Ophthalmic microsurgical instrument

Abstract

In some embodiments, a microsurgical instrument includes a trocar having a hollow rigid shaft formed with an internal lumen extending from a proximal end to a distal end of the shaft. The distal end of the shaft can be shaped for tissue penetration. The instrument can further include a composite microcannula slidably engaged with the trocar in the internal lumen. The microcannula includes a light guide and a flexible hollow tube having an outer diameter that is less than an inner diameter of the internal lumen in the trocar. Other embodiments include placing the microcannula in the internal lumen of the trocar, illuminating an end of the trocar by illuminating an end of the microcannula, advancing the trocar from a selected entry point on an eye into a selected structure in the eye, and extending the illuminated end of the microcannula from the trocar into the selected structure.

Description

[0001] Cross-references to related applications

[0002] This application is a continuation-in-part of co-pending application serial number 15 / 892,833, filed February 9, 2018, the entire contents of which are incorporated herein by reference, and claims the benefit of U.S. Provisional Patent Application No. 62 / 574,136, filed October 18, 2017, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The embodiments relate to surgical devices for treating eye diseases such as glaucoma. Background Technology

[0004] Aqueous humor is a clear, watery fluid that is produced within the eye, filling the anterior and posterior chambers, delivering substances needed by the eye tissues, and helping to maintain the eye's rounded shape through fluid pressure. Aqueous humor drains from the eye through a porous circumferential fluid channel that includes the trabecular meshwork and scleral sinuses, connecting to collector channels, and a venous drainage network. Blockage or collapse of any part of the eye's drainage network can lead to increased intraocular pressure, a condition that may be associated with decreased vision and eye diseases such as glaucoma.

[0005] Surgical treatments can be used to lower intraocular pressure by improving the flow of aqueous humor. Some surgical treatments involve making a relatively large incision through the sclera, the hard white outer covering of the eye, to create a tissue flap, which is then folded back to expose the trabecular meshwork or other parts of the aqueous humor flow path. The exposed portion of the drainage network can then be modified by removing tissue or creating new drainage channels. Incisions through the sclera can result in a loss of fluid pressure within the eye and collapse of one or more chambers. It may be necessary to support the natural shape of the eye by injecting a viscoelastic fluid into one of the chambers. Viscoelastic fluids have a viscosity that changes from a dynamic to a static flow state, flows with a relatively low viscosity when subjected to shear stress, and exhibits a gel-like high-viscosity state under static conditions.

[0006] Surgical treatments involving eye incisions may increase the risk of postoperative complications such as infection and scar tissue formation. Other treatment procedures with less invasiveness to the eye have been developed. For example, aqueous humor flow can be improved by passing a microcannula through portions of the eye's drainage network to remove obstructions or reopen collapsed fluid channels. Additionally, delivery of medications or drug-eluting devices or materials into tissue structures can be advantageous. Notably, because the scleral venous sinuses are located outside the immune-reserved region within the body of the human eye, delivery of medications and drug-eluting devices to the scleral venous sinuses can be beneficial. Microcannulas can comprise flexible hollow tubes with an outer diameter small enough to allow introduction of the microcannula into the scleral venous sinuses or another portion of the eye's drainage network. The microcannula can be flexible enough to bend along another portion of the scleral venous sinuses or drainage network when pushed in from outside the eye (e.g., through a surgically created flap as previously described or through a puncture site across the sclera). Miniature cannulas can be used to mechanically dilate selected portions of drainage channels in the eye, or to inject materials, objects, fluids, drugs, or viscoelastic substances to apply fluid pressure and thus improve flow through the eye's drainage system. Alternatively, microsurgical cutting, penetrating, or grasping instruments can be passed through miniature cannulas to guide the instrument to the site in the eye that needs to be surgically modified.

[0007] Some microsurgical instruments have microcannulas that slidably engage with a hollow, flexible outer sheath. The flexible outer sheath can be used to position the entry point of the microcannulas inside the eye, where the microcannulas passes through an inner lumen within the flexible outer sheath, and the outer sheath remains stationary relative to the eye. The tip of the microcannulas can extend from the tip of the sheath into a selected portion of the eye. However, the flexibility of the outer sheath may make it difficult for the sheath to penetrate the sclera or other tissues, thus preventing the microcannulas from reaching drainage structures or other treatment areas within the eye. It may be necessary to use a separate instrument for incision or puncture to allow for precise positioning of the flexible sheath for placement and guidance of the microcannulas. Alternatively, the microcannulas may be provided with an end shaped for tissue penetration, which may limit their use for delivering payloads into the eye. Summary of the Invention

[0008] An exemplary device embodiment includes a cannula and a composite microcannula. An embodiment of the cannula includes a rigid shaft having a proximal end and a distal end. The rigid shaft may be formed to have a lumen extending from the proximal end to the distal end. The distal end of the rigid shaft on the cannula may be shaped for tissue penetration.

[0009] The composite microcannula can be positioned within the lumen of the cannula. Examples of the composite microcannula may include a flexible hollow tube with an outer diameter smaller than the inner diameter of the lumen of the cannula. Examples of the composite microcannula may further include a light guide.

[0010] Another exemplary device embodiment includes a cannula for ophthalmic surgery. An example of the cannula includes a hollow rigid shaft having a distal end shaped for tissue penetration. The hollow shaft forms a lumen extending from the distal end to the proximal end of the hollow shaft. The example of the cannula further includes a transition structure attached to the proximal end of the hollow shaft. The transition structure may be formed with an aperture for allowing a composite microcannula to enter the lumen. The example of the cannula may further include a light source arranged to illuminate the distal end of the hollow rigid shaft. The distal edge of the lumen in the hollow shaft may be smoothed to reduce abrasion and / or cutting caused by solids passing through the lumen and exiting the cannula. The example of the cannula may further include a finger gripper extending outward from the transition structure.

[0011] An exemplary method embodiment includes: placing the distal end of a composite microcannula within the lumen of a trocar; irradiating the distal end of the composite microcannula, thereby irradiating the distal end of the trocar; selecting a trocar entry point on an eye and positioning the trocar at the selected entry point; advancing the trocar at the selected entry point until the irradiated distal end of the trocar is observed to enter a selected structure in the eye; and extending the composite microcannula from the distal end of the trocar toward a target region in the eye, thereby changing the irradiation from the distal end of the trocar to irradiating tissue outside the trocar.

[0012] Another exemplary device includes: a handheld component; an actuator slidably coupled to the handheld component; an insert slidably coupled to the handheld component; a hollow tube attached to the actuator; and a filament passing through the hollow tube, a first end of the filament being attached to the handheld component and a second end of the filament being attached to the insert.

[0013] Another exemplary cannula for ophthalmic surgery includes a hollow rigid shaft with an inner lumen for receiving a cannula, particularly a composite microcannula, wherein the shaft has a distal end shaped for tissue penetration.

[0014] The distal end of the shaft can be beveled or tapered. Alternatively or additionally, the distal end of the shaft is shaped to allow tissue penetration resulting in a single puncture of the tissue.

[0015] The inner surface at the distal end of the shaft may be smoother than at least a portion of the inner surface of the rest of the shaft. Furthermore, the distal edge of the shaft may be smoother than at least a portion of the inner surface of the rest of the shaft. The outer surface of the shaft may include a lubricating coating.

[0016] The cannula may include a light guide and / or a light source arranged such that the distal end of the axis can be irradiated. Specifically, one end of the light guide may be used to irradiate the distal end of the axis and / or tissue. The cross-section of this end of the light guide may be larger than the cross-section of at least a portion of the rest of the light guide, and / or the other end of the light guide may be connected to a light source for providing visible and invisible light.

[0017] The light guide can be attached to the axis or can be an integral part of the axis.

[0018] Another exemplary device may include the aforementioned cannula and a catheter. The catheter may be a composite microcatheter and / or may be disposed within the lumen of the cannula.

[0019] The stiffness of the cannula can be less than that of the shaft. The diameter of the cannula can range from 100 micrometers to 250 micrometers.

[0020] The cannula may include an inner lumen extending between its two ends. Through the cannula, and particularly through its inner lumen, a payload may be permitted to enter the tissue as the cannula extends from the distal end of the hollow shaft, and / or through the cannula, a payload may be permitted to enter the tissue, wherein the shaft remains in the same position during the period during which the payload is permitted to enter the tissue.

[0021] The device may include a conversion structure, particularly a cannula connector. The cannula, especially the proximal end of the shaft, may connect to the conversion structure. Furthermore, the cannula may extend through the conversion structure.

[0022] The light guide or another light guide may be connected to the cannula. In particular, the light guide or another light guide may be attached to the cannula or may be an integral part of the cannula. Alternatively, the light guide may be arranged such that this end of the axis can be illuminated, regardless of the presence or position of the cannula.

[0023] The light guide and / or another light guide may be connected to the light source. The device may include a reflector arranged to guide light from the light source to the proximal end of the axis.

[0024] The lumen of the cannula can be fluidly connected to an injector for materials, especially viscoelastic materials. Attached Figure Description

[0025] Figure 1This is an illustration of an exemplary microsurgical instrument, which includes a cannula with a hollow rigid shaft and a flexible composite microcannula.

[0026] Figure 2 This is a top view of an example of a cannula according to an embodiment.

[0027] Figure 3 yes Figure 2 A side view of an example cannula.

[0028] Figure 4 yes Figure 1-3 A cross-sectional view AA of an example cannula needle. Figure 3 The cross-section line marked AA shows Figure 4 The position and viewing direction of the cross-sectional view.

[0029] Figure 5 yes Figure 1-4 A partially enlarged cross-sectional view B of the hollow rigid shaft shows an example of the distal end shaped for tissue penetration, and further shows an example of the smoothed distal edge of the lumen in the cannula. Figure 5 The position of view B in the middle is Figure 4 The text is marked with a dashed line.

[0030] Figure 6 This is a partial top view of an example of a composite microcannula according to an embodiment of a microsurgical instrument.

[0031] Figure 7 yes Figure 6 A cross-sectional view CC of an exemplary composite microcannula. Figure 7 The position and viewing direction of the cross-sectional view CC in the middle are determined by... Figure 6 The longitudinal section line CC is marked in the diagram.

[0032] Figure 8 yes Figure 6 A cross-sectional view of an exemplary composite microcannula (DD). Figure 8 The position and viewing direction of the cross-sectional view DD in the diagram are determined by... Figure 6 The transverse cross-section line DD in the diagram is marked.

[0033] Figure 9 This is an alternative cross-sectional view DD of another example of a composite microcannula according to an embodiment of a microsurgical instrument. Figure 9 The position and viewing direction of the alternative cross-sectional view DD in the diagram are determined by... Figure 6 The transverse cross-section line DD in the diagram is marked.

[0034] Figure 10This is an alternative cross-sectional view DD of another example of a composite microcannula according to an embodiment of a microsurgical instrument. Figure 10 The position and viewing direction of the alternative cross-sectional view DD in the diagram are determined by... Figure 6 The transverse cross-section line DD in the diagram is marked.

[0035] Figure 11 This is an alternative cross-sectional view DD of another example of a composite microcannula according to an embodiment of a microsurgical instrument. Figure 11 The position and viewing direction of the alternative cross-sectional view DD in the diagram are determined by... Figure 6 The transverse cross-section line DD in the diagram is marked.

[0036] Figure 12 Alternative cross-sectional view AA is another example of a trocar needle, further showing an example of a composite microcannula deviating from the distal end of the trocar needle in a proximal direction, and further showing an example of the irradiated distal end of the trocar needle.

[0037] Figure 13 yes Figure 12 A continuation of the example shows an example of the irradiated distal end of the composite microcannula extending outward from the distal end of the lumen in the cannula.

[0038] Figure 14 The alternative cross-sectional view DD shows another example of a composite microcannulas with two light guides within a longitudinal void inside the flexible hollow tube of the composite microcannulas.

[0039] Figure 15 The alternative cross-sectional view DD shows another example of a composite microcannula with two light guides, one located inside the flexible hollow tube of the composite microcannula, and the other in contact with the outer surface of the flexible hollow tube.

[0040] Figure 16 The alternative cross-sectional view DD shows another example of a composite microcannula with two light guides, one located inside the flexible hollow tube of the composite microcannula, and the other located between the hollow tube and the outer tube.

[0041] Figure 17 The alternative cross-sectional view DD shows another example of a composite microcannula with two light guides, one located inside the flexible hollow tube of the composite microcannula, and the second light guide held against the flexible hollow tube by an outer coating applied to the second light guide and the flexible hollow tube.

[0042] Figure 18This is a block diagram of an alternative device embodiment, which includes a positioner for displacing a composite microcannula relative to a cannula needle, and optionally includes a fluid injector for introducing fluid into the composite microcannula.

[0043] Figure 19 A top view shows an example of a microsurgical instrument embodiment with a locator and a cannula.

[0044] Figure 20 yes Figure 19 A cross-sectional view of the locator EE. Figure 20 The position and viewing direction of the cross-sectional view EE in the diagram are determined by... Figure 19 Mark the longitudinal section line with the designation EE.

[0045] Figure 21 An illustration of an exemplary embodiment of a microsurgical instrument is shown, which includes a locator in which the distal end of a cannula passes through the sclera of the eye into the scleral venous sinus, demonstrating an example of how light emitted from the illuminated distal end of the cannula accurately indicates the position of the cannula.

[0046] Figure 22 Exemplary microsurgical instruments and cannulas are shown in relation to the scleral venous sinuses. Figure 21 The same location is illustrated, and an example is shown where the irradiated distal tip of the composite microcannula extends outward from the cannula along the circumferential path of the scleral venous sinus.

[0047] Figure 23 yes Figure 1 Another alternative cross-sectional view AA of the cannula shows an example of the composite microcannula and its optical guide passing through the lumen of the cannula, and further shows an optional second optical guide positioned in the lumen, separate from the optical guide in the composite microcannula.

[0048] Figure 24 As shown Figure 23 A partial view of a cannula with a composite microcannula and a second light guide, similar to the example, shows an example of the irradiated distal ends of the cannula and the composite microcannula being separated from each other along the circumferential path of the scleral venous sinus.

[0049] Figure 25 An alternative cross-sectional view DD is shown as an example of a composite microcannula embodiment carrying an optional fluid payload and an optional solid payload within a flexible hollow tube.

[0050] Figure 26 A diagram showing an example of a cannula entry point marker is provided.

[0051] Figure 27 It shows Figure 26 An example view of the marking surface on the marking pad of the point marker.

[0052] Figure 28 It shows Figure 26-27 A side view of an exemplary cannula needle entry point marker.

[0053] Figure 29 A view showing an example of the sclera and iris of the human eye, demonstrating the structure formed by... Figure 26-28 An example of the pattern of the tangent formed by the cannula needle entry point marker.

[0054] Figure 30 Examples of some of the steps involved in a method for inserting a cannula through the sclera of the eye and pushing a composite microcannula from the cannula into structures such as the scleral venous sinus are shown.

[0055] Figure 31 This is a partial top view of another example of a composite microcannula according to an embodiment of a microsurgical instrument.

[0056] Figure 32 yes Figure 31 A cross-sectional view of an exemplary composite microcannula (FF). Figure 32 The position and viewing direction of the cross-sectional view FF in the middle are determined by... Figure 31 The longitudinal section line FF is marked in the text.

[0057] Figure 33 yes Figures 30-31 A cross-sectional view of an exemplary composite microcannula, GG. Figure 33 The position and viewing direction of the cross-sectional view GG in the middle are determined by... Figure 31 The transverse section GG is marked.

[0058] Figure 34 This is a top-side view of another example of a microsurgical instrument embodiment with a locator and a cannula.

[0059] Figure 35 yes Figure 34 The following are side views of two examples of microsurgical instruments, with the upper device showing an example of a composite microcannula in a retracted position and the lower device showing an example of a composite microcannula in an extended position.

[0060] Figure 36 yes Figures 34-35 The following figures illustrate examples of microsurgical instruments with the composite microcannula in the retracted position (HH) and with the composite microcannula in the extended position (KK). The positions of sections HH and KK are shown using... Figure 35 The cross-sectional lines HH and KK are marked. Detailed Implementation

[0061] This document describes exemplary embodiments of the invention. A cannula with a hollow rigid shaft having a distal end shaped for tissue penetration, the cannula being configured to puncture biological tissue (e.g., the sclera of the eye), thereby forming a very small entry point for allowing a composite microcannula to pass through the lumen of the cannula. The composite microcannula (also referred to herein as a microcatheter) includes a light guide for illuminating the distal end of the microcannula. A light source may be coupled to the composite microcannula and / or the cannula to illuminate the distal end of the hollow rigid shaft by guiding the light through the light guide into the lumen of the cannula, thereby enabling accurate determination of the position of the distal end of the cannula, a visual indication of the cannula's entry into ocular structures, and a visual indication of the position of its distal end as the composite microcannula travels toward a target treatment area. The illuminating distal end of the composite microcannula can be used to determine when the microcannula deviates from a preferred path, for example, leaving a preferred path through the scleral venous sinus and entering another channel or chamber, such as a collector channel or another part of an ocular drainage system.

[0062] By observing light emitted from the cannula passing through tissues (which may include the sclera, trabecular meshwork, or other tissues, including those unrelated to the eye), the embodiments effectively provide a visual indication of the distal end of the cannula. Light passing through the sclera or other tissues from the cannula further indicates the direction of travel of the cannula. The location and direction of travel of the composite microcannula can also be accurately determined by visual observation of light emitted from the tip of the microcannula. The embodiments can be precisely guided into tissues and / or interstitial spaces, such as, but not limited to, the trabecular meshwork, scleral sinuses, and collector channels. Conversely, the embodiments can be precisely guided to specifically avoid entering selected tissues or interstitial spaces. The location and direction of travel of the embodiments can be directly observed in the eye and in the tissues using a camera, gonioscopy, other optical aids, or any combination of these devices and methods.

[0063] In some embodiments, the second light guide enables independent and optional simultaneous irradiation of the distal ends of the cannula and the composite microcannula. In other embodiments, a payload comprising fluid and / or solid matter can be delivered through the composite microcannula to a target region in the eye. Examples of fluid payloads include, but are not limited to, gene therapy, stem cell and other fluid-based drugs, viscoelastic fluids, water, and saline solutions. Examples of solid payloads include, but are not limited to, devices, particles, nanoparticles, small devices including drug-eluting examples of solid payloads, microsurgical instruments such as forceps, instruments for penetrating and / or cutting tissue, scaffolds, light guides, and filaments. As used herein, a light guide is an optical element capable of transmitting electromagnetic energy received at an input surface through an intermediate optical medium to an output surface. Examples of light guides include, but are not limited to, one or more mirrors arranged to guide a beam of light from a source to an endpoint, flexible optical fibers, a bundle of optical fibers, and rigid light guides.

[0064] Some embodiments include a locator for displacing the distal end of the composite microcannula relative to the cannula needle. The locator may optionally include a microcannula displacement mechanism configured to extend and optionally retract the composite microcannula. The locator may further optionally include a fluid injector configured to move fluid from a fluid reservoir into the composite microcannula and to a selected target region within the eye. Some embodiments of the locator include a light source arranged to emit light into a light guide of the composite microcannula and, when a second light guide is provided, optionally into a second light guide coupled to the cannula needle. This locator allows the composite microcannula to travel and / or retract accurately without interfering with the microcannula entry point into the eye, thereby reducing the amount of time required to complete the treatment procedure and lowering the risk of damage to ocular tissue.

[0065] Examples of ophthalmic microsurgical instruments can be configured to smoothly and continuously transition from the distal end of the irradiation cannula to the tissue outside the irradiation cannula, thereby enabling very precise positioning of the cannula and composite microcannula relative to structures in the eye. The small puncture created by the cannula in the sclera or other parts of the eye contrasts with the relatively large incisions required by previous surgical techniques to elevate tissue flaps from the sclera to access structures inside the eye. The smaller puncture reduces patient discomfort and the risk of postoperative complications such as scarring and infection. The preparation, monitoring, and closure of the surgical area are faster and simpler compared to methods using incisions through the sclera. This allows the embodiments to be performed with lower levels of sterility and patient monitoring than surgical procedures can be performed in an operating room, and allows patients to recover and heal more quickly from surgery.

[0066] Figure 1 Exemplary embodiments of microsurgical instruments are illustrated. Exemplary embodiment 100 includes a cannula 200 configured to receive a composite microcannula 300. The composite microcannula 300 may slidably engage with the cannula 200, passing through a cannula connector 222, a transition structure 214 at a proximal end 204 of the cannula, and an inner cavity 208 formed in a hollow rigid shaft 206 extending outwardly from the transition structure 214 to a distal end 202 of the cannula 200. The hollow rigid shaft 206 is preferably formed with a distal end 210 shaped for tissue penetration. One or more optional finger grippers 216 may be attached to the cannula connector 222 and / or the transition structure 214, or alternatively formed as an integral part thereof.

[0067] exist Figure 1 In the example, the composite microcannula 300 is shown as having several bends and curves to demonstrate the flexibility of the hollow tube 302 forming the majority of the composite microcannula's length. The flexibility of the composite microcannula allows it to conform to ocular structures such as the curved walls of the scleral venous sinuses without puncturing or damaging the walls of these structures. Embodiments of the composite microcannula 300 can be characterized by a flexural stiffness ranging from 3.0 x 10⁻⁶. -11 kN-m 2 Up to 2.9x 10 -10 kN-m 2 Multiple microcannula segments are formed within the range. The distal and / or proximal portions of the composite microcannula may optionally be more rigid than other portions of the composite microcannula. The hollow rigid shaft 206 of the cannula needle 200 is significantly stiffer than the composite microcannula and is preferably formed to have a minimum of 1.5 x 10⁻⁶. -8 kN-m 2 The flexural stiffness is high enough to allow it to easily penetrate the sclera and other tissues in the eye. A cannula with a flexural stiffness greater than the preferred minimum value eliminates the need for separate surgical instruments to create a puncture site across the outer surface of the eye.

[0068] The composite microcannula 300 may include an optional microcannula connector 314 located at the proximal end 310 of the flexible hollow tube 302. The microcannula connector may include connections for introducing a payload into the composite microcannula and for coupling light from a light source into the composite microcannula. A liquid, solid, or gaseous payload introduced into the proximal end 310 may be transported through the hollow tube 302 to the distal end 308 of the composite microcannula for delivery to a target region in the eye. Light incident on the proximal end 310 may travel to the distal end 308 to form an irradiated distal end 326 of the composite microcannula. An optional light diffuser 311 may be disposed at the distal end 308 to disperse the light in a number of directions, thereby indicating the precise position of the distal end of the composite microcannula as it moves through the channels and chambers of the eye. Light can travel from the proximal end to the distal end of the composite microcannula by passing through the wall of the flexible hollow tube 302 through the liquid introduced into the hollow tube 302, or through the internal reflection of one or more light guides included in some embodiments of the composite microcannula.

[0069] Figure 2 A top view of an exemplary embodiment of the cannula 200 is shown, and Figure 3 Its side view is shown. Figure 3 In the example, it has been omitted Figure 2 Optional finger gripper 216 is visible. The cannula connector 222 at the proximal end 204 of the cannula 200 can be a Luer connector, such as a sliding fit or torsion-locking Luer connector. Alternatively, other connectors capable of forming a leak-proof seal can be used. The hollow rigid shaft 206 of the cannula 200 is attached to the transition structure 214. The lumen 208 in the hollow rigid shaft 206 is in fluid communication with the gap in the transition structure and the cannula connector, thereby enabling fluid to be introduced into the lumen 208. The lumen 208 of the cannula 200 extends through the distal end 210, which is shaped for tissue penetration.

[0070] Figure 4 Sectional view AA and Figure 5 Partial enlarged view B in the figure shows some internal details of an example of the cannula 200 according to an embodiment. The hollow rigid shaft 206 is securely held by a transition structure 214 attached to the cannula connector 222. The inner cavity 208 through the hollow rigid shaft 206 is in fluid communication with a gap 224 in the cannula connector 222. The gap 224 can be formed with a tapered microcannula guide surface 221 near the proximal end of the hollow shaft 206. The tapered surface 221 allows the composite microcannula to deflect toward the inner cavity 208 through a hole 223 formed in the transition structure 214 near the distal end of the gap 224.

[0071] The distal edge 212 of the lumen 208 is preferably smoothed, for example, by rounding the edge 212 that is always located around the distal end of the lumen. A smoothed distal edge 212 reduces material abrasion or cutting from the microcannula as the composite microcannula slides across the cannula lumen. If left unsmooth, the distal edge of the cannula lumen could become sharp enough to remove material from the composite microcannula. Reducing the amount of material cut or abraded from the composite microcannula reduces unwanted deposition of such material in the eye.

[0072] Figure 5 View B further illustrates an example of the outer diameter 219 of the hollow rigid shaft 206 and the inner diameter 218 of the cavity 208 passing through the hollow rigid shaft 206. The outer diameter 219 can range from about 200 micrometers to about 700 micrometers. For example, some cannula embodiments have a hollow rigid shaft with an outer diameter 219 of 450 micrometers. Other cannula embodiments have a hollow rigid shaft with an outer diameter 219 of 250 micrometers. The inner diameter 218 is preferably larger than the maximum lateral dimension 306 of the composite microcannula configured to slidably pass through the cavity, such as the outer diameter 306 of the flexible hollow tube 302, the maximum lateral dimension 306 of the tube 302 and the outer coating 321 applied to the tube, the maximum lateral dimension 306 of the external light guide 304 that crosses the hollow tube 302 and contacts the tube, or the outer diameter 306 of the cannula 320 surrounding the tube 302.

[0073] Figure 6 A top view of an exemplary embodiment of the composite microcannula 300 is shown. Figure 7 Its longitudinal section view CC is shown, and Figure 8-11 An alternative transverse section view DD is shown. (As shown) Figure 6 , Figure 7 and Figure 8 As indicated, the light guide 304 can be positioned within a longitudinal gap 303 extending from the proximal end 310 to the distal end 308 of the flexible hollow tube 302. The longitudinal gap 303 within the composite microcannula 300 is also referred to as the lumen 303 of the composite microcannula. The gap 303 can serve as a fluid path 324 for fluid introduced into the flexible hollow tube 302. The payload introduced onto the composite microcannula follows the fluid path 324 as it moves from the proximal end 310 to the distal end 308.

[0074] The light guide 304 can be formed separately from the flexible hollow tube, as suggested in the previous examples. Alternatively, the light guide can be formed as an inner layer of the flexible hollow tube 302, such as... Figure 31 , Figure 32 and Figure 33As shown in the example, the light guide 304 can be arranged as a concentric material layer adjacent to the void 303 in the composite microcannula 300. The refractive index of the material of the light guide 304 is preferably sufficiently different from that of the material of the flexible hollow tube 302, so that light from the light source can be effectively coupled to the distal end 308 via internal reflection through the light guide. The material layer forming the light guide 304 can be formed by molding, chemical deposition, or by mechanically inserting the hollow tube into the flexible hollow tube 302. Although the figures show an example of a light guide formed from a single material layer, the light guide can alternatively be made of several material layers, each having a selected refractive index value, or can alternatively be made such that its refractive index varies with distance from the edge of the light guide.

[0075] Figure 31 , Figure 32 and Figure 33 An example of a light diffuser 311 is further shown, which has the same characteristics as... Figure 6 and Figure 7 In the example, the outer diameter of the light diffuser 311 is reduced compared to the outer diameter 312. The light diffuser 311 can alternatively be formed as the circular end of the flexible hollow tube 302, wherein the radius of the diffuser is equal to half the diameter 313 of the flexible hollow tube.

[0076] A second light guide and / or other liquid or solid payload may pass through the gap 303 surrounded by the light guide 304. In some embodiments, the light guide 304 completely surrounds the gap 303 in the flexible hollow tube 302. Alternatively, the light guide may not completely surround the gap, for example, in a longitudinally separated hollow tube formed as half, a quarter, or some other part of a complete hollow tube.

[0077] The outer diameter 306 of the composite microcannula 300 can be the maximum diameter on the composite microcannula, for example... Figure 6 The diameter 312 in the inner cavity 208 of the cannula 200. The outer diameter 306 (e.g., the larger of the outer diameter 312 at the distal end 308 of the optional light diffuser 311 and the outer diameter 313 of the hollow tube 302) is preferably smaller than the inner diameter 218 of the inner cavity 208 in the cannula 200.

[0078] When light incident on the proximal end 310 of the light guide 304 is emitted from the distal end 308, the distal end 308 of the composite microcannula corresponds to the irradiated end 326. For example... Figure 6 and Figure 7 As suggested, the distal end 308 of the composite microcannula can be circular to reduce tissue trauma and to disperse light from the light diffuser 311 in multiple directions to enhance the visibility of the irradiated distal end 326. The outer diameter 312 of the light diffuser can be larger than the outer diameter 313 of the hollow tube 302. Alternatively, the diameters (312, 313) can be approximately equal to each other.

[0079] In some examples, the length of the flexible segment 322 of the composite microcannula 300 can be several millimeters longer than the circumferential length of the scleral venous sinus. The circumferential length of the scleral venous sinus in the human eye is approximately 36 millimeters. In some embodiments of the composite microcannula 300, the length of the flexible segment 322 can be greater than 40 millimeters (1.6 inches). The length of the flexible segment 322 can optionally be significantly longer than the circumferential length of the scleral venous sinus, for example, to allow the composite microcannula to be connected to a light source or fluid injection device, or to provide a convenient length on the proximal exterior of the cannula for grasping the composite microcannula with forceps or fingers.

[0080] Alternatively, the flexible segment 322 of the composite microcannula 300 can be approximately 20 mm in length, thereby allowing for two cannulations of the scleral venous sinus. The first cannulation can proceed clockwise through approximately half the length of the scleral venous sinus. The second cannulation can proceed counterclockwise through the other half of the scleral venous sinus.

[0081] exist Figure 8 In the example of the composite microcannula 300, the light guide 304 is positioned within the longitudinal gap 303. The diameter of the light guide is smaller than the inner diameter 307 of the flexible hollow tube 302. The outer diameter 306 of the composite microcannula 300 can be the outer diameter of the hollow tube 302.

[0082] exist Figure 9 In the example of the composite microcannula 300, the light guide 304 is positioned on the outer surface of the flexible tube 302, thereby leaving space within the flexible tube 302 for delivering a payload through the composite microcannula. Figure 9 In the example, the outer diameter 306 of the composite microcannula includes the dimensions of the flexible tube 302 and the light guide 304.

[0083] Figure 10 and Figure 11 Further examples of the composite microcannula 300 according to embodiment 100 of microsurgical instruments are shown. Figure 10 The exemplary composite microcannula 300 positions the light guide 304 outside the void 303 within the flexible hollow tube 302. An outer tube 320 surrounds the light guide 304 and the flexible tube 302. The outer diameter 306 of the composite microcannula can correspond to... Figure 10 The outer diameter of the sleeve is 320. Figure 11 In the example, a coating 321 has already been applied to the light guide 304 and the flexible hollow tube 302. The outer diameter 306 along the flexible section of the composite microcannula includes the dimensions of the hollow tube 302, the light guide 304, and the outer coating 321. Figure 10 and Figure 11 Both exemplary embodiments provide a complete inner diameter 307 of a hollow tube 302 for carrying a payload through a longitudinal gap 303.

[0084] The composite microcannula can be positioned inside the lumen of the cannula to irradiate the distal end of the cannula when it is inserted into the eye. Figure 12 and Figure 13 Examples of alternative configurations for the conversion structure 214 and examples of the location of the composite microcannula are shown. Figure 12 In this configuration, the composite microcannula is positioned at the distal end 202 of the hollow rigid shaft 206 of the irradiation cannula needle. The distal end 308 of the composite microcannula (in...) Figure 12-13 In this example, the distal end (also the illuminated end 326 of the microcannula) can be mounted within the lumen of the cannula, offset from the distal end 202 of the cannula by a preferred distance 626. Internal reflection within the cannula lumen causes light 614 emitted from the distal end of the composite microcannula to exit from the distal end of the cannula, as the light 612 is dispersed over a wide angular range, making the cannula tip visible from different viewing directions. The illuminated distal end 220 of the cannula can be used to pinpoint the precise location of the cannula tip within the eye tissue. For example, easily perceptible variations in the brightness of the emitted light 612 (e.g., observable under a corneal microscope via the trabecular meshwork) indicate when the distal end of the cannula crosses the sclera and enters the scleral venous sinus.

[0085] Pushing the irradiated distal end 326 of the composite microcannula out of the lumen of the cannula results in a smooth transition from irradiating the cannula tip to irradiating tissue outside the cannula. Figure 13 In the example, light 614 emitted from the illuminated distal end 326 of the composite microcannula can be dispersed over a wide angular range to accurately indicate the position of the tip of the composite microcannula within the eye.

[0086] Some alternative embodiments of the composite microcannula include two light guides, such as... Figure 14-17 As shown. In Figure 14 In an example of the composite microcannula 300, a first light guide 304 and a second light guide 412 are arranged within the inner cavity 303 of the hollow tube 302. Figure 15 In the example, the first light guide 304 can be located outside the inner cavity 303 of the hollow tube 302, while the second light guide 412 can be located inside it. Figure 16 In the example, the two light guides can be as follows: Figure 15 The positioning shown indicates that the outer sleeve 320 surrounds the flexible hollow tube 302 and the first optical guide 304. Figure 17 In the example, these two light guides can also be like Figure 15 The positioning is shown, but an outer coating 321 is applied to the first light guide 304 and the flexible hollow tube 302.

[0087] Some embodiments of microsurgical instruments include locators for displacing composite microcannulas relative to the cannula needle. Figure 18The example illustrates a block diagram of an alternative embodiment of a microsurgical instrument 100 with a locator. The locator 400 may include a handpiece 420 holding a microcannula displacement mechanism 425, configured to extend and optionally retract a composite microcannula 300 from and optionally retract a cannula 200. The cannula 200 may be attached to a cannula receiver 422, such as a receiver for a Luer connector on a cannula. The composite microcannula may pass through a hollow cannula 433 disposed between the cannula receiver 422 and the microcannula displacement mechanism 425. The hollow cannula 433 can improve the smooth extension and retraction of the composite microcannula by reducing buckling or kinking of the flexible portion of the composite microcannula within the locator 400 during operation of the microcannula displacement mechanism. An actuator 424 mechanically coupled to the microcannula displacement mechanism 425 allows manual control of the length of extension of the composite microcannula from the distal end of the cannula.

[0088] An optional light source 328 may be disposed within the locator 400. Light output from the light source 328 may be coupled to a microcannula connector 314 attached to the composite microcannula 300. The microcannula connector 314 may optionally be configured to receive light from an external light source 330. In some embodiments, the light source 328 may be arranged to transmit light through a second light guide 412, possibly through an intermediate sleeve receiver 422, into the lumen of the sleeve 200.

[0089] The miniature cannula connector 314 may optionally provide a fluid connection to a fluid injector 446, which is arranged to deliver fluid from a fluid reservoir 442 within the handheld unit 420 to the composite miniature cannula 300. Alternatively, the miniature cannula connector 314 may be connected to an external fluid injector 448, which is configured to transfer fluid from an external fluid reservoir 444 into the composite miniature cannula 300.

[0090] Figure 19 and Figure 20 Some details of an example of a microsurgical instrument embodiment 100 including a locator 400 are shown. A cannula connector 222 connects to a cannula receiver 422 at the distal end 418 of the locator 400 at the proximal end of the cannula 200. The cannula receiver 422 may be formed as an integral part of the handpiece 420, or alternatively formed separately or securely attached to the handpiece. An actuator 424 slidably engages with the handpiece 420 along an actuator bore 428 to extend a composite microcannula from the cannula. The actuator may be attached to a guide block 426 or alternatively formed as an integral part thereof, the guide block being configured for tracking along a guide ridge 430 within the handpiece 420.

[0091] The hollow cannula 433 can be connected to the guide block 426 at its proximal end and to the cannula needle 200 at its distal end. Composite microcannula (in...) Figures 19-20 The hollow cannula (not visible in the center) can be positioned within the hollow cannula 433. The hollow cannula may include a fixed section 436 and a movable section 434, the fixed section being attached to or alternatively formed integrally with the cannula needle 200, and the movable section being connected to the actuating block 426, wherein the length 438 of the hollow cannula 433 includes both the fixed and movable sections. The fixed and movable sections of the hollow cannula 433 may alternatively be implemented as a hollow, foldable, and extendable corrugated cannula with foldable sides. The length 438 of the hollow cannula 433 can change with displacement of the composite microcannula 300 relative to the cannula needle 200.

[0092] End cap 440 can close the proximal end 416 of locator 400. End cap 440 can form a covered hole 482 to allow the compound microcannula to extend from the proximal end 416.

[0093] Figure 21 and Figure 22 The image shows the location of the cannula entry point on the eye and an example of the compound microcannula extending along the circumferential path of the scleral venous sinus. Figure 21 and Figure 22 Both figures show diagrams illustrating the locator 400 in the same position and orientation relative to the eye 1000. Other parts of the generally spherical eye 1000, shown in simplified form in the figures, include the sclera 1002, iris 1006, pupil 1016, and the circumferential path of the scleral venous sinus 1010 near the limbus of the eye. The scleral venous sinus 1010 includes a porous, generally circular drainage channel for receiving aqueous humor flowing through the trabecular meshwork near the outer edge of the iris. The scleral venous sinus is marked with a hidden line in the figures to indicate its approximate location behind the outer surface of the sclera 1002. It can be considered that in Figure 21 and Figure 22 There is a cornea extending outward toward the observer above the iris 1006, but it is transparent and unmarked. The center 1018 of the pupil 1016 also indicates the approximate center of the iris 1006.

[0094] exist Figure 21 and Figure 22 In the example, the distal end 202 of the cannula 200 has been inserted into the sclera 1002 at the preferred cannula entry point 606, thereby puncturing the sclera to create a small hole with a diameter approximately equal to the outer diameter of the hollow rigid shaft 206. The cannula can travel in direction 610 along a line 604 tangent to the scleral venous sinus 1010. Figure 21In this example, the distal end 202 of the cannula 200 is positioned just inside the scleral venous sinus 1010. The position of the distal end of the cannula can be seen by light 612 radiated from the lumen of the cannula. In some embodiments 100, light 612 has been emitted from the distal end of a light guide, which is offset from the distal end of the lumen 208 of the cannula by a selected distance 626 (see [link to embodiment 1]). Figure 12 The visual appearance of light 612 radiating from the interior of the scleral venous sinus through the sclera can be a bright spot located outside the eye when viewed from outside the eye, and the visual appearance of this light radiating from the interior of the scleral venous sinus through the trabecular meshwork can be a clearly visible bright spot across the anterior chamber of the eye. This bright spot is a visual indicator of the precise location of the distal end 202 of the cannula 200. In the accompanying drawings, light 612 emanating from the tip of the cannula and light 614 emanating from the tip of the composite microcannula are indicated by short wavy lines. An anterior chamber gonioscope can be used to view the bright spot marking the location of the cannula and the composite microcannula.

[0095] Figure 21 An example is shown where the cannula 200 passes through the sclera at a preferred entry point 606 along a line 604 tangential to the scleral venous sinus. The entry point 606 of the cannula 200 into the sclera 1002 can be offset from the limbus on the tangent 604 by a predetermined distance. This offset distance can be selected to cause the cannula to penetrate into the interior of the scleral venous sinus when inserted at the preferred entry point 606, wherein the axis 206 of the cannula is parallel to the tangent. A cannula entry point marker can be used to mark the preferred entry point 606 and the direction of travel of the cannula along the tangent 604 on the surface of the eye, as shown in [reference]. Figure 26-29 A more detailed explanation.

[0096] exist Figure 21 In the example of the positioner 400, the actuator 424 is shown near the proximal end of the actuator's travel range. As the actuator moves from its position... Figure 21 The position moved along the distal direction to Figure 22 The position shown indicates that the microcannula displacement mechanism 425 (may include) Figure 20 The actuator block 426 and hollow sleeve 433 of the positioner embodiment 400 cause the composite microcannula to extend outward from the distal end of the cannula needle. Figure 22 The example of the displacement distance 630 corresponds to the length by which a portion of the composite microcannula extends outward from the distal end of the cannula needle by the movement of the actuator 424.

[0097] exist Figure 22In the example, the segment of the composite microcannula extending outward from the distal end 202 of the cannula 200 follows the circumferential path of the scleral venous sinus 1010 in a counterclockwise direction 611 from the cannula entry point 606. Light 614 emitted from the distal end of the composite microcannula 300 can be seen through the sclera as a small spot of light, accurately indicating the position of the distal end of the composite microcannula. Alternatively, the composite microcannula can follow the scleral venous sinus counterclockwise by reorienting the locator 400. If the composite microcannula deviates from the preferred path, for example, leaving the scleral venous sinus and entering the collector channel, this path will quickly become apparent due to the irradiated distal end of the microcannula.

[0098] Positioner 400 can remain stationary relative to eye 1000 as the composite microcannula moves through the scleral venous sinus or other parts of the eye. For example, positioner 400 can keep the composite microcannula stationary relative to the eye when delivering a payload through the composite microcannula to a target area within the eye. Although Figure 19-22 The examples of cannulas do not include finger grippers, but these examples also apply to cannulas with finger grippers. Finger grippers can be used, for example, to immobilize the locator by securing the finger gripper to the patient's skin with adhesive tape or temporary sutures.

[0099] Some embodiments of the cannula are configured to receive two light guides. One light guide may be included in a composite microcannula, as previously described. The second light guide may be located in another composite microcannula or may be disposed independently of the composite microcannula. Figure 23 and Figure 24 An example of a cannula needle suitable for two optical guides is shown. Figure 23 In the example, the composite microcannula 300 is shown with its distal end 308 extending from the distal end 202 of the trocar 200, and light 614 emanating from a light guide within the composite microcannula. An optional second light guide 412 is also positioned within the lumen of the trocar 200, with its distal end 413 retained within the trocar, thereby allowing light 612 to radiate from the distal end of the trocar. Figure 24 As indicated, the two light guides may optionally illuminate only the distal end 202 of the cannula 200, only the distal end 326 of the composite microcannula, or both, sequentially or simultaneously. The emitted light (612, 614) may optionally have a wavelength and / or intensity invisible to the naked eye.

[0100] An optional camera 616 can be configured to capture images of emitted light (612, 614) passing through the cannula and / or microcannula into the eye tissue. The positions of the composite microcannula and cannula can be seen in the image from camera 616 displayed on a computer monitor, smartphone display, and / or instrument display. In some microsurgical instrument embodiments 100, both the composite microcannula 300 and the second light guide 412 can receive light from the same light source. The composite microcannula can travel until it reaches the target area 1014, such as the area to be cleared of obstacles or narrow sections, or the area where the payload delivered through the composite microcannula will be received.

[0101] Figure 25 An example is shown where a payload 620 is carried within a void 303 within a flexible hollow tube 302 of a composite microcannula 300. The payload can follow a fluid path 324 through the composite microcannula. Therefore, the composite microcannula can be used to precisely position the payload in a target region of the eye. The payload 620 can be a solid 624, a fluid 622 (e.g., a fluid comprising gas and / or liquid), or both. The fluid can optionally be used to deliver the solid 624, or a long solid payload can be pushed in from the proximal end of the composite microcannula until the payload extends from the distal end of the composite microcannula. Figure 25 An example of the composite microcannula 300 has a light guide 304 within a flexible hollow tube. Other embodiments of the composite microcannula 300 disclosed herein can also be used to deliver a payload 620.

[0102] Figure 26 , Figure 27 and Figure 28 An example of a cannula entry point marker 800, also referred to as a marking clamp 800, is shown. This marker can be used to form a tangential pattern on the sclera of the eye. The pattern of lines marks at least one, and optionally more than one, preferred cannula entry point and preferred cannula insertion direction for guiding the cannula 200 through the sclera into the internal fluid passage of the scleral venous sinus. The marker 800 includes at least a pair of marking pads 810, 812. Each marking pad 810, 812 is preferably positioned to form a line tangential to the scleral venous sinus when the edge 808 of the aiming aperture through the confluence 806 is concentric with the pupil of the eye. Dye applied to the contact surface 814 on each marking pad 810, 812 can be transferred to the sclera 1002 as intersecting line segments when these contact surfaces come into contact with the surface of the eye.

[0103] The two marking pads 810, 812 in each pair of marking pads are arranged at an angle relative to each other, such that the intersection of two line segments formed on the eye marks the preferred cannula entry point 606. The intersection of the two line segments is preferably offset from the limbus 1008 by a predetermined interval 826, measured radially from the pupil center 1018. The limbus 1008 indicates the basic position of the scleral venous sinus 1010 with sufficient accuracy so that the marking formed by the two pads 810, 812 accurately indicates the insertion position and direction of the distal end of the cannula into the scleral venous sinus. This predetermined interval distance can be determined based on the selected length of each line segment to be marked on the eye and the number of individual cannula entry points 606 to be marked on the eye.

[0104] Multiple pairs of gaskets 810, 812 can be connected to the central manifold 806. A handle 802 can be attached to the central manifold 806. Gaskets 810, 812 can be directly connected to the manifold, or alternatively, connected to the manifold via an intermediate radial arm 804. Figure 26 An example of a cannula needle entry point marker 800 includes a converging portion 806 having seven radial arms 804. A first marking pad 810 and a second marking pad arranged at an angle to the first marking pad 812 are connected to each radial arm 804. Alternative embodiments of the marking fixture 800 may have a different number of radial arms and marking pads than those shown in the figures.

[0105] Figure 29 It shows the way Figure 26-28 An example of a marker 800 marking the cannula entry point on the outer surface of the eye. Figure 29 In the example, iris 1006 is represented as the shaded area between the edge of pupil 1016 and limbus 1008, where scleral venous sinus 1010 is close to limbus. Figure 29 The edges of the limbus 1008, scleral venous sinus 1010, and pupil 1016 are indicated by dashed lines to distinguish these lines from the markings formed by instrument 800. Figure 29 In this context, the sclera 1002 is represented by the area outside the periphery of the limbus 1008.

[0106] Each pair of marking pads 810, 812 is printed with a corresponding pair of line segments 818, 820 tangent to the scleral venous sinus 1010. Each pair of line segments 818, 820 converges at an intersection point 822 corresponding to the cannula entry point 606 on the sclera. More than one entry point 606 can be marked to provide selection of the cannula insertion point for reaching the target area in the eye. Each intersection point 822 is offset radially from the limbus 1008 by a predetermined interval distance 826. Dots or other markings can be placed at each intersection point 822 to enhance the visibility of the location of the cannula entry point 606.

[0107] The marking device 800 at the cannula entry point marks the pattern of intersecting line segments from... Figure 29 After the sample is transferred to the surface of the eye, an intersection point 822 can be selected for inserting the cannula through the sclera. The distal end 210 of the cannula 200 is preferably positioned to directly contact the intersection point 822 on the sclera. Preferably, the axis 206 of the cannula is parallel to one of the line segments 818, 820, and the cannula travels parallel to this line segment in the direction from the intersection point 822 to the limbus 1008 until the irradiated distal end 220 of the cannula is observed to enter the scleral venous sinus 1010. After the cannula enters the scleral venous sinus, the composite microcannula 300 can be extended from the tip of the cannula, as per [reference to...]. Figure 21 and Figure 22 The example described.

[0108] Figure 30 Examples of some steps included in a method embodiment are shown. The method according to embodiment 700 may include one or more of the following steps in any combination:

[0109] In step 702, the distal end of the composite microcannula is placed inside the lumen of the cannula needle;

[0110] In step 704, a structure in the eye is selected for receiving the cannula. Scleral venous sinuses, collector channels, and blood vessels are examples of selectable structures; however, it should be understood that embodiments of the microsurgical instrument 100 can be used to introduce the composite microcannula into other chambers, blood vessels, or channels in the eye or into another organ.

[0111] Examples of method implementation embodiments may further include:

[0112] In step 706, select the insertion point of the cannula on the eye;

[0113] In optional step 708, a marking fixture (e.g.) is used. Figure 26 The example uses a cannula entry point marker 800 to mark the cannula entry point;

[0114] In step 710, the distal end of the composite microcannula is irradiated, thereby irradiating the distal end of the cannula needle;

[0115] In step 712, the cannula is positioned at the selected cannula entry point;

[0116] In step 714, the cannula is advanced from the selected cannula entry point until the irradiated distal end of the cannula is observed to enter the selected structure in the eye; and

[0117] In step 716, the composite microcannula is extended from the distal end of the cannula toward the target area in the eye, thereby changing the irradiation from the distal end of the cannula to the tissue outside the cannula. Examples of target areas include, but are not limited to, atria, blood vessels, channels or venous sinuses blocked by obstructing material, and collapsed or narrowed spaces to be enlarged or reopened.

[0118] Exemplary method embodiments may optionally include one or more of the following:

[0119] Keep the distal end of the composite microcannula stationary relative to the cannula needle;

[0120] The scleral venous sinus was chosen as the structure to be entered distal to the irradiated end of the cannula.

[0121] The cannula is advanced from the selected cannula entry point along a line tangent to the scleral venous sinus.

[0122] Mark the cannula entry point at the intersection of the two lines, each of which is tangent to the scleral venous sinus;

[0123] Locate these two tangents at the optimal distance where they intersect the limbus of the eye;

[0124] Center the marker over the pupil of the eye and press the marker against the eye to mark the two tangent lines on the surface of the eye;

[0125] Each time the marker is pressed against the eye, mark one or more cannula entry points;

[0126] Use another optical guide to illuminate the distal end of the cannula;

[0127] The payload is inserted into the composite microcannula and delivered to the target region;

[0128] The distal end of the cannula is irradiated with electromagnetic radiation, and the distal end of the cannula is observed with a camera sensitive to the electromagnetic radiation, the wavelength of which is invisible to the naked eye.

[0129] While keeping the cannula at the cannula entry point, remove the composite microcannula from the cannula;

[0130] Insert the payload into the composite microcannula;

[0131] This allows the payload to move through the composite microcannula to reach the target area.

[0132] Retracting the composite microcannula allows the payload to remain within the target area; and

[0133] After the distal end of the cannula enters the selected structure in the eye, the cannula is kept stationary relative to the eye.

[0134] Figure 34 , Figure 35 and Figure 36 Another example of a microsurgical instrument with a locator configured to extend and retract a composite microcannula through the lumen of a trocar. The locator 400 is configured to attach the trocar 200 to the distal end 418 of a handpiece 420. The composite microcannula 300 extends through the lumen of the trocar 300 and the handpiece 420, wherein the microcannula is coupled to an insert 488 slidably engaged with the handpiece 420. As explained in more detail below, sliding the actuator 424 a selected distance 484 in a slot 428 on the handpiece 420 causes the composite microcannula to be displaced correspondingly by a distance 486 relative to the end of the hollow rigid shaft 206 of the trocar, a distance equal to twice the displacement distance 484 of the actuator. The cannula 200 and the composite microcannula 300 can be set separately from the positioner 400 and can be removable for replacement in case the cannula or microcannula is damaged or otherwise cannot be used for a particular surgical procedure.

[0135] Figure 36 Two cross-sectional views show Figure 34 Some internal features of the exemplary locator 400. Figure 36 Section HH shows the actuator 424 retracting toward the proximal end 416 of the handpiece 420. Section JJ shows the actuator traveling toward the distal end 418 of the handpiece 420. Figure 36 The two views of the middle handpiece 420 are referenced to each other, allowing for an accurate comparison of the positions of the internal components between these sections.

[0136] The insert 488 slidably engages with the inner surface of the cavity formed within the handheld member 420. The actuator 424 travels along one or more guide ridges 430. A U-shaped hollow tube 492 attached to the actuator 424 moves with the actuator. An insertion displacement wire 490 slidably passes through the inner cavity of the U-shaped hollow tube 492. One end of the insertion displacement wire 490 is attached to the insert 488. The opposite end of the insertion displacement wire 490 is attached to an anchor post 494, which is securely attached to the handheld member 420 or alternatively formed as an integral part thereof. The insertion displacement wire 490 is preferably flexible enough to easily slide around the bend of the U-shaped hollow tube 492, and also stiff enough to push the insert 488 in the distal direction (i.e., away from the cannula 200) when the actuator is displaced in the distal direction.

[0137] With one end of the insertion displacement wire 490 fixed to the handpiece at the anchor post 494 and the other end of the wire fixed to the insert 488, the actuator 424 slides a certain distance "d" 484 along the handpiece, causing the U-shaped hollow tube 492 to shift by the same distance "d", and the insert 488 to shift twice (2 x d), which is represented in the figures by the relative displacement 486 of the insert between sections HH and KK. The composite microcannula 300 is sufficiently securely connected to the insert 488 to keep the composite microcannula stationary relative to the insert when the actuator moves relative to the handpiece. Since the insert causes the actuator to move twice the displacement distance 484, the composite microcannula also causes the actuator to move twice the displacement distance 484. Moving the actuator proximally a distance "d" 484 causes the composite microcannula to extend a distance "2 x d" 486 from the cannula needle. The actuator is moved a distance "d" to the distal side to retract the composite microcannula a distance "2x d".

[0138] The composite microcannula 300 can pass through a hollow sleeve having a fixed section 436, which is attached to or alternatively formed as an integral part of the hollow rigid shaft 206 of the cannula needle 200. A movable section 434 of the hollow sleeve is slidably engaged at one end with the fixed section 436 and attached to the insert 488 at the other end. As the actuator travels and retracts, the hollow sleeve restricts the lateral deflection of the composite microcannula, thereby forcing the composite microcannula to travel and retract without twisting or significantly bending within the handpiece.

[0139] like Figure 36 As suggested by the example, the composite microcannula 300 can extend outward from the proximal end 416 of the locator 400 and the insert 488. The proximal extension of the composite microcannula can be configured to receive solid and / or liquid payloads, surgical instruments, and one or more optical fibers, as previously described.

[0140] Unless otherwise expressly stated herein, common terms have their corresponding common meanings within the appropriate context in which they are referred to, and common terms in the art have their corresponding conventional meanings.

Claims

1. An apparatus comprising: A cannula, the cannula comprising a rigid shaft having a proximal end and a distal end, the rigid shaft forming an inner cavity extending from the proximal end to the distal end, the distal end being shaped for puncturing the sclera of the eye. A composite microcannula positioned within the lumen, the composite microcannula comprising: A flexible hollow tube, wherein the outer diameter of the flexible hollow tube is smaller than the inner diameter of the inner cavity; and The material layer inside the flexible hollow tube surrounds the inner cavity of the flexible hollow tube and forms a light guide. The material layer has a refractive index different from that of the flexible hollow tube. It is used to transmit light coupled to the proximal end of the composite micro-insertion tube to the distal end of the composite micro-insertion tube as the composite micro-insertion tube extends beyond the distal end of the rigid axis. In this process, after scleral puncture is completed, the composite micro-cannula can be controllably extended beyond the distal end of the cannula needle to further enter the eye. Handheld component, to which the cannula needle is attached; An actuator that can be slidably connected to the handheld device; An insert that can be slidably connected to the handheld component; The hollow tube attached to the actuator; and A wire passes through the hollow tube of the actuator, with a first end attached to the handpiece and a second end attached to the insert.

2. The device according to claim 1, further comprising: the flexible hollow tube having longitudinal voids extending from its proximal end to its distal end; and the material layer being concentrically arranged around the longitudinal voids within the flexible hollow tube.

3. The device according to claim 1, further comprising, wherein the composite microcannula is connected to the insert.

4. The device of claim 3, further comprising a movable sleeve slidably engaged with the rigid shaft, the movable sleeve being attached to the insert, and the composite microcannula passing through the movable sleeve.

5. The device according to claim 1, wherein, The hollow tube of the actuator is U-shaped.

6. The device according to claim 1, wherein, The composite microcannulas have flexural stiffness and outer diameter configured to allow the composite microcannulas to follow the Schrem tube.

7. An apparatus comprising: A cannula, the cannula comprising a rigid shaft having a proximal end and a distal end, the rigid shaft forming an inner cavity extending from the proximal end to the distal end, the distal end being shaped for puncturing the sclera of the eye. A composite microcannula positioned within the lumen, the composite microcannula comprising: A flexible hollow tube, wherein the outer diameter of the flexible hollow tube is smaller than the inner diameter of the inner cavity; and The material layer inside the flexible hollow tube has a refractive index different from that of the flexible hollow tube; In this process, after scleral puncture is completed, the composite micro-cannula can be controllably extended beyond the distal end of the cannula needle to further enter the eye. Handheld component, to which the cannula needle is attached; An actuator that can be slidably connected to the handheld device; An insert that can be slidably connected to the handheld component; The hollow tube attached to the actuator; and A wire passes through the hollow tube of the actuator, with a first end attached to the handpiece and a second end attached to the insert.

8. The device of claim 7, further comprising, wherein the composite microcannula is coupled to the insert.

9. The device of claim 7, further comprising a movable sleeve slidably engaged with the rigid shaft, the movable sleeve being attached to the insert, and the composite microcannula passing through the movable sleeve.

10. The device according to claim 7, wherein, The hollow tube of the actuator is U-shaped.

Images