Steerable guidewire with soft adjustable tip

• US 4,886,067 A
• Filed: 01/03/1989
• Issued: 12/12/1989
• Est. Priority Date: 01/03/1989
• Status: Expired due to Term

• Current Assignee: Medtronic Ave Incorporated (Medtronic Plc)
• Original Assignee: C.R. Bard, Inc. (Becton, Dickinson & Co)
• Inventors: Palermo, Thomas J.
• Primary Examiner(s): Hindenburg, Max
• Assistant Examiner(s): Citrin, Randy
• Application Number:
  US07/292,934
• Time in Patent Office: 343 Days
• Field of Search: 128/657, 128/772, 604/95, 604/164, 604/170, 604/280, 604/282
• US Class Current: 600/434
• CPC Class Codes: A61M 2025/09175 having specific characteristics at the distal tip
• CPC Class Codes: A61M 25/09033 with fixed mandrils, e.g. mandrils fixed to tip; Tensionable wires

Abstract

A steerable guidewire for guiding a catheter includes an elongate hollow shaft having a distal core wire mounted at its distal end. The distal core wire tapers in a distal direction and has a flexible distral tip. The core wire is received within a helical coil mounted to the distal end of the guidewire, the distal tip of the core wire being attached to the distal tip of the helical coil. A pull wire extends the length of the guidewire through the hollow shaft and the helical coil and is connected, eccentrically, to the distal tip of the helical coil by a small diameter internal spring, the proximal end of which is attached to the distal end of the pull wire and the distal end of which is attached to the distal end of the helical coil. Pulling on the pull wire causes the distal tip of the guidewire to assume a curved configutation. The resilience of the internal spring, however, permits the distal tip of the guidewire to assume a more straightened configuration even while the pull wire is tensioned whereby the distal tip of the guidewire may yield to conform to irregularities in a patient'"'"'s vasculature.

Claims

1. A steerable guidewire comprising:

an elongate solid walled tubular main wire having a proximal and a distal end;

an elongate helical coil having proximal and distal ends and being connected at its proximal end to the distal end of the main wire and extending distally of the main wire;

a distal core wire having proximal and distal ends and being connected to and extending distally from the distal end of the main wire, the core wire extending through the lumen of the coil and having a distal tip connected to the distal tip of the coil at a rounded end cap;

means defining a pull wire opening adjacent to the distal end of the main wire and adjacent the proximal end of the distal core wire;

a pull wire having a proximal end and a distal end, the distal end of the pull wire terminating short of the distal tip of the helical coil;

a longitudinally yieldable spring internal of the helical coil connecting the distal end of the pull wire with the distal end of the helical coil;

the pull wire extending proximally between the core wire and the coil and through the opening into the lumen of the main wire, the pull wire extending proximally through the lumen of the main wire to the proximal end of the main wire;

whereby the proximal end of the pull wire may be pulled to apply tension to the pull wire thereby to tension the internal spring and to draw at least a portion of the distal end of the helical coil into a curved configuration.

2. A steerable guidewire as defined in claim 1 wherein the outer diameter of the main wire is not greater than about 0.020".

3. A guidewire as defined in claims 1 or 2 wherein the core wire is tapered in a distal direction and in which the distal tip of the distal core wire is flat.

4. A guidewire as defined in claim 3 wherein the internal spring is disposed eccentrically in the helical coil and extends along the flat face of the flattened distal tip portion of the core wire.

5. A guidewire as defined in claim 4 wherein the distal end of the pull wire from a location proximally of the pull wire opening and extending to the connection thereof with the internal spring is reduced diameter.