Method of anchoring pullwire directly articulatable region in catheter
A catheter comprises a flexible polymer catheter body including a proximal shaft section and a distal working section, a wire support structure embedded within the distal working section of the catheter body, a proximal adapter mounted to the proximal shaft section of the catheter body, and a wire disposed within the catheter body. The wire has a proximal end and a distal end. The proximal end of the wire being operably connected to the proximal adapter, and the distal end of the wire is anchored to the wire support structure.
1. A robotically controlled steerable catheter system, comprising:
a catheter comprising a shaft portion, a proximal articulating section positioned distal to the shaft portion, and a distal articulating section positioned distal to the proximal articulating section, wherein the distal articulating section has a flexural stiffness that is less than the proximal articulating section, and wherein articulation of the proximal articulating section and the distal articulating section are independently controlled;
four pullwires extending through at least a proximal portion of the catheter, within the proximal portion the four pullwires extending along a first side of the catheter, wherein at least three of the four pullwires are coupled to the distal articulating section and a fourth pullwire is coupled to the proximal articulating section at a location within the proximal articulating section, the three pullwires extending along the first side of the proximal articulating section that circumferentially opposes the location within the proximal articulation section where the fourth pullwire is attached;
a robotic instrument driver;
a mechanical interface coupling the four pullwires and the proximal end of the catheter to the robotic instrument driver; and
a control station communicatively coupled to the instrument driver, wherein the control station comprises a master input device for interfacing with a user and a computing device programmed to provide control of a distal articulation angle and a distal roll of the catheter, and wherein the computing device provides control of the catheter by computing a displacement of each of the pullwires independently.
2. The robotically controlled steerable catheter system of claim 1 , wherein each of the three of the four pullwires is equally spaced circumferentially around the distal articulating section.
3. The robotically controlled steerable catheter system of claim 2 , wherein each of the three of the four pullwires is configured to be selectively tensioned to bend the distal articulating section in any direction.
4. The robotically controlled steerable catheter system of claim 3 , wherein the catheter is configured such that simultaneously tensioning the fourth pullwire with the selective tensioning of the three of the four pullwires prevents unwanted deflection of the proximal articulating section.
5. The robotically controlled steerable catheter system of claim 4 , wherein the catheter is configured such that further tensioning of the fourth pullwire causes the proximal articulating section to bend in one direction.
6. The robotically controlled steerable catheter system of claim 5 , wherein the catheter is configured such that subsequent equal tensioning of the three of the four pullwires bends the proximal articulating section in one direction without causing further bending of the distal articulating section.
7. The robotically controlled steerable catheter system of claim 1 , wherein each of the three of the four pullwires is configured to be selectively tensioned and released in a sequential fashion to rotate the distal articulating section.
8. The robotically controlled steerable catheter system of claim 7 , wherein the distal articulating section is rotatable in 360 degrees.
9. The robotically controlled steerable catheter system of claim 1 , wherein a working lumen and four pullwire lumens extend through the catheter, the four pullwire lumens positioned between an outer diameter of the catheter and the working lumen.
10. The robotically controlled steerable catheter system of claim 1 , further comprising a transition section disposed between the distal and proximal articulating sections.
11. The robotically controlled steerable catheter system of claim 10 , wherein the three of the four pullwires are positioned in a spiral configuration around the transition section such that the three of the four pullwires are equally spaced at a distal end of the transition section and converge at a proximal end of the transition section.
12. The robotically controlled steerable catheter system of claim 11 , wherein the converged portion of the three of the four pullwires is positioned opposite the fourth pullwire.
13. The robotically controlled steerable catheter system of claim 1 , wherein the computing device is configured to compute a required displacement for each of the pullwires based on elastic behavior of the distal and proximal articulating sections and catheter stiffness.
14. The robotically controlled steerable catheter system of claim 1 , wherein the flexible shaft portion comprises a length greater than each of the proximal articulating section and the distal articulating section.
15. The robotically controlled steerable catheter system of claim 14 , wherein the flexible shaft portion comprises a length greater than the proximal articulating section and the distal articulating section combined.
16. The robotically controlled steerable catheter system of claim 1 , wherein the proximal articulating section is manufactured separately from the distal articulating section, and wherein the proximal articulating section is mounted to the distal articulating section.