STEERABLE CATHETER

• US 3,773,034 A
• Filed: 11/24/1971
• Issued: 11/20/1973
• Est. Priority Date: 11/24/1971
• Status: Expired due to Term

• Current Assignee: Charles Thomas Ogden, Marvin Burns, Richard A. Rodzen
• Original Assignee: Charles Thomas Ogden, Marvin Burns, Richard A. Rodzen
• Inventors: Burns, Marvin, Ogden, Charles Thomas, Rodzen, Richard A.
• Primary Examiner(s): Truluck, Dalton L.
• Application Number:
  US05/201,912
• Time in Patent Office: 727 Days
• Field of Search: 128/4,6-8,348-351,356,DIG.9,2M,2R,2.5D,2.5R
• US Class Current: 600/434
• CPC Class Codes: A61M 25/0155 with hydraulic or pneumatic means, e.g. balloons or inflatable compartments

Abstract

A tip on a catheter is bent to steer the distal end of the catheter by displacing a control fluid within an elongated fluid conduit to stretch one longitudinally extending side of the tip relative to an opposite longitudinally extending side of the tip. The stretched side bends about the shorter side with a radius of curvature larger than the radius of curvature for the shorter side of the tip. A longitudinal restraining means may be applied to the tip to assure that the tip always bends in the same direction with the fluid displacement. On the other hand, other catheters may be bent in several and predetermined directions by providing a plurality of discrete fluid control conduits and by establishing a fluid pressure differential in at least one of the conduits to cause its associated side to lengthen and bend relative to a portion of the tip associated with another control conduit. The catheter may be small in dimension, made inexpensively and restrained against expanding in diameter by a circumferential restraining means.

Claims

1. An elongated steerable catheter extending from a proximal to a distal end for passing through channels defined by walls in a body, said caTheter comprising an elongated tube having a longitudinally extending passageway therein extending from the proximal end to a discharge opening adjacent the distal end, at least one control conduit means receiving a control fluid associated with the elongated tube and extending longitudinally from said proximal end to said distal end, said distal end of said tube being formed of a flexible, thin stretchable and contractible material for axial elongation with increase in pressure in said control conduit means and for contraction with reduction of said increase in pressure, said catheter having a predetermined overall length and a predetermined external crosssectional dimension remaining substantially unchanged with increase of pressure in said control tube, and steering control means for displacing said control fluid in said control conduit to cause one portion of said elongated tube at the distal end of the catheter which is the least restrained by the walls of the channel to stretch and to lengthen further into said channel and relative to another portion of said elongated tube which is more restrained by engagement with the walls of said channels, said lengthened portion being free to bend about said another portion in proportion to the pressure of control fluid and at various locations dependent upon the location of the restraint of said another portion so that tip may bend with varying radii dependent upon the radii of the channel.

2. A catheter in accordance with claim 1 in which said control conduit means is an inner tube having a hollow central passageway and in which said elongated tube is an outer tube coaxial with said inner tube and in which said passageway of said elongated tube is annular in cross section, said discharge opening of said elongated tube being radially directed and in said outer tube.

3. A catheter in accordance with claim 1 in which means are provided in said distal end of said tube passageway to hold the same against collapsing inwardly and closing said tube passageway when bending the catheter distal end.

4. A catheter in accordance with claim 3 in which said means to hold said tube passageway against collapsing is a coiled spring inserted into said lumen at said distal end thereof.

5. A catheter in accordance with claim 3 in which a plurality of longitudinal extending control conduits are spaced circumferentially about said tube and in which said steering control means is connected to each of said control conduits to provide a pressure differential within and between said control conduits to stretch said one portion of said tube thereby causing said distal end to bend.

6. A catheter in accordance with claim 1 in which a circumferential restraining means holds said control conduit means from a substantial radially outward expansion with an increase of pressure in said control conduit.

7. A catheter in accordance with claim 6 in which said circumferential restraining means comprises helically wound wraps of opposite lays which permit lengthening of one portion of the distal end of the tube relative to the other portion.

8. An elongated steerable catheter extending from a proximal to a distal end, said catheter comprising an elongated tube having a longitudinally extending passageway therein extending from the proximal end to a discharge opening adjacent the distal end, an elongated control conduit for receiving a control fluid associated with the elongated tube and extending longitudinally from said proximal end to said distal end, a constraining means for constraining one portion of said tube at said distal end against lengthening longitudinally to the extent that another portion lengthens under fluid pressure in said control conduit, and steering control means for increasing the pressure of said control fluid in said control conduit to elongate said other portion of said tube relative to said one portion causing said distal end to bend with said other portion having a larger radius of curvature than the one portion of the tube. Pg,17

9. An elongated catheter extending from a proximal end to a distal end which is steerable in multiple directions, said catheter comprising an elongated tube having a longitudinally extending passageway therein extending from the proximal end to a discharge opening adjacent the distal end, said distal end of said tube being stretchable and contractible, a plurality of discrete longitudinally extending control conduits spaced circumferentially about said tube and extending from said proximal end to said distal end, said control conduits being connected to said distal end of said steerable catheter at circumferentially spaced positions for stretching an associated portion of said distal end of said tube with establishment of a differential fluid pressure and displacement of fluid among said control conduits, and a steering control means having a plurality of selectively operable pressure increasing means each associated with one of said control conduits for increasing the pressure of fluid in its associated discrete control conduit for stretching its associated portion of the distal end of said tube, selective operations of said pressure increasing means establishing pressure differentials causing the tube distal end to bend in different directions.

10. A catheter in accordance with claim 9 in which said control conduits comprise three separate tubes each extending along and secured about an outer wall for said elongated tube and in which a restraining means is helically wound about said control tubes to limit the radially outward expansion thereof with an increase in fluid pressure within the respective ones of the control tubes.

11. A catheter in accordance with claim 10 in which means are provided in said distal end of said tube passageway to hold the same against collpsing inwardly and closing said tube passageway when bending the catheter distal end.

12. An elongated steerable catheter extending from a proximal to a distal end, said catheter comprising an elongated tube having a longitudinally extending passageway therein extending from the proximal end to a discharge opening adjacent the distal end, at least one control conduit means receiving a control fluid associated with the elongated tube and extending longitudinally from said proximal end to said distal end, steering control means for displacing said control fluid in said control conduit to cause one portion of said elongated tube at the distal end of the catheter to lengthen relative to another portion of said elongated tube causing the distal end to bend with the lengthened portion having a larger radius of curvature than the other portion of the elongated tube, means in said distal end of said tube passageway for holding the same against collapsing inwardly and closing said tube passageway when bending the catheter distal end, and a constraining means constraining said other portion of the tube against lengthening longitudinally to the extent that said one portion lengthens whereby the constrained other portion of the tube is at the smaller inside radius of curvature for the bent end of the catheter.