Deflectable catheter

• US 5,562,619 A
• Filed: 10/19/1993
• Issued: 10/08/1996
• Est. Priority Date: 08/19/1993
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Corporation
• Inventors: Koblish, Josef V., Peterson, Thomas H., Kline, Craig R., Mirarchi, Thomas F., Hunjan, Kulbir S.
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): DAWSON, GLENN K
• Application Number:
  US08/138,863
• Time in Patent Office: 1,085 Days
• Field of Search: 604/95, 604/280-282, 604/164, 604/264, 128/657, 128/772, 606/1, 606/108, 606/110, 606/113, 606/32-52, 606/167, 606/170
• US Class Current: 604/95.04
• CPC Class Codes: A61B 17/221 Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions surgical snare instruments A61B17/32056
• CPC Class Codes: A61B 17/2909 Handles
• CPC Class Codes: A61B 17/32056 Surgical snare instruments for removing or smashing calculi A61B2017/2212; tonsillotomes A61B17/26
• CPC Class Codes: A61B 18/24 with a catheter A61B18/26, A61B18/28 take precedence
• CPC Class Codes: A61B 2017/00849 with respect to tissue, e.g. hollow organs
• CPC Class Codes: A61B 2017/00853 low friction, hydrophobic and corrosion-resistant fluorocarbon resin coating (ptf, ptfe, polytetrafluoroethylene)
• CPC Class Codes: A61B 2017/22038 with a guide wire
• CPC Class Codes: A61B 2017/22051 with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation A61B2017/22048, A61B2017/3486 take precedence
• CPC Class Codes: A61B 2017/2212 having a closed distal end, e.g. a loop
• CPC Class Codes: A61B 2017/2215 having an open distal end
• CPC Class Codes: A61B 2017/2912 transmission of forces to actuating rod or piston
• CPC Class Codes: A61B 2017/292 connection of actuating rod to handle, e.g. ball end in recess
• CPC Class Codes: A61B 2017/301 with three legs
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61M 2025/015 Details of the distal fixation of the movable mechanical means
• CPC Class Codes: A61M 25/0133 Tip steering devices
• 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: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00

Abstract

For achieving, e.g., an improved electrophysiology catheter for examination of the heart, or a catheter accessing the brain, the invention, in one aspect, features an elongated wound wire coil extending through the hollow catheter body of a steerable catheter, the coil constructed and arranged to enable the catheter body to withstand reactive compressive load without distortion during application of tension on the pull wire and to transmit torque from the proximal to the distal tip portion of the catheter to enhance fidelity of rotational positioning of the distal tip in response to rotational orientation of the proximal portion of the catheter. The coil is shown in frictional torque-transmitting relationship with the interior of the hollow shaft substantially along the common length of the catheter body when the catheter is bent. Steerable catheters with augmented throw for one-handed operation and important improvements in construction features are also shown.

Claims

1. An axially elongated steerable catheter sized and constructed for advancement through the vasculature of a said catheter comprising:

an elongated flexible outer hollow catheter body having proximal and distal portions respectively terminating at proximal and distal ends, said hollow catheter body being defined by an elongated tubular member having an inner wall surface defining an interior characterized by an inner diameter;

a deflectable distal tip portion deflectable relative to said hollow catheter body about a point and having a proximal end coupled to the distal end of said hollow catheter body and further having a proximal end;

a pull wire having a distal end and further having a distal end coupled to a distal point of attachment on said deflectable tip portion that is distal of the proximal end of the deflectable tip portion, said pull wire extending from the distal point of attachment and through the interior of said hollow catheter body to the proximal end thereof, said pull wire being arranged to apply tension on said deflectable tip portion to produce tip deflection; and

an elongated wound wire coil extending through the interior of said hollow catheter body over a selected length and having a proximal end positioned in the vicinity of the proximal end of the hollow catheter body and having a distal end positioned in the vicinity of the distal end of the hollow catheter body, said coil having an outer diameter selected so that a slight clearance exists between the outer diameter of said wire coil and the inner diameter of the interior of said hollow catheter body, said wire coil enabling said hollow catheter body to withstand reactive compressive load without distortion during application of tension on said pull wire and transmitting torque along a longitudinal axis from the proximal portion to the distal portion of said hollow catheter body to enhance the fidelity of rotational positioning of the distal portion of the hollow catheter body in response to rotation of the proximal portion of the hollow catheter body, said wire coil being in torque-transmitting relationship With the inner wall surface of said hollow catheter body substantially along the selected length of extension of said wire coil through said hollow catheter body so that when said hollow catheter body has a bend and rotational drag is imposed on said hollow catheter body that tends to cause rotation of the distal portion thereof to lag rotation of the proximal portion of said hollow catheter body, said wire coil applies torque to said hollow catheter body to provide high fidelity transmission of rotational position from said proximal end of the hollow catheter body to said distal portion of said hollow catheter body while said slight clearance enables turns of said wire coil to separate and accommodate the bend in said hollow catheter body without substantial buckling during advancement of the catheter through the vasculature of the patient.

2. The steerable catheter of claim 1 wherein said wire coil is formed from wire that is spirally wound about a longitudinal axis, said wire having a radial width defined along a direction substantially transverse to the longitudinal axis about which the wire is wound wherein the ratio of the slight clearance to the radial width of said wire is less than 0.9.

3. The steerable catheter of claim 2 wherein said wound wire comprises wire having a rectangular cross-section.

4. The steerable catheter of claim 2 wherein said wound wire comprises wire with a circular cross-section and said ratio of said slight clearance to the radial width of said wire is less than 0.6.

5. The catheter of claim 1 wherein the proximal end of said wire coil is fixedly attached to the proximal end of said hollow catheter body.

6. The catheter of claim 1 wherein said hollow catheter body comprises an inner abutment near its distal end and the distal end of said coil is positioned to abut against the abutment when said catheter is bent.

7. The catheter of claim 1 wherein said wire coil has an outside diameter that is at most 0.010 inch less than the inner diameter of the interior of said hollow catheter body.

8. The catheter of claim 1 wherein said clearance is selected so that said wire coil and the inner wall surface defining the interior of said outer hollow catheter body are exposed and adapted for torque-transmitting contact with each other in regions where the catheter is bent, wherein the coefficient of friction of the inner wall surface defining the interior of said hollow catheter body is at least about 0.3.

9. The catheter of claim 8 wherein the inner wall surface defining the interior of said hollow catheter body is formed from polymeric material and said wire coil has an outer surface formed from metallic material.

10. The catheter of claim 1 wherein said catheter is an electrophysiology catheter and further comprises at least one electrode mounted on said deflectable tip portion and an insulated conducting wire fixedly attached to said electrode extending through the interior of said hollow catheter body to the proximal end thereof, said conducting wire being constructed to deliver electrical signals to and from said at least one electrode for mapping or ablation of myocardium tissue.

11. The catheter of claim 1 wherein said pull wire is generally coaxial with said hollow catheter body.

12. The catheter of claim 1 wherein said hollow catheter body comprises a braided metal wire shaft with a polymeric coating.

13. The steerable catheter of claim 1 wherein at least a distal portion of said wire coil includes a flattened surface region constructed and arranged to facilitate bending of said wire coil in a direction normal to the flattened surface region of the wire coil.

14. The catheter of claim 1 further comprising

a control handle attached to the proximal end of said hollow catheter body, said control handle comprising:

a housing having a piston chamber therein; and

a piston having proximal and distal ends and a longitudinal bore therethrough, said piston being slidably mounted in the piston chamber, said distal end of said piston being fixedly coupled to the proximal end of said hollow catheter body;

the proximal end of said pull wire being attached to said housing at a location proximal to the piston chamber, said pull wire extending through the bore on the piston, the interior of the hollow catheter body and into a distal lumen of the deflectable tip portion, whereby longitudinal movement of the piston relative to the housing results in deflection of the deflectable tip portion.

15. The steerable catheter of claim 1 further comprising a handle attached to the proximal portion of said hollow catheter body constructed for one-handed operation, said handle having a movable actuating member slidably engaging a proximal portion of said pull wire, said handle further having a fixed member attached to the proximal end of said pull wire, said handle being characterized in that movement of said movable actuating member in a direction along the longitudinal axis of said hollow catheter body a given distance relative to said hollow catheter body causes the distal end of said pull wire to move in a direction along the longitudinal axis of said hollow catheter body a substantially greater distance than said given distance, thereby enhancing the range of tip deflection.

16. The catheter of claim 15 wherein said movable actuating member includes a pulley surface bodily movable therewith, said pull wire being trained about said pulley surface.

17. The catheter of claim 16 wherein said pulley surface is defined by a rigid formation rigidly joined to said actuating member and about which relative sliding motion of said pull wire occurs during actuation.

18. The catheter of claim 1 wherein said deflectable tip portion is constructed from a material more flexible than said catheter body and the proximal end of said deflectable tip portion is bonded to the distal end of said catheter body, and further comprising a safety wire fixedly attached to both said deflectable tip portion and said catheter body.

19. The catheter of claim 1 further comprising:

a control handle attached to the proximal end of the hollow catheter body, said control handle comprising

a housing having a piston chamber therein, said piston chamber having proximal and distal ends, and

a piston having proximal and distal ends and a longitudinal bore therethrough, said piston being slidably mounted in the piston chamber, said piston capable of longitudinal movement relative to said housing within said piston chamber a distance corresponding to a maximum operating length, said distal end of said piston being fixedly coupled to the proximal end of said hollow catheter body; and

a lubricous sheath disposed about the pull wire and extending from a location proximal of the proximal end of the piston chamber to a distal location spaced proximally from the distal end of said pull wire by a distance greater than or equal to the maximum operating length of longitudinal movement of said piston relative to said housing.

20. An axially elongated steerable electrophysiology catheter sized and constructed for advancement through the vasculature of a said catheter comprising:

an elongated flexible outer hollow catheter body having proximal and distal portions respectively terminating at proximal and distal ends, said hollow catheter body being defined by an elongated tubular member having an inner wall surface defining an interior characterized by an inner diameter;

a deflectable distal tip portion deflectable relative to said hollow catheter body about a point and having a proximal end coupled to the distal end of said hollow catheter body and further having a proximal end;

a pull wire having a distal end and further having a distal end coupled to a distal point of attachment on said deflectable tip portion that is distal of the proximal end of the deflectable tip portion, said pull wire extending from the distal point of attachment and through the interior of said hollow catheter body to the proximal end thereof, said pull wire being arranged to apply tension on said deflectable tip portion to produce tip deflection;

a handle attached to the proximal portion of said hollow catheter body constructed for one-handed operation, said handle having a movable actuating member attached to a proximal portion of said pull wire, said handle being characterized in that movement of said movable member in a direction along the longitudinal axis of said hollow catheter body a given distance relative to said catheter body causes the distal end of said pull wire to move in a direction along the longitudinal axis of said hollow catheter body a substantially greater distance than said given distance, thereby enhancing the range of tip deflection;

at least one electrode mounted on said deflectable tip portion; and

an insulated conducting wire fixedly attached to said electrode extending through the interior of said hollow catheter body to the proximal end thereof, said conducting wire being constructed to deliver electrical signals to and from said at least one electrode for mapping or ablation of myocardium tissue.

21. The steerable electrophysiology catheter of claim 20 further comprising an elongated wound wire coil extending through the interior of said hollow catheter body over a selected length and having a proximal end positioned in the vicinity of the proximal end of the hollow catheter body and having a distal end positioned in the vicinity of the distal end of the hollow catheter body, said coil having an outer diameter selected so that a slight clearance exists between the outer diameter of said wire coil and the inner diameter of the interior of said hollow catheter body, said coil enabling said hollow catheter body to withstand reactive compressive load without distortion during application of tension on said pull wire and transmitting torque along a longitudinal axis from the proximal portion to the distal portion of said hollow catheter body to enhance the fidelity of rotational positioning of the distal portion of the hollow catheter body in response to rotation of the proximal portion of the hollow catheter body, said coil being in torque-transmitting relationship with the inner wall surface of said hollow catheter body substantially over the selected length of extension of said coil through said hollow catheter body so that when said hollow catheter body, has a bend and rotational drag is imposed on said hollow catheter body that tends to cause rotation of the distal portion to lag rotation of the proximal portion of said hollow catheter body, said coil applies torque to said hollow catheter body to provide high fidelity transmission of rotational position from said proximal end to said distal portion of said hollow catheter body while said selected clearance enables turns of said coil to separate and accommodate the bend in said hollow catheter body without substantial buckling during advancement of the catheter through the vasculature of the patient.