Guidewire with internal pressure sensor

Abstract

A pressure guidewire is provided having a proximal end and a distal end. The pressure guidewire has a proximal section, a sensor housing section, and an intermediate section. The proximal section extends from the proximal end of the pressure guidewire to the distal end of the proximal section. The sensor housing section is disposed adjacent to the distal end of the pressure guidewire. The intermediate section is disposed between the proximal section and the sensor housing section. The intermediate section has a proximal end separated from the proximal section. The proximal end can be coupled to the distal end of the proximal section. The pressure guidewire has a tubular body positioned within the intermediate section. A pressure sensor is positioned in the sensor housing section.

Description

[Technical field]

[0001] Incorporation by reference of any priority application Any and all applications for which a foreign or domestic priority claim is identified in an Application Data Sheet filed with this application are hereby incorporated by reference under 37 C.FR § 1.57.

[0002] This application is directed to the advancement of pressure guidewire technology. [Background technology]

[0003] Guidewires are known for delivering catheters to many vascular locations within the body. Access to remote and tortuous vasculature is facilitated by a combination of mechanical properties such as flexibility, pushability, and torqueability.

[0004] Coronary catheters can be advanced over simple coronary guidewires into the coronary vasculature and used to position dilatation balloons and stents of treatment devices. Some coronary guidewires can also measure blood pressure within portions of the coronary vasculature. Upon measuring blood pressure, therapeutic diagnostics can be used to guide the treatment performed. For example, measurements such as fractional flow reserve (FFR) can be used to determine which patients should be treated with balloons, stents, or other approaches.

[0005] Although pressure measuring guidewires have been described and sold for many years, such devices could be improved. Summary of the Invention [Problem to be solved by the invention]

[0006] There is a need for more robust pressure guidewires. Pressure guidewires are very thin, but house intricately assembled and sophisticated devices. The assembly process and usage requirements can lead to fracture and other failure modes. Thus, such guidewires should be constructed with robust connections between the various functional components. Such guidewires should be made with joints that protect the delicate structures that measure pressure. Such guidewires should be constructed to be kink resistant. [Means for solving the problem]

[0007] In one embodiment, a pressure guidewire is provided that includes a shaft tube assembly, a hypotube, and a tip pressure sensor. The shaft tube assembly may have a proximal section, a central section, and a sensor housing section. The proximal section may have a first tubular body. The first tubular body may have a proximal end, a distal end, a proximal outer surface, and a proximal inner surface. The proximal inner surface may surround a proximal portion of the central lumen. The proximal outer surface may include or form an outer surface of the pressure guidewire. The central section may have a proximal end, a central section outer surface, and a central section inner surface. The central section inner surface may be disposed about a space inside the pressure guidewire. The proximal end of the central section may be separate from the distal end of the proximal section. The proximal end of the central section may be coupled to the distal end of the proximal section. The sensor housing section may extend distally relative to the central section. The hypotube may have a proximal end portion and a distal end portion. The hypotube may extend through a space about which the midsection inner surface is disposed. The proximal end portion of the hypotube may be coupled to a distal end of the proximal section. The distal end portion of the hypotube may be coupled to a sensor housing. The tip pressure sensor may be positioned within the sensor housing section.

[0008] In another embodiment, a pressure guidewire is provided having a proximal end and a distal end. The pressure guidewire has a proximal section, a sensor housing section, and an intermediate section. The proximal section extends from the proximal end of the pressure guidewire to the distal end of the proximal section. The sensor housing section is disposed adjacent to the distal end of the pressure guidewire. The intermediate section is disposed between the proximal section and the sensor housing section. The intermediate section has a proximal end separated from the proximal section. The proximal end may be coupled to the distal end of the proximal section. The pressure guidewire has a tubular body and a pressure sensor. The tubular body has a proximal end portion and a distal end portion. The tubular body is positioned inside the intermediate section. The pressure sensor is positioned within the sensor housing section. The pressure sensor has a signal conductor disposed through the tubular body proximal to the sensor housing.

[0009] The pressure guidewire provides greater flexibility in the mid-section than in the proximal section. In one embodiment, the wall thickness of the pressure guidewire is thinner in the mid-section than in the proximal section. In one embodiment, the pressure guidewire provides a graded lumen profile. In one embodiment, the wall thickness of the pressure guidewire is thinner in the mid-section than in the proximal section, and the pressure guidewire provides a graded lumen profile.

[0010] The thinner wall section allows a tubular body, e.g., a hypotube, to be placed in the middle portion of the assembly. The tubular body, e.g., a hypotube, can have a smaller outer diameter that provides more flexibility than the larger outer diameter and thicker walls of the proximal section.

[0011] In some embodiments, the sensors that perform the pressure measurements include very small and very precise Micro-Electro-Mechanical Systems (MEMS) devices. The assembly of the MEMS devices in the pressure guidewire must be done carefully to reduce the possibility of damage to the MEMS devices and / or sources of measurement error that may result from damage to the MEMS structures.

[0012] In some cases, the guidewire assembly includes a tip assembly including an atraumatic tip, a corewire, and a coil structure. The atraumatic tip may be coupled to the corewire by a suitable technique, for example, by welding. The corewire may include a heat shield or heat sink to contain heat applied to the structure and move the heat affected zone away from the vicinity of smaller sections of the corewire.

[0013] In another embodiment, a guidewire assembly is provided that includes a proximal section and a distal section. The distal section extends distally of the proximal section. The distal section has an outer metal body portion, a sensor assembly, and a metal ring member. The sensor assembly has a sensor body and a signal conductor coupled to the sensor body. The sensor assembly is disposed through the outer body portion. The metal ring member is disposed between the outer metal body portion and the signal conductor of the sensor assembly. The outer metal body is bonded to the metal ring member to provide two metal layers around the sensor assembly.

[0014] In another embodiment, a method of forming a guidewire assembly is provided, the sensor body being coupled to a metallic ring member, the metallic ring member being disposed within an outer metallic body, and a portion of an outer surface of the metallic ring member being joined to a portion of an inner surface of the outer metallic body.

[0015] In another embodiment, a guidewire assembly is provided that includes a proximal section, a distal portion, and a junction. The proximal section has a proximal end and a distal end. The distal portion has a proximal end coupled to the distal end of the proximal section. A detector is disposed at or adjacent to the distal end of the distal portion. The junction includes the distal end of the proximal section and the proximal end of the distal portion. The junction has a zone of enhanced ductility. The zone of enhanced ductility includes a length of the distal portion including its proximal end, a length of the proximal section including its distal end, or a length of the distal portion including its proximal end and a length of the proximal section including its distal end.

[0016] In another embodiment, a method of forming a pressure guidewire is provided. In the method, a proximal body is provided. The proximal body has a first tubular wall with a first wall thickness and a lumen with a first diameter. A distal body is provided with a second tubular wall with a second wall thickness and a lumen with a second diameter. The first diameter is smaller than the second diameter. The first wall thickness is greater than the second wall thickness. The distal end of the proximal body is coupled to the proximal end of the distal body to provide a continuous assembly from proximal to distal to the proximal end of the distal catheter body. Heat is applied to the continuous assembly after coupling, e.g., welding, to increase ductility of at least a portion of the continuous assembly located proximal to distal to the proximal end of the distal body.

[0017] In another embodiment, a pressure guidewire is provided having a shaft tube assembly, a pressure sensor disposed at a distal portion of the shaft tube assembly, and a tip assembly. The pressure sensor is coupled to a signal conduit to communicate a pressure signal to a processor. The tip assembly includes a core wire and an atraumatic tip. The core wire has a proximal end coupled to the distal portion of the shaft tube assembly and an elongated tapered body having a reduced diameter toward the distal end. The atraumatic tip portion has a proximal end coupled to the distal end of the core wire and a rounded distal end. The proximal end is configured to inhibit heat gain at the distal end of the core wire to prevent changes in material properties at the distal end of the core wire.

[0018] In another embodiment, a method of forming a pressure sensing guidewire is provided. A shaft tube assembly is provided having a distal portion with a pressure sensor disposed therein and a distal end. A proximal end of a core wire is coupled to the distal end of the shaft tube assembly. The wire has an elongated tapered body having a smaller size toward its distal end than adjacent its proximal end. The core wire has a tip member disposed at the distal end of the elongated tapered body. A coil is positioned over the core wire. The coil is coupled to the proximal portion of the core wire. The tip member is heated to melt the distal portion and form an atraumatic tip portion having a convex shape. The tip member has sufficient thermal capacity to prevent a change in material properties in the core wire and to allow the distal portion to be formed with a convex shape after heating.

[0019] These and other features, aspects, and advantages are described below with reference to the drawings, which are intended for illustrative purposes and should not be construed as limiting the scope of the embodiments in any way. Moreover, various features of the various disclosed embodiments can be combined to form additional embodiments that are part of this disclosure. In the drawings, like reference characters indicate corresponding features consistently throughout similar embodiments. Below is a brief description of each of the drawings. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a schematic diagram showing a blood vessel having a cutout, such as in a patient's aorta, with a pressure guidewire inserted proximally spaced therefrom and a guide catheter positioned proximal to the cutout. [Diagram 2] 1 is a schematic diagram of a diagnostic system that may include any one of the embodiments of the pressure guidewire disclosed herein. [Diagram 3] FIG. 2 is a side view of an embodiment of a pressure guidewire according to one embodiment disclosed herein. [Figure 4] FIG. 4 is a cross-sectional view of the central section of the pressure guidewire of FIG. 3 taken at cross-sectional plane 4-4. [Diagram 5] 5 is a cross-sectional view of the proximal section of the pressure guidewire of FIG. 3 taken at cross-sectional plane 5-5. [Figure 6] FIG. 6 is a longitudinal cross-sectional view of the pressure guidewire of FIG. 3 taken at cross-sectional plane 6-6. [Figure 7] 7 is a cross-sectional view of the sensor housing section of the pressure guidewire of FIG. 3 taken at cross-sectional plane 7-7 shown in FIG. 6. [Figure 8] FIG. 7 is a detailed view of a portion of the longitudinal cross-sectional view of FIG. 6 showing details of the sensor housing section and tip assembly. [Figure 9] FIG. 1 is an exploded view of the tip assembly, generally showing the atraumatic tip member. [Figure 10] 7 is a detailed view of a portion of the longitudinal cross-sectional view of FIG. 6 showing details of a section disposed between the sensor housing section and the proximal section. [Figure 11] FIG. 11 is an enlarged view of a portion of the view of FIG. 10 showing the outer tubular member above the helical portion. [Figure 12] FIG. 13 shows an approach to connecting the proximal section of the pressure guidewire to its central section. [Figure 13]FIG. 4 is a view similar to FIG. 3 showing two additional cross sections related to illustrate additional embodiments. [Figure 14] FIG. 14 is a cross-sectional view of section plane 9-9 of FIG. 13 according to one embodiment. [Figure 15] 14 is a cross-sectional view of section plane 9-9 of FIG. 13 according to another embodiment. [Figure 16] 14 is a cross-sectional view of section plane 9-9 of FIG. 13 according to another embodiment. [Figure 17] 14 is a cross-sectional view of section plane 9-9 of FIG. 13 according to another embodiment. [Figure 18] 14 is a cross-sectional view of section plane 9-9 of FIG. 13 according to another embodiment. [Figure 19] 14 is a cross-sectional view of section plane 9-9 of FIG. 13 according to another embodiment. [Figure 20] 14 is a cross-sectional view of section plane 8-8 of FIG. 13 according to one embodiment. [Figure 21] 14 is a cross-sectional view of section plane 8-8 of FIG. 13 according to one embodiment. [Figure 22] 14 is a cross-sectional view of section plane 8-8 of FIG. 13 according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] This application relates to improved design and construction techniques for pressure guidewires that provide robust connections between separate structures and enhance crush resistance, providing connections that protect delicate structures from damage caused by stress concentrations caused by material degradation within localized heat-affected zones, such as those that can occur during welding and other heat-generating manufacturing steps.

[0022] I. Overview of the Pressure Wire System and its Use 1 and 2 illustrate a lesion diagnostic system 100 and its use within a patient's vasculature. FIG. 1 illustrates a left coronary vasculature with a pressure guidewire 116 disposed in a proximal portion of the left anterior descending artery (LAD). The pressure guidewire 116 is positioned within the LAD, with its distal portion distal to an occlusion OCL. The pressure guidewire 116 is positioned through a guide catheter 114, which may be positioned, for example, within the aorta. Blood flow within the LAD is generally from proximal to distal through the occlusion OCL and over the distal tip of the pressure guidewire 116, when the guidewire 116 is positioned as shown. The occlusion OCL impedes flow at least to some extent. The lesion diagnostic system 100 is configured to determine whether a vessel is blocked to the extent that balloon angioplasty, a stent, or other catheter intervention should be performed.

[0023] FIG. 2 shows the pressure guidewire 116 disposed at the distal end of the diagnostic system 100 and the monitor assembly 104 positioned at the opposite end of the system 100 from the pressure guidewire 116. The monitor assembly 104 may be disposed at the proximal end of the diagnostic system 100. The distal end of the diagnostic system 100 is the end adapted to be positioned within the patient, for example, within the left anterior descending artery LAD as previously described. The proximal end of the diagnostic system 100 includes the portion close to the cardiologist and, in the case of the monitor assembly 104, the portion outside the patient. One or more devices may be used to connect the pressure guidewire 116 to the monitor assembly 104. As discussed further below, the pressure guidewire 116 may be configured to measure pressure using an optical sensor. In such an embodiment, the pressure guidewire 116 may be coupled to the monitor assembly 104 by the handle 108 and the fiber optic interface cable 112. The fiber optic interface cable 112 conveys optical signals from the pressure guidewire 116 to the monitor assembly 104. The handle 108 connects the fiber optic interface cable 112 to the monitor assembly 104.

[0024] In one approach, the monitor assembly 104 and the handle 108 are reusable components of the diagnostic system 100. The pressure guidewire 116, the fiber optic interface cable 112, or both may be disposable components. In some variations, the handle 108 and the fiber optic interface cable 112 are a single unit.

[0025] II. Pressure Guidewire as an Example FIG. 3 shows the overall configuration of the pressure guidewire 116 according to one embodiment. The pressure guidewire 116 may include a shaft tube assembly 120 including a proximal section 124, a central section 148, a sensor housing section 180, and a tip assembly 182. The shaft tube assembly 120A shown in FIGS. 13-21 and corresponding text describe additional embodiments of the pressure guidewire 116. These components extend along and define the outer surface of the pressure guidewire 116. The structure and design of the pressure guidewire 116 may be improved by providing two or more components forming the outer surface of the wire, for example in the proximal section 124 and in the central section 148. As discussed below, the pressure guidewire 116 is formed by joining a first annular surface 224 of the proximal tubular member to a second annular surface 228 of the distal tubular member. An advantageous connection is provided between the proximal section 124 and the central section 148. Advantageous connections are provided in the sensor housing section 180. An improved assembly is provided in the tip assembly 182.

[0026] 3, 5, and 6 show features of the proximal section 124. The proximal section 124 includes a first tubular body 126 extending between a proximal end 128 and a distal end 132 of the proximal section 124. The tubular body 126 includes a proximal outer surface 136 and a proximal inner surface 140. The proximal outer surface 136 of the tubular body 126 defines a proximal portion of the outer surface of the pressure guidewire 116. The diameter of the proximal outer surface 136 is configured such that the guidewire 116 can have a treatment catheter slidably advanced thereover, for example, between the proximal outer surface 136 and the inner surface of the guide catheter 114. The proximal outer surface 136 can be between 0.2 mm and 2.0 mm, for example, about 0.36 mm in one embodiment.

[0027] The proximal inner surface 140 may be sized to allow the signal conductor 220 to extend therethrough. The signal conductor 220 may extend through a central lumen 144 disposed within the proximal inner surface 140. The proximal inner surface may have a size that approximates the size of the signal conductor 220. The wall thickness of the proximal section 124 between the outer surface 136 and the inner surface 140 may be approximately 0.1 mm. The inner diameter of the proximal section 124 may be between 0.05 mm and 0.25 mm, such as approximately 0.16 mm in one embodiment. The size of the lumen 144 may be between 0.05 mm and 0.25 mm, such as approximately 0.16 mm in one embodiment. In one embodiment, the diameter of the lumen 144 may be less than the sum of the wall thicknesses of the proximal section 124 on either side of the lumen 144. The diameter of the lumen 144 can be between 20% and 100% of the sum of the wall thicknesses of the proximal sections 124 on either side of the lumen 144. The diameter of the lumen 144 can be between 60% and 90%, such as about 80% in some embodiments, of the sum of the wall thicknesses of the proximal sections 124 on either side of the central lumen 144. The gap between the inner surface 140 and the outer surface of the signal conductor 220 can be at least about 0.0127 mm, such as about 0.025 mm.

[0028] The proximal section 124 provides an improved proximal section configuration in allowing the signal conductor 220 to be centrally disposed in the central lumen 144 of the pressure guidewire 116. The proximal section 124 may be configured to provide sufficient support in the proximal section 124 such that the pressure guidewire 116 may be assembled without any core wire or similar reinforcing structure in the proximal section 124. The wall thickness of the proximal section 124 provides sufficient mechanical performance, e.g., pushability, torqueability, and kink resistance, without additional reinforcement. The proximal section 124 may include a continuously concave surface 240 disposed around the signal conductor 220. The continuously concave surface 240 may be formed by the proximal inner surface 140 of the proximal section 124 in one embodiment. The continuously concave surface 240 may be separated from the signal conductor 220 only by an annular gap between the signal conductor 220 and the proximal section 124.

[0029] The proximal section 124 may be configured such that the tubular body 126 has a first thickness 208 between the proximal outer surface 136 and the proximal inner surface 140. The first thickness 208 may be sufficient to provide the necessary support to avoid any kinking or fracturing that would render the pressure guidewire 116 inoperable. The first thickness 208 may be substantially constant from the proximal end 128 to the distal end 132. FIG. 12 shows that the tubular body 126 may have a first annular surface 224 at the distal end 132. The first annular surface 224 is configured to couple with a second annular surface 228 of the central section 148 at a junction 150 between the proximal section 124 and the central section 148, as discussed further below.

[0030] 3, 4, and 6 show details of central section 148. Central section 148 includes a proximal end 152 and a tubular body 149 extending from proximal end 152 to a distal end. The distal end may be coupled to sensor housing section 180 in one embodiment. In another embodiment, the distal end of central section 148 may extend into sensor housing section 180 and form a portion thereof, such as an outer surface.

[0031] The tubular body 149 has a central section outer surface 156 and a central section inner surface 160. The central section outer surface 156 may form a portion of the outer surface of the pressure guidewire 116. Figures 4 and 6 show that the central section outer surface 156 and the proximal outer surface 136 of the proximal section 124 may form a substantially continuous outer surface of the pressure guidewire 116 from the distal end 132 of the proximal section 124 to the proximal end 152 of the central section 148. The tubular body 149 may have an outer diameter defined by the central section outer surface 156 that is the same or substantially the same as the diameter of the proximal outer surface 136. The central section 148 may have an outer diameter of 0.2 mm to 2.0 mm, for example, in various embodiments, about 0.36 mm, about 0.46 mm, about 0.89 mm, and about 0.97 mm.

[0032] The tubular body 149 can be configured to allow the pressure guidewire 116 to have enhanced flexibility in the central section 148 .

[0033] The central section 148 can be made significantly more flexible by forming at least a portion of the tubular body 149 into a discontinuous configuration, such as a ribbon, spiral, coil, or other suitable configuration. The ribbon configuration (FIG. 14) can be formed by spiraling a ribbon 503, preferably a square or rectangular ribbon, at intervals 502. The ribbon can be made of, preferably, stainless steel, cobalt chrome, or other metal, or can be made of a polymer ribbon, such as, for example, Teflon™, polyimide (PI), polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), polystyrene (PS), nylon, polyethylene terephthalate (PET), polycarbonate (PC), acrylonitrile butadiene (ABS), polyether ether ketone (PEEK), polyether block amide (PEBA), and polyurethane (PU). The ribbon or other metallic structure of the pressure guidewire 116, including the proximal section 124, may include materials such as stainless steel, e.g., 304V, 304L, and 316LV stainless steel, 17-7PH stainless steel, mild steel, nickel-titanium alloys, e.g., linear elastic and / or superelastic Nitinol.Also, other nickel alloys, such as nickel chromium molybdenum alloys (e.g., UNS:N06625, e.g., INCONEL® 625, UNS:N06022, e.g., HASTELLOY®, UNS:N10276, e.g., HASTELLOY® C276®, other HASTELLOY® alloys, etc.), nickel copper alloys (e.g., UNS:N04400, e.g., MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc.), nickel cobalt chromium molybdenum alloys (e.g., UNS:R30035, such as MP35-N®, nickel-molybdenum alloys (e.g., UNS:N10665, such as HASTELLOY® alloy B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS:R30003, such as ELGILOY®, PHYNOX®, etc.), platinum enriched stainless steel, titanium, combinations thereof, etc., or any other suitable material may be used. The proximal end surface 505 of the ribbon 503 may be flattened to match the distal end surface of the proximal section 501. The helical configuration (FIG. 15) may be made by laser cutting a helical gap 510 in at least a portion 511 of the central section 148, preferably made of stainless steel, other metal, or polymer tubing. The coil configuration (FIG. 16) may be made by coiling a wire 520, preferably made of stainless steel, platinum, palladium, or other platinum or palladium based metals, other metals, or polymers, to form the central section.

[0034] The central section 148 may be reinforced to enhance or optimize torque transmission, pushability, support, kink and / or crush resistance of the pressure guidewire 116 at the central section 148. In one embodiment, a hypotube 184 may be positioned in the central section 148. FIG. 6 shows that the hypotube 184 may extend from proximal to the ribbon, spiral, or coil portion of the tubular body 149 to distal to the ribbon, spiral, or coil portion. The hypotube 184 may have an inner surface that forms a portion of the central lumen 144 of the pressure guidewire 116. The inner surface of the hypotube 184 may form substantially the same diameter as the inner diameter of the tubular body 126 at the proximal end 128. Preferably, the inner diameter of the hypotube 184 may be adapted to accommodate the outer diameter of the signal conductor 220. The inner diameter of the hypotube 184 may be between 0.05 mm and 0.2 mm, for example, about 0.13 mm in one embodiment. The central lumen 144 may have a substantially constant inner diameter, in one embodiment, for example, from the proximal end to the distal end of the pressure guidewire 116. In one variation, the inner diameter of the hypotube 184 may be smaller than the inner diameter of the tubular body 126, such that the clearance between the outer surface of the signal conductor 220 and the inner surface of the hypotube 184 is smaller than the clearance between the outer surface of the signal conductor 220 and the inner surface of the tubular body 126. The larger clearance between the signal conductor 220 and the tubular body 126 allows the optical fiber 236 to advance more easily through the tubular body 126. On the other hand, the inner diameter of the hypotube 184 may be smaller than the inner diameter of the tubular body 126, such that the wall thickness of the hypotube 184 may be thicker.

[0035] In another embodiment shown in FIG. 17, the central section 148 is made by cutting a spiral 600 along at least a portion of the central section. The cut 600 is preferably made through the entire thickness of the wall of the tubular body at the central section 148. In one variation, the cut 600 passes partially through the wall of the tubular body to change the flexibility of the central section 148. The proximal end face 505 of the central section 148 may be butt-bonded to the distal end face of the proximal section 610 to form a joint 622. Butt-bonding assembly methods include direct laser welding, soldering, and other methods. The proximal end of the hypotube 184 may be bonded to the proximal end of the central section tubular body 602 by providing an adhesive 186 between the outer surface of the hypotube 184 and the inner surface of the central section tubular body 602. The tubular body 602 may include an opening 601 that facilitates the movement of adhesive in the proximal region where the hypotube is bonded to the central section.

[0036] In another embodiment shown in FIG. 18, the inner diameter of the proximal section 710 is not constant. More specifically, the inner diameter of the distal portion of the proximal section 711 may be enlarged to accommodate the hypotube 184, while the remaining proximal inner diameter 712 is smaller to accommodate the signal conductor, e.g., the optical fiber 236. The enlarged inner diameter portion may be as short as 1 mm or less, or as long as 5 mm or more, with the length preferably being about 2-3 mm long. The enlarged portion may be drilled using a drill bit, laser beam, or other methods known in the art. The hypotube 184 is preferably bonded to and within the distal enlarged portion of the proximal section 711 using adhesive 186. The distal portion 711 may include an opening 714 to facilitate the movement of adhesive 186 between the outer surface of the hypotube and the inner surface of the enlarged portion of the proximal section. The central section 713 may be made in a ribbon, spiral, or coil configuration. The proximal end face of the central section may be butt bonded to the distal end face of the proximal section. The proximal portion of the central section may also be joined to the proximal portion of the hypotube by using an adhesive between the inner proximal surface of the central section and the outer proximal surface of the hypotube. The central section 713 may also be joined to the proximal section 711 by butt bonding. The central section 713 may be bonded to the hypotube by an adhesive as previously described.

[0037] In another embodiment shown in FIG. 19, a coupler 721 is attached to the distal end of the proximal section 730. The coupler 721 has an inner diameter to receive the hypotube 184. The coupler 721 can be as short as 1 mm or less and as long as 5 mm or more, preferably about 2-3 mm long. The proximal end face of the coupler 721 can be butt-bonded to the distal end face of the proximal section 730 to form a joint 722. The proximal end of the hypotube 184 can be bonded to and within the coupler 721 using adhesive 186. The coupler 721 can include an opening 715 to facilitate transfer of adhesive 186 between the outer surface of the hypotube 184 and the inner surface of the coupler 721. The central section 713 can be made of or include a ribbon, helix, or coil configuration. The proximal end face of the central section 713 can be butt-bonded to the distal end face of the coupler 721. The proximal portion of the central section may also be joined to the proximal portion of the hypotube 184 by using an adhesive between the inner proximal surface of the central section and the outer proximal surface of the hypotube. The central section 713 may also be joined to the proximal section 730 by a butt bond. The central section 713 may be joined to the hypotube 184 by an adhesive as previously described.

[0038] The hypotube 184 may be shaped to provide varying flexibility along the length of the hypotube 184, and thus along the length of the central section 148. Preferably, the outer surface of the hypotube 184 has a gradually decreasing outer diameter forming a localized tapered portion toward the distal end of the hypotube. The hypotube 184 may include a distal end portion 192, which is cylindrical and enlarged relative to the tapered portion 232 of the hypotube 184 as shown in FIGS. 20, 21. The purpose of the enlarged section 192 may be to join the distal end of the hypotube 184 to the inner surface of the proximal end of the sensor housing 750. The sensor housing 750 may be a tubular body separate from the tubular body of the central section 148. The enlarged section 192 may also be joined at its proximal end to the inner surface of the sensor housing 751. The sensor housing 750 may be an extension of the tubular body of the central section 752. The hypotube 184 may have a cylindrical portion proximal to the tapered section, as shown in Figures 6 and 10. The hypotube 184 may be made of a highly elastic or superelastic material, such as a nickel titanium alloy (nitinol). Other materials that may be used or the hypotube 184 include stainless steel, cobalt chrome, and other materials that are elastic in the expected strain regime.

[0039] The manner in which the junctions 150, 622, and 722 are formed is important to maintaining the structural integrity of the pressure guidewire 116. The junction 150 may include a junction between the tubular body 126 of the proximal section 124 and the tubular body 149 of the central section 148. The junction 150 may include a junction between the hypotube 184 and the tubular body 149. The junction 150 may include a junction between the hypotube 184 and the tubular body 126 of the proximal section 124. The junction 622 may include a junction between the distal end of the proximal section 610 and the proximal end of the central section 602. The junction may include a junction between the distal end of the proximal section 710 and the proximal end of the tubular body of the central section 713. The junction may include a junction between the distal end of the proximal section 730 and the proximal end of the coupler 721. The joint may include a joint between a distal end of the coupler 721 and a proximal end of the tubular body of the central section 713 .

[0040] In one embodiment, an adhesive 185 is provided between the outer surface of the distal end portion 192 of the hypotube 184 and the central section inner surface 160. A seal, for example by adhesive, may be provided between the outer surface of the distal end portion 192 of the hypotube 184 and the central section inner surface 160. In one embodiment, an adhesive 186 is provided between the outer surface of the proximal portion of the hypotube 184 adjacent the proximal end 152 and the central section inner surface 160. A seal may be provided between the outer surface of the proximal portion of the hypotube 184 adjacent the proximal end 152 and the central section inner surface 160. In one embodiment, the adhesive 186 also provides a seal between the outer surface of the proximal portion of the hypotube 184 adjacent the proximal end 152 and the central section inner surface 160.

[0041] FIG. 12 shows details of the joint 150. The joint 150 may be formed between the proximal section 124 and the central section 148. The tubular body 126 of the proximal section 124 has a first annular surface 224. The tubular body 149 of the central section 148 has a second annular surface 228 or coupler, such as any of those disclosed herein, such as those disclosed in FIG. 19. The first annular surface 224 and the second annular surface 228 are secured to one another at the joint 150. FIG. 12 shows that the first thickness 208 at the first annular surface 224 may be thicker than the second thickness 212 at the second annular surface 228. The first annular surface 224 and the second annular surface 228 may be joined by any suitable technique. In one embodiment, a weld zone 151 is provided between the tubular body 126 of the proximal section 124 and the tubular body 149 of the central section 148. The weld zone 151 is shown as a short cylindrical section primarily for illustrative purposes. The weld zone 151 may be a weld line formed during laser welding when the first annular surface 224 and the second annular surface 228 are held together or adjacent to one another. The joint 150 may include a butt joint. The joint 150 may be formed between any two tubular bodies 155 and 156, including between the proximal sections 610, 710, and 730 and the central sections 148 and 713 or the coupler 721.

[0042] In addition to forming a weld zone 151 when connecting the two tubular bodies 155 and 156 at the joint 150, in some embodiments, the joint 150 is configured to enhance kink or crush resistance. In some laser welding techniques, the laser welding can affect the mechanical properties of the material being welded. More specifically, the elastic modulus, tensile strength, yield strength, or a combination thereof, can be adversely affected within the heat affected zone. The change in mechanical properties can soften the material. A typical laser weld joint can be highly localized, i.e., the heat affected zone can be highly localized at the joint. When mechanically challenged, for example when the device is bent within or around the joint, the majority of the strain (deformation) ends up being concentrated in a highly localized area of ​​the heat affected zone 151C. Thus, the risk of crushing increases quite significantly. In one approach, a ductile reinforcement zone 151A is provided on the tubular body 149 of the central section 148. The ductile reinforcement zone 151A may extend along the length of the tubular body 149 in the central section 148 from the proximal end 152 toward the distal end of the tubular body 149. The ductile reinforcement zone 151A may extend at least an approximate distance equal to the outer diameter of the central section 148. The ductile reinforcement zone 151A may extend at least an approximate distance equal to about two, three, four, or five times the outer diameter of the central section 148. The ductile reinforcement zone 151A may extend at least 10% of the distance from the proximal end 152 to the ribbon portion of the central section 148. The ductile reinforcement zone 151A may extend at least 20% of the distance from the proximal end 152 to the ribbon portion of the central section 148. The ductile reinforcement zone 151A may extend at least 30% of the distance from the proximal end 152 to the ribbon portion of the central section 148. The ductile reinforcement zone 151A can extend at least 40% of the distance from the proximal end 152 to the ribbon portion of the central section 148.

[0043] In one embodiment, the joint 150 is configured such that a ductile reinforcement zone 151B is provided within the tubular body 126 of the proximal section 124. The ductile reinforcement zone 151B can be similar to the ductile reinforcement zone 151A and extend proximally from the distal end 132 towards the proximal end 128. The ductile reinforcement zone 151B can have a similar or the same length as the ductile reinforcement zone 151A.

[0044] In another embodiment, the joint 150 is configured such that a ductile reinforced zone is provided in the coupler 721 and / or in a distal region of the proximal section 730. The joint is configured such that a ductile reinforced zone is provided in a region of the proximal section 710 where the inner diameter abruptly decreases.

[0045] In one embodiment, a ductile strengthening zone 151C may be provided in the weld zone 151. In other words, some or all of the weld lines or zones may comprise the weld zone 151.

[0046] The joint 150 may have a ductility enhanced zone, which may include at least a portion of the tubular body 126, at least a portion of the tubular body 149, or at least a portion of the weld zone 151. The weld zone ductility enhanced zone 151 extends from proximal to the first annular surface 224 to distal to the second annular surface 228. Ductility may be provided above a threshold level from ductility enhanced zone 151B through ductility enhanced zone 151C into ductility enhanced zone 151A. The ductility enhanced zone 151C may have a lower ductility than the initial (pre-processing) ductility. The post-processing ductility may be about 90% of the pre-processing ductility, in some cases 20-90% of the pre-processing ductility, in some cases 30-80% of the pre-processing ductility, in some cases 40-70% of the pre-processing ductility, in some cases 45-60% of the pre-processing ductility. The ductility may be as measured using a three-point bend test, as known to those skilled in the art.

[0047] The hypotube 184 may be secured within the pressure guidewire 116 by one or more adhesive bonds as previously described. The hypotube 184 may also be secured within the joint 150. The hypotube 184 may be secured at the weld zone 151. The proximal surface of the hypotube 184 may be joined to the first annular surface 224 of the tubular body 126. In other words, both the second annular surface 228 and the proximal surface of the hypotube 184 may be welded to the tubular body 126.

[0048] One way to increase the ductility of the joint 150 is to provide a localized heat treatment of at least a portion of the pressure guidewire 116 including the joint 150. An example of heat treatment is heating the weld area to a temperature above or about the annealing temperature. More specifically, the heat treatment may include heating the joint 150 to a temperature of at or near 1100° C. for a short period of time and cooling it in air.

[0049] 6-8 show details of the sensor housing section 180. The sensor housing section 180 includes a portion of the pressure guidewire 116 where a sensing device is placed in pressure communication with blood in a vessel in use of the pressure guidewire 116 as described above in connection with FIGS. 1-2. The sensor housing section 180 includes a tip pressure sensor 196. The tip pressure sensor 196 may include a MEMS sensor unit capable of detecting pressure. The MEMS sensor unit is one example of a detector. The MEMS sensor unit may be a device mounted on a small tubular body made of glass, metal, or another material. The MEMS sensor unit may include or be coupled to an optical fiber assembly. The MEMS sensor unit may be integrated into the sensor body 300. The sensor body 300 may include one or more features such as, for example, minimizing assembly-induced stress by providing a flat bonding surface that allows for a thin layer of adhesive to hold the sensor, aligning the sensor inside the tube of the pressure guidewire 116, preventing adhesive from reaching the sensor when assembling the sensor to the inner surface of the tubular body, and other features. The MEMS sensor may utilize optical detection principles. The tip pressure sensor 196 may be located within the sensor housing section 180 in a location such that it is in pressure communication with the blood in the blood vessel. The tip pressure sensor 196 may include a precision structure that requires a secure connection within the pressure guidewire 116 and also requires that the sensor is not damaged in the manufacturing process. The tip pressure sensor 196 may be secured with a ring member 304. The ring member 304 may be secured to the optical fiber 220 near and proximal to the sensor body 300 of the tip pressure sensor 196. The ring member 304 may be secured by an adhesive layer 312 disposed between the ring member 304 and the optical fiber 220.

[0050] FIG. 7 shows that the adhesive layer 312 may be an annular layer between the ring member 304 and the optical fiber 220. The adhesive layer 312 may be positioned to substantially center the sensor body 300 and the fiber 220 relative to the ring member 304. The ring member 304 may securely hold the sensor body 300 of the tip pressure sensor 196 in place within the sensor housing section 180. FIG. 7 shows that the sensor housing section 180 may have an outer tubular body 308 that may be separate from the tubular body 149 of the central section 148 or may be an integral extension thereof. The outer tubular body 308 may have a ring member 304 disposed therein. The ring member 304 may be substantially centered within the outer tubular body 308. The ring member 304 may be held within the outer tubular body 308 by a material bridge 336 extending between an outer surface of the ring member 304 and an inner surface of the outer tubular body 308. The bridge of material 336 may be a separate material, such as an adhesive, in one embodiment. In another embodiment, the bridge of material 336 is a fusion weld line between the ring member 304 and the outer tubular body 308.

[0051] The ring member 304 may be made of a variety of materials, such as polymers, glass, or metals. In one embodiment, the ring member 304 may include a metal ring. The metal ring may be bonded to a glass structure, such as a glass ring, that may be part of the sensor body 300. In one case, the ring member 304 may include a metal ring bonded to a glass ring, which is further coupled to the sensor body 300, which may or may not include another glass ring that holds the MEMS sensor unit or structure. The ring member 304 may be made of a material that may be fusion welded / bonded to the inner surface of the sensor housing by localized sensor housing heating. Preferably, the ring member is made of a metal that may be fused or welded to the sensor housing, such as stainless steel. One or more laser beams may be used to heat and form a material bridge 336 to secure the ring member 304 to the outer tubular body 308. Directing laser welding energy toward or around the ring member 304 may cause damage to the sensor body 300 or the optical fiber 220. Thus, the material bridge 336 is configured or shaped to protect the sensor body 300 and the optical fiber 220 from damage during the attachment process, for example by laser welding.

[0052] A coupling zone 316 is provided on the pressure guidewire 116, particularly within the sensor housing section 180. The coupling zone 316 is configured to prevent the laser welding energy from potentially affecting the optical fiber 220. The coupling zone 316 may be limited to a portion of the cross section of the sensor housing section 180 where the optical fiber 220 is not located, i.e., the coupling zone is offset from the central axis of the sensor housing section where the optical fiber 220 resides. The coupling zone 316 may be so limited in the manner in which the ring member 304 is joined to the outer tubular body using a laser welding process. The laser may be directed toward the exterior surface of the ring member 304, but not toward the optical fiber 220.

[0053] A welding process may be defined that limits where energy is applied to within a boundary. The boundary may be defined as the portion of the cross section of the sensor housing section 180 that does not intersect the optical fiber 220. The direction of the laser beam is offset from the central axis of the sensor housing where the optical fiber resides. Thus, the transfer of heat towards the optical fiber is minimized.

[0054] The methods described above may be used to form a bridge of material 336 (e.g., a weld line). The bridge of material 336 is disposed between an inner surface of the outer tubular body 308 and an outer surface of the ring member 304. The outer tubular body 308 may span the tubular body forming the central section 148 and the outer surface of the sensor housing section 180. The bridge of material 336 may span an arc corresponding to an angle of at least 5° of the outer surface of the ring member 304. The bridge of material 336 may span an angle of at least 10° of the outer surface of the ring member 304. The bridge of material 336 may span an angle of at least 15° of the outer surface of the ring member 304. The bridge of material 336 may span an angle of at least 20° of the outer surface of the ring member 304. The bridge of material 336 may span an angle of at least 5° of the inner surface of the outer tubular body 308. The material bridge 336 can span an angle of at least 10° of the inner surface of the outer tubular body 308. The material bridge 336 can span an angle of at least 15° of the inner surface of the outer tubular body 308. The material bridge 336 can span an angle of at least 20° of the inner surface of the outer tubular body 308. The material bridge 336 can span angles of 5° to 90°, 10° to 70°, and 20° to 40°.

[0055] The bridge of material 336 may extend along the axial length of the ring member 304, such as along at least 30% of the length of the ring member 304. The bridge of material 336 may extend at least 20% of the length of the ring member 304. The bridge of material 336 may extend at least 10% of the length of the ring member 304.

[0056] To allow the guidewire to be easily steered within the vasculature, it is desirable to have an advantageous, e.g., optimal, flexibility profile, and more particularly, to reduce or minimize interruptions in the continuous flexibility profile. A continuous flexibility profile can be achieved by reducing or minimizing the length of stiff regions along the guidewire, among other specific flexibility profile parameters. The primary function of the sensor housing is to protect the sensor from external mechanical stresses, which may otherwise compromise the stability of the measurements. Thus, stiffness of the sensor housing is a desirable feature. To reduce or minimize the effect of the sensor housing on the flexibility profile, the length of the sensor housing must be reduced or minimized as much as possible. Thus, shortening the overall length of the sensor assembly and ring members is of paramount importance in some embodiments. The sensor assembly shown in FIG. 22 allows the sensor assembly, and thus the sensor housing, to be further shortened. The MEMS device 760 can be part of a sensor that includes a septum and a base that supports the septum. The septum may be made of silicon and the base may be made of glass, typically Pyrex® or other glass compatible with anodic bonding to silicon. An advantageous sensor assembly includes a MEMS pressure portion 760 mounted directly on a ring member 761. The ring member is preferably made of a metal that can be fusion welded to the inside of a sensor housing or other tubular body. A preferred embodiment is a MEMS pressure device bonded to the distal face of a ring member made of stainless steel 304 or other metal, with signal conductors or optical fibers bonded to and through the inside of the ring member to make optical contact with the MEMS proximal surface.

[0057] 8-9 show the tip assembly 182 in further detail. As previously mentioned, the pressure guidewire 116 is inserted into the sensitive and delicate vasculature of the patient's heart. Therefore, the tip assembly 182 must gently engage the vascular tissue. Also, the tip assembly 182 must be able to bend and flex in such interactions without kinking or fracturing. These requirements result in a very complex structure. The tip assembly 182 offers a state-of-the-art design, which at the same time preserves the material properties of the components of the tip assembly 182.

[0058] The tip assembly 182 includes a core wire 364 disposed within the coil 360. The core wire 364 extends from a first (or proximal) end coupled to a distal end of the outer tubular body 308. FIG. 8 shows that the proximal end of the core wire 364 can be inserted into a distal opening of the outer tubular body 308. The proximal end of the core wire 364 can form a distal boundary of a sampling region 339 of the pressure guidewire 116. The sampling region 339 is an area where blood can enter the pressure guidewire 116 and be sensed by the sensor body 300. The connection between the outer tubular body 308 and the proximal end of the core wire 364 can be made by any suitable technique, for example, by laser welding.

[0059] The core wire 364 may have a tapered profile from the proximal portion to the distal portion as shown in Figures 8 and 9. Figure 8 shows a more simplified embodiment of the core wire 364. Figure 9 shows that the core wire 364 may have a proximal portion 372 having a first outer diameter. The core wire 364 may have a profiled distal portion 376. The profiled distal portion 376 may include a first proximal taper and a second distal taper. The core wire 364 of Figure 9 may have a hole to receive an end portion of the coil 360. The proximal portion 372 may extend into the interior of the coil 360.

[0060] 9 illustrates that the profiled distal section 376 dramatically reduces the diameter of the core wire 364. The small diameter of the core wire 364 at the distal section can be less than one-half the diameter of the core wire 364 at the proximal section 372. The small diameter of the core wire 364 at the distal section is less than one-fifth the diameter of the core wire 364 at the proximal section 372. The small diameter of the core wire 364 at the distal section can be less than one-eighth the diameter of the core wire 364 at the proximal section 372. The small diameter of the core wire 364 at the distal section is less than one-tenth the diameter of the core wire 364 at the proximal section 372.

[0061] The tapering of the profiled distal section 376 provides desirable flexibility at the distal end of the tip assembly 182, and the small diameter at the distal section limits options for connecting the core wire 364 to the atraumatic tip member 368 of the tip assembly 182. This connection may be made by welding. Welding generates high heat that may degrade the performance of the core wire 364. The atraumatic tip member 368 provides a safe initial contact member for the pressure guidewire 116 as it advances through the vasculature. This may protect the blood vessel itself and any vulnerable plaque within the vessel that the pressure guidewire 116 may have to engage and cross.

[0062] The core wire 364 is configured to protect the properties and performance of the core wire 364 while allowing the atraumatic tip member 368 to be connected thereto by a welding process. Laser fusion welding can create the atraumatic tip member 368 from the core wire enlarged distal section 380 and the radiopaque coil 360. Due to the slender nature of the core wire 364 at the profiled distal portion 381, the heat generated by the welding process can potentially change the material properties of the tip assembly 182. Specifically, the core wire 364 is treated, e.g., cold worked, to have high tensile and yield strength to avoid fracture and undesirable plastic deformation. The heat of a typical laser welding process anneals the material to the point where these properties are lost or impaired. The zone where the material properties are affected by the heating process is sometimes referred to herein as the heat affected zone (HAZ).

[0063] FIG. 9 illustrates that the core wire 364 may include a distal portion 380 configured to protect the slender, e.g., narrowest section, of the profiled distal portion 376, so that their desirable material properties are maintained. The distal portion 380 includes a length of expansion member configured to absorb heat in the process of melting the distal portion 380 and the radiopaque coil 360 to create the atraumatic tip member 368. In one embodiment, the atraumatic tip member 368 has a recess configured to receive the distal portion 380. The distal portion 380 may be disposed within the recess of the atraumatic tip member 368. After the distal portion 380 is advanced into the atraumatic tip member 368, energy may be applied to the distal portion 380 and the atraumatic tip member 368 to couple these components together. The size and length of the distal portion 380 prevents the application of heat to the distal end of the distal portion 380 from transferring heat into the reduced diameter section 381 of the core wire, thus preventing excessive heat from transferring and reaching the narrowed portion 381 of the core wire 364. The distal portion 380 may be two times larger in diameter than the small diameter section of the profiled distal portion 376. The distal portion 380 may be three times larger in diameter than the small diameter section of the profiled distal portion 376. The distal portion 380 may be four times larger in diameter than the small diameter section of the profiled distal portion 376. The distal portion 380 may be five times larger in diameter than the small diameter section of the profiled distal portion 376. The distal portion 380 may be seven times larger in diameter than the small diameter section of the profiled distal portion 376. The narrowest portion of the profiled distal portion 376 can be maintained below a temperature corresponding to the melting temperature, for example for stainless steel 304, or below an annealing temperature, such as 1000° C. as a non-limiting example, while the distal portion 380 is melted with the radiopaque coil to create the atraumatic tip 368. The narrowest portion of the profiled distal portion 376 cannot exceed the annealing temperature of the material used to avoid any reduction in the ultimate tensile strength of the tip assembly 182.

[0064] In another embodiment, the core wire 364 is formed or ground with a profile that includes the distal portion 380. The outer diameter of the distal portion 380 is formed to fit within the coil 360. The clearance between the coil and the distal portion allows for the formation of an atraumatic tip member 368 by melting the distal end portion 380 and fusing it together with the portion of the coil that covers the distal portion 380. Any heat affected zone is kept away from the narrow portion 381 of the core wire 364 by fusing the distal end of the distal portion 380 to the coil. The distal portion is made at a length that results in a thermal gradient where the heat affected zone does not reach the proximal end of the distal end 380 and therefore the narrow portion 381 of the core wire 364.

[0065] The pressure guidewire 116 may also include a novel assembly for providing sealed flexibility to the central section 148. The central section 148 may be configured with a helix, ribbon section, or coil configuration as previously described. The helix section may be disposed around a central portion of the hypotube 184 as previously described. The helix, ribbon, or coil may be enclosed, at least in part, within an outer sleeve 400. The outer sleeve 400 may be made of a suitable material. In one embodiment, the outer sleeve 400 is formed of PET. Other suitable materials may also be used. FIG. 11 illustrates a portion of the central section 148 with enhanced flexibility. The central section 148 may have a helix break, ribbon, or coil as previously described. FIG. 11 illustrates an outer portion of the central section 148, with the hypotube 184 omitted for clarity. The outer sleeve 400 includes an outer surface portion 404 and an extension portion 408. The outer surface portion 404 comprises a tubular member attached to the outer surface of the helical portion of the central section 148. The extension portion 408 can span between adjacent helical sections of the helical break portion of the central section 148. The extension portion 408 can extend into the gap between adjacent helical sections of the helical break portion of the ribbon or the coil portion. The extension portion 408 can comprise a flexible span of material having a length greater than the gap between adjacent helical sections of the helical break portion. The gap can be any value between 0.01 mm and 2.5 mm in the undeflected state, e.g., 0.01 mm to 0.25 mm, 0.015 to 0.05 mm, 0.0254 mm, or any value at or between any endpoint of the aforementioned ranges. The gap can vary from the nominal value stated above in the deflected, e.g., curved or bent, state. These gap dimensions also apply to the embodiment including spacing 502 and helical gap 510 described above. The flexible span of extension portion 408 allows adjacent helices of the helical break to move relative to one another, so that central section 148 can flexibly torque and bend and then retract to a straight configuration.

[0066] The outer sleeve 400 may be used to receive a coating having certain characteristics along a portion of the central section, such as a hydrophilic coating or other coating. The outer sleeve 400 may be used to promote adhesion of a coating on the outer surface of the central section 148. The outer sleeve 400 may also be used to prevent substances, such as coatings, from reaching and entering the interface between the helical break, ribbon, or coil portion of the central section 148 and the hypotube 184. The outer sleeve 400 ensures that the hypotube 184 can rotate freely relative to the central section 148, thus maintaining flexibility and torque transmission, while keeping the interface between the outer surface of the hypotube 184 and the inner surface of the central section 148 free of coatings.

[0067] term As used herein, the relative terms "proximal" and "distal" are intended to be defined from the perspective of a user of the system, such that proximal refers to a direction toward the user of the system and distal refers to a direction away from the user of the system.

[0068] Conditional words, such as "can," "could," "might," or "may," are generally intended to mean that certain embodiments include certain features, elements, and / or steps, but other embodiments do not, unless specifically stated otherwise or understood otherwise within the context as used. Thus, such conditional words are generally not intended to imply that features, elements, and / or steps are in any way required for one or more embodiments.

[0069] The terms "comprising," "including," "having," and the like are synonymous and are used in an inclusive, open-ended manner and do not exclude additional elements, features, acts, operations, etc. Also, the term "or" is used in an inclusive (and not exclusive) sense, so that, for example, when used to connect a list of elements, the term "or" means one, some, or all of the elements of the list.

[0070] As used herein, the terms "approximately," "about," "generally," and "substantially" refer to an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms "approximately," "about," "generally," and "substantially" can refer to an amount that is within 10% of the stated amount, as the context may dictate.

[0071] Ranges disclosed herein also encompass any and all overlaps, subranges, and combinations thereof. Words such as "up to," "at least," "more than," "less than," "between," and the like include the recited numbers. Numbers preceded by terms such as "about" or "approximately" include the recited number. For example, "about 4" includes "4."

[0072] Any methods disclosed herein do not have to be performed in the order recited. Methods disclosed herein include certain actions taken by a practitioner, but may also include any third-party direction of those actions, whether explicit or implied. For example, an action such as "distally move a locking element" includes "directing distal movement of the locking element."

[0073] Although certain embodiments and examples have been described herein, those skilled in the art will appreciate that many aspects of the humeral assembly shown and described in this disclosure may be otherwise combined and / or modified to form further embodiments or acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. A wide variety of designs and approaches are possible. No feature, structure, or step disclosed herein is essential or indispensable.

[0074] Some embodiments have been described with reference to the accompanying drawings. However, it should be understood that the drawings are not drawn to scale. Distances, angles, etc. are merely illustrative and do not necessarily bear a strict relationship to the actual dimensions and layout of the illustrated devices. Components may be added, removed, and / or rearranged. Furthermore, any particular features, aspects, methods, properties, attributes, qualities, attributes, elements, etc. disclosed herein in connection with various embodiments may be used in all other embodiments described herein. Furthermore, it will be recognized that any method described herein may be implemented using any device suitable for performing the recited steps.

[0075] For the purpose of this disclosure, certain aspects, advantages, and novel features are described herein. It is understood that not all such advantages can be achieved according to any particular embodiment. Thus, for example, a person skilled in the art will recognize that the present disclosure can be embodied or carried out in a manner that achieves one advantage or group of advantages as taught herein, without necessarily achieving other advantages as taught or suggested herein.

[0076] Moreover, while exemplary embodiments are described herein, the scope of any and all embodiments has equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and / or alterations that would be recognized by one of ordinary skill in the art based on this disclosure. The limitations in the claims are to be interpreted broadly based on the words used in the claims and are not limited to the examples described herein or during the prosecution of this application, which examples are to be interpreted as non-exclusive. Furthermore, the actions of the disclosed processes and methods may be modified in any manner, including by rearranging actions and / or incorporating additional actions and / or deleting actions. Thus, the specification and examples are to be considered as exemplary only, with the exact scope and spirit being indicated by the full scope of the claims and equivalents. [Explanation of symbols]

[0077] 100 Lesion diagnosis system 104 Monitor Assembly 108 Handle 112 Fiber Optic Interface Cable 114 Guide Catheter 116 Pressure Guidewire 120 Shaft tube assembly 120A Shaft Tube Assembly 124 Proximal Section 126 First tubular body 128 Proximal end 132 Distal end 136 Proximal lateral surface 140 Proximal medial surface 144 Central lumen 148 Central Section 149 Tubular body 150 Joint 151 Welding Zone 151A Ductile Strengthening Zone 151B Ductile Strengthening Zone 151C Heat Affected Zone 151C Ductile Strengthened Zone 152 Proximal end 155 Tubular body 156 Center section outer surface 156 Tubular body 160 Center section inner surface 180 Sensor Housing Section 182 Tip assembly 184 Hypotube 185 Adhesive 186 Adhesive 192 Distal end section 192 Expanded Section 196 Tip pressure sensor 208 First Thickness 212 Second Thickness 220 Signal Conductor 224 First Circular Surface 228 Second Circular Surface 232 Tapered section 236 Optical Fiber 240 Continuously concave surfaces 300 Sensor body 304 Ring member 308 Outer tubular body 312 Adhesive layer 316 Connected Zone 336 Material Bridge 339 Sampling Area 360 Coil 360 Radiopaque coil 364 Core Wire 368 Atraumatic Tip Member 372 Proximal part 376 Profiled Distal Section 380 Corewire Expanded Distal Section 380 Distal part 380 Distal end section 380 Distal end 381 Profiled Distal Section 381 Reduced diameter section 381 Narrow Part 400 Outer Sleeve 404 Outer surface area 408 Extension 501 Proximal Section 502 interval 503 Ribbon 505 Proximal end face 510 Spiral Gap 520 Wire 600 spiral 600 cuts 601 Opening 602 Central section tubular body 602 Central Section 610 Proximal Section 622 Joint 710 Proximal Section 711 Proximal Section 711 Distal part 712 Remaining proximal inner diameter 713 Central Section 714 Opening 715 Opening 721 Coupler 722 Joint 730 Proximal Section 750 Sensor Housing 751 Sensor Housing 752 Central Section 760 MEMS Devices 760 MEMS pressure part 761 Ring material LAD left anterior descending artery OCL occlusion

Claims

1. A pressure guidewire, 1. A shaft tube assembly comprising: a proximal section including a first tubular body including a proximal end, a distal end, a proximal outer surface, and a proximal inner surface, the proximal inner surface surrounding a proximal portion of a central lumen, the proximal outer surface including an outer surface of the pressure guidewire; a central section including a proximal end, a central section outer surface, and a central section inner surface, the central section inner surface being disposed about a space within the pressure guidewire, the proximal end of the central section being separate from and connected to the distal end of the proximal section; The central section, a sensor housing section extending distally relative to the central section; a tip assembly extending distally relative to the sensor housing section; and a hypotube including a proximal end portion and a distal end portion, the hypotube extending through the space about which the central section inner surface is disposed, the proximal end portion of the hypotube being coupled to the distal end of the proximal section, and the distal end portion of the hypotube being coupled to the sensor housing section; a tip pressure sensor positioned within the sensor housing section; a metallic ring member disposed in the sensor housing section, the metallic ring member being coupled to the tip pressure sensor and a signal conductor, the metallic ring member being disposed adjacent to the tip pressure sensor; 4. A pressure guidewire comprising:

2. The pressure guidewire of claim 1 , wherein the proximal inner surface has a first diameter and the central section inner surface has a second diameter, the first diameter being smaller than the second diameter.

3. The pressure guidewire of claim 1, wherein a first thickness is defined between the proximal inner surface and the proximal outer surface, and a second thickness is defined between the central section inner surface and the central section outer surface, the first thickness being thicker than the second thickness.

4. The pressure guidewire of claim 1, wherein the tip pressure sensor includes a signal conductor disposed through the central section and through the proximal section, and at least a portion of the signal conductor disposed inside the proximal inner surface is centered on a central longitudinal axis of the proximal section.

5. The pressure guidewire of claim 1 , wherein the tip pressure sensor includes a signal conductor disposed through the central section and through the proximal section.

6. The pressure guidewire of claim 1, wherein the distal end of the proximal section includes a first annular surface disposed perpendicular to a longitudinal axis of the proximal section, the proximal end of the central section includes a second annular surface disposed perpendicular to the longitudinal axis of the central section, the first annular surface and the second annular surface contact each other, and the connection between the proximal section and the central section includes a weld.

7. The pressure guidewire of claim 1 , wherein the central section includes a cut pattern configured to provide greater flexibility to the central section than to the proximal section.

8. The pressure guidewire of claim 7, wherein the proximal end portion of the hypotube is joined to the proximal section proximal to the proximal end of the cut pattern and the distal end portion of the hypotube is joined to the sensor housing section distal to the distal end of the cut pattern.

9. The pressure guidewire of claim 1 , wherein the central section comprises a helical ribbon, a coil, and / or a laser cut pattern.

10. The pressure guidewire of claim 9, further comprising a sleeve disposed over the spiral ribbon, the coil and / or the laser cut pattern, the sleeve configured to reduce or prevent ingress of matter into the space between the hypotube and the central section or onto the hypotube.

11. The pressure guidewire of claim 1, wherein the proximal end portion of the hypotube is joined to an inner surface within the lumen of the pressure guidewire, and the distal end portion of the hypotube is joined to an inner surface within the lumen of the pressure guidewire proximal to the tip pressure sensor.

12. The pressure guidewire of claim 1 , wherein the distal end portion of the hypotube is positioned within the sensor housing section.

13. The pressure guidewire of claim 1 , wherein the hypotube includes a tapered portion proximal to the distal end portion, the tapered portion tapering in a distal direction.

14. The pressure guidewire of claim 13 , wherein the distal end portion of the hypotube is enlarged relative to the tapered portion.

15. The pressure guidewire of claim 1 , further comprising an optical fiber centered within the pressure guidewire in the proximal section and centered within the hypotube in the central section.

16. The pressure guidewire of claim 15 , wherein the optical fiber is surrounded by a continuously concave surface within the proximal section.

17. A pressure guidewire, A proximal end portion; A distal end portion. a proximal section extending from the proximal end of the pressure guidewire to a distal end of the proximal section; a sensor housing section disposed adjacent the distal end of the pressure guidewire; an intermediate section disposed between the proximal section and the sensor housing section, the intermediate section being separate from the distal end of the proximal section and having a proximal end coupled to the distal end of the proximal section; a tubular body including a proximal end portion and a distal end portion, the tubular body being positioned within the intermediate section; a pressure sensor positioned within the sensor housing section and having a signal conductor disposed through the tubular body proximal to the sensor housing section; a metallic ring member disposed in the sensor housing section, the metallic ring member being coupled to the pressure sensor and a signal conductor, the metallic ring member being disposed adjacent to the pressure sensor; Including, a wall thickness of the pressure guidewire is thinner in the intermediate section than in the proximal section to provide a graduated lumen profile; The metal ring member is configured to be held to the sensor housing section by a material bridge, the material bridge being disposed only in a portion of a cross section of the pressure guidewire that intersects the metal ring member across a central longitudinal axis of the pressure guidewire, the portion of the cross section not including the pressure sensor. Pressure guidewire.

18. The pressure guidewire of claim 17 , wherein the proximal section includes an annular wall defining an inner diameter smaller than an outer diameter of the tubular body positioned within the intermediate section.

19. 2. The pressure guidewire according to claim 1, the tip assembly includes a core wire having a proximal end connected to the sensor housing section. Pressure guidewire.

20. The pressure guidewire of claim 19 , wherein the core wire is disposed within a coil.

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