MRI COMPATIBLE HANDLE AND STEERABLE SHEATH

• US 20140100445A1
• Filed: 12/13/2013
• Published: 04/10/2014
• Est. Priority Date: 12/15/2011
• Status: Active Grant

• Current Assignee: Imricor Medical Systems, Inc.
• Original Assignee: Imricor Medical Systems, Inc.
• Inventors: Stenzel, Gregg S., Wedan, Steven R., Lloyd, Thomas W., Brutlag, Bryan, Page, Doug A., Kalthoff, James Alan
• Granted Patent: US 9,138,561 B2
• Time in Patent Office: Days
• US Class Current: 600/417
• CPC Class Codes: A61M 25/0052 Localized reinforcement, e.g. where only a specific part of the catheter is reinforced, for rapid exchange guidewire port
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility
• CPC Class Codes: A61M 25/01 Introducing, guiding, advancing, emplacing or holding catheters A61M25/10 takes precedence
• CPC Class Codes: A61M 25/0108 using radio-opaque or ultrasound markers
• CPC Class Codes: A61M 25/0127 Magnetic means; Magnetic markers
• CPC Class Codes: A61M 25/0136 Handles therefor
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires
• CPC Class Codes: G01R 33/285 Invasive instruments, e.g. catheters or biopsy needles, specially adapted for tracking, guiding or visualization by NMR
• CPC Class Codes: G01R 33/286 involving passive visualization of interventional instruments, i.e. making the instrument visible as part of the normal MR process
• CPC Class Codes: G01R 33/287 involving active visualization of interventional instruments, e.g. using active tracking RF coils or coils for intentionally creating magnetic field inhomogeneities
• CPC Class Codes: G01R 33/48 NMR imaging systems

Abstract

An MR compatible deflectable catheter and method of using the same is provided. The MR compatible deflectable catheter includes a steerable sheath having a tubular shaft. The tubular shaft receives first and second longitudinal movement wires at a distal end thereof A control handle is coupled to a proximal end of the first and second longitudinal movement wires and causes longitudinal movement of the wires.

Claims

1. An MR compatible deflectable catheter comprising:

a steerable sheath having a tubular shaft, said tubular shaft receiving first and second longitudinal movement wires operably coupled to a distal end thereof;

a control handle having a main body configured to receive first and second rack screws, said second rack screw including a threaded portion on an outer surface at a distal end thereof;

said first longitudinal movement wire operably coupled to said first rack screw and said second longitudinal movement operably coupled to said second rack screw; and

a rotatable adjustment knob operably engageable with said control handle, said rotatable adjustment knob having an internal threaded portion matingly engageable with the threaded portion of said second rack screw, said rotatable adjustment knob moveable between a first position in which the internal thread is configured to engage the thread on the outer surface of said second rack screw and cause said second rack screw to move proximally to cause proximal longitudinal movement of the second longitudinal movement wire and a second position in which the internal thread is configured to move said second rack screw in a distal direction to release tension on the second longitudinal movement wire.

2. The MR compatible deflectable catheter of claim 1 wherein said proximal longitudinal movement of said second longitudinal movement wire causes the distal end of said steerable sheath to deflect about 180 degrees from a longitudinal axis of the tubular shaft in a first direction.

3. The MR compatible deflectable catheter of claim 1 wherein said tubular shaft further includes a pull ring at a distal end thereof and said first and second longitudinal movement wires are operably coupled thereto.

4. The MR compatible deflectable catheter of claim 1 wherein said tubular shaft further includes two internal lumens positioned on opposite sides of said tubular shaft for housing said first and second longitudinal movement wires.

5. The MR compatible deflectable catheter of claim 2 wherein said tubular shaft includes a reinforcement construct at the distal end thereof configured to allow said steerable sheath to deflect at least 180 degrees from the longitudinal axis of the tubular shaft.

6. The MR compatible deflectable catheter of claim 5 wherein said reinforcement construct is selected from a braided configuration, a coiled configuration, a slit tube configuration and combinations of the foregoing.

7. The MR compatible deflectable catheter of claim 1 wherein said shaft includes one or more pressure relief holes.

8. The MR compatible deflectable catheter of claim 1 wherein said shaft includes a transition section having a durometer that is higher than the durometer of the distal end of the shaft and less than the durometers of the proximal end of said shaft.

9. The MR compatible deflectable catheter of claim 1 wherein a lumen of said tubular shaft is lined or coated with a hydrophilic material.

10. The MR compatible deflectable catheter of claim 1 wherein said tubular shaft further includes a ferrous marker, a magnetic marker or a fluoroscopy marker disposed on said tubular shaft.

11. The MR compatible deflectable catheter of claim 1 wherein said tubular shaft further includes an active tracking coil along a length, said active tracking coil comprising chokes, transformers, impedances and combinations of the foregoing.

12. The MR compatible deflectable catheter of claim 11 wherein said active tracking coil comprises traces on a circuit board, a coiled wire, a dipole and combinations of the foregoing.

13. The MR compatible deflectable catheter of claim 1 wherein said tubular shaft further includes one or more fluid ports configured to allow for hemostasis of the steerable sheath.

14. The MR compatible deflectable catheter of claim 5 wherein said reinforcement construct comprises a non-metallic material selected from Kevlar, PEEK, Nylon, fabric, polyimide, fiber optic, silica glass and combinations of the foregoing.

15. The MR compatible deflectable catheter of claim 5 wherein said reinforcement construct comprises a combination of metallic and non-metallic materials.

16. The MR compatible deflectable catheter of claim 1 further comprising first and second pinion gears operably engageable with an inner threaded channel of said first and second rack screws, wherein the proximal longitudinal movement of said second rack screw is configured to cause engagement of said first and second pinion gears to cause said first rack screw to move distally and release tension on said first longitudinal movement wire.

17. The MR compatible deflectable catheter of claim 16 wherein said second position of said adjustable rotation knob is configured to cause longitudinal distal movement of said second rack screw and release of tension on said second longitudinal movement wire.

18. The MR compatible deflectable catheter of claim 17 wherein said second position of said adjustable rotation knob is configured to cause longitudinal proximal movement of said first rack screw and tension on said first longitudinal movement wire.

19. The MR compatible deflectable catheter of claim 18 wherein said tension of said first longitudinal movement wire is configured to cause the distal end of said steerable sheath to deflect at least 180 degrees from a longitudinal axis of the tubular shaft in a second direction.

21. The MR compatible steerable sheath of claim 9 wherein said hydrophilic material is selected from polytetrafluoroethylene, fluorinated ethylene propylene copolymer, nylons and combinations of the foregoing.

22. The MR compatible steerable sheath of claim 1 wherein the steerable sheath comprises a reinforced polymer tube in which the reinforcing material is non-metallic or a hybrid of metallic and non-metallic materials.

20. A method of deflecting a deflectable catheter comprising:

providing a steerable sheath having a tubular shaft, said tubular shaft receiving first and second longitudinal movement wires having first and second ends, said first end operably coupled to a distal end of said tubular shaft;

providing a control handle having a main body configured to receive first and second rack screws, said first and second rack screws including an inner threaded channel and an outer surface, the outer surface of said second rack screw including a thread at a distal end thereof, wherein the second end of said first longitudinal movement wire is operably coupled to said first rack screw and wherein the second end of said second longitudinal movement is operably coupled to said second rack screw;

first and second pinion gears coupled to the tubular shaft of said steerable sheath and operably engageable with the inner threaded channel of said first and second rack screws; and

a rotatable adjustment knob having an internal thread engageable with the threaded outer surface of said second rack screw and moveable between a first position and second position;

rotating said rotatable adjustment knob in said first position to cause engagement of the outer thread of said second rack screw such that said second rack screw moves proximally longitudinally, wherein said proximal longitudinal movement of said second rack screw causes engagement of said pinion gears on said inner threaded channel;

causing said pinion gears to movably advance along the threaded internal channel in the distal direction relative to the second rack screw and in the proximal direction relative the first rack screw thereby causing said first rack screw to move distally thereby releasing tension on said first longitudinal movement wire and causing said second rack screw to move proximally thereby causing tension on said second longitudinal movement wire to moveably cause the distal end of the steerable sheath to deflect to at least 180 degrees in a first direction from a longitudinal axis of said tubular shaft;

rotating said rotatable adjustment knob in said second direction;

causing said pinion gears to movably advance along the threaded internal channel in the proximal direction relative to the second rack screw and in the distal direction relative to the first rack screw thereby causing said second rack screw to move distally thereby releasing tension on said second longitudinal movement wire and causing said first rack screw to move proximally thereby causing tension of said first longitudinal movement wire thereby causing the distal end of the steerable sheath to deflect to at least 180 degrees in a second direction from a longitudinal axis of said tubular shaft.

23. The MR compatible steerable sheath of claim 20 wherein the reinforcing material is selected from Kevlar, PEEK, Nylon, fabric, polyimide or combinations of the foregoing.