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  Dimensionally stable balloonsRelated Patent Categories: Surgery, Instruments, Internal Pressure Applicator (e.g., Dilator), Inflatable Or Expandible By FluidDimensionally stable balloons description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20050234500, Dimensionally stable balloons. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of copending U.S. patent application Ser. No. 09/426384. BACKGROUND OF THE INVENTION [0002] Medical catheters having a balloon mounted thereon are useful in a variety of medical procedures. A balloon may be used to widen a vessel into which the catheter is inserted by dilating the blocked vessel, such as in an angioplasty procedure. More significant to the present invention however, is the use of a catheter to deliver a medical device, such as a stent, into a body lumen. Some examples of stent delivery balloons are disclosed in U.S. Pat. No. 5,702,418, and U.S. Pat. No. 5,797,877, the entire contents of both patents is hereby incorporated by reference. In these and other medical device delivery applications, radial expansion of a balloon may be used to expand or inflate a stent at a desired positioned within the body. Using a balloon equipped catheter to deliver a stent requires precise positioning of the balloon and stent as well as a balloon with accurate and predictable expansion properties. A known drawback of many previous delivery catheters and balloons is that when a balloon is radially inflated to a desired extent, the balloon will also expand longitudinally. As a result of longitudinal expansion of a balloon during the delivery of a medical device, the balloon itself, the medical device mounted thereupon or both apparatuses may be shifted from their pre-inflation position resulting in improper delivery of the medical device. [0003] In balloons where longitudinal expansion occurs, the balloon may expand longitudinally past one or both of the stent ends. Typical stent delivery balloons will expand longitudinally at least 5% beyond ihe original pre-inflation state. In addition to potentially mis-delivering the medical device as described above, the resulting extended balloon may cause the edges of the stent to push against the vessel wall to a greater extent than they would from radial expansion alone. The protruding stent edges may damage or tear the surrounding vessel resulting:in potentially serious trauma for the patient. [0004] It has recently been discovered that Liqud Crystal Polymers (LCP) may be effectively blended with other materials and extruded to form high strength medical balloons. In copending U.S. application Ser. No. 08/926,905 (corresponding to PCT/US98/18345 filed Sep. 4, 1998), and Ser. No. 09/257,677 filed Feb. 25, 1999 there are described medical balloons made from LCP blends. The entire contents of both of these applications is hereby incorporated by reference. [0005] U.S. Pat. No. 5,389,314 to Wang discloses an inflatable medical device which has a plurality of longitudinally oriented conduits which extend through out the length of the device. The device may be formed by co-extruding two dissimilar plastic materials. The first material form defining a discrete phase which forms fibers and the other material or continuous phase which forms the remaining balloon material. After extrusion the discrete phase is withdrawn from the continuous phase, leaving the continuous phase with a plurality of conduits therethrough. BRIEF SUMMARY OF THE INVENTION [0006] The present invention is directed generally to medical balloons which expand only to a predetermined extent, and which have minimal longitudinal and/or minimal radial growth during expansion. Specifically, the invention is directed to a stent delivery balloon composed of a micro-composite material which includes a longitudinal fibril structure that is either parallel to the longitudinal axis of the balloon structure, or that is diagonal to the longitudinal axis at the molecular level of the balloon. The orientation of the fibril structure can limit longitudinal expansion of the balloon and allow the balloon to expand radially as desired, but minimally, or not at all in the longitudinal direction if the fibrils are parallel to the balloon axis, or when the fibrils are oriented diagonally about the axis, can limit both longitudinal and radial expansion of the balloon when inflated. [0007] The micro-composite material is made up of a combination of a fibril component, a semi-compliant balloon material which acts as a matrix, and optionally a compatibilizer material which may act to create a less distinctive phase boundary between the fibril and matrix components, but which does not solubilize the LCP polymer in the matrix at human body temperature. [0008] The present invention provides for a balloon which utilizes LCP materials or other oriented materials such as PET, in combination with a thermoplastic elastomer matrix and an optional compatibilizer to form a micro-composite material. The present micro-composite material is suitable for construction balloons which exhibit minimal or no longitudinal growth during balloon expansion but which expands as desired in the radial direction, or the present micro-composite material is suitable for construction of balloons that exhibit minimal expansion both in the longitudinal and radial directions. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0009] A detailed description of the invention is hereinafter described with specific reference being made to the drawings in which: [0010] FIG. 1 is a schematic representation of side view of a tubular parison used to produce a balloon of the invention from a the micro-fiber composite material; [0011] FIG. 2 is a schematic side view of a medical device delivery balloon constructed from micro-composite material shown at nominal diameter wherein the fibril component is oriented parallel to the longitudinal balloon axis. [0012] FIG. 3 is a view of the medical device delivery balloon shown in FIG. 2 in an inflated state at a pressure higher which causes radial growth of the balloon; [0013] FIG. 4 is a cross-sectional view of a tubular parison for producing balloon of an alternative embodiment of the invention; and [0014] FIG. 5 is a perspective view of the embodiment shown in FIG. 4. [0015] FIG. 6 is perspective view of a dilatation balloon preform in a tubular parison form constructed from micro-composite material wherein the inner and outer fibril components have been oriented diagonally to the longitudinal axis of the tubular preform and in crossing relationship relative to each other by use of a counter-rotating extrusion die. [0016] FIG. 7 is another perspective view of only the outer surface of a dilatation balloon preform constructed from micro-composite material wherein the fibril component is oriented diagonally to the longitudinal axis of the tubular preform by use of a rotating die. [0017] FIG. 8 is a schematic side-view of a blow molded dilatation balloon constructed from micro-composite material depicting the fibril component oriented diagonally to the longitudinal axis of the balloon. DETAILED DESCRIPTION OF THE INVENTION [0018] While this invention may be embodied in many different forms, there are shown in the drawings and described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. [0019] As noted above, the present invention relates to medical catheters which have one or more balloon portions constructed from a specially configured micro-composite material. The particular micro-composite material and configuration provides physical properties which allow a balloon to expand radially to a predetermined extent, but which allow only minimal, or more preferably, no longitudinal growth during expansion. The micro-composite material includes a longitudinal fibril component which exhibits micro-fibers at the molecular level in combination with a matrix of any semi-compliant balloon material. Depending on the specific fibril component, as well as the method of extrusion utilized to extrude the balloon material, the micro-fibers may be randomly scattered through out the balloon material or may be precisely spaced about the balloon and extending through the entire balloon length. The fibril structure is oriented or directed in the longitudinal direction of the balloon providing the balloon with desirable radial expansion characteristics and minimal longitudinal growth when the balloon is inflated. Continue reading about Dimensionally stable balloons... Full patent description for Dimensionally stable balloons Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Dimensionally stable balloons patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Dimensionally stable balloons or other areas of interest. ### Previous Patent Application: Dilatable balloon implant Next Patent Application: Multi-lumen balloon catheter including manifold Industry Class: Surgery ### FreshPatents.com Support Thank you for viewing the Dimensionally stable balloons patent info. 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