal end 40A to the distal end 40B and defines a lumen 42. In some examples, catheter body 40 includes a tubular body. Catheter body 40 has a suitable length for accessing a target tissue site within the patient from a vascular access point. The length may be measured along a central longitudinal axis of catheter body 40. In some examples, catheter body 40 has a length within a range from about 80 cm to about 150 cm.
Catheter body 40 can be relatively thin-walled, such that it defines a relatively large inner diameter for a given outer diameter. For example, in some examples, an outer diameter of catheter body 40 may be about 3 French. The measurement term French, abbreviated Fr or F, is three times the diameter of a device as measured in mm. Thus, a 6 French diameter is about 2 millimeters (mm), a 5 French diameter is about 1.67 mm, a 4 French diameter is about 1.33 mm, and a 3 French diameter is about 1 mm. The term “about” as used herein with dimensions may refer to the exact value of the such as when used to describe numerical values, “about” or “approximately” refers to a range within the numerical value resulting from manufacturing tolerances and/or within 1%, 5%, or 10% of the numerical value. For example, a length of about 10 mm refers to a length of 10 mm to the extent permitted by manufacturing tolerances, or a length of 10 mm +/−0.1 mm, +/−0.5 mm, or +/−1 mm in various examples.
Balloon 36 can be configured (e.g., sized and shaped) for any suitable medical procedure. In some examples, balloon 36 may include a high equator-to-neck ratio balloon. For example, balloon 36 can be configured to be inflated to facilitate a pulmonary vein isolation for treating atrial fibrillation. Balloon 36 can have any suitable length. In some examples, balloon 36 has a length of about 10 mm to about 300 mm.
Balloon 36 can be relatively thin-walled, such that it defines a relatively large inner diameter for a given outer diameter. In some examples, the thickness of a wall 44 of balloon 36 may be substantially constant from a proximal end 46A to a distal end 46B. For example, lumen 48 may have a thickness of about 0.00762 mm to about 0.254 mm. In other examples, the thickness of wall 44 may taper from a first thickness at a proximal portion that includes proximal end 46A to a second thickness at a distal portion that includes distal end 46B, the second thickness being smaller than the first thickness. (as shown in
A lumen 48 of balloon 36 may receive distal end 40B of catheter body 40. The overlapped region of balloon 36 and catheter 38 forms a joint region 50, which is configured to receive an energy beam to thermally weld balloon 36 to catheter 38.
A compression sleeve 52 may be disposed over catheter body 40 at joint region 50 to constrain balloon 36 and catheter 38 in a substantially fixed position before welding and may be removed after welding. In some examples, compression sleeve 52 may include a tubular heat-shrinkable sleeve, such as a heat-shrinkable tube. In some examples, compression sleeve 52 may include a non-tubular heat-shrinkable sleeve, such as a heat-shrinkable wrap.
After welding, balloon 36 is connected to catheter 38. Balloon 36 is configured to expand from a collapsed configuration to an expanded configuration via an inflation fluid delivered to balloon 36 via lumen 42 of catheter body 40. Balloon 36 may be inflated to any suitable pressure via an inflation fluid (e.g., saline) delivered to the balloon.
Balloon 36 is a balloon with high equator to neck ratio. As illustrated in
Compression sleeve 70 may define a lumen sized to receive at least a portion of first tubular member 58 (e.g., distal end 58B of first tubular member 58) at joint region 54. As illustrated in
In some examples, compression of first tubular member 58 and second tubular member 62 at joint region 54 may hold first tubular member 58 and second tubular member 62 together during thermal welding. For example, compression of first tubular member 58 and second tubular member 62 at joint region 54 may cause a radially inner surface 72 of compression sleeve 70 compresses against a radially outer surface 74 of first tubular member 58, which causes pressure between inner surface 72 of compression sleeve 70 and outer surface 74 of first tubular member 58. Additionally, or alternative, a radially inner surface 76 of first tubular member 58 may compress against a radially outer surface 78 of second tubular member 62, to cause pressure between inner surface 76 of first tubular member 58 and outer surface 78 of second tubular member 62. The pressure between inner surface 72 of compression sleeve 70 and outer surface 74 of first tubular member 58 and/or the pressure between inner surface 76 of first tubular member 58 and outer surface 78 of second tubular member 62 may constrain first tubular member 58 and second tubular member 62 in a substantially fixed position.
During thermal welding, one or more energy beams may be directed and/or focused at joint region 54, e.g., outer surface 78 of second tubular member 62. Compression sleeve 70 is configured to compress first tubular member 58 and/or second tubular member 62 to form a tapered joint region 54. Additionally, or alternatively, compression sleeve 70 may constrain first tubular member 58 and second tubular member 62 maintain axial alignment and/or concentric alignment, e.g., relative to common axis 68, of first tubular member 58 and second tubular member 62.
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In some examples, directing the energy beam may include directing a first energy beam toward joint region 54 and directing a second, different energy beam toward joint region 54. For example, the first energy beam may be directed toward joint region 54 at a first axial position of first tubular member 58 and/or second tubular member 62 having a first thickness, and the second energy beam may be directed toward joint region 54 at a second axial position of first tubular member 58 and/or second tubular member 62 having a second, different thickness. In some examples, directing the energy beam may include directing a plurality of energy beam toward joint region 54, each energy beam of the plurality of energy beams having a selected wavelength of radiation.
The technique illustrated in
In some examples, the systems described herein may be used to thermally weld non-tubular polymeric components, such as polymeric sheets or other rectilinear or irregular shapes that are not tubular in shape. For example,
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Attempts to bond the extension tube 308 to the irrigation tube 304, and the extension tube 308 to the luer 306, with adhesives resulted in formation that weakened the joints between the components and caused fluid leakage.
As shown in
Referring now to
A beam 322 from a thulium fiber laser at a wavelength of 1940 nm was focused at an interface 324 to bond the extension tube 308 and the luer 306.
Testing with an irrigation fluid revealed that the bonds between the irrigation tube 304 and the extension tube 308, and between the extension tube 308 and the luer 306, were liquid-tight under normal operating pressures.
Various examples have been described. These and other examples are within the scope of the following claims.
This application claims the benefit of U.S. Provisional Patent Application No. 63/104,782, filed Oct. 23, 2020, the entire content of which is incorporated herein by reference.
Number | Date | Country | |
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63104782 | Oct 2020 | US |