The present disclosure generally relates to the field of phacoemulsification, and more specifically the field of infusion sleeves.
Typical phacoemulsification ultrasonic surgical devices consist of an ultrasonically driven handpiece with an attached cutting tip and irrigating sleeve, also known as an infusion sleeve, with an electronic control module. The handpiece generally includes an irrigation line, aspiration line and a power cord, all of which are generally interconnected to, and controlled by, the control module. In use, the cutting tip and attached infusion sleeve are inserted into a small incision in a cornea, or other location. The control module varies a power level in the handpiece to ultrasonically vibrate the cutting tip, while providing irrigation between the infusion sleeve and cutting tip. The control module also provides a vacuum through a port in the cutting tip.
The infusion sleeve is the only part, other than the cutting tip, that comes into contact with a patient. Thus, the infusion sleeve's operability is extremely important for the overall performance of the phacoemulsification equipment. One concern in phacoemulsification surgical procedures is the problem of heat build-up in the cutting tip. Wound pressure on the infusion sleeve walls compresses the walls and causes both reduced fluid flow to and from the cutting tip and heat-producing frictional contact between the vibrating cutting tip and the walls of the infusion sleeve. Thus, as cooling fluid flow is diminished, frictional heat increases without a means to dissipate the heat. The heat build-up can cause scleral or corneal burns very quickly. This problem becomes an increasing concern when higher frequency (i.e. higher energy) vibrations are used. Passively, corneal burns may be mitigated by a surgeon through appropriate adjustments of a combination of operating parameters, such as the amount of phaco power delivered and the volume of irrigation/aspiration flow. Additionally, some prior art handpiece assemblies (or probes) generally have relied solely on a textured inner sleeve wall and the flow of the irrigant between the cutting tip and the sleeve and the flow of aspirated material into the cutting tip bore to cool the cutting tip. However, a viscoelastic material injected into the anterior ocular chamber during a typical phacoemulsification procedure resists the flow of the irrigant out of the sleeve and is highly resistant to aspiration flow into the cutting tip bore. Therefore, the flow of aspiration and irrigation fluids into and out of the eye can be momentarily occluded whenever the cutting tip and sleeve come into contact with the viscoelastic material. This momentary occlusion can result in sudden cutting tip overheating and resultant scleral and/or corneal lesions. Thus, because cutting tip overheating occurs very rapidly (within 1 to 3 seconds), even short term exposure to such overheating can cause injury to delicate eye tissue.
Other prior art attempts to prevent heat transmission methods have been employed through the use of “Mackool tips.” A Mackool tip is a two part infusion sleeve having an inner rigid sleeve that is inserted into and surrounded by an outer malleable sleeve. The inner rigid sleeve is considered as part of the Mackool phaco tip and sits loosely on a main shaft portion of the Mackool phaco tip. The purpose of the inner rigid sleeve is to decouple the vibrating needle from the infusion sleeve. The inclusion of the inner rigid sleeve results in a much more dramatic reduction of heat.
While the Mackool tip has been proven effective in reducing heat generation, there remains room for improvement. Specifically, the need arises for an infusion sleeve that eliminates the use of the separate inner rigid sleeve, while still providing additional heat reducing properties with reduced friction in a single piece infusion sleeve.
A phacoemulsification system is disclosed. The system includes a phacoemulsification handpiece and selectively detachable infusion sleeve. The infusion sleeve may include a single body portion defined by a first open end and a second open end and having a hollow interior portion therein. The body portion may include multiple layers with at least one inner layer and at least one outer layer, such that the layers are constructed of separate and distinct materials.
Exemplary embodiments of the present disclosure will now be described by way of example in greater detail with reference to the attached figures, in which:
Referring now to the discussion that follows and also to the drawings, illustrative approaches to the disclosed devices and methods are shown in detail. Although the drawings represent some possible approaches, the drawings are not necessarily to scale and certain features may be exaggerated, removed, or partially sectioned to better illustrate and explain the present disclosure. Further the descriptions set forth herein are not intended to be exhaustive or otherwise limit or restrict the claims to the precise forms and configurations shown in the drawings and disclosed in the following detailed description.
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Additionally, the inner surface layer 62 may be made with materials providing a relatively stiff surface that may have a relatively low coefficient of friction such that the surface friction is minimized against the vibrating cutting tip 22. Generally, such inner surface layer 62 materials may include, but are not limited to an injection-moldable polyimide, and an acetal. These materials may typically have a coefficient of friction value approximately in a range of 0.1 to 0.3. The inner surface layer 62 may also include mechanical features, such as, but not limited to, bumps 80 (see
Multiple layers may be used to simultaneously impart additional heat and friction-reducing properties, as opposed to the previous single material designs and previous multi-piece designs. In one exemplary arrangement, the two layers 62, 64 may be created using multi-layer injection molding or overmolding processes. Merely by way of example, multi-component, multi-shot and over-molding process may be employed to create a multiple layered infusion sleeve in a unitary construction.
Multi-component molding may be further subdivided into co-injection, bi-injection and interval injection. Co-injection molding involves making sequential injections into the same mold with one material as the core and one as the skin. It may also be known as sandwich molding because the core is fully encapsulated. Bi-injection molding is the simultaneous injection of different materials through different gates. Interval injection molding, also known as marbling, is the simultaneous injection of different materials through different gates giving limited mixing.
Multi-shot molding describes any process where distinct material shots are applied to produce the final component. This includes transfer molding, injection molding, core back molding and rotating tool molding. Where multiple slugs of different materials may be injected into the mold to create the multiple layered product.
Over-molding includes both insert molding and lost core molding, the latter produces hollow parts. Over-molding allows the desired part to be preformed and then reinserted into a mold for an additional layer of material to be applied to the original part.
In use, the infusion sleeve threads 68 may be rotatively engaged with corresponding threads in the body portion 16 to lock the two pieces as one unit. Further assembly includes attaching the aspiration line 32, irrigation line 34 and power cord 30 to the control module to create a phacoemulsification assembly. It should be known that the infusion sleeve 50 may be of various diameters and lengths to accommodate specific phacoemulsification cannula 20 and body portions 16. Infusion sleeve 50 selection may include selecting a sleeve to allow the cutting tip 22 to extend a predetermined distance from the end of the infusion sleeve 50 to allow for proper alignment of the cutting tip 22 extending past the fluid ports 70. This may allow the cutting tip 22 to provide enough ultrasonic vibration to breakup or emulsify the cataract and draw in just the cataract tissue and not draw additional liquid from the incision. This predetermined distance may also help to eliminate any irrigant from being drawn directly from the hollow area 60 within the infusion sleeve 50.
Once the assembly is created, an operator may activate the control module to cause the phacoemulsification device cannula 20 to vibrate ultrasonically, and these vibrations are transmitted along to the cutting tip 22 where the vibrations are used to fracture or emulsify a cataract or other phaco-type tissue. A vacuum source may be activated to draw the emulsified tissue or aspirant through a central lumen 24 in the cannula 20 (illustrated in
As discussed above, the interaction between the infusion sleeve 50 and the cannula 20 may result in overheating and unwanted vibration. Therefore the exemplary infusion sleeve 50 may be constructed with an additional layer 72 of material, as illustrated in
It will be appreciated that the devices and methods described herein have broad applications. The foregoing embodiments were chosen and described in order to illustrate principles of the methods and apparatuses as well as some practical applications. The preceding description enables others skilled in the art to utilize methods and apparatuses in various embodiments and with various modifications as are suited to the particular use contemplated. In accordance with the provisions of the patent statutes, the principles and modes of operation of this disclosure have been explained and illustrated in exemplary embodiments.
It is intended that the scope of the present methods and apparatuses be defined by the following claims. However, it must be understood that the exemplary embodiments may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. It should be understood by those skilled in the art that various alternatives to the embodiments described herein may be employed in practicing the claims without departing from the spirit and scope as defined in the following claims. The scope of the disclosure should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future examples. Furthermore, all terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. It is intended that the following claims define the scope of the disclosure and that the method and apparatus within the scope of these claims and their equivalents be covered thereby. In sum, it should be understood that the exemplary embodiment is capable of modification and variation and is limited only by the following claims.
This application claims the benefit of priority of U.S. Provisional Patent Application Ser. No. 61/423,183 titled “Infusion Sleeve With Multiple Material Layers”, filed on Dec. 15, 2010, whose inventors are Grace Chuang Liao and Karen T. Hong, which is hereby incorporated by reference in its entirety as though fully and completely set forth herein.
Number | Date | Country | |
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61423183 | Dec 2010 | US |