Thermally robust laser probe assembly

Abstract

To provide a thermally robust laser probe assembly.SOLUTION: Certain embodiments of the present disclosure provide a thermally robust laser probe assembly. The probe assembly comprises a cannula through which one or more optical fibers extend at least partially for transmitting laser light from a laser source to a target location. The probe assembly further comprises a lens housed in the cannula, and a protective component at the distal end of the cannula. The lens is positioned between the protective component and the one or more optical fibers. The distal end of the cannula is sealed at a sealing location of the probe assembly.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] The present disclosure generally relates to methods and systems for manufacturing thermally robust laser probe assemblies.

Background Art

[0002] Laser probe assemblies can be used during many different procedures and surgeries. As an example, laser probe assemblies can be used, among other things, during retinal laser surgery to seal retinal tears. Laser light is typically transmitted from a laser source through an optical fiber cable. The optical fiber cable terminates proximally at a laser connector that is connected to the laser source and distally at a probe assembly that is manipulated by a surgeon. Note that, herein, the distal end of a component refers to the end that is closer to the patient's body or the end from which laser light is emitted from the laser probe. On the other hand, the proximal end of a component refers to the end that is directed away from the patient's body or the end that is near, for example, the laser source.

[0003] The probe assembly includes a handpiece coupled to a cannula that is partially inserted into the patient's eye. The optical fiber cable extends through the handpiece and the cannula and transmits laser light onto the patient's retina. A lens can also be used to collimate and project the laser beam propagated by the optical fiber onto the patient's retina to improve performance. Typically, the lens is disposed in front of the optical fiber and attached to the cannula.

[0004] In certain cases, because the fiber optic cable houses multiple optical fibers, the laser probe assembly can emit multiple photocoagulation beams simultaneously. For example, in certain cases, the fiber optic cable may house four optical fibers or multicore optical fibers. In such cases, high power throughput in a limited space (e.g., inside a cannula) can cause the cannula and lens to experience excessive heat if blood or other dark material is present in front of the tip of the cannula or lens, or at least partially blocked or in contact with the tip. In certain cases, the laser beam propagated by the optical fiber is reflected back by blood or dark material on the lens, on the cannula, and on the adhesive between the lens and the cannula, generating excessive heat. This overheating and thermal runaway can cause the cannula and lens to melt, and the lens to separate from the cannula. [Overview of the project] [Means for solving the problem]

[0005] This disclosure relates, in general terms, to methods and systems for manufacturing thermally robust laser probe assemblies.

[0006] A particular embodiment of the present invention provides a probe assembly comprising a cannula through which one or more optical fibers extend at least partially to transmit laser light from a laser source to a target position. The probe assembly further comprises a lens housed in the cannula and a protective component at the distal end of the cannula, wherein the lens is positioned between one or more optical fibers and the protective component, and the distal end of the cannula is sealed at a sealing position of the probe assembly.

[0007] A particular embodiment of the present invention provides a sealant application system comprising a stage machine, which includes a mount configured to hold a sealant applicator including a wire, wherein the stage machine is configured to position the wire at a sealing position at the distal end of a cannula of a probe assembly. The sealant application system also includes a cannula holder having a groove for holding the cannula, and an actuator configured to rotate the cannula when the stage machine positions the wire at the sealing position so that sealant on the wire can be applied to the sealing position.

[0008] A particular embodiment of the present invention provides a method for manufacturing a probe assembly. The method includes positioning a sealant-coated wire at a sealing position at the distal end of the cannula of the probe assembly. The method further includes rotating the cannula to apply the sealant to the sealing position.

[0009] The following description and related drawings illustrate in detail specific exemplary features of one or more embodiments.

[0010] The attached figures illustrate specific aspects of one or more embodiments of the present invention and should not be considered to limit the scope of this disclosure. [Brief explanation of the drawing]

[0011] [Figure 1A] Figure 1A shows a probe assembly including a handpiece and cannula according to a specific embodiment of the present invention. [Figure 1B] Figure 1B shows a cross-sectional view of the tip of the cannula shown in Figure 1A. [Figure 2A] Figure 2A shows a cross-sectional view of a protective component positioned at the tip of a cannula according to a specific embodiment of the present invention. [Figure 2B] Figure 2B shows a three-dimensional view of the protective component shown in Figure 2A. [Figure 2C] Figure 2C shows a front view of the tip of the cannula shown in Figure 2A. [Figure 2D] Figure 2D shows a three-dimensional view of the tip of the cannula shown in Figure 2A. [Figure 3] Figure 3 shows an exemplary gap between the inner surface of the distal end of the cannula and the outer surface of the distal end of the protective component housed by the cannula. [Figure 4A] Figure 4A shows an example of a contaminated protective component. [Figure 4B] Figure 4B shows a cross-sectional view of the sealed distal end of a cannula according to a specific embodiment of the present invention. [Figure 5A] Figure 5A shows a sealant application system according to a specific embodiment of the present invention. [Figure 5B] Figure 5B shows a front view of a cannula holder that holds a cannula in a U-shaped groove, according to a specific embodiment of the present invention. [Figure 6A] Figure 6A shows the stages of a sealant application procedure according to a specific embodiment of the present invention. [Figure 6B] Figure 6B shows the stages of a sealant application procedure according to a specific embodiment of the present invention. [Figure 6C] Figure 6C shows the stages of a sealant application procedure according to a specific embodiment of the present invention. [Figure 6D] Figure 6D shows the stages of a sealant application procedure according to a specific embodiment of the present invention. [Figure 7] Figure 7 shows additional components of the sealant application system shown in Figure 5. [Figure 8] Figure 8 shows a sealant application system according to a specific embodiment of the present invention. [Figure 9] Figure 9 shows a cannula holder with a clamp according to a specific embodiment of the present invention. [Figure 10] Figure 10 shows an exemplary operation for sealing a laser probe according to a particular embodiment of the present invention. [Modes for carrying out the invention]

[0012] For ease of understanding, where possible, the same reference numbers are used to denote identical elements common to the drawings. Elements and features of one embodiment are believed to be advantageously incorporated in other embodiments without further elaboration.

[0013] Aspects of the present disclosure provide methods and systems for manufacturing a thermally robust laser probe assembly.

[0014] As noted above, a probe assembly having a high output throughput may experience overheating such that a lens within the cannula may melt (e.g., if blood contaminates the lens or blocks the laser beam). The melted lens may separate from the cannula and cause malfunction of the probe assembly.

[0015] FIG. 1A shows an example of a probe assembly 100 that includes a handpiece 102 and a cannula 104. A surgeon uses the handpiece 102 to guide the cannula 104 (e.g., a cylindrical hollow tube) to a body part of a patient that may be the patient's eye. As shown, the probe assembly 100 provides a plurality of photocoagulation beams 106 simultaneously to generate a plurality of laser spots. The power of each laser spot may be about 250 to about 500 milliwatts (mW) such that the minimum power passing through the cannula 104 can be about 1 watt (W) by providing a plurality of laser spots. A lens (e.g., lens 100 of FIG. 1B) may be disposed in front of the optical fiber extending through the cannula and projects the laser beam, for example, onto the retinal surface of the patient's eye.

[0016] Figure 1B shows a cross-sectional view of the tip of the cannula 104, where the lens 110 is positioned to collimate and project a beam 106 propagated by multiple optical fibers 108 extending through the cannula 104. In certain embodiments of the present invention, the optical fibers 108 may be optical fiber arrays or multicore optical fibers. When the cannula 104 is placed on a patient's body part through a trocar cannula or the like, the beam 106 may be reflected back into the cannula 104 if blood or other dark material is present in front of the tip of the cannula 104 or partially blocks or contacts the lens 110. The reflection of the laser beam back into the cannula 104 is added to the amount of heat already generated within the cannula 104. This overheating may melt the cannula 104 and the lens 110, and may also separate the lens 110 from the cannula 104.

[0017] In certain embodiments of the present invention, to protect the lens 110, a protective component is attached to and / or inserted into the distal end of the cannula of the probe assembly. The protective component (e.g., a protective window) is positioned in front of the distal end of the lens, which itself is positioned in front of one or more optical fibers. The protective component protects the lens by restricting the movement of the lens along the cannula and / or by preventing the lens from separating from the cannula.

[0018] Figure 2A shows a cross-sectional view of an exemplary protective component 212 positioned at the tip of the cannula 104. As shown, the protective component 212 is positioned at the distal end 205 of the cannula 104, while the proximal end 207 of the cannula 104 is connected to a handpiece (e.g., the handpiece 102 shown in Figure 1A). As described above, the distal end 205 of the cannula 104 is the end that is inserted into a part of the patient's body or is configured to emit laser light from the probe assembly 100. In certain embodiments, the cannula 104 includes materials such as stainless steel, nitinol (NiTi), or platinum-iridium alloy (Pt-Ir).

[0019] The protective component 212 includes a proximal end 215 and a distal end 213. In certain embodiments, the protective component 212 includes an optically clear or transparent material. Examples of suitable transparent materials include sapphire, fused silica, or other glass or ceramic materials having a high transition temperature.

[0020] In certain embodiments, the protective component 212 is attached to the cannula 104 by press-fitting the component 212 into the cannula 104. Press-fitting, also known as interference fitting or friction fitting, is a technique for securing the protective component 212 to the cannula 104, and the securing is achieved by friction between the protective component 212 and the cannula 104 after the protective component 212 has been pushed into the cannula 104. In certain embodiments, the protective component 212 may be attached to the cannula 104 using a brazing technique.

[0021] Figure 2B shows a three-dimensional view of the protective component 212. In certain embodiments, the protective component 212 is a cylindrical component positioned within the cylindrical opening at the distal end of the cannula 104. The protective component 212 shown in Figures 2A and 2B is a cylindrical component with a flat end, but in certain embodiments, the protective component 212 may have a different shape. For example, in certain embodiments, the proximal end of the protective component 212 may be spherical or non-spherical.

[0022] Figure 2C shows a front view of the tip of the cannula 104 that houses the protective component 212.

[0023] Figure 2D shows a three-dimensional view of the tip of the cannula 104. As shown, the protective component 212 partially extends outside the cannula 104.

[0024] In certain cases, the dimensional tolerances of the protective component 212 and the cannula 104 do not match. Dimensional tolerances are assigned to parts such as the protective component 212 and the cannula 104 as acceptable build boundaries for manufacturing purposes. In situations where the tolerances of the protective component 212 and the cannula 104 do not match, the inner diameter of the cannula 104 may be larger than the outer diameter of the protective component 212 in certain areas, resulting in a gap. Also, in some situations, the protective component 212 and the cannula 104 may have different degrees of surface roughness. Such incompatibility and differences in dimensional tolerances and surface roughness can make the probe prone to leakage. For example, fluids such as equilibrium salt solution (BSS), perfluorooctane (PFO), or blood may leak into the cannula and reach the interior between the lens and fiber (e.g., lens 210 and fiber 108 in Figure 2A), causing malfunction of the lens 210 and therefore the probe assembly 100. For example, fluid leaking into cannula 104 may come into contact with an anti-reflective coated surface, which could result in reduced laser beam transmittance, overheating of the probe tip, and thermal runaway.

[0025] Figure 3 shows an exemplary front view of a cannula 104 housing a protective component 212 according to a particular embodiment of the present invention. In the example of Figure 3, the inner diameter 330 of the cannula 104 is larger than the outer diameter 332 of the protective component 212, resulting in a gap 334. As mentioned above, this gap may result from incompatibility and differences in dimensional tolerances and surface roughness between the protective component 212 and the cannula 104. It should be noted that the size and shape of the gap 334 are exemplary and exaggerated for illustrative purposes. In actual applications, the gap 334 may be much smaller, for example, a micrometer. However, even a very small gap can make the probe assembly 110 prone to leakage.

[0026] Accordingly, the specific embodiments described herein relate to sealant application techniques for sealing an internal opening or gap between the inner diameter of the distal end of a cannula and the outer diameter of a protective component attached to the distal end of the cannula.

[0027] Because the protective components and cannula tips are miniature in size, accurately applying very small amounts of sealant (e.g., adhesive) to the cannula and protective components can be difficult at the sealing locations described below. Without well-controlled sealant application techniques, the protective components may become contaminated with sealant, potentially blocking the laser beam and causing the probe assembly to malfunction. Additionally, excessive sealant may be applied to the outer surface of the distal end of the cannula, resulting in an enlargement of the outer diameter of the distal end of the cannula, which makes it difficult for the surgeon to insert the probe assembly cannula into or remove it from a trocar cannula that has been inserted into a part of the patient's body.

[0028] Figure 4A shows an example of sealant 402 that has contaminated the protective component 212 and has overflowed onto the outer surface of the distal end of the cannula 104. The sealant application technique described herein overcomes the challenge of sealing the probe by applying a small amount of sealant without contaminating the protective component 212 or overflowing onto the outer surface of the cannula 104.

[0029] Figure 4B shows an exemplary cross-sectional view of the distal end of cannula 104 sealed using the sealant application technique described herein. As shown, the sealant 406 is applied only to sealing locations 430 that point to any opening or gap (e.g., gap 334 in Figure 3) between the inner surface of the distal end of cannula 104 and the outer surface of the distal end of protective component 212. Therefore, as shown, the sealant 406 does not contaminate the protective component 212 or apply to the outer surface of the distal end of cannula 104. In certain embodiments of the present invention, the sealant is a double-curing sealant. The sealant may also have a viscosity in the range of about 500 to about 5000 centipoise (cP).

[0030] Figure 5A shows an exemplary sealant application system 500 for sealing the distal end of a cannula 104 using the sealant application technique described herein. As shown, the system 500 includes a cannula holder 520 having a U-shaped groove (e.g., groove 540 in Figure 5B) on which the cannula 104 can be positioned and rotated along a rotation axis (e.g., rotation axis 505 in Figure 5B) parallel to the cannula 104 itself. Figure 5B shows a front view of the cannula holder 520 holding the cannula 104 in the U-shaped groove 540. As shown, the U-shaped groove 540 is configured such that a portion of the cannula 104 remains above the stopping surface of the cannula holder 520. Figure 5B also shows a rotation axis 505 on which the cannula 104 and protective components 212 are configured to rotate relative to the cannula holder 520.

[0031] Referring again to Figure 5A, the system 500 also includes an XYZ stage machine (not shown) on which a sealant applicator 530 can be mounted. The XYZ stage machine can provide movement along the X, Y, and Z planes, as shown. As shown, the sealant applicator 530 includes a handpiece 534 having a rigid tube 535 and a wire 532 extending out of the rigid tube 535. The user uses the handpiece 534 to dip the wire 532 into the sealant to be used during the sealing process. The user then positions the sealant applicator 530 on the XYZ stage machine and adjusts the position of the sealant applicator 530. In certain embodiments, the wire 532 is a very thin wire having a diameter in the range of about 20 to about 40 microns (μm). For example, the wire 532 may have a diameter of about 40 μm. The very small diameter of the wire 532 ensures that when the wire 532 is immersed in the sealant, only a very small and controlled amount of sealant is picked up by the wire 532. In addition, in certain embodiments, the wire 532 is advantageous because it may be flexible and bend in response to being pushed up or down against the protective component 212 when the wire is positioned at the sealing location (e.g., sealing location 430 in Figure 4B). The flexible wire 532 can also facilitate uniform and smooth application of the sealant to the sealing location. As an example, the wire 532 may be made of nitinol.

[0032] By using an XYZ stage machine, the wire 532 can be precisely positioned at the sealing location so that the sealant contacts both the protective component 212 and the cannula 104 at the sealing location. Once the wire 532 is positioned at the sealing location, the cannula 104 can be rotated so that the sealant is evenly distributed and applied around the entire surface of the protective component 212 at the sealing location.

[0033] Simultaneously, as shown in Figure 6C, the sealant applicator 530 can also be moved to ensure that sufficient sealant is applied to the sealing location (for example, to apply additional sealant on other areas of the wire 532 to the sealing location). By using a thin wire 532, it is ensured that the sealant is applied only to the sealing location and not to any additional areas of the surface of the protective component. In other words, by using a thin wire 532, more precise application of the sealant is possible. Exemplary stages of a sealant application procedure according to a particular embodiment of the present invention are shown in Figures 6A to 6D.

[0034] Figure 6A shows a cannula 104 containing the wire 532 and protective component 212 immersed in sealant. As described above, the wire 532 can be precisely positioned at the sealing position 430 using an XYZ stage machine.

[0035] Figure 6B shows the tip of the wire 532 positioned at the sealing position 430. Although not shown, once the wire 532 is positioned at the sealing position 430, the cannula 104 can be rotated (for example, along the rotation axis 505 in Figure 5), thereby allowing the sealant to be applied uniformly around the entire circumference of the protective component 212 at the sealing position 430. However, after a certain number of rotations, there may not be enough sealant remaining on the tip of the wire 532. As a result, the wire 532 may be moved horizontally forward so that the sealant on the underside of the wire 532 can be used for sealing, as shown in Figure 6C.

[0036] Figure 6C shows wire 532 being pushed forward horizontally (for example, by an XYZ stage machine (not shown)) to apply sealant to the lower part of wire 532 at the sealing position 430. In another example, if the sealant on the lower part of wire 532 is used first, wire 532 may be pulled backward to use the sealant on the upper part of wire 532.

[0037] Figure 6D shows an exemplary sealing location 430 that has been completely sealed using the sealant application technique described above.

[0038] Figure 7 shows additional components of the sealant application system 500 described in relation to Figures 5A and 5B. For example, Figure 7 shows an XYZ stage mount 740 on which a sealant applicator 530 is mounted. The XYZ stage 740 mount can be coupled to an XYZ stage machine (not shown) that can move the XYZ stage mount 740 along the X, Y, and Z planes. As shown, using this mechanism, the wire 532 can be precisely positioned at a sealing position (e.g., sealing position 430 in Figure 4B) and adjusted (e.g., pushed forward or backward) during the sealant application process. Figure 7 also provides a front view of the stage 750 coupled to an actuator (not shown) for rotating a cannula 104 positioned in a U-shaped groove (e.g., groove 540 in Figure 5B) of a cannula holder 520. In certain embodiments, the actuator is operated by a user who can turn the actuator on and off. When the actuator is turned on, it rotates the cannula 104 around a rotation axis parallel to the cannula 104 (for example, rotation axis 505 in Figure 5B).

[0039] In certain embodiments, the duration and speed at which the cannula 104 rotates are user-controllable and adjustable parameters. In certain other embodiments, the actuator is controlled and operated by a control module. In such embodiments, the control module operates the actuator at a specific speed for a specific number of rotations (or, for example, a specific amount of time). The control module may also be configured to terminate the operation of the actuator after a user-defined number of rotations has been performed.

[0040] In certain embodiments, a clamp may be used to further secure the cannula 104 and prevent any undesirable movement during the sealant application process. The use of a clamp is particularly advantageous when the cannula 104 is not straight. For example, in some cases, the distal end of the cannula is curved, as shown in Figure 1A. In such cases, the curved cannula, which may be made of an elastic material such as nitinol, can be temporarily straightened and placed in the U-shaped groove of the cannula holder. The cannula can then be clamped to prevent the tip of the cannula from wobbling when the tip of the cannula rotates during the sealant application procedure.

[0041] Figure 8 shows an exemplary sealant application system 800 for sealing a cannula having a curved tip. However, it should be noted that system 800 can also be used to seal a straight cannula in the same way. The sealant application system 800 includes a fixed housing 840 and a rotary stage 850 which includes a rotatable wheel 830 coupled to a cannula holder 820. The rotatable wheel 830 is configured to rotate the cannula holder 820 together with the cannula 104 (e.g., a curved cannula) which is clamped by a clamp 860. In other words, unlike Figure 7 in which only the cannula 104 rotates during the sealant application procedure, in the embodiment shown in Figure 8, the cannula 104, together with the cannula holder 820 and the rotatable wheel 830, all rotate together around an axis of rotation parallel to the cannula 104 (e.g., parallel to the X-axis as shown). In certain embodiments, the rotatable wheel 830 may be coupled to an actuator configured to rotate the rotatable wheel 830.

[0042] As shown in Figure 8, the cannula holder 820 has an opening 870 that provides some handroom, thereby allowing the user to manipulate the cannula 104 and adjust its position, etc. In Figure 8, the cannula holder 820 is shown to be connected to the clamp 860 by screws 862a and 862b. However, in other embodiments, the clamp 860 may be connected to the cannula holder 820 using elements other than screws.

[0043] Figure 9 shows another view of the cannula holder 820 coupled to a clamp 860 for clamping the cannula 104. The clamp 860 can secure the cannula 104 by applying pressure to the top of the cannula 104. In certain embodiments, the clamp 860 is made of a flexible material so that the clamped cannula 104 does not damage the cannula 104. Note that, as described above, if the cannula 104 is curved, the tip of the distal end of the cannula 104 (e.g., shown as tip 980) may be removed from the U-shaped groove to prevent the cannula 104 from wobbling during rotation.

[0044] Figure 10 shows a flowchart 1000 representing steps in a method for sealing a laser probe according to a particular embodiment of the present invention. In some embodiments, the steps of flowchart 1000 are performed using a sealant application system (e.g., sealant application system 500). In certain embodiments, a user participates in the execution of steps 1002-1012, while in other embodiments, the sealant application system 500 may be configured to automatically perform at least some of steps 1002-1012.

[0045] In step 1002, the cannula of the probe assembly (e.g., cannula 104) is placed in the U-shaped groove of the cannula holder by the user or other means. As described with reference to Figure 2A, the protective component is located at the distal end of the cannula. At its proximal end, the cannula is coupled to an actuator for rotating the cannula.

[0046] In step 1004, the wire of the sealant applicator is immersed in the sealant.

[0047] In step 1006, the sealant applicator is positioned on the XYZ stage mount of the XYZ stage machine.

[0048] In step 1008, the position of the sealant dispenser is adjusted so that the wire of the sealant dispenser is positioned at the sealing position of the laser probe. By positioning the wire at the sealing position, the sealant on the wire is applied to at least the area of ​​the sealing position (e.g., sealing position 430 in Figure 4).

[0049] In step 1010, the actuator for rotating the cannula is initiated. Rotating the cannula allows the sealant on the wire to be applied to the entire area of ​​the sealing position.

[0050] In step 1012, optionally, the XYZ stage machine moves the wire forward to apply sealant to other areas of the wire (e.g., lower areas) to the sealing position. The actuator continues to rotate the cannula until the sealing position is completely sealed.

[0051] By performing steps 1002-1010 (and optionally 1012) of flowchart 1000, a thermally robust laser probe assembly with a sealed distal end is obtained that prevents or at least reduces the amount of fluid that may leak into the probe. In certain embodiments, after the sealing position is sealed, the probe may be double-cured (ultraviolet (UV) + thermal curing of adhesive).

[0052] The foregoing description is provided to enable those skilled in the art to implement the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments. Accordingly, the claims are not intended to be limited to the embodiments shown herein, but rather should be given the entire scope consistent with the language of the claims.

Claims

1. A sealant application system, A sealant applicator including a wire, A stage machine configured to hold the sealant applicator and to position the wire at the sealing position at the distal end of the cannula of the probe assembly, An actuator is configured to rotate the cannula when the stage machine positions the wire at the sealing position, so that the sealant on the wire can be applied to the sealing position. A sealant application system including a sealant coating system.

2. The sealant application system according to claim 1, wherein the stage machine is configured to move the wire forward or backward while the actuator rotates the cannula.

3. The sealant application system according to claim 1, wherein the sealing position is sealed with a sealant having a viscosity in the range of about 500 to about 5000 centipores.

4. The sealant application system according to claim 1, wherein the sealing position is sealed with a double-curing sealant.

5. The sealant application system according to claim 1, further comprising a cannula holder configured to fix the cannula during the application of the sealant.

6. The sealant application system according to claim 5, wherein the actuator is configured to rotate the cannula holder together with the cannula.

7. The sealant coating system according to claim 1, wherein the diameter of the wire is in the range of about 20 to about 40 micrometers.

8. A method for manufacturing a probe assembly, The sealant-coated wire is positioned at the sealing location at the distal end of the cannula of the probe assembly. The cannula is rotated to apply the sealant to the sealing position. A method that includes this.

9. The method according to claim 8, further comprising moving the wire forward and backward during the rotation.

10. The method according to claim 8, further comprising double-curing the sealing position after the sealing position has been sealed.

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