# US 5,437,288 A · Flexible catheter guidewire > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,437,288 A - Document ID: US5437288A - Status: Granted - Kind: A - Application number: 07/940,523 - Filed: 1992-09-04 - Granted: 1995-08-01 - Earliest claimed: 1992-09-04 - Assignees: Mayo Foundation for Medical Education and Research - Inventors: Robert S. Schwartz; David Berry; Frederick S. Halverson; James V. Donadio, III - Web page: https://patentgrep.com/patent/US5437288A ## CPC - A61M 25/09: Guide wires - A61M 2025/09075: {having a core without a coil possibly combined with a sheath} - A61M 2025/09133: {having specific material compositions or coatings; Materials with specific mechanical behaviours, e.g. stiffness, strength to transmit torque} - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract An apparatus for use as a catheter guidewire and a method for making a catheter guidewire. The apparatus comprises an elongate non-coiled wire having a proximal portion, a distal tip and a flexible portion located between the proximal portion and the distal tip having axially spaced grooves cut therein. The method for making the guidewire includes burnishing one end of a wire to create a rounded distal tip and cutting a predetermined pattern of axially spaced grooves in a length of wire adjacent to the distal tip to create a flexible portion. ## Claims ### Claim 1 A guidewire with a flexible distal end for use with catheters or the like comprising: a metal wire having a proximal portion, a distal tip and a flexible portion therebetween, the flexible portion having a plurality of grooves formed in the metal wire so as to provide a desired flexibility, the grooves increasing in depth toward the distal tip to create a generally tapered core. ### Claim 2 (depends on 1) A guidewire according to claim 1, wherein the metal wire is made of nitinol. ### Claim 3 (depends on 1) A guidewire according to claim 1, wherein the core of the flexible portion has a continuously sloped taper. ### Claim 4 (depends on 1) A guidewire according to claim 1, wherein the guidewire further comprises a polymer coating over the metal wire to increase the mobility of the guidewire. ### Claim 5 (depends on 4) A guidewire according to claim 4, wherein the guidewire further comprises an outer hydrogel coating over the polymer coating. ### Claim 6 (depends on 1) A guidewire according to claim 1, wherein the guidewire includes a central axis and the plurality of grooves comprise non-circumferential axially spaced grooves formed generally perpendicular to the central axis. ### Claim 7 (depends on 6) A guidewire according to claim 6, wherein adjacent non-circumferential axially spaced grooves are offset by an angle. ### Claim 8 (depends on 1) A guidewire according to claim 1, wherein the guidewire further comprises a tapered portion between the proximal and flexible portions having a decreasing diameter toward the flexible portion. ### Claim 9 (depends on 1) A guidewire according to claim 1, wherein the distal tip is plated with a radiopaque material. ### Claim 10 A guidewire with a flexible distal end for use with catheters or the like comprising: a. a continuous metal wire having a proximal portion, a distal tip having a rounded end and a flexible portion generally located between the proximal portion and distal tip, the flexible portion having axially spaced grooves formed in the metal wire that are arranged and configured to create a core in the flexible portion that tapers inward toward the distal tip; and b. coating means to increase the mobility of the guidewire. ### Claim 11 (depends on 10) A guidewire according to claim 10, wherein the coating means is a polymer coating applied to the guidewire which is covered with a hydrogel coating. ### Claim 12 A process for making a guidewire with a flexible distal end for use with catheters or the like comprising the steps of: a. providing a metal wire having a distal tip; b. cutting a plurality of axially spaced grooves in the metal wire along a length of the wire adjacent the distal tip; and c. increasing the depth of the grooves toward the distal tip to create a flexible portion of the distal end of the guidewire. ### Claim 13 (depends on 12) A process for making a guidewire according to claim 12, wherein the grooves are cut using an electrostatic discharge machining tool. ### Claim 14 (depends on 12) A process for making a guidewire according to claim 12, wherein the length of the flexible portion having the axially spaced grooves is between 5 and 30 cm and the width and spacing of the axially spaced grooves is about between 5-10 mils. ### Claim 15 (depends on 12) A process for making a guidewire according to claim 12, wherein the grooves are cut to be non-circumferential with adjacent grooves offset by an angle. ### Claim 16 (depends on 12) A process for making a guidewire according to claim 12, wherein the process further comprises the step of grinding the flexible portion to create a flexible portion with a diameter less than a diameter of a proximal portion; and grinding a tapered portion between the flexible portion and the proximal portion. ### Claim 17 A process for making a guidewire with a flexible distal end for use with catheters or the like comprising the steps of: a. providing a continuous metal wire having a distal tip; b. burnishing the distal tip to a rounded shape; c. cutting a predetermined pattern of axially spaced grooves in the metal wire along a predetermined length of the wire adjacent to the distal tip to create a flexible portion of the distal end of the guidewire; d. coating the guidewire with a polymer to increase the mobility of the guidewire; and e. plating the distal tip with a radiopaque material to enable the guidewire to be viewed on an x-ray. ### Claim 18 (depends on 17) A process for making a guidewire according to claim 17, wherein the guidewire is coated by dipping the guidewire in a liquid polymer to create a plastic jacket over the guidewire; and then dipping the guidewire with the plastic jacket into a hydrogel solution to form an outer coating. ### Claim 19 (depends on 6) A guidewire according to claim 6, wherein the length of the flexible portion is between 15-30 cm and the width and spacing of the axially spaced grooves are about between 5-10 mils. ### Claim 20 (depends on 1) A guidewire according to claim 1, wherein the plurality of grooves comprise a continuous helical groove along the flexible portion. ### Claim 21 (depends on 12) A guidewire according to claim 12, wherein the grooves are cut with a laser. ### Claim 22 (depends on 12) A guidewire according to claim 12, wherein the process further comprises the step of burnishing the distal tip of the metal wire so that it is rounded.