Patent Application
20070078500
1. Field of the Invention
Embodiments of the present invention are directed to systems and methods for the analysis and treatment of a lumen. More particularly, the present invention relates to a balloon catheter that is used to perform an angioplasty of endovascular lesions and a method of treatment using such a balloon catheter.
2. Description of the Related Art
With the continual expansion of minimally-invasive procedures in medicine, one procedure that has been highlighted in recent years has been percutaneous transluminal angioplasty, or “PTA”. The most prevalent use of this procedure is in the coronary arteries, which is more specifically called a percutaneous coronary transluminal angioplasty, or “PTCA”. These procedures utilize a flexible catheter with an inflation lumen to expand, under relatively high pressure, a balloon at the distal end of the catheter to expand a stenotic lesion.
The PTA and PTCA procedures are now commonly used in conjunction with expandable tubular structures known as stents and an angioplasty balloon is often used to expand and permanently place the stent within the lumen. An angioplasty balloon utilized with a stent is referred to as a stent delivery system. Conventional stents have been shown to be more effective than angioplasty alone in maintaining patency in most types of lesions and also reducing other near-term endovascular events. A risk with a conventional stent, however, is the reduction in efficacy of the stent due to the growth of the tissues surrounding the stent which can again result in the stenosis of the lumen, often referred to as restenosis. In recent years, new stents that are coated with a pharmaceutical agents, often in combination with a polymer, have been introduced and shown to significantly reduce the rate of restenosis. These coated stents are generally referred to as drug-eluting stents, though some coated stents have a passive coating instead of an active pharmaceutical agent.
With the advent of these advanced technologies for PTA and PTCA, there has been a substantial amount of clinical and pathology literature published about the pathophysiologic or morphologic factors within an endovascular lesion that contribute to its restenosis or other acute events such as thrombosis. These features include, but are not limited to, collagen content, lipid content, calcium content, inflammatory factors, and the relative positioning of these features within the plaque. Several studies have been provided showing the promise of identifying the above factors through the use of visible and/or near infrared spectroscopy (i.e. across wavelengths ranging between about 250 to 2500 nm), including those studies referenced in U.S. Publication No. US2004/0111016A1 by Casscells, III et al., U.S. Publication No. US2004/0077950A1 by Marshik-Geurts et al., U.S. Pat. No. 5,304,173 by Kittrell et al., and U.S. Pat. No. 6,095,982 by Richards-Kortum, et al., the contents of each of which are herein incorporated by reference. However, there are very few, if any, highly safe and commercially viable applications making use of this spectroscopic data for combining diagnosis and treatment in a PTA or PTCA procedure.
Unfortunately, the most common diagnostic procedure associated with PTA or PTCA is angiography by fluoroscopy. This X-ray technology simply supplies an image of the blood flow within a lumen, thus identifying a stenosis, but giving no information about the endovascular wall of the plaque. Some important diseases located on non- or minor stenosis regions, such as a vulnerable plaque which is fatal to a patient life, are often missed. Other technologies, such as intravascular ultrasound, require expensive additional catheters and potentially dangerous additional procedures that can cause more harm than good and still not supply sufficient information about the plaque to be beneficial. There is currently no option for physicians to gain this useful information about the lumen wall in an accurate, cost-effective, and efficient manner that presents a reasonable risk profile for the patient.
Conventional balloon catheters suffer from a number of shortcomings and are used for other purposes than analysis of the pathophysiologic or morphologic features of the lumen wall at the lumen-expansion site. Prior use of optical fibers within an angioplasty catheter permit functions such as visualization to occur, but no optical analysis is obtained. Conventional balloon catheters therefore have no capacity to collect any information beyond the surface of the endovascular wall. While lower-pressure balloon catheters are available to occlude the blood flow proximal to the optical analysis window of a catheter, no lumen expansion is performed and no analysis can be performed within the balloon itself. Other systems support the use of optical feedback within a balloon catheter to atraumatically minimize the blood path between the balloon catheter and the endovascular wall. However, these systems likewise provide no ability to perform a complete optical analysis of the lumen wall.
The systems and methods described in the present specification provide physicians performing a lumen-expansion procedure with very useful information about the lumen wall without any significant increase in their procedure time or cost, and with little to no additional risk to the patient. Included are a number of implementations of the distal fiber-optic configuration to optimally facilitate illumination of the lumen wall and collection of resultant optical signal. These implementations also provide manufacturability and relatively low-cost production required for a disposable medical device.
In accordance with aspects of the invention, there are provided systems and methods that perform both a lumen expansion and optical analysis of a lumen wall. In one embodiment, the apparatus comprises a lumen-expanding balloon catheter having one or more delivery waveguides and one or more collection waveguides to perform optical analysis of the tissues surrounding the lumen undergoing expansion. In this manner, the delivery and collection of optical radiation is performed within the balloon of the catheter itself. Preferably, the optical analysis is performed when the lumen-expanding balloon is fully inflated, facilitating a relatively unobstructed optical path to the expanded lumen wall. Upon performing the lumen-expanding procedure and optical analysis, a computer can be utilized to analyze the optical signal to provide pathophysiologic or morphologic information about the lumen wall and thus guide appropriate additional treatment.
In one embodiment, optical analysis of the plaque is performed within the same catheter utilized for angioplasty during a PTA or PTCA procedure. This optical analysis could include, but not limited to, Raman spectroscopy, infrared spectroscopy, fluorescence spectroscopy, optical coherence reflectometery, optical coherence tomography, but most preferably diffuse-reflective, near-infrared spectroscopy. The embodiment provides optical analysis, and thus the pathophysiologic or morphologic features diagnosis, of a plaque during an angioplasty procedure without any significant additional cost, risk, or work for the physician. With access to this information, a physician could potentially choose from a selection of drug-eluting stents with different doses or agents, or even select a stent without a drug if indicated. By performing multiple angioplasties during a single visit by a patient, a physician could learn more about the general status of the patient's vasculature which can guide systemic therapies. New emerging technologies such as bioabsorbable stents could be enabled by the embodiments of the invention to optimize their use in the correct type of lesion.
Other advantages and novel features, including optical methods and designs of illuminating and collecting an optical signal of a lumen wall through a lumen-expanding balloon, are described within the detailed description of the various embodiments of the present specification.
In one aspect, a catheter for placement within a body lumen comprises: a flexible conduit that is elongated along a longitudinal axis, the flexible conduit having a proximal end and a distal end; at least one delivery waveguide and at least one collection waveguide positioned along the flexible conduit, the at least one delivery waveguide and the at least one collection waveguide constructed and arranged to transmit radiation at a wavelength in a range of about 250 to 2500 nanometers; and a lumen-expanding inflatable balloon disposed about a portion of the conduit, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide located within the balloon.
In one embodiment, the lumen-expanding balloon can comprise an angioplasty balloon.
In another embodiment, the transmission output of the at least one delivery waveguide and the transmission input of the at least one collection waveguide are contiguously retained to the flexible conduit.
In another embodiment, the catheter further comprises a fiber holder disposed about the conduit that contiguously retains the transmission output of the at least one delivery waveguide and the transmission input of the at least one collection waveguide to the flexible conduit.
In another embodiment, the fiber holder comprises at least one holder body having a plurality of holes that are substantially aligned with the longitudinal axis of the conduit when mounted thereto, the at least one delivery waveguide and the at least one collection waveguide being secured to the fiber holder at the holes.
In another embodiment, the fiber holder comprises at least one holder body having a plurality of grooves on a surface thereof, the at least one delivery waveguide and the at least one collection waveguide being secured to the fiber holder at the grooves.
In another embodiment, the plurality of grooves are arranged in a helix.
In another embodiment, the plurality of grooves are substantially aligned with the longitudinal axis of the conduit when the fiber holder is mounted thereto.
In another embodiment, the fiber holder is longitudinally translatable relative to the longitudinal axis of the flexible conduit so that the transmission output of the at least one delivery waveguide and the transmission input of the at least one collection waveguide are translatable between a first longitudinal position and a second longitudinal position of the conduit.
In another embodiment, the fiber holder is rotatable about the longitudinal axis of the flexible conduit so that the transmission output of the at least one delivery waveguide and the transmission input of the at least one collection waveguide can be rotated about the conduit.
In another embodiment, the transmission output of the at least one delivery waveguide and the transmission input of the at least one collection waveguide are spaced apart at a predetermined distance in order to facilitate collection of radiation emitted from tissue of a predetermined depth from the lumen-expanding inflatable balloon through the transmission input.
In another embodiment, the at least one delivery waveguide comprises at least one delivery fiber optic and wherein the at least one collection waveguide comprises at least one collection fiber optic.
In another embodiment, the at least one delivery fiber optic has a tapered end that operates as a reflection surface for changing a direction of a path of radiation transmitted along a longitudinal axis of the delivery fiber optic so that the radiation is emitted in a direction that is transverse to the longitudinal axis of the fiber.
In another embodiment, the at least one collection fiber optic has a tapered end that operates as a reflection surface for changing a direction of a path of radiation transmitted into the transmission input of the collection fiber optic so that the radiation is transmitted along a longitudinal axis of the collection fiber optic.
In another embodiment, the catheter further comprises an optical element disposed about the flexible conduit, the optical element including an array of multiple facets that lie at an acute angle relative to the longitudinal axis of the flexible conduit for changing a direction of radiation transmitted along a longitudinal axis of the at least one delivery waveguide so that the radiation is emitted in a direction that is transverse to the longitudinal axis of the at least one delivery waveguide.
In another embodiment, the catheter further comprises an optical element disposed about the flexible conduit, the optical element including an array of multiple facets that lie at an acute angle relative to the longitudinal axis of the flexible conduit for changing a direction of radiation transmitted into the transmission input of the at least one collection waveguides so that the radiation is transmitted along longitudinal axes of the collection waveguides.
In another embodiment, the distal ends of the at least one collection waveguide in the region of the transmission input lie along a helical path about the longitudinal axis of the conduit.
In another embodiment, distal ends of the at least one delivery waveguide in the region of the transmission output lie along a helical path about the longitudinal axis of the conduit.
In another embodiment, the transmission output of the at least one delivery waveguide and the transmission input of the at least one collection waveguide are spaced apart at a predetermined distance in a longitudinal direction along the longitudinal axis of the conduit.
In another embodiment, the balloon comprises a polymer material that is substantially transparent to radiation at the wavelength in the range of about 250 to 2500 nanometers.
In another embodiment, the polymer material is selected from the group of materials consisting of nylon and polyethylene.
In another embodiment, the at least one delivery waveguide comprises a plurality of delivery waveguides and wherein the at least one collection waveguide comprises a plurality of collection waveguides.
In another embodiment, the at least one delivery waveguide comprises two, three or four delivery waveguides and wherein the at least one collection waveguide comprises two, three or four collection waveguides.
In another embodiment, the plurality of transmission outputs of the plurality of delivery waveguides are arranged to illuminate an interior wall of a lumen about a 360 degree portion thereof through the balloon, when the balloon is inflated within the lumen, and wherein the plurality of transmission inputs of the plurality of collection waveguides are arranged to receive radiation from the interior wall of the lumen about the illuminated 360 degree portion thereof through the balloon.
In another embodiment, the at least one delivery waveguide comprises first and second delivery waveguides and wherein the at least one collection waveguide comprises first and second collection waveguides, and wherein the transmission outputs of the first and second delivery waveguides are positioned circumferentially opposite each other relative to the flexible conduit and wherein the transmission inputs of the first and second collection waveguides are positioned circumferentially opposite each other relative to the flexible conduit, so that four quadrants of a 360 degree portion of an interior wall of the lumen can be illuminated by the radiation through the balloon and so that reflected radiation can be received from the four quadrants of the interior wall through the balloon.
In another embodiment, the transmission output of the at least one delivery waveguide comprises an uncladded fiber core sealed within a covering that is substantially transparent to radiation at the wavelength in the range of about 250 to 2500 nanometers.
In another embodiment, the substantially transparent covering comprises a cylindrical capsule containing a material having an index of refraction so as to provide an interface between the uncladded fiber core and the material in the capsule to direct incident radiation in a predetermined direction.
In another embodiment, the transmission output of the at least one delivery waveguide comprises scattering particles and a reflective terminating member so as to direct radiation in a direction that is transverse to a longitudinal axis of the at least one delivery waveguide.
In another embodiment, the balloon is sealed to the flexible conduit at a first longitudinal position and the second longitudinal position of the flexible conduit.
In another embodiment, the balloon is coupled to the conduit at a first longitudinal position of the conduit at a first portion of the balloon and wherein the balloon is coupled to the conduit at a second longitudinal position of the conduit at a second portion of the balloon, and wherein the transmission output of the at least one delivery waveguide and the transmission input of the at least one collection waveguide are located within the balloon between the first and second longitudinal positions of the conduit.
In another embodiment, the catheter further comprises a guidewire sheath coupled to the conduit at the distal end of the conduit, wherein the balloon is coupled to the guidewire sheath and conduit at a first portion of the balloon and wherein the balloon is coupled to the guidewire sheath at a second portion of the balloon.
In another embodiment, the flexible conduit comprises a core tube including a guidewire lumen.
In another embodiment, the at least one collection waveguide and the at least one delivery waveguide are positioned within a fluid transfer lumen of the core tube along a majority of its length.
In another embodiment, the at least one collection waveguide and the at least one delivery waveguide are positioned within a catheter sheath surrounding the core tube along a majority of its length.
In another embodiment, at least one of the at least one delivery waveguide and the at least one collection waveguide comprises graded-index optical fiber.
In another embodiment, at least one of the at least one delivery waveguide and the at least one collection waveguide has a numerical aperture between approximately 0.22 and 0.4.
In another embodiment, the at least one delivery waveguide comprises a fiber having a fiber core diameter of between about 9 and 100 microns.
In another embodiment, the at least one collection waveguide comprises a fiber having a fiber core diameter of between about 50 and 200 microns.
In another embodiment, the at least one delivery waveguide comprises a fiber having a fiber core diameter of about 50 microns and wherein the at least one collection waveguide comprises a fiber having a fiber core diameter of about 100 microns.
In another embodiment, a maximum outer diameter of the catheter including the flexible conduit, the at least one delivery waveguide, the at least one collection waveguide and the balloon is less than about 1.5 millimeters when the balloon is uninflated.
In another aspect, a system for probing and treating a body lumen comprises: a flexible conduit that is elongated along a longitudinal axis suitable for insertion into a body lumen, the conduit having a proximal end and a distal end; at least one delivery waveguide and at least one collection waveguide integrated with the flexible conduit; at least one radiation source connected to a transmission input of the at least one delivery waveguide, the radiation source constructed and arranged to provide radiation at a wavelength in a range of about 250 to 2500 nanometers; at least one optical detector connected to a transmission output of the at least one collection waveguide; and a lumen-expanding inflatable balloon disposed about a portion of the conduit, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide located within the balloon.
In one embodiment, the transmission output of the at least one collection waveguide is connected to a spectrometer, the spectrometer constructed and arranged to scan radiation and perform spectroscopy at the wavelength in the range of about 250 nm to 2500 nm.
In another embodiment, the spectrometer is configured to perform spectroscopy selected from the group of spectroscopy methods consisting of fluorescence, light scatter, optical coherence reflectometry, optical coherence tomography, speckle correlometry, Raman, and diffuse reflectance spectroscopy.
In another embodiment, the spectrometer is constructed and arranged to scan radiation and perform spectroscopy at a wavelength within the range of about 750 nm to 2500 nm.
In another embodiment, the spectrometer is constructed and arranged to scan radiation and perform spectroscopy using one or more ranges of wavelengths.
In another embodiment, a scan using the one or more ranges of wavelengths includes a scan using one or more discrete wavelengths.
In another embodiment, the system further comprises a controller that is programmed to automate control of activation and deactivation of the at least one radiation sources and the at least one optical detectors, to further control analysis of data collected by the system.
In another embodiment, the system is constructed and arranged for use in a medical care facility including a hospital or outpatient unit.
In another embodiment, the controller is programmed to operate a human-interactive interface that provides an operator with feedback about data and analysis of the spectroscopy, the interface providing information for real-time diagnosis.
In another embodiment, the controller is programmed to identify one or more characteristics of targeted tissue including at least one of: presence of chemical components, tissue morphological structures, water content, blood content, temperature, pH, and color.
In another embodiment, the controller is further programmed to discriminate between tissue characteristics and non-relevant artifacts including elements of the catheter and other elements artificially introduced into the body lumen.
In another embodiment, the artificially introduced elements include at least one of stents and the coatings of stents.
In another embodiment, the system further comprises a switch coupled between the at least one radiation source and the at least one delivery waveguide that selects between multiple radiation sources for application of radiation to the at least one delivery waveguide.
In another embodiment, the system further comprises a switch coupled between the at least one radiation source and the at least one delivery waveguide that selectively applies the at least one radiation source to the at least one delivery waveguide.
In another embodiment, the system further comprises a therapy delivery subsystem.
In another embodiment, the therapy delivery subsystem further comprises a tube associated with the flexible conduit through which at least one of treatment drugs and agents can be delivered.
In another embodiment, the one or more radiation sources are configured to produce an output power of the radiation of less than about 20 milliwatts at locations outside the balloon when inflated.
In another aspect, a catheter for placement within a body lumen comprises: a flexible conduit that is elongated along a longitudinal axis, the flexible conduit having a proximal end and a distal end; at least one delivery waveguide and at least one collection waveguide positioned along the flexible conduit; and a lumen-expanding inflatable balloon disposed about a portion of the conduit, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide located within the balloon, wherein the maximum outer diameter of the catheter, including the flexible conduit, the at least one delivery waveguide, the at least one collection waveguide and the balloon is less than about 1.5 millimeters when the balloon is uninflated.
In one embodiment, the at least one delivery waveguide and the at least one collection waveguide are constructed and arranged to transmit radiation at a wavelength in a range of about 250 to 2500 nanometers
In another embodiment, at least one of the at least one delivery waveguide and the at least one collection waveguide comprises graded-index optical fiber.
In another embodiment, at least one of the at least one delivery waveguide and the at least one collection waveguide has a numerical aperture between approximately 0.22 and 0.4.
In another embodiment, the at least one delivery waveguide comprises a fiber having a fiber core diameter of between about 9 and 100 microns.
In another embodiment, the at least one collection waveguide comprises a fiber having a fiber core diameter of between about 50 and 200 microns.
In another embodiment, the at least one delivery waveguide comprises a fiber having a fiber core diameter of about 50 microns and wherein the at least one collection waveguide comprises a fiber having a fiber core diameter of about 100 microns.
In another aspect, a method for providing analysis and treatment of a body lumen comprises: inserting into a body lumen a catheter including a flexible conduit, a lumen-expanding balloon, at least one delivery waveguide and at least one collection waveguide, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide being located within the balloon; maneuvering the conduit into a designated region of the body lumen designated for treatment or analysis; expanding the balloon in the designated region of the body lumen; executing spectroscopic analysis of the designated region of the body lumen using radiation at a wavelength in a range of about 250 to 2500 nanometers by radiating the designated region of the body lumen with the radiation that is supplied at the transmission output of the at least one delivery waveguide, the supplied radiation passing through the balloon where it is incident on the designated region of the body lumen, and wherein radiation is returned through the balloon to the transmission input of the at least one collection waveguide.
In one embodiment, expanding the balloon therapeutically expands the body lumen.
In another embodiment, expanding the balloon to therapeutically expand the body lumen dilates the body lumen in the designated region.
In another embodiment, executing spectroscopic analysis is performed while the balloon is expanded.
In another embodiment, the insertion and maneuvering of the conduit and the expansion of the balloon follow procedures in accordance with percutaneous transluminal angioplasty.
In another embodiment, the insertion and maneuvering of the conduit and the expansion of the balloon follow procedures in accordance with percutaneous coronary transluminal angioplasty.
In another embodiment, the balloon is expanded such that the flow of blood between the balloon and the surrounding lumen tissue is substantially stopped.
In another embodiment, the spectroscopic analysis includes the characterization of one or more pathophysiologic or morphologic factors of surrounding tissue within an endovascular region.
In another embodiment, the pathophysiologic or morphologic factors include characterizing the presence, volume, and positioning of plaque within the endovascular region.
In another embodiment, the pathophysiologic or morphologic factors further include characteristics of plaque including at least one of collagen content, lipid content, calcium content, inflammation, or the relative positioning of pathophysiologic conditions within the plaque.
In another embodiment, the method further comprises providing a stent on the lumen-expanding balloon for delivery in the designated region at the time of expanding the balloon.
In another embodiment, executing spectroscopic analysis further comprises: collecting analysis data based on the radiation that is returned through the at least one collection waveguide; and discriminating between collected analysis data associated with targeted tissue in the designated region and analysis data associated with artifacts including at least one of the balloon, a balloon expansion media, a guidewire, a stent, and an artificial material placed on a stent.
In another embodiment, the analysis data associated with artificial materials placed on stents include data associated with polymers.
In another embodiment, the analysis data associated with artificial materials placed on stents include data associated with drugs.
In another embodiment, the method further comprises determining an appropriate treatment for the designated region using the spectroscopic analysis.
In another embodiment, determining an appropriate treatment includes selecting a type of stent most appropriate for insertion.
In another embodiment, determining a type of stent most appropriate for insertion includes selecting a drug and dosage to be eluted from the stent.
In another embodiment, executing spectroscopic analysis is performed while the balloon is partially inflated.
In another embodiment, the spectroscopic analysis performed while the balloon is partially inflated is used to calculate the location of damaged tissue.
In another embodiment, the calculation of the location of damaged tissue is used to guide the position of the conduit in the lumen prior to full inflation of the balloon.
In another embodiment, the method further comprises determining a level of expansion of the balloon using the spectroscopic analysis.
In another embodiment, the spectroscopic analysis is executed on a 360 degree portion of a wall of the lumen.
In another embodiment, executing spectroscopic analysis includes selectively switching delivery of radiation between separate ones of the at least one delivery waveguides.
In another embodiment, the selective switching distributes radiation to radiate predefined quadrants about the circumference of the balloon.
In another embodiment, the selective switching comprises selective operation of multiple radiation sources.
In another embodiment, executing spectroscopic analysis includes selectively scanning across one or more ranges of wavelengths.
In another embodiment, executing spectroscopic analysis includes scanning using one or more ranges of wavelengths between about 750 nm and 2500 nm.
In another embodiment, the one or more ranges of wavelengths are selected from ranges of approximately 250-930 nanometers, 1100-1385 nanometers, 1600-1850 nanometers, and 2100-2500 nanometers.
In another embodiment, selectively scanning across one or more ranges of wavelengths includes scanning using one or more discrete wavelengths.
In another embodiment, expanding the balloon comprises expanding the balloon with a biocompatible liquid that substantially minimizes the effects of scattering, distortion, and deflection of the radiation.
In another embodiment, the biocompatible liquid is at least one selected from the group consisting of: carbon dioxide, saline, deuterium oxide, and glycerin.
In another embodiment, the biocompatible liquid comprises super-saturated saline solution.
In another embodiment, executing spectroscopic analysis further comprises collecting analysis data based on the radiation that is received through the at least one collection waveguide.
In another embodiment, collecting analysis data occurs within a time period of less than about 1 second.
In another embodiment, the method further comprises analyzing the collected analysis data.
In another embodiment, an amount of power emitted from the lumen-expanding balloon during the spectroscopic analysis is less than about 20 milliwatts.
In another aspect, a method of forming a catheter for placement within a body lumen comprises: providing a flexible conduit that is elongated along a longitudinal axis suitable for insertion into a body lumen, the flexible conduit having a proximal end and a distal end; providing at least one delivery waveguide and at least one collection waveguide along the flexible conduit, the at least one delivery waveguide and the at least one collection waveguide constructed and arranged to transmit radiation at a wavelength in a range of about 250 to 2500 nanometers; and providing a lumen-expanding inflatable balloon about a portion of the conduit so that a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide are located within the balloon.
In one embodiment, the method further comprises forming distal portions of the at least one delivery waveguide and the at least one collection waveguide in a helical arrangement by: stripping end portions of the waveguides of outer jacketing; securing unstripped portions of the waveguides; applying a heat source to the end portions of the waveguides to be helically arranged, the heat source sufficient to make malleable the end portions; and applying forces to rotate the waveguides about a core segment and to translate longitudinally the end portions of the waveguides in the direction of their secured unstripped portions.
In another embodiment, the waveguides are helically arranged at predetermined angles by applying in a predetermined manner the forces to rotate and translate longitudinally the ends of the waveguides.
In another embodiment, securing the unstripped portions of the waveguides is performed using at least one locking member disposed about the core segment and the forces for rotating and translating are applied with a rotatably and translatably movable member disposed about the core segment.
In another embodiment, the end portions of the waveguides are translated a distance ranging from about 2 microns to 2 millimeters, while the end portions of the waveguides are rotated about 30 to 360 degrees about the core segment.
In another embodiment, the heat source provides heat at about 1600 Celsius.
In another embodiment, the balloon is laser welded to the conduit.
In another embodiment, the method further comprises providing a waveguide holder for contiguously retaining the at least one delivery waveguide and at least one collection waveguide to the flexible conduit.
In another embodiment, the at least one delivery waveguide and at least one collection waveguide are assembled with said waveguide holder prior to providing said at least one delivery waveguide and the at least one collection waveguide along the flexible conduit.
In another embodiment, the method further comprises shaping the transmission output of said at least one delivery waveguide after the assembly with said waveguide holder.
In another embodiment, the method further comprises shaping the transmission input of said at least one collection waveguide after the assembly with said waveguide holder.
In another embodiment, the waveguide holder for holding the at least one delivery waveguide and at least one collection waveguide comprises a holder body having a plurality of holes.
In another embodiment, the method further comprises aligning and fixing the plurality of holes with the longitudinal axis of the flexible conduit.
In another embodiment, the method further comprises correspondingly aligning and fixing the plurality of holes with one or more reflective surfaces.
In another embodiment, said one or more reflective surfaces are disposed radially about the flexible conduit as part of a multi-faceted reflecting element.
In another embodiment, said one or more reflective surfaces comprises a cone-shaped reflecting element aligned with the longitudinal axis of the flexible conduit.
In another embodiment, the waveguide holder for holding the at least one delivery waveguide and at least one collection waveguide comprises a holder body having a plurality of grooves disposed radially about the flexible conduit.
In another aspect, a catheter for placement within a body lumen comprises: a flexible conduit that is elongated along a longitudinal axis, the flexible conduit having a proximal end and a distal end; at least one delivery waveguide and at least one collection waveguide positioned along the flexible conduit, the at least one delivery waveguide and the at least one collection waveguide constructed and arranged to transmit radiation at a wavelength in a range of about 250 to 2500 nanometers; and a lumen-expanding inflatable balloon disposed about a portion of the conduit, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide being positioned along an outer surface of the balloon.
In one embodiment, the catheter further comprises a ring that couples body portions of the at least one delivery waveguide and the at least one collection waveguide to the flexible conduit.
In another embodiment, the transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide are mounted on the outer surface of the balloon.
In another aspect, a catheter for placement within a body lumen comprises: a flexible conduit that is elongated along a longitudinal axis, the flexible conduit having a proximal end and a distal end; at least one delivery waveguide and at least one collection waveguide positioned along the flexible conduit, the at least one delivery waveguide and the at least one collection waveguide constructed and arranged to transmit radiation at a wavelength in a range of about 250 to 2500 nanometers; and a lumen-expanding inflatable balloon disposed about a portion of the conduit, a transmission output of the at least one delivery waveguide and a transmission input of the at least one collection waveguide being mounted to an inner surface of the balloon.
In one embodiment, the catheter further comprises a ring that couples body portions of the at least one delivery waveguide and the at least one collection waveguide to the flexible conduit.
The foregoing and other objects, features, and advantages of the invention will be apparent from the more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
The accompanying drawings are described below, in which example embodiments in accordance with the present invention are shown. Specific structural and functional details disclosed herein are merely representative. This invention may be embodied in many alternate forms and should not be construed as limited to example embodiments set forth herein.
Accordingly, specific embodiments are shown by way of example in the drawings. It should be understood, however, that there is no intent to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the claims. Like numbers refer to like elements throughout the description of the figures.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that when an element is referred to as being “on,” “connected to” or “coupled to” another element, it can be directly on, connected to or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.).
The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise,” “comprises,” “comprising,” “include,” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
As used herein, the term “contiguously retained”, when referring to the interrelationship of the delivery and collection waveguides to the flexible conduit of the catheter to which they are attached, means that they are retained in a position that is proximal, or near, the conduit. For example, the waveguides can be bonded directly to the conduit, for example as shown and described in connection with the embodiment of
Connector subassembly 255 includes a flushing port 250 for supplying or removing liquid/gas 258 through port 70 for expanding or contracting balloon 111. Liquid/gas 258 is held in a tank 256 from which it is pumped in or removed from balloon 111 by actuation of a knob 254. Liquid/gas 258 can alternatively be pumped with the use of automated components (e.g. switches/compressors/vacuums). Solutions for expansion of the balloon are preferably non-toxic to humans (e.g. saline solution) and are substantially translucent to the selected light radiation.
Further reference is now made to
The catheter 110 can further comprise a therapy tube (not shown) that is attached to a therapy system, which can be used, for example, to treat a diseased artery. In this example, drugs can be delivered to the diseased artery via the therapy tube.
At least one energy source 180 is attached to a proximal end of the delivery fiber 112. At least one detector 170 is attached to a proximal end of the collection fiber 113. The energy source 180 generates electromagnetic radiation, for example, optical radiation, that is transmitted from the proximal end of the delivery fiber 112 to a distal end. The distal end of the delivery fiber 112 is positioned within the balloon and emits the optical radiation at the balloon 111, whereby the radiation is directed to the target region at an inner surface of the body lumen wall. Radiation is reflected from the body lumen wall and collected at a distal end of the collection fiber at the treatment end of the catheter 110. The spectral features of the lumen wall determine the amount and type of radiation that is reflected and/or otherwise emitted from the lumen wall. The collected radiation is captured at the distal end of the collection fiber 113 and is directed by the collection fiber 113 to the proximal end, whereby the detector 170 processes the reflected radiation as signal data.
As shown in
Embodiments include one or more commercially available spectrometers for scanning across multiple bands. For example, a single spectrometer can be employed, such as an AXSUN Technologies, Inc. (of Billerica, Mass.) IntegraSpec XL (Uno) CH spectrometer that provides a complete scan range of approximately 1550 to 1800 nm at about 25 milliseconds per scan and scans about 32 times to capture a set of data in about 0.8 seconds. Another embodiment includes one or more StellarNet, Inc. (of Tampa, Fla.) EPP2000 fiber optic spectrometers which can provide scans in the wavelength range of about 190 to 1700 nm. Ocean Optics, Inc. (of Dunedin, Fla.) provides many user-configurable spectrometers for output in the wavelength range of between about 200 to 1100 nm.
The reflected and collected radiation includes information which can be spectroscopically analyzed to obtain certain characteristics of the lumen wall, such as a change of chemical components, tissue morphological structures, water/blood content, and physiological parameters (e.g. temperature, pH, color, intensity) on the lumen wall. A spectroscopic analysis system 150 is connected to the detector 170, for processing the signal data received by the detector 170. The processed signal data can be output to a display 151 in the form of user-readable text and graphics. In this manner, the data can be analyzed by a user, for example, a physician, in real time, if desired.
In this manner, a physician can obtain real-time information from the diseased area undergoing treatment. This information may include all of pathological and/or pathophysiologic results, which, in the conventional approaches, are needed to sample tissue and/or blood from the lumen wall and which may require up to several days to analyze the information. The present invention permits the physician to immediately select the most suitable treatment for his/her patients according to the information obtained and processed from received optical radiation.
As shown in
In a preferred embodiment, the balloon 111 is an angioplasty balloon. The angioplasty balloon 111 can be inflated with a fluid that is transferred from a fluid source (not shown) through a fluid transfer lumen 116 in parallel with the guidewire lumen 130, wherein the fluid transfer lumen 116 and the guidewire lumen 130 are both surrounded by the core tube 131. The fluid is output to the balloon 111 via a port 117 that is connected to the fluid transfer lumen 116. The port 117 is located in the portion of the core tube 131 that is surrounded by the balloon 111. The port 117 and fluid transfer lumen 116 also permit the fluid to be removed from the balloon during deflation of the balloon, for example, prior to removal of the catheter from the body lumen. Directed optical radiation, for example, light, from the delivery fiber 112, and reflected optical radiation, for example, light, from the lumen wall may both be transmitted through the fluid-filled balloon during lumen wall data collection. It is therefore preferred that the properties of the fluid are such that the fluid minimizes any undesirable optical effects such as absorption, scattering, deflection, or distortion of the optical radiation that may occur as the optical radiation passes through the balloon 111 to/from the lumen wall. In this manner, the fluid that fills the balloon 111 can be either a liquid or gas, and preferably comprises saline, deuterium oxide, glycerin, or other liquids or gases that minimize the abovementioned optical effects.
During a balloon angioplasty therapy treatment, which can be performed in conjunction with the optical lumen wall analysis procedure described herein, the angioplasty balloon 111 is inflated with the fluid supplied via the port 117 at a sufficient pressure until the balloon 111 is sufficiently expanded against the stenosis region for treatment. At this time, the pressure of the balloon 111 against the lumen wall is preferably sufficient to obstruct blood flow. This feature is preferable for optical radiation collection from a blood vessel wall, since the balloon 111 is in direct contact with the wall. It is preferred that no blood is interposed between the balloon 111 and the lumen wall that may cause optical loss such as absorbance to occur, or other undesirable optical effects. Since there is little or no blood between the balloon 111 and the lumen wall, spectral features of the lumen wall 160 can therefore be measured with a high degree of accuracy. The embodiments of the present disclosure are also advantageous over conventional balloon catheters, which can only be used for treatment purposes. In contrast, the disclosed embodiments allow for simultaneously performing both optical analysis and angioplasty treatment, such as an angioplasty procedure or stent insertion, to gain the benefit of both treatment and diagnosis, wherein both spectroscopic analysis and angioplasty treatment can be performed in the same procedure, by the same catheter, without the need for removing and inserting different catheters for the two different purposes.
Fiber construction and size can be selected based on parameters relating to the type of analysis being performed, the number and sizes of discrete regions being analyzed, space, strength, and flexibility constraints and/or cost constraints. In various embodiments, fibers may be constructed of different materials and thicknesses of core, cladding, and jackets. Fibers may also be constructed of graded-index cores in order to increase the numerical aperture and power while retaining small core diameters. Embodiments of the invention include graded index fibers of numerical apertures between approximately 0.22 and 0.4. Embodiments include the use of delivery waveguides with core diameters between about 9 and 100 microns and the use of collection waveguides with a fiber core between about 50 and 200 microns. Lucent Technologies Specialty Fiber Group, for example, provides fibers having core diameters between about 62.5 μm to 1500 μm and numerical apertures between about 0.11 to 0.48. Yangtze Optical Fiber and Cable Co., Ltd. of Wuhan, China (See http://yofcfiber.com) provides single-mode fiber cores with diameters as small as about 9 μm.
In one embodiment, two delivery fibers and two collection fibers are included, wherein the delivery fibers have a numerical aperture of approximately 0.31, a graded core diameter of approximately 50 micrometers, a cladding layer thickness of approximately 9 to 10 micrometers, and a jacket of approximately 4 to 5 micrometers. Corresponding collection fibers can, for example, be graded indexed with a core numerical aperture of about 0.22, a core diameter of approximately 100 micrometers, a cladding layer thickness of approximately 10 micrometers, and a jacket thickness of approximately 10 micrometers. Smaller sized fibers with relatively high numerical apertures (NAs) (e.g. between about 0.22 and 0.4) allow for embodiments of a catheter system in accordance with the invention which have maximum outer diameters of about 1.5 mm or less, assuming an uninflated balloon that can provide smooth deployment within the cardiovascular system.
In one embodiment, the collection fibers 113 receive the reflected optical radiation from the lumen wall through the balloon 111 in a transverse direction relative to the longitudinal axis of the core tube 131, and direct the reflected optical radiation in a longitudinal direction from the distal end of the collection fibers 113 to the proximal end of the collection fibers 113, whereby the received optical radiation is transmitted to a detector 170. The collection fibers 113, like the delivery fibers 112, can comprise optical fibers including a core, a doped cladding, and a protective jacket. The optical radiation is received at the distal end of each collection fiber 113, and is directed from the distal end to the proximal end of the collection fiber 113. The term “transverse” as used herein for example when referring to a direction of emission or collection of radiation relative to a longitudinal axis of a fiber core or conduit includes all angles, whether acute, obtuse, or perpendicular, other than parallel to the longitudinal axis of the fiber or conduit.
The collection fibers 113 can be arranged to receive optical radiation at the treatment region much in the same manner as the delivery fibers 112 transmit radiation in the treatment region, but in an opposite direction. For example, in one embodiment, the collection fibers 113 extend along longitudinal axes, and are arranged in parallel with, and adjacent to, the delivery fibers 112 and the core tube 131. The distal end of each collection fiber 113 receives reflected optical radiation in a similar manner as delivery fibers 112 distribute radiation, whereby the reflected optical radiation impinges on an optical component at the distal end of the collection fiber 113. Optical components can include lenses, mirrors or optical reflectors. The optical components can optionally be integrated into the respective distal ends of each collection fiber 113 and/or delivery fiber 112 such as, for example, in accordance with the “side-fire” arrangement described further in reference to
The balloon 111 can be composed of a material such as nylon, or other translucent polymers. In one example, balloon 111 comprises, for example, a thin, optically clear, polyethylene balloon. In embodiments where the optical radiation is directed through the surface of the balloon, it is preferred that the surface of the balloon be sufficiently transparent or translucent to permit a maximum amount of directed and reflected optical radiation to be transmitted through the balloon surface, while minimizing any reflectance or loss.
Returning to
During operation, each delivery fiber 112 transmits optical radiation output by the source 180 from the proximal end to the distal end of the delivery fiber 112. At the distal end of the fiber, the optical radiation is then directed to a target region on the lumen wall. The radiation propagates from the distal end of the delivery fiber 112 through the fluid of the interior of the balloon 111, and through the surface of the balloon 111 that is in contact with the lumen wall, and is incident on the target region of the lumen wall.
The optical radiation is directed from the proximal end of each delivery fiber 112 in an axial and/or a radial direction to the target region, in accordance with one or more embodiments disclosed in the present specification. In one embodiment, the delivery fibers 112 are positioned along a longitudinal axis of, and parallel to, the core tube 131 and the balloon 111. The emitted optical radiation impinges on an optical component attached to an angled fiber tip at the distal end of each delivery fiber 112. Such optical components can include mirrors or optical reflectors that are integrated into the respective distal ends of the delivery fibers 112. Alternatively, the optical components may be external to the delivery fibers 112, but in relative proximity to the distal ends of the delivery fibers 112 to permit the optical radiation to transversely, radially, or axially exit the catheter 110. The optical components external to the fibers may be controlled by the spectroscopic analysis system 150, for example, to change the reflected surface angle of the mirrors or reflectors. Alternatively, the emitted and collected radiation can be transmitted directly from, and received directly by, the delivery and collection fibers 112, 113, in accordance with embodiments described in detail herein.
In the example embodiments described herein, optical radiation is transmitted through the balloon 111, and impinges on a target region at the lumen wall to be analyzed, the lumen wall abutting the outer surface of the balloon 111. Also, in the embodiments described herein, the reflective surface of a cleaved or polished fiber, mirror, or optical reflector can be adjusted or shaped to deliver a wider or narrower beam of optical radiation to the target area, thereby increasing or decreasing the area of radiation. In addition, multiple delivery fibers can be spaced accordingly to each direct a beam of optical radiation at a specific target region, wherein the multiple beams of optical radiation impinge multiple target regions. The target region, for example, a diseased area, can be partitioned into the more specific regions, whereby additional detailed information about the smaller diseased area can be obtained. Here, each of the beams passes through the surface of the balloon and impinges a respective section of the target region, for example, one or more quadrants of the target region. Alternatively, each fiber having a respective reflective surface can be configured to permit multiple beams of optical radiation of the delivery fibers to overlap or intersect each other, and thereby impinge a single target region.
The reflected radiation is collected at a distal end of each collection fiber 113 and transmitted to the proximal end to a detector 170. The detector 170 generates highly accurate signals from the received radiation. The spectroscopic analysis system 150 receives the signals from the detectors, and processes the signals, resulting in data that can be used by a system operator, for example, to determine lumen properties such as an amount of, or type of, plaque on the vascular wall. The spectroscopic analysis system 150 is attached to the proximal end of the collection fibers, and outputs the processed signal data to a display 151 in the form of user-readable text and graphics.
The spectroscopic analysis system 150 can perform conventional spectroscopy, for example, Raman spectroscopy, by using a commercially available spectrometer. Alternatively, infrared and near-infrared spectroscopy, fluorescence spectroscopy, optical coherence reflectometery, optical coherence tomography, or diffuse-reflective, near-infrared spectroscopy may be performed. In addition, the spectroscopic analysis system 150 can optionally perform control and management functions of various elements of the instrument 100, such as the source 180 and detector 170. For example, the spectroscopic analysis system 150 can control the source 180 to generate a beam of optical radiation at a given wavelength or range of wavelengths and/or at a required power. In another example, the spectroscopic analysis system 150 can adjust the angle of mirrors and reflectors that are integrated with the fiber tips or provided external to the fiber tips. This permits the area of radiation on the balloon surface to be changed, and to thereby increase or decrease the area of target region.
In one embodiment, prior to a lumen wall analysis, the catheter 110 can be made to collect data, and the spectroscopic analysis system 150 can be made to process the data and discriminate between relevant data for making a diagnosis, such as data from targeted tissue, and other data not pertinent for making diagnosis including, for example, data on the spectral features of the balloon 111. Such features may include, for example, the spectral strength of the balloon, or an area of expansion of an inflated balloon, or guidewire and/or stent “shadows” or spectral strength of the fluid in the balloon 111. These spectral features pose a risk of interfering with received radiation, but this risk can be mitigated or eliminated by a software program in a data analysis procedure via the spectroscopic analysis system 150 that compensates for such features.
In the example embodiments of
The fiber holder 133 can be formed of a material similar to those materials commonly used in stents, such as stainless steel, alloy steel and gold. In the embodiment illustrated, the distal ends of the fibers 112, 113 are cleaved and/or polished at an angle, for example, at 45 degrees relative to the longitudinal axis. In this embodiment, the optical radiation is partially or totally reflected at an angle from the tip of the delivery fiber 112, whereby the optical radiation radially exits the delivery fiber 112 through a sidewall, or delivery window, of the delivery fiber 112. This will be described in further detail below, for example, in reference to
In the example embodiment of
In the illustrative example of
Referring to
In the same manner described above, in this embodiment, the core tube 131, fibers 112, 113, fiber holder 133, balloon 111, and catheter sheath 138 are oriented along the longitudinal axis A, and the fiber holder 133 is translatable along the longitudinal axis A relative to the balloon 111 and the lumen wall. In this manner, spectral measurements of the target region of a lumen can be measured in the region of translation along the length of the longitudinal axis A, and about 360 degrees of rotation about the longitudinal axis A.
In the embodiment of
The embodiment of
The embodiment of
In the sense that the balloon is one that is capable of therapeutically expanding the lumen, it is referred to herein as a “lumen-expanding” balloon. “Therapeutic expansion” of the lumen, as used herein, refers to more than mere anchoring of the balloon in the lumen wall, or hindering or stopping blood flow in the lumen; but further refers to actually expanding, dilating, or stretching the lumen tissue so as to increase the diameter or cross-sectional area of the lumen, as in an angioplasty procedure.
In this embodiment, a source 180 is coupled to an optical switch 181, which, in turn, is coupled to a first delivery fiber 1121 and a second delivery fiber 1122. A first detector 171 is coupled to a first collection fiber 1131, and a second detector 172 is coupled to a second collection fiber 1132. In this example, lumen wall 160 is partitioned into quadrants: first quadrant I, second quadrant II, third quadrant III, and fourth quadrant IV. An additional optical switch can be used to perform optical analysis on the third and fourth quadrants, without the need for an additional light source, collection fibers, or detectors.
In the example of
In the example of
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Referring to
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In addition, the second delivery fiber 1122 directs optical radiation to the third quadrant III and fourth quadrant IV of a target region of the lumen wall 160. The first collection fiber 1131 receives the reflected optical radiation from the fourth quadrant IV of the lumen wall, and the second collection fiber 1132 receives the reflected optical radiation from the third quadrant III. The first and second collection fibers 1131, 1132 transmit the reflected optical radiation received from the third and fourth quadrants to detectors (not shown).
The fibers are positioned relative to each other such that the first delivery fiber 1121 is separated from each of the third and fourth collection fibers 1133, 1134 by a distance d, and the second delivery fiber 1122 is separated from each of the first and second collection fibers 1131, 1132 by a distance d. This distance d, also referred to as a delivery-collection fiber separation distance is, in part, determinative of the depth of the path of light into the lumen wall collected by collection fibers 113. Although signals may weaken when the travel path through tissue increases, greater fiber separation provides more information about tissue deeper into the lumen wall 160.
The balloon 111 surrounds the distal ends of the delivery fiber 112 and collection fibers 113, and a portion of the core tube 131. In this manner, the inner surface of the balloon 111 may be illuminated in a 360 degree radius by the optical radiation. Since the diffusing head 415 outputs optical radiation in all directions, and since the core tube 131 is in the path of a portion of the optical radiation, it is preferred that the core tube 131 be composed of absorbing materials that reduce the risk of any optical radiation impinging on the guidewire sheath that may interfere with optical radiation that is intended to be received by the target region at the lumen wall. The “shadow” caused by the guidewire sheath in received radiation can be eliminated as a background by a software program in a data analysis procedure that cancels its effect.
The first portion of the core tube 131 having the delivery fiber 512 including the diffusing head and the second portion of the core tube 131 having the guidewire sheath 531 and the guidewire port 534 are both positioned along a longitudinal axis. In embodiments illustrated above, the core tube 131 can be composed of plastic or other suitable medium for optical transmission. In the embodiment illustrated in
In
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An angle and polish shaper 902 is applied to the angled fiber tips 913′, whereby the tips 913′ are further shaped and polished to achieve an accurate, optimum fiber tip angle having desired integrated optical properties, such as high-reflectance properties.
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This feature is advantageous over conventional catheters, for example, catheters relying on fluoroscopy, since fluoroscopy merely enables a user to guide the conventional catheter to the diseased area. However, fluoroscopy can only provide information on a diseased area of a lumen in two-dimensions (e.g. blood vessel stenosis in a two-dimensional cross-section), and therefore an incomplete analysis is provided. This is particularly important in certain applications, wherein some disease regions may require a treatment, but conventional methods involving fluoroscopy cannot identify vulnerable plaque in a non- or minor stenosis area. Since the present invention can also identify weaknesses along the lumen wall prior to deploying an angioplasty balloon at a target region of the lumen wall, the present invention can reduce the risk of a rupture occurring at or near the blockage 1062 during or after the angioplasty procedure.
In another embodiment, the catheter 1010 collects data on the spectral features of the balloon 1011. This data can be used to determine the distance of the balloon surface from the guidewire lumen 1030 during inflation or deflation of the balloon 1011 or to measure the volume of expansion of the balloon 1011 during inflation.
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After or during a therapy such as a balloon angioplasty treatment, another collection of spectral features can be performed. As shown in
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Embodiments of the invention can thus integrate the gathering of critical information about vessel walls with many therapies for blocked/diseased vessels, including lumen-expansion therapy and stenting. For example, because an area that is targeted for a stent procedure is often obstructed, it is commonly preferable to have a pre-dilation step (a step that occurs in about seventy percent of all stenting procedures) in which an angioplasty balloon is deployed without a stent and expanded within the vessel to initially unblock the targeted area. This pre-dilation step facilitates and optimizes placement of the stent and helps ensure apposition against the vessel. The use of embodiments of the present invention with this pre-dilation step will greatly enhance the amount of information gathered prior to insertion of a stent. This information can include improved estimates of whether or not a stent is the preferred course of treatment, the position, type and size of the stent, if any, to be deployed, and the preferred type of coatings on the stent and/or drugs to be eluted from the stent.
It will be understood by those with knowledge in related fields that uses of alternate or varied forms or materials and modifications to the methods disclosed are apparent. This disclosure is intended to cover these and other variations, uses, or other departures from the specific embodiments as come within the art to which the invention pertains.
This application claims the benefit of U.S. Provisional Patent Application No. 60/722,753 filed on Sep. 30, 2005, U.S. Provisional Patent Application No. 60/761,649 filed on Jan. 24, 2006, U.S. Provisional Patent Application No. 60/821,623 filed on Aug. 7, 2006, U.S. Provisional Patent Application No. 60/823,812 filed on Aug. 29, 2006, and U.S. Provisional Patent Application No. 60/824,915 filed on Sep. 8, 2006, the contents of each being incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60722753 | Sep 2005 | US | |
| 60761649 | Jan 2006 | US | |
| 60821623 | Aug 2006 | US | |
| 60823812 | Aug 2006 | US | |
| 60824915 | Sep 2006 | US |
