Patent Publication Number: US-2021161398-A1

Title: Intravascular devices having information stored thereon and/or wireless communication functionality, including associated devices, systems, and methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 14/133,331, filed on Dec. 18, 2013, which claims priority to and the benefit of U.S. Provisional Patent Application No. 61/747,140, filed Dec. 28, 2012, each of which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to intravascular devices, systems, and methods. In some embodiments, the intravascular devices are guide-wires that include one or more sensing components and memory storing information about the guide-wire. In some embodiments, the intravascular devices are guide-wires that include wireless communication functionality. 
     BACKGROUND 
     Heart disease is very serious and often requires emergency operations to save lives. A main cause of heart disease is the accumulation of plaque inside the blood vessels, which eventually occludes the blood vessels. Common treatment options available to open up the occluded vessel include balloon angioplasty, rotational atherectomy, and intravascular stents. Traditionally, surgeons have relied on X-ray fluoroscopic images that are planar images showing the external shape of the silhouette of the lumen of blood vessels to guide treatment. Unfortunately, with X-ray fluoroscopic images, there is a great deal of uncertainty about the exact extent and orientation of the stenosis responsible for the occlusion, making it difficult to find the exact location of the stenosis. In addition, though it is known that restenosis can occur at the same place, it is difficult to check the condition inside the vessels after surgery with X-ray. 
     A currently accepted technique for assessing the severity of a stenosis in a blood vessel, including ischemia causing lesions, is fractional flow reserve (FFR). FFR is a calculation of the ratio of a distal pressure measurement (taken on the distal side of the stenosis) relative to a proximal pressure measurement (taken on the proximal side of the stenosis). FFR provides an index of stenosis severity that allows determination as to whether the blockage limits blood flow within the vessel to an extent that treatment is required. The normal value of FFR in a healthy vessel is 1.00, while values less than about 0.80 are generally deemed significant and require treatment. 
     Often intravascular catheters and guide-wires are utilized to measure the pressure within the blood vessel, visualize the inner lumen of the blood vessel, and/or otherwise obtain data related to the blood vessel. To date, guide-wires containing pressure sensors, imaging elements, and/or other electronic, optical, or electro-optical components have suffered from reduced performance characteristics compared to standard guide-wires that do not contain such components. For example, the handling performance of previous guide-wires containing electronic components have been hampered, in some instances, by the need to physically couple the proximal end of the device to a communication line in order to obtain data from the guide-wire, the limited space available for the core wire after accounting for the space needed for the conductors or communication lines of the electronic component(s), the stiffness and size of the rigid housing containing the electronic component(s), and/or other limitations associated with providing the functionality of the electronic components in the limited space available within a guide-wire. 
     Accordingly, there remains a need for improved intravascular devices, systems, and methods that include one or more electronic, optical, or electro-optical sensing components along with memory for storing information about the guide-wire and/or one or more components that facilitate wireless communication between the guide-wire and another device. 
     SUMMARY 
     Embodiments of the present disclosure are directed to intravascular devices, systems, and methods. 
     In one embodiment, a guide-wire is provided. The guide-wire comprises: an elongate flexible element having a proximal portion and a distal portion, the elongate flexible element having an outer diameter of 0.018″ or less; a pressure sensing component coupled to the distal portion of the elongate flexible element; a sensor control module coupled to the elongate flexible element, the sensor control module being in electrical communication with the pressure sensing component and storing information about the pressure sensing component; and at least one conductor having a proximal section and a distal section, wherein the distal section of the at least one conductor is coupled to the sensor control module and the proximal section of the at least one conductor is coupled to at least one connector. In some instances, the sensor control module includes an electrically erasable programmable read-only memory (EEPROM). In some implementations, the information about the pressure sensing component includes calibration information. In some embodiments, three to five conductors are utilized and coupled to three to five connectors, each comprising a conductive band. 
     In another embodiment, an intravascular pressure-sensing system is provided. The system comprises: a pressure-sensing guide-wire having features similar to those described above; a processing system configured to receive the information originating at the sensor; and an interface configured to communicatively couple the sensor to the processing system such that the sensor output is conditioned and communicated to the processing system. In some instances, the interface comprises a communication cable that includes a first connector portion for interfacing with the at least one connector of the pressure-sensing guide-wire and a second connector portion for interfacing with a component of the processing system. In some embodiments, the component of the processing system is a patient interface module (PIM). 
     In another embodiment a method is provided that includes: obtaining information about a pressure sensing component of a pressure-sensing guide-wire having an outer diameter of 0.018″ or less from a sensor control module coupled to a pressure-sensing guide-wire, the pressure sensing component being coupled to the distal portion of the pressure-sensing guide-wire; and normalizing data received from the pressure sensing component based on the information about the pressure sensing component stored in the memory of the sensor control module. In some instances, the information about the pressure sensing component includes calibration information about the pressure sensing component. 
     Additional aspects, features, and advantages of the present disclosure will become apparent from the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Illustrative embodiments of the present disclosure will be described with reference to the accompanying drawings, of which: 
         FIG. 1  is a diagrammatic, schematic side view of an intravascular device according to an embodiment of the present disclosure. 
         FIG. 2  is diagrammatic cross-sectional side view of an intravascular device according to an embodiment of the present disclosure. 
         FIG. 3  is a diagrammatic, schematic view of an intravascular system according to an embodiment of the present disclosure. 
         FIG. 4  is a diagrammatic, schematic view of an intravascular system similar to that of  FIG. 3 , but illustrating an alternative embodiment of the present disclosure. 
         FIG. 5  is a diagrammatic, schematic view of an intravascular system similar to those of  FIGS. 3 and 4 , but illustrating an alternative embodiment of the present disclosure. 
         FIG. 6  is a diagrammatic, schematic view of a plurality of different mounting options for components of the intravascular devices of the present disclosure. 
         FIG. 7  is a diagrammatic, schematic view of an intravascular system similar to those of  FIGS. 3-5 , but illustrating an alternative embodiment of the present disclosure. 
         FIG. 8  is a diagrammatic, side view of an intravascular device according to another embodiment of the present disclosure. 
         FIG. 9  is a diagrammatic, top view of a component of the distal portion of the intravascular device of  FIG. 8 . 
         FIG. 10  is a diagrammatic, side view a distal portion of the intravascular device shown in  FIG. 8  being coupled to a plurality of different intravascular devices in accordance with the present disclosure. 
         FIG. 11  is a diagrammatic, schematic view of an intravascular device positioned within the body of a patient in communication with a hemostat system according to an embodiment of the present disclosure. 
         FIG. 12  is a flow chart illustrating a method of performing an intravascular procedure according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It is nevertheless understood that no limitation to the scope of the disclosure is intended. Any alterations and further modifications to the described devices, systems, and methods, and any further application of the principles of the present disclosure are fully contemplated and included within the present disclosure as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one embodiment may be combined with the features, components, and/or steps described with respect to other embodiments of the present disclosure. For the sake of brevity, however, the numerous iterations of these combinations will not be described separately. 
     As used herein, “flexible elongate member” or “elongate flexible member” includes at least any thin, long, flexible structure that can be inserted into the vasculature of a patient. While the illustrated embodiments of the “flexible elongate members” of the present disclosure have a cylindrical profile with a circular cross-sectional profile that defines an outer diameter of the flexible elongate member, in other instances all or a portion of the flexible elongate members may have other geometric cross-sectional profiles (e.g., oval, rectangular, square, elliptical, etc.) or non-geometric cross-sectional profiles. Flexible elongate members include, for example, guide-wires and catheters. In that regard, catheters may or may not include a lumen extending along its length for receiving and/or guiding other instruments. If the catheter includes a lumen, the lumen may be centered or offset with respect to the cross-sectional profile of the device. 
     In most embodiments, the flexible elongate members of the present disclosure include one or more electronic, optical, or electro-optical components. For example, without limitation, a flexible elongate member may include one or more of the following types of components: a pressure sensor, a temperature sensor, an imaging element, an optical fiber, an ultrasound transducer, a reflector, a mirror, a prism, an ablation element, an RF electrode, a conductor, and/or combinations thereof. Generally, these components are configured to obtain data related to a vessel or other portion of the anatomy in which the flexible elongate member is disposed. Often the components are also configured to communicate the data to an external device for processing and/or display. In some aspects, embodiments of the present disclosure include imaging devices for imaging within the lumen of a vessel, including both medical and non-medical applications. However, some embodiments of the present disclosure are particularly suited for use in the context of human vasculature. Imaging of the intravascular space, particularly the interior walls of human vasculature can be accomplished by a number of different techniques, including ultrasound (often referred to as intravascular ultrasound (“IVUS”) and intracardiac echocardiography (“ICE”)) and optical coherence tomography (“OCT”). In other instances, infrared, thermal, or other imaging modalities are utilized. 
     The electronic, optical, and/or electro-optical components of the present disclosure are often disposed within a distal portion of the flexible elongate member. As used herein, “distal portion” of the flexible elongate member includes any portion of the flexible elongate member from the mid-point to the distal tip. As flexible elongate members can be solid, some embodiments of the present disclosure will include a housing portion at the distal portion for receiving the electronic components. Such housing portions can be tubular structures attached to the distal portion of the elongate member. Some flexible elongate members are tubular and have one or more lumens in which the electronic components can be positioned within the distal portion. 
     The electronic, optical, and/or electro-optical components and the associated communication lines are sized and shaped to allow for the diameter of the flexible elongate member to be very small. For example, the outside diameter of the elongate member, such as a guide-wire or catheter, containing one or more electronic, optical, and/or electro-optical components as described herein are between about 0.0007″ (0.0178 mm) and about 0.118″ (3.0 mm), with some particular embodiments having outer diameters of approximately 0.014″ (0.3556 mm) and approximately 0.018″ (0.4572 mm)). As such, the flexible elongate members incorporating the electronic, optical, and/or electro-optical component(s) of the present application are suitable for use in a wide variety of lumens within a human patient besides those that are part or immediately surround the heart, including veins and arteries of the extremities, renal arteries, blood vessels in and around the brain, and other lumens. 
     “Connected” and variations thereof as used herein includes direct connections, such as being glued or otherwise fastened directly to, on, within, etc. another element, as well as indirect connections where one or more elements are disposed between the connected elements. 
     “Secured” and variations thereof as used herein includes methods by which an element is directly secured to another element, such as being glued or otherwise fastened directly to, on, within, etc. another element, as well as indirect techniques of securing two elements together where one or more elements are disposed between the secured elements. 
     Referring now to  FIG. 1 , shown therein is a portion of an intravascular device  100  according to an embodiment of the present disclosure. In that regard, the intravascular device  100  includes a flexible elongate member  102  having a distal portion  104  adjacent a distal end  105  and a proximal portion  106  adjacent a proximal end  107 . A component  108  is positioned within the distal portion  104  of the flexible elongate member  102  proximal of the distal tip  105 . Generally, the component  108  is representative of one or more electronic, optical, or electro-optical components. In that regard, the component  108  is a pressure sensor, a temperature sensor, an imaging element, an optical fiber, an ultrasound transducer, a reflector, a mirror, a prism, an ablation element, an RF electrode, a conductor, and/or combinations thereof. The specific type of component or combination of components can be selected based on an intended use of the intravascular device. In some instances, the component  108  is positioned less than 10 cm, less than 5, or less than 3 cm from the distal tip  105 . In some instances, the component  108  is positioned within a housing of the flexible elongate member  102 . In that regard, the housing is a separate component secured to the flexible elongate member  102  in some instances. In other instances, the housing is integrally formed as a part of the flexible elongate member  102 . 
     The intravascular device  100  also includes a connector  110  adjacent the proximal portion  106  of the device. In that regard, the connector  110  is spaced from the proximal end  107  of the flexible elongate member  102  by a distance  112 . Generally, the distance  112  is between 0% and 50% of the total length of the flexible elongate member  102 . While the total length of the flexible elongate member can be any length, in some embodiments the total length is between about 1300 mm and about 4000 mm, with some specific embodiments have a length of 1400 mm, 1900 mm, and 3000 mm. Accordingly, in some instances the connector  110  is positioned at the proximal end  107 . In other instances, the connector  110  is spaced from the proximal end  107 . For example, in some instances the connector  110  is spaced from the proximal end  107  between about 0 mm and about 1400 mm. In some specific embodiments, the connector  110  is spaced from the proximal end by a distance of 0 mm, 300 mm, and 1400 mm. 
     The connector  110  is configured to facilitate communication between the intravascular device  100  and another device. More specifically, in some embodiments the connector  110  is configured to facilitate communication of data obtained by the component  108  to another device, such as a computing device or processor. Accordingly, in some embodiments the connector  110  is an electrical connector. In such instances, the connector  110  provides an electrical connection to one or more electrical conductors that extend along the length of the flexible elongate member  102  and are electrically coupled to the component  108 . In other embodiments, the connector  110  is an optical connector. In such instances, the connector  110  provides an optical connection to one or more optical communication pathways (e.g., fiber optic cable) that extend along the length of the flexible elongate member  102  and are optically coupled to the component  108 . Further, in some embodiments the connector  110  provides both electrical and optical connections to both electrical conductor(s) and optical communication pathway(s) coupled to the component  108 . In that regard, it should again be noted that component  108  is comprised of a plurality of elements in some instances. In some instances, the connector  110  is configured to provide a physical connection to another device, either directly or indirectly. In other instances, the connector  110  is configured to facilitate wireless communication between the intravascular device  100  and another device. Generally, any current or future developed wireless protocol(s) may be utilized. In yet other instances, the connector  110  facilitates both physical and wireless connection to another device. 
     As noted above, in some instances the connector  110  provides a connection between the component  108  of the intravascular device  100  and an external device. Accordingly, in some embodiments one or more electrical conductors, one or more optical pathways, and/or combinations thereof extend along the length of the flexible elongate member  102  between the connector  110  and the component  108  to facilitate communication between the connector  110  and the component  108 . Generally, any number of electrical conductors, optical pathways, and/or combinations thereof can extend along the length of the flexible elongate member  102  between the connector  110  and the component  108 . In some instances, between one and ten electrical conductors and/or optical pathways extend along the length of the flexible elongate member  102  between the connector  110  and the component  108 . For the sake of clarity and simplicity, the embodiments of the present disclosure described below include three electrical conductors. However, it is understood that the total number of communication pathways and/or the number of electrical conductors and/or optical pathways is different in other embodiments. More specifically, the number of communication pathways and the number of electrical conductors and optical pathways extending along the length of the flexible elongate member  102  is determined by the desired functionality of the component  108  and the corresponding elements that define component  108  to provide such functionality. 
     Referring now to  FIG. 2 , shown therein is a cross-sectional side view of an intravascular device  200  according to an embodiment of the present disclosure. In that regard, the intravascular device  200  is provided as an exemplary embodiment of the type of intravascular device into which the mounting structures, including the associated structural components and methods, described below with respect to  FIGS. 3-12  can be implemented. However, it is understood that no limitation is intended thereby and that the concepts of the present disclosure are applicable to a wide variety of intravascular devices, including those described in U.S. Pat. No. 7,967,762 and U.S. Patent Application Publication No. 2009/0088650, each of which is hereby incorporated by reference in its entirety. 
     As shown in  FIG. 2 , the intravascular device  200  includes a proximal portion  202 , a middle portion  204 , and a distal portion  206 . Generally, the proximal portion  202  is configured to be positioned outside of a patient, while the distal portion  206  and a majority of the middle portion  204  are configured to be inserted into the patient, including within human vasculature. In that regard, the middle portion  204  and/or distal portion  206  have an outer diameter between about 0.0007″ (0.0178 mm) and about 0.118″ (3.0 mm) in some embodiments, with some particular embodiments having an outer diameter of approximately 0.014″ (0.3556 mm) or approximately 0.018″ (0.4572 mm)). In the illustrated embodiment of  FIG. 2 , the middle and distal portions  204 ,  206  of the intravascular device  200  each have an outer diameter of 0.014″ (0.3556 mm). 
     As shown, the distal portion  206  of the intravascular device  200  has a distal tip  207  defined by an element  208 . In the illustrated embodiment, the distal tip  207  has a rounded profile. In some instances, the element  208  is radiopaque such that the distal tip  207  is identifiable under x-ray, fluoroscopy, and/or other imaging modalities when positioned within a patient. In some particular instances, the element  208  is solder secured to a flexible element  210  and/or a flattened tip core  212 . In that regard, in some instances the flexible element  210  is a coil spring. The flattened tip core  212  extends distally from a distal portion of a core  214 . As shown, the distal core  214  tapers to a narrow profile as it extends distally towards the distal tip  207 . In some instances, the distal core  214  is formed of a stainless steel that has been ground down to have the desired tapered profile. In some particular instances, the distal core  214  is formed of high tensile strength 304V stainless steel. In an alternative embodiment, the distal core  214  is formed by wrapping a stainless steel shaping ribbon around a nitinol core. In some embodiments, the distal core  214  is secured to a mounting structure  218  by mechanical interface, solder, adhesive, combinations thereof, and/or other suitable techniques as indicted by reference numerals  216 . The mounting structure  218  is configured to receive and securely hold a component  220 . In that regard, the component  220  is one or more of an electronic component, an optical component, and/or electro-optical component. For example, without limitation, the component  220  may be one or more of the following types of components: a pressure sensor, a temperature sensor, an imaging element, an optical fiber, an ultrasound transducer, a reflector, a mirror, a prism, an ablation element, an RF electrode, a conductor, and/or combinations thereof. 
     The mounting structure  218  is fixedly secured within the distal portion  206  of the intravascular device  200 . As will be discussed below in the context of the exemplary embodiments of  FIGS. 3-12 , the mounting structure  218  may be fixedly secured to a core wire (i.e., a single core running along the length of the mounting structure), flexible elements or other components surrounding at least a portion of the mounting structure (e.g., coils, polymer tubing, etc.), and/or other structure(s) of the intravascular device positioned adjacent to the mounting structure. In the illustrated embodiment, the mounting structure is disposed at least partially within flexible element  210  and/or a flexible element  224  and secured in place by an adhesive or solder  222 . In some embodiments, the mounting structure  218  is disposed entirely within flexible element  210  and/or flexible element  224 . In some instances, the flexible elements  210  and  224  are flexible coils. In one particular embodiment, the flexible element  224  is ribbon coil covered with a polymer coating. For example, in one embodiment the flexible element  224  is a stainless steel ribbon wire coil coated with polyethylene terephthalate (PET). In another embodiment, the flexible element is a polyimide tubing that has a ribbon wire coil embedded therein. An adhesive is utilized to secure the mounting structure  218  to the flexible element  210  and/or the flexible element  224  in some implementations. Accordingly, in some instances the adhesive is urethane acrylate, cyanoacrylate, silicone, epoxy, and/or combinations thereof. 
     The mounting structure  218  is also secured to a core  226  that extends proximally from the mounting structure towards the middle portion  204  of the intravascular device  200 . In that regard, core  226  and distal core  214  are integrally formed in some embodiments such that a continuous core passes through the mounting structure. In the illustrated embodiment, a portion  228  of the core  226  tapers as it extends distally towards mounting structure  218 . However, in other embodiments the core  226  has a substantially constant profile along its length. In some implementations, the diameter or outer profile (for non-circular cross-sectional profiles) of core  226  and core  214  are the same. Like distal core  214 , the core  226  is fixedly secured to the mounting structure  218 . In some instances, solder and/or adhesive is used to secure the core  226  to the mounting structure  218 . In the illustrated embodiment, solder/adhesive  230  surrounds at least a part of the portion  228  of the core  226 . In some instances, the solder/adhesive  230  is the solder/adhesive  222  used to secure the mounting structure  218  to the flexible element  210  and/or flexible element  224 . In other instances, solder/adhesive  230  is a different type of solder or adhesive than solder/adhesive  222 . In one particular embodiment, adhesive or solder  222  is particularly suited to secure the mounting structure  218  to flexible element  210 , while solder/adhesive  230  is particularly suited to secure the mounting structure to flexible element  224 . 
     A communication cable  232  extends along the length of the intravascular device  200  from the proximal portion  202  to the distal portion  206 . In that regard, the distal end of the communication cable  232  is coupled to the component  220  at junction  234 . The type of communication cable utilized is dependent on the type of electronic, optical, and/or electro-optical components that make up the component  220 . In that regard, the communication cable  232  may include one or more of an electrical conductor, an optical fiber, and/or combinations thereof. Appropriate connections are utilized at the junction  234  based on the type of communication lines included within communication cable  232 . For example, electrical connections are soldered in some instances, while optical connections pass through an optical connector in some instances. In some embodiments, the communication cable  232  is a trifilar structure, a bifilar structure, a single conductor (which may be a conductive core or a conductor separate from the core). Further, it is understood that all and/or portions of each of the proximal, middle, and/or distal portions  202 ,  204 ,  206  of the intravascular device  200  may have cross-sectional profiles as shown in FIGS. 2-5 of U.S. Provisional Patent Application No. 61/665,697 filed on Jun. 28, 2012, which is hereby incorporated by reference in its entirety. 
     Further, in some embodiments, the proximal portion  202  and/or the distal portion  206  incorporate spiral ribbon tubing as disclosed in U.S. Provisional Patent Application No. 61/665,697 filed on Jun. 28, 2012. In some instances, the use of such spiral ribbon tubing allows a further increase in the available lumen space within the device. For example, in some instances use of a spiral ribbon tubing having a wall thickness between about 0.001″ and about 0.002″ facilitates the use of a core wire having an outer diameter of at least 0.0095″ within a 0.014″ outer diameter guide-wire using a trifilar with circular cross-sectional conductor profiles. The size of the core wire can be further increased to at least 0.010″ by using a trifilar with the flattened oblong cross-section conductor profiles. The availability to use a core wire having an increased diameter allows the use of materials having a lower modulus of elasticity than a standard stainless steel core wire (e.g., superelastic materials such as Nitinol or NiTiCo are utilized in some instances) without adversely affecting the handling performance or structural integrity of the guide-wire and, in many instances, provides improvement to the handling performance of the guide-wire, especially when a superelastic material with an increased core diameter (e.g., a core diameter of 0.0075″ or greater) is utilized within the distal portion  206 . 
     The distal portion  206  of the intravascular device  200  also optionally includes at least one imaging marker  236 . In that regard, the imaging marker  236  is configured to be identifiable using an external imaging modality, such as x-ray, fluoroscopy, angiograph, CT scan, MRI, or otherwise, when the distal portion  206  of the intravascular device  200  is positioned within a patient. In the illustrated embodiment, the imaging marker  236  is a radiopaque coil positioned around the tapered distal portion  228  of the core  226 . Visualization of the imaging marker  236  during a procedure can give the medical personnel an indication of the size of a lesion or region of interest within the patient. To that end, the imaging marker  236  can have a known length (e.g., 0.5 cm or 1.0 cm) and/or be spaced from the element  218  by a known distance (e.g., 3.0 cm) such that visualization of the imaging marker  236  and/or the element  218  along with the anatomical structure allows a user to estimate the size or length of a region of interest of the anatomical structure. It is understood that a plurality of imaging markers  236  are utilized in some instances. In that regard, in some instances the imaging markers  236  are spaced a known distance from one another to further facilitate measuring the size or length of the region of interest. 
     In some instances, a proximal portion of the core  226  is secured to a core  238  that extends through the middle portion  204  of the intravascular device. In that regard, the transition between the core  226  and the core  238  may occur within the distal portion  206 , within the middle portion  204 , and/or at the transition between the distal portion  206  and the middle portion  204 . For example, in the illustrated embodiment the transition between core  226  and core  238  occurs in the vicinity of a transition between the flexible element  224  and a flexible element  240 . The flexible element  240  in the illustrated embodiment is a hypotube. In some particular instances, the flexible element is a stainless steel hypotube. Further, in the illustrated embodiment a portion of the flexible element  240  is covered with a coating  242 . In that regard, the coating  242  is a hydrophobic coating in some instances. In some embodiments, the coating  242  is a polytetrafluoroethylene (PTFE) coating. 
     The proximal portion of core  226  is fixedly secured to the distal portion of core  238 . In that regard, any suitable technique for securing the cores  226 ,  238  to one another may be used. In some embodiments, at least one of the cores  226 ,  238  includes a plunge grind or other structural modification that is utilized to couple the cores together. In some instances, the cores  226 ,  238  are soldered together. In some instances, an adhesive is utilized to secure the cores  226 ,  238  together. In some embodiments, combinations of structural interfaces, soldering, and/or adhesives are utilized to secure the cores  226 ,  238  together. In other instances, the core  226  is not fixedly secured to core  238 . For example, in some instances, the core  226  and the core  246  are fixedly secured to the hypotube  240  and the core  238  is positioned between the cores  226  and  246 , which maintains the position of the core  238  between cores  226  and  246 . In some implementations, the cores  226 ,  238 , and  246  are integrally formed as a single core. 
     In some embodiments, the core  238  is formed of a different material than the core  226 . For example, in some instances the core  226  is formed of nitinol and the core  238  is formed of stainless steel. In other instances, the core  238  and the core  226  are formed of the same material. In some instances the core  238  has a different profile than the core  226 , such as a larger or smaller diameter and/or a non-circular cross-sectional profile. For example, in some instances the core  238  has a D-shaped cross-sectional profile. In that regard, a D-shaped cross-sectional profile has some advantages in the context of an intravascular device  200  that includes one or more electronic, optical, or electro-optical component in that it provides a natural space to run any necessary communication cables while providing increased strength than a full diameter core. In other instances, core  238  and core  226  are made of the same material and/or have the same structure profiles such that the cores  226  and  238  form a continuous, monolithic core. 
     In some instances, a proximal portion of the core  238  is secured to a core  246  that extends through at least a portion of the proximal portion  202  of the intravascular device  200 . In that regard, the transition between the core  238  and the core  246  may occur within the proximal portion  202 , within the middle portion  204 , and/or at the transition between the proximal portion  202  and the middle portion  204 . For example, in the illustrated embodiment the transition between core  238  and core  246  is positioned distal of a plurality of conducting bands  248 . In that regard, in some instances the conductive bands  248  are portions of a hypotube. Proximal portions of the communication cable  232  are coupled to the conductive bands  248 . In that regard, in some instances each of the conductive bands is associated with a corresponding communication line of the communication cable  232 . For example, in embodiments where the communication cable  232  consists of a trifilar, each of the three conductive bands  248  are connected to one of the conductors of the trifilar, for example by soldering each of the conductive bands to the respective conductor. Where the communication cable  232  includes optical communication line(s), the proximal portion  202  of the intravascular device  200  includes an optical connector in addition to or instead of one or more of the conductive bands  248 . An insulating layer or sleeve  250  separates the conductive bands  248  from the core  246 . In some instances, the insulating layer  250  is formed of polyimide. 
     As noted above, the proximal portion of core  238  is fixedly secured to the distal portion of core  246 . In that regard, any suitable technique for securing the cores  238 ,  246  to one another may be used. In some embodiments, at least one of the cores includes a structural feature that is utilized to couple the cores together. In the illustrated embodiment, the core  238  includes an extension  252  that extends around a distal portion of the core  246 . In some instances, the cores  238 ,  246  are soldered together. In some instances, an adhesive is utilized to secure the cores  238 ,  246  together. In some embodiments, combinations of structural interfaces, soldering, and/or adhesives are utilized to secure the cores  238 ,  246  together. In other instances, the core  226  is not fixedly secured to core  238 . For example, in some instances and as noted above, the core  226  and the core  246  are fixedly secured to the hypotube  240  and the core  238  is positioned between the cores  226  and  246 , which maintains the position of the core  238  between cores  226  and  246 . In some embodiments, the core  246  is formed of a different material than the core  238 . For example, in some instances the core  246  is formed of Nitinol and/or NiTiCo (nickel-titanium-cobalt alloy) and the core  238  is formed of stainless steel. In that regard, by utilizing a nitinol core within the conductive bands  248  instead of a stainless steel the likelihood of kinking is greatly reduced because of the increased flexibility of the nitinol core compared to a stainless steel core. In other instances, the core  238  and the core  246  are formed of the same material. In some instances the core  238  has a different profile than the core  246 , such as a larger or smaller diameter and/or a non-circular cross-sectional profile. In other instances, core  238  and core  246  are made of the same material and/or have the same structure profiles such that the cores  238  and  246  form a continuous, monolithic core. 
     Additional embodiments of the present disclosure will now be described in the context of  FIGS. 3-12 . To this end, various implementations of intravascular devices will be described. It is understood that, for the sake of brevity, some details of these intravascular devices will not be explicitly described with respect to each implementation. Those skilled in the art understand that one or more features, including various combinations thereof, described above in the context of the intravascular devices of  FIGS. 1 and 2 , including the disclosures in the references incorporated by reference, are utilized for the other embodiments of the present disclosure described below. Thus, unless otherwise stated, any one or more features described above may be included in the intravascular devices described below. 
     Referring now to  FIG. 3 , shown therein is an intravascular system  300  according to an embodiment of the present disclosure. As shown, the intravascular system  300  includes an intravascular device  302 , an interface  304 , and a processing system  306 . Generally, the interface  304  facilitates communication between the intravascular device  302  and the processing system  306 . In the illustrated embodiment, the intravascular device  302  is a guide-wire having an outer diameter of 0.018″, 0.014″, or less. Further, the intravascular device  302  includes a sensing component  308  coupled to a distal portion of the device that is communicatively coupled to a plurality of connectors  310 ,  312 ,  314  at a proximal portion of the device. In some instances, the sensing component  308  is electrically coupled to the connectors  310 ,  312 ,  314  and the connectors  310 ,  312 ,  314  are themselves electrically conductive elements. 
     The interface  304  communicatively couples the intravascular device  302  to the processing system  306 . To that end, the interface  304  includes a custom connector  316  for interfacing with the connectors  310 ,  312 ,  314  of the intravascular device. The interface  304  also includes a cable  318  that extends from the custom connector  316  to a modular connector  320 . In that regard, the modular connector  320  is configured to interface with the processing system  306 . The modular connector  320  includes, or is in communication with a memory unit  322  that stores information about the intravascular device  302  and, in particular, the sensing component  308 . In some instances, the memory unit  322  stores device-specific information such as: device ID, usage limit, sensor ID, temperature coefficient, zero offset, scale factor, sensitivity, manufacture date, manufacture time, and manufacture location. In addition, the memory unit  322  may store information related to one or more specific periods of device activation or use, such as: count, date, time, location, system ID, pressure minimum, pressure maximum, velocity minimum, velocity maximum, temperature minimum, temperature maximum, and centered (y/n). To that end, the memory unit  322  can be any suitable type of memory device, including without limitation EEPROM or Flash, stand-alone or embedded, and/or combinations thereof. 
     The processing system  306  is coupled to the modular connector  320  of the interface  304 . In the illustrated embodiment, the processing system  306  includes a patient interface module (PIM)  324  that includes a socket  326  for mating engagement with the modular connector  320 . In some implementations, the PIM  324  includes a separate housing from other portions of the processing system  306  that the PIM communicates with, such as a workstation, console, desktop computer, laptop computer, tablet, and/or other processing component. In some implementations, the PIM is integrated into the same housing as one or more other portions of the processing system  306 . 
     While the arrangement of the intravascular system  300  of  FIG. 3  is adequate for its intended purpose, it is less than ideal because it requires that the memory unit  322  of the interface  304  be packaged and utilized exclusively with the paired intravascular device  302 . For example, in some instances the memory unit  322  carries sensor specific calibration information that is utilized to normalize the output of the paired sensor to behave similarly to every other sensor/guide-wire. Accordingly, it is imperative that the matching interface  304  and intravascular device  302  be used together. 
     Referring now to  FIG. 4 , shown therein is an intravascular system  350  according to an embodiment of the present disclosure. As shown, the intravascular system  350  includes an intravascular device  352 , a cable/connector interface  354 , and a processing system  356 . Generally, the cable/connector interface  354  facilitates communication between the intravascular device  352  and the processing system  356 . In the illustrated embodiment, the intravascular device  352  is a guide-wire having an outer diameter of 0.018″, 0.014″, or less. Further, the intravascular device  352  includes a sensing component  308  coupled to a distal portion of the device. The intravascular device  352  also includes a memory/normalization module  358 . In some implementations, the memory/normalization module  358  is communicatively coupled to the sensing component  308 . In other implementations, the memory/normalization module  358  is communicatively isolated from the sensing component  308 . The memory/normalization module  358  stores information about the intravascular device  302  and, in particular, the sensing component  308 . In some instances, the memory/normalization module  358  stores device-specific information such as: device ID, usage limit, sensor ID, temperature coefficient, zero offset, scale factor, sensitivity, manufacture date, manufacture time, and manufacture location. In addition, the memory/normalization module  358  may store information related to one or more specific periods of device activation or use, such as: count, date, time, location, system ID, pressure minimum, pressure maximum, velocity minimum, velocity maximum, temperature minimum, temperature maximum, and centered (y/n). 
     In order to be disposed within the intravascular device  352  without adversely affecting performance or usefulness of the intravascular device  352 , the memory/normalization module  358  must have a profile that allows it to be positioned within the intravascular device  352  without increasing the outer profile of the intravascular device  352 . For example, in instances where the intravascular device  352  has an outer diameter of 0.014″, the memory/normalization module  358  has a height between about 0.02 mm and about 0.075 mm, a width between about 0.125 mm and about 0.35 mm, and a length between about 0.200 mm and about 7.0 mm, however sizes outside these ranges are contemplated. To that end, applicants have found that the memory unit  358  can be any suitable type of memory device, including without limitation EEPROM or Flash, stand-alone or embedded. 
     To facilitate retrieval of the information from the memory/normalization module  358 , the memory/normalization module  358  is communicatively coupled to a plurality of connectors  310 ,  312 ,  314  at a proximal portion of the device. In some instances, the sensing component  308  is communicatively coupled to the connectors  310 ,  312 ,  314  via memory/normalization module  358 . In some instances, the sensing component  308  is electrically coupled to the connectors  310 ,  312 ,  314  through memory/normalization module  358  and the connectors  310 ,  312 ,  314  are electrically conductive elements. The cable/connector interface  354  communicatively couples the intravascular device  352  to the processing system  356 . To that end, the cable/connector interface  354  includes a custom connector  316  for interfacing with the connectors  310 ,  312 , and  314  of the intravascular device. The cable/connector interface  354  also includes a cable  318  that extends from the custom connector  316  to a modular connector  320 . In that regard, the modular connector  320  is configured to interface with the processing system  356 . In contrast to the embodiment of  FIG. 3 , the cable/connector interface  354  and, in particular, the modular connector  320  does not include a memory unit, and is device-neutral. Instead, relevant information about the intravascular device  352  is stored in the memory/normalization module  358  integrated into the intravascular device  352  itself. As a result, there is no need for cable/connector interface  354  to be associated with a particular intravascular device  352 . Instead, the same cable/connector interface  354  is suitable for use with a plurality of different intravascular devices  352 , including devices that may have different calibration and/or operating parameters. 
     The processing system  356  is coupled to the modular connector  320  of the cable/connector interface  354 . In the illustrated embodiment, the processing system  356  includes a patient interface module (PIM)  324  that includes a socket  326  for mating engagement with the modular connector  320 . In some implementations, the PIM  324  includes a separate housing from other portions of the processing system  356  that the PIM  324  communicates with, such as a workstation, console, desktop computer, laptop computer, tablet, and/or other processing component. In some implementations, the PIM  324  is integrated into the same housing as one or more other portions of the processing system  356 . In use, the processing system  356  is able to obtain any necessary information about the intravascular device  352 , including information about the sensing component  308 , from the memory/normalization module  358  via the connections provided by the cable/connector interface  354 . Accordingly, in instances where the memory/normalization module  358  carries calibration information about the sensing component  308  of the intravascular device  352 , the processing system  356  is able to obtain and utilize the calibration information from the memory/normalization module  358  to render accurate measurements based on the data provided by the intravascular device  352 . 
     Referring now to  FIG. 5 , shown therein is an intravascular system  400  according to an embodiment of the present disclosure. As shown, the intravascular system  400  includes an intravascular device  402 , a reader interface  404 , and a processing system  406 . Generally, the reader interface  404  facilitates communication between the intravascular device  402  and the processing system  406 . In the illustrated embodiment, the intravascular device  402  is a guide-wire having an outer diameter of 0.018″, 0.014″, or less. Further, the intravascular device  402  includes a sensing component  408  coupled to a distal portion of the device. The intravascular device  402  may also include integrated circuits for data storage, signal conditioning, rectification, energy storage, and telemetry. In some implementations, energy is stored in one or more discrete components. In some implementations, the signal conditioning, communications, and rectification elements are integrated into an application specific integrated circuit. 
     Generally, the energy storage element(s), the application specific integrated circuit, the memory chip, and the sensor may be arranged in any suitable manner meeting the stringent size requirements for positioning within the distal portion of a guide-wire having an outer diameter of 0.018″, 0.014″, or less. In some implementations, the energy storage element(s), the application specific integrated circuit, the memory chip, and the sensor are positioned one atop another in a vertical stack. In other implementations, the energy storage element(s), the application specific integrated circuit, the memory chip, and the sensor are independently positioned on a substrate. In some implementations, the substrate is fabricated flat and mounted flat within the elongate member. In another implementation the substrate is fabricated flat, and is then wrapped around the core wire. In another implementation, the substrate is fabricated directly on the non-planar surface of the core wire. 
     A visual representation  430  of exemplary combinations of arrangements for a sensor, RFIC, and memory chip are shown in  FIG. 6 . In particular, the visual representation  430  includes three columns labeled “A”, “B”, and “C” and two rows labeled “1” and “2”. The “A” column corresponds to arrangements where the sensor, RFIC, and memory chip are mounted separately; the “B” column corresponds to arrangements where the RFIC and memory chip are stacked and mounted separately from the sensor; and the “C” column corresponds to arrangements where the sensor, RFIC, and memory chip are stacked together. The “1” row corresponds to mounting arrangements that do not include a common substrate, while the “2” row represents mounting arrangements where the sensor, RFIC, and memory chip are mounted to a common substrate (e.g., flex circuit, semiconductor substrate, PCB, or otherwise). Accordingly, the sensor, RFIC, and memory chip may be mounted using any of arrangements represented by A- 1 , A- 2 , B- 1 , B- 2 , C- 1 , and C- 2 . It is understood that these arrangements are representative of the different types of stacked, partially stacked, and separated mounting arrangements on a substrate or not that may be implemented in the context of the present disclosure. These concepts can be expanded to any number of components and corresponding combinations of stacked, partially, and separated mounting arrangements on a common substrate, a partially-common substrate (i.e., more than one but less than all components mounted to the same substrate), and no common substrate. Any quantity, combination, and physical arrangement of application specific integrated circuit(s), memory die, discrete component(s), substrate(s), antenna(s), and sensor(s), is collectively referred to herein as the sensor control module  410  and may be located within the intravascular device  402 . 
     The sensor control module  410  stores information about the intravascular device  402  and, in particular, the unique characteristics of the sensing component  408  to which it is paired. In some instances, the sensor control module  410  stores device-specific information such as: device ID, usage limit, sensor ID, temperature coefficient, zero offset, scale factor, sensitivity, manufacture date, manufacture time, and manufacture location. In addition, the sensor control module  410  may store information related to one or more specific periods of device activation or use, such as: count, date, time, location, system ID, pressure minimum, pressure maximum, velocity minimum, velocity maximum, temperature minimum, temperature maximum, centered (y/n), and reader ID. 
     In order to be disposed within the intravascular device  402  without adversely affecting performance or usefulness of the intravascular device  402 , the sensor control module  410  must have a profile that allows it to be positioned within the intravascular device  402  without increasing the outer profile of the intravascular device  402 . For example, in instances where the intravascular device  402  has an outer diameter of 0.014″, the sensor control module  410  has a height between about 0.02 mm and about 0.075 mm, a width between about 0.125 mm and about 0.35 mm, and a length between about 0.200 mm and about 7.0 mm, however sizes outside these ranges are contemplated. Further, as described below, the sensor control module  410  of the present embodiment is also suitable for wireless communication with reader interface  404  via a guide-wire antenna  412 . To that end, applicants have found that suitable sensor control module  410  can include any suitable type of memory device, including without limitation EEPROM or Flash, stand-alone or embedded, and/or combinations thereof. 
     To facilitate retrieval of the information from the sensing component  408 , the sensor control module  410  is communicatively coupled to at least one guide-wire antenna  412 . In some configurations, the guide-wire antenna  412  constitutes the proximal portion of the intravascular device  402 . In some embodiments, the guide-wire antenna  412  may be configured to reside completely outside of the patient during a procedure. In another embodiment, the guide-wire antenna  412  might extend from the proximal tip to a distal extent that resides within the patient during a procedure. In some embodiments, the guide-wire antenna  412  is confined exclusively to the middle region, or exclusively to the distal region of the elongate member. The guide-wire antenna  412  may be a monopole, dipole, meandering, straight, helical, or other suitable arrangement. 
     The reader interface  404  communicatively couples the intravascular device  402  to the processing system  406 . In some configurations, the reader interface  404  includes a reader antenna  416  for communicating with the guide-wire antenna  412  of the intravascular device  402 . The reader antenna  416  may be positioned or installed in any suitable location in the room within range of the use-envelope of the guide-wire antenna  412 . The reader antenna  416  communicates with the reader module  418  via a cable interface. The reader module  418  receives power from a power source  658 , which may be an AC outlet, power-over-Ethernet (POE), or suitable power supply. In some instances, the reader module  418  communicates with the processing system  406  through a cable  420  and connector pair. In the illustrated embodiment, the connector  422  is a USB connector that connects to a USB connector of the processing system  406 . However, it is understood that essentially any type of wired connection between the reader interface  404  and the processing system  406  may be utilized. In the illustrated embodiment, at least a portion of the reader interface  404  is a patient interface module (PIM). In some implementations, the PIM includes a separate housing from the processing system  406  that the PIM communicates with, such as a workstation, console, desktop computer, laptop computer, tablet, and/or other processing component. In some implementations, the PIM is integrated into the same housing as one or more components of the processing system  406 . 
     Similar to the embodiment of  FIG. 4 , the reader interface  404  is device-neutral. The relevant information about the intravascular device  402  is stored in the sensor control module  410  and integrated into the intravascular device  402  itself. As a result, there is no need for the reader interface  404  to be associated with any specific intravascular device  402 . Instead, the same reader interface  404  is suitable for use with a plurality of intravascular devices  402 , including devices that may have different calibration and/or operating parameters. In use, the processing system  406  is able to obtain any necessary information about the intravascular device  402  as described previously. 
     Referring now to  FIG. 7 , shown therein is an intravascular system  450  according to an embodiment of the present disclosure. As shown, the intravascular system  450  includes an intravascular device  452 , a reader interface  454 , and a processing system  456 . Generally, the reader interface  454  facilitates communication between the intravascular device  452  and the processing system  456 . In the illustrated embodiment, the intravascular device  452  is a guide-wire having an outer diameter of 0.018″, 0.014″, or less. Further, the intravascular device  452  includes a sensing component  408  coupled to a distal portion of the device. The intravascular device  452  may also include integrated circuits for data storage, signal conditioning, rectification, energy storage, and telemetry. In some implementations, energy is stored in one or more discrete components. In some implementations, the signal conditioning, communications, and rectification elements are integrated into an application specific integrated circuit and coupled with memory to form a sensor control module  410 . In some implementations, the energy storage element(s), the application specific integrated circuit, the memory chip, and the sensor are positioned one atop another in a vertical stack (e.g., arrangement C- 1  of  FIG. 6 ). In some implementations, the energy storage element(s), the application specific integrated circuit, the memory chip, and the sensor are independently positioned on a substrate (e.g., arrangement A- 2  of  FIG. 6 ). In some implementations, the substrate is fabricated flat and mounted flat within the elongate member. In another implementation the substrate is fabricated flat, and is then wrapped around the core wire. In another implementation, the substrate is fabricated directly on the non-planar surface of the core wire. Any quantity, combination, and physical arrangement of application specific integrated circuit(s), memory die, discrete component(s), substrate(s), antenna(s), and sensor(s) may be located within the elongate unit. The sensor control module  410  stores information about the intravascular device  452  and, in particular, the unique characteristics of the sensing component  408  to which it is paired. In some instances, the sensor control module  410  stores device-specific information such as: device ID, usage limit, sensor ID, temperature coefficient, zero offset, scale factor, sensitivity, manufacture date, manufacture time, and manufacture location. In addition, the sensor control module  410  may store information related to one or more specific periods of device activation or use, such as: count, date, time, location, system ID, pressure minimum, pressure maximum, velocity minimum, velocity maximum, temperature minimum, temperature maximum, centered (y/n), and reader ID. 
     In order to be disposed within the intravascular device  452  without adversely affecting performance or usefulness of the intravascular device  452 , the sensor control module  410  must have a profile that allows it to be positioned within the intravascular device  452  without increasing the outer profile. For example, in instances where the intravascular device  452  has an outer diameter of 0.014″, the sensor control module  410  has a height between about 0.02 mm and about 0.075 mm, a width between about 0.125 mm and about 0.35 mm, and a length between about 0.200 mm and about 7.0 mm, however sizes outside these ranges are contemplated. Further, as described below, the sensor control module  410  of the present embodiment is also suitable for wireless communication with reader interface  454  via a guide-wire antenna  412 . To that end, applicants have found that suitable sensor control module  410  can include any suitable type of memory device, including without limitation EEPROM or Flash, stand-alone or embedded. 
     To facilitate retrieval of the information from the sensing component  408 , the sensor control module  410  is communicatively coupled to at least one guide-wire antenna  412 . In some configurations, the guide-wire antenna  412  constitutes the proximal portion of the intravascular device  402 . In some embodiments, the guide-wire antenna  412  may be configured to reside completely outside of the patient during a procedure. In another embodiment, the guide-wire antenna  412  might extend from the proximal tip to a distal extent that resides within the patient during a procedure. In some embodiments, the guide-wire antenna  412  is confined exclusively to the middle region, or exclusively to the distal region of the elongate member. The guide-wire antenna  412  may be a monopole, dipole, meandering, straight, helical, or other suitable arrangement. 
     The reader interface  454  communicatively couples the intravascular device  452  to the processing system  456 . To that end, the reader interface  454  includes a reader antenna  416  for communicating with the guide-wire antenna  412  of the intravascular device  452 ; and a link antenna  462  for communicating with the system antenna  464  of the processing system  456  that is in communication with processing component  466 . The reader antenna  416  may be positioned or installed in any suitable location in the room within range of the use-envelope of the guide-wire antenna  412 . The link antenna  462  may be positioned or installed in any suitable location in the room within range of the system antenna  464 , and the same is true for the system antenna  464  relative to the link antenna  462 . The reader module  418  may be powered by an AC outlet, by power-over-Ethernet (POE), or by other suitable power supply. The reader module  418  communicates with the telemetry module  460  which communicates with the processing system  456  through the link antenna  462  to system antenna  464  coupling. The communication protocol between the reader interface  454  and the processing system  456  (and between the reader interface  454  and the intravascular device  452 ) may be one or any combination of industry standard and/or proprietary types (Bluetooth, Wi-Fi, UHF, HF, etc.). In the illustrated embodiment, at least a portion of the reader interface  454  is a patient interface module (PIM). In some implementations, the PIM includes a separate housing from the processing system  456  that the PIM communicates with, such as a workstation, console, desktop computer, laptop computer, tablet, and/or other processing component. In some implementations, the PIM is integrated into the same housing as one or more components of the processing system  456 . 
     Similar to the embodiments of  FIGS. 4 and 5 , the reader interface  454  is device-neutral. The relevant information about the intravascular device  452  is stored in the sensor control module  410  and integrated into the intravascular device  452  itself. As a result, there is no need for reader interface  454  to be associated with a particular intravascular device  452 . Instead, the same reader interface  454  is suitable for use with a plurality of different intravascular devices  452 , including devices that may have different calibration and/or operating parameters. In use, the processing system  456  is able to wirelessly obtain any necessary information about the intravascular device  452 , including information about the sensing component  408 , from the sensor control module  410  via the wireless connection between the reader interface  454  and the intravascular device  452  and the wireless connection between the reader interface  454  and the processing system  456 . Accordingly, in instances where the sensor control module  410  carries calibration information about the sensing component  408  of the intravascular device  452 , the processing system  456  is able to obtain and utilize the calibration information from the sensor control module  410  to render accurate measurements based on the data provided by the intravascular device  452 . 
     Referring now to  FIGS. 8-12 , aspects of wireless intravascular devices and associated systems and methods will now be described. Referring more specifically to  FIGS. 8 and 9 , shown therein are aspects of an intravascular device  500  according to another embodiment of the present disclosure. The intravascular device  500  includes an elongate, flexible proximal portion  502  coupled to an elongate, flexible distal portion  504 . In that regard, proximal portion  502  may include one or more features similar to those of the proximal portion  106 , and/or proximal portion  202 , and/or middle portion  204  described above. Likewise, the distal portion  504  may include one or more features similar to those of distal portion  104  and/or distal portion  206  described above. The distal portion  504  is fixedly secured to the proximal portion  502 . To that end, the distal portion  504  may be mechanically coupled, chemically bonded, and/or otherwise secured to the proximal portion  502 . For example, in some instances, the distal portion  504  includes a coil structure that is threaded onto a mating coil structure of the proximal portion  502 . In addition to or in lieu of the coil structure(s), the distal portion  504  may be welded, and/or bonded to the proximal portion using an adhesive (e.g., epoxy, glue, etc.), solder, and/or other suitable bonding agent. Generally, the distal portion  504  may be coupled to the proximal portion  502  in any suitable way. Further, as discussed below in the context of  FIG. 10 , in some implementations the distal portion  504  and the proximal portion  502  have a standardized connection arrangement such that various combinations of available distal portions and proximal portions can be easily and conveniently put together to form intravascular devices having features specifically selected based on user preferences, procedure needs, and/or combinations thereof. 
     In some implementations, the proximal portion  502  is configured to facilitate operation of the intravascular device  500  such that power and data are wirelessly transferred from a reader interface  454  to the proximal portion  502 , and data is wirelessly transferred from the proximal portion  502  to the reader interface  454 . More specifically, the proximal portion  502  is configured as an antenna to harvest energy and to facilitate operation of electrical, optical, and/or electro-optical components coupled to the proximal portion  502  such that data obtained by the electrical, optical, and/or electro-optical components can be wirelessly communicated to a reader interface  454  during a procedure (i.e., while the distal portion  504  is positioned within the body of a patient) and/or following a procedure (i.e., after the distal portion  504  has been removed from the body of the patient). As described below, in some implementations the proximal portion  502  is configured to receive power from the reader interface  454  and to selectively distribute said energy to the electrical, optical, and/or electro-optical component(s). Due to the wireless connection, there is no need for a connector/cable interface between the proximal portion  502  and a Patient Interface Module (PIM). As a result, the intravascular device is more easily handled and steered by users. 
     In some implementations, the distal portion  504  is configured to facilitate operation of the intravascular device  500  such that power and data are wirelessly transferred from a reader interface  454  to the distal portion  504 , and data is wirelessly transferred from the distal portion  504  to the reader interface  454 . More specifically, the distal portion  504  is configured with an antenna to harvest energy and to facilitate operation of electrical, optical, and/or electro-optical components coupled to the distal portion  504  such that data obtained by the electrical, optical, and/or electro-optical components can be wirelessly communicated to a reader interface  454  during a procedure (i.e., while the distal portion  504  is positioned within the body of a patient) and/or following a procedure (i.e., after the distal portion  504  has been removed from the body of the patient). As described below, in some implementations the distal portion  504  is configured to receive power from the reader interface  454  and to selectively distribute said energy to the electrical, optical, and/or electro-optical component(s). Due to the wireless connection, there is no need for a connector/cable interface between the distal portion  504  and a Patient Interface Module (PIM). As a result, the intravascular device is more easily handled and steered by users. 
     Referring now to  FIG. 9 , in the illustrated embodiment the sensor module  510  includes a sensor  512  having a diaphragm  514  and associated electrical contacts  516 . Generally, the sensor  512  may take any form suitable for use within an intravascular device sized and shaped for use within vessels of a patient, including piezoresistive pressure sensors, capacitive pressure sensors, optical pressures sensors, piezoelectric pressure sensors, and/or electromagnetic pressure sensors. In some implementations, the sensor  512  includes one or more features similar to the pressure sensors described in one or more of U.S. Pat. No. 7,967,762, titled “ULTRA MINIATURE PRESSURE SENSOR,” U.S. patent application Ser. No. 13/415,514, titled “MINIATURE HIGH SENSITIVITY PRESSURE SENSOR,” U.S. Pat. No. 6,167,763, titled “PRESSURE SENSOR AND GUIDE WIRE ASSEMBLY FOR BIOLOGICAL PRESSURE MEASUREMENTS,” and U.S. Pat. No. 6,461,301, titled “RESONANCE BASED PRESSURE TRANSDUCER SYSTEM,” each of which is hereby incorporated by reference in its entirety. 
     Electrical contacts  518  of a sensor control module  520  are electrically coupled to the electrical contacts  516  of the sensing component  512 . The sensor control module  520  couples to at least one antenna that is configured to facilitate wireless communication between the sensor control module  520  and an external device. For example, an adjoining structural coil could be electrically connected to the electrical contacts  522  of the sensor control module  520  and function as an antenna for the distal portion  504  of the intravascular device  500 . In some instances, the structural arrangement of the coil (e.g., diameter, length, winding pitch, winding spacing, wire cross-sectional shape, wire thickness, and/or other parameters) are selected to optimize wireless transmission for a particular wireless protocol by, for example, taking into consideration the frequency range and/or power of desired wireless transmissions. In other instances, the coil does not act as an antenna for the intravascular device. The external device is part of processing system in some instances. In some instances, the external device is an intermediary between the intravascular device  500  and the processing system. Generally, the processing system is configured to process data obtained by the sensor module  510  (including pressure sensor  512  in the illustrated embodiment) and may take the form of any suitable computer processing system, including desktop, laptop, tablet, handheld device, mobile phone, server, other hardware components, and/or combinations thereof and may be implemented utilizing local software application(s), networked software application(s), and/or cloud-based software application(s). 
     Sensor module  510  is inert in the absence of an external energy source. To that end, one or more sensor modules  510  can be energized by an external device. The sensor control module  520  can then be queried by the external device to extract sensor specific setup parameters which the processing system employs to calibrate the sensor module  512 . With the pressure sensor(s)  512  activated, the sensor control module  520  is utilized to, store sensor usage data and to communicate with the external device. Additional features related to using the intravascular device  500  will be described below in the context of  FIGS. 11 and 12 . 
     Referring now to  FIG. 10 , shown therein is the distal portion  504  coupled to a plurality of different proximal portions. In particular, the distal portion  504  is shown being coupled to a proximal portion  550  via a connector portion  552 . Similarly, the distal portion  504  is shown being coupled to a proximal portion  554  via the connector portion  552 . In this regard, the connector portion  552  is representative of a standardized connection arrangement that allows the distal portion  504  to be coupled to any proximal portion having the connector portion  552 . The connector portion  552  is configured to allow the distal portion  504  to be fixedly secured to the proximal portion(s). To that end, the connector portion  552  may facilitate mechanical coupling, chemical bonding, and/or otherwise securing a connection between the distal portion  504  and the proximal portion(s). In the illustrated embodiment, the connector portion  552  includes a coil structure that is threaded onto a mating coil structure of the distal portion  504 . It is understood that in addition to the coil interface, the distal portion  504  may be welded and/or bonded to the connector portion  552  and/or other part of the proximal portion using an adhesive (e.g., epoxy, glue, etc.), solder, and/or other suitable bonding agent. 
     The standardized connection arrangement provided by connector portion  552  allows the distal portion  504  to be connected to the proximal portion of any intravascular device that includes the connector portion. Accordingly, the particular characteristics of the proximal portion can be selected based on user preference, procedure needs, and/or other parameters. Since the distal portion  504  provides full sensing and may include communication functionality without the need for communication lines extending through the proximal portion, proximal portions having different handling characteristics can be utilized. In that regard, to date guide-wires containing pressure sensors, imaging elements, and/or other electronic, optical, or electro-optical components have suffered from reduced performance characteristics compared to standard guide-wires that do not contain integrated electronics. For example, the handling performance of state-of-the-art guide-wires containing electronic components have been hampered, in some instances, by the limited space available for the core wire after accounting for the space needed for the conductive bands, spacers, conductors, sensor(s), and electronic component(s). 
     Further, in a similar manner, the connector portion  552  allows a particular proximal portion to be connected to any one of a plurality of different distal portions configured to mate with the connector portion  552 . For example, distal portions having varying features, such as type(s) of sensing element(s), arrangement of sensing element(s), structural arrangements (e.g., outer diameter, length, mounting arrangements, flexible member type, etc.), and/or other features, may be selected based on user preference, procedure needs, and/or other factors. By providing both a plurality of available proximal portions having varying characteristics and a plurality of available distal portions having varying characteristics, a family of intravascular devices having the most desirable combination of features can be provided. This approach can be utilized to simply manufacturing processes (e.g., separating the manufacturing of the proximal and distal portions and then having an assembly stage where the various combinations of proximal and distal portions are assembled together) and/or allow a user-selectable intravascular device to be assembled in the context of a particular procedure based on a plurality of available proximal and distal portions. 
     Referring now to  FIGS. 11 and 12 , aspects of using an intravascular device, such as the intravascular devices described in the context of  FIGS. 8-10 , will be described in accordance with embodiments of the present disclosure. As shown in  FIG. 11 , at least the distal portion  504  of the intravascular device  652  is positioned within a patient  604 . A boundary  601  represents the distinction between regions inside the patient  604  and regions outside the patient  602 . In that regard, it is understood that the depending on the configuration of the intravascular device  652 , that (1) all of the electrical, optical, and/or electro-optical elements are positioned inside the patient  604  during a procedure or (2) some of the electrical, optical, and/or electro-optical elements are positioned inside the patient  604  while at least a portion of one or more of the electrical, optical, and/or electro-optical elements are positioned in the region  602  outside the patient during a procedure. For example, in the illustrated embodiment the antenna  612  is partially positioned inside the patient  604  and partially positioned outside the patient in region  602  as the antenna extends through section  603  of the patient boundary  601 . In other implementations, the antenna  612  and/or the sensor control module  610  are positioned entirely in the region  602  outside the patient  604 . It is understood that the particular region inside the patient  604  will depend on the size and type of intravascular device  652  being utilized, but in general the region inside the patient  604  can be any vasculature, cavity, passageway, or other area of interest. Accordingly, it is also understood that the exact distance from the distal portion  504  of the intravascular device  652  to the region outside the patient  602  will vary. Further, the air-interface protocol between the intravascular device(s)  652  and the reader interface  654  and between the reader interface  654  and the processing system  656  may include any one or combination of the following: ISO18000-2 (130 kHz), ISO18000-3 (13.56 MHz), ISO18000-4 (2.4 GHz), ISO18000-6c (870-930 MHz). 
     In the illustrated embodiment of  FIG. 11 , the guide-wire antenna  612  is configured to harvest energy from the reader antenna  616 , and communicate with the reader antenna  616 . The reader antenna  616  is strategically oriented and positioned near the guide-wire antenna  612  to optimize the energy and data transmission between the processing system and an in-use intravascular device  652 . The reader antenna  616  may be rigid or flexible, reusable or disposable, and may be deployed as a plurality of antennas, antenna types, and antenna locations. The reader antenna  616  may be within the following dimensions: 150-500 mm wide, 150-2000 mm long, and 1-100 mm thick. The reader antenna  616  may be mounted beneath the mat that separates the patient from the operating table, mounted onto the underside of the operating table, integrated into the mat, integrated into the top-side or bottom-side of the operating table, mounted on the floor, mounted on the ceiling or in the crawl-space above the ceiling, mounted inside or to an outer surface of the operating table pedestal, mounted to the monitor boom on a side or behind the monitors, mounted to an articulating ceiling or bedside arm, mounted to a bedside pole a roll-around IV pole or processing system  656 . The reader antenna  616  communicates with a reader module  618  via a cable interface  620  or other suitable connection. The reader module  618  receives power from a power source  658 , which may be an AC outlet, power-over-Ethernet (POE), or suitable power supply. 
     Energy harvested by guide-wire antenna  612  energizes sensor control module  610  and sensing component  608 . In some instances, a telemetry module  660  communicates sensor output as received by reader module  618  to a processing system  656  via an antenna  662 . In particular, a system antenna  664  of the processing system  656  that is in communication with a processing component  666  communicates with the antenna  662 . In some instances, the processing system  656  is a hemostat system, such as Siemens AXIOM Sensis, Mennen Horizon XVu, and Philips Xper IM Physiomonitoring 5. In some particular instances, the processing system  656  is configured to obtain pressure data related to a vessel of the patient in which the distal portion  504  is positioned. In some particular instances, the processing system  656  utilizes data from the hemostat system and the intravascular device  652  to calculate fractional flow reserve (FFR). 
     Referring now to  FIG. 12 , a method  700  of performing a medical procedure in accordance with the present disclosure will be described. It is understood that the “reader antenna,” “intravascular device,” and associated elements (e.g., “sensor control module”, “device ID”, “sensor,” etc.) referred to may be singular or plural in some embodiments. In that regard, the method described below encompasses the use of some of the exemplary embodiments of intravascular devices described in the present disclosure. Accordingly, a more specific understanding of the steps of the method may be achieved by considering the particular features of one or more of the exemplary intravascular devices described above. It is also understood that the steps of method  700  are exemplary in nature and that one or more of the steps may be omitted, one or more additional steps may be added, and/or the order of the steps may be changed without departing from the scope of the present disclosure. 
     At step  702 , the remote sensing system is activated. At step  704 , the intravascular device is placed within the read-envelope of the reader antenna. At step  706 , the intravascular device is energized by the reader interface. At step  708 , the sensor control module sends the device ID for the intravascular device to the reader interface. At step  710 , the reader interface sends the device ID to the processing system. At step  712 , the device ID is validated (or not) by processing system. If the device ID is not validated, then the procedure is stopped or more information may be required for the procedure to continue. At step  714 , the sensor of the intravascular device is energized by the sensor control module of the intravascular device. At step  716 , the sensor analog data is normalized, digitized, and zeroed by the sensor control module. At step  718 , at least the distal portion of the intravascular device containing the sensor is positioned within the patient. At step  720 , the sensor analog data obtained within the patient is normalized and digitized by the sensor control module. At step  722 , the sensor control module sends the digital data corresponding to the analog sensor data to reader interface. In some instances, the sending of the digital data is performed in real time. In other instances, the digital data is stored, either temporarily or permanently, locally within the intravascular device and later retrieved by the reader interface. At step  724 , the reader interface sends the digital sensor data to the processing system. At step  726 , the processing system calculates and displays the sensor data. 
     In some instances a unique identifier and usage history are stored in the memory of the intravascular device. When the intravascular device is energized, all sensing and/or imaging capabilities are disabled by default, and enabled or activated only after the unique identifier and relevant usage parameters are vetted and approved by the processing system. The vetting process helps prevent the use of counterfeit goods, and/or use of non-sterilized goods, and/or use of expired goods, and/or overuse of goods, etc. The stored elements might include, but are not limited to the following manufacturing assigned elements: device ID, usage limit, sensor ID, temperature coefficient, zero offset, scale factor, sensitivity, manufacture date, manufacture time, and manufacture location. In addition, the stored elements might include, but are not limited to the following time-of-use data elements: use count, date, time, location, system ID, pressure minimum, pressure maximum, velocity minimum, velocity maximum, temperature minimum, temperature maximum, centered (y/n), and reader ID. 
     Energized sensing element(s) detect local environmental parameters. In some instances, the at least one sensing element of the intravascular device is moved through the region of interest (e.g., a pullback is performed) during data acquisition. In some instances, movement of the proximal portion of the intravascular device is monitored, or movement of the guide-wire antenna is measured by reader antenna(s). The measured movement is correlated to the relative position of the associated sensor through the region of interest. In that regard, since the relative position of the guide-wire antenna may be fixed relative to the at least one sensing element, the movement of the guide-wire antenna can be utilized as proxy for movement of the at least one sensing element. 
     Persons skilled in the art will also recognize that the apparatus, systems, and methods described above can be modified in various ways. Accordingly, persons of ordinary skill in the art will appreciate that the embodiments encompassed by the present disclosure are not limited to the particular exemplary embodiments described above. In that regard, although illustrative embodiments have been shown and described, a wide range of modification, change, and substitution is contemplated in the foregoing disclosure. It is understood that such variations may be made to the foregoing without departing from the scope of the present disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the present disclosure.