Reducing mechanical stress on conductors and connection points in a position determinable interventional medical device
A medical device configured for diagnosis or treatment of tissues within a body is provided. The device includes an elongate, deformable member configured to be received within a lumen in the body and having proximal and distal ends. A position sensor is disposed at the distal end. In one embodiment, a conductor is wound about the member. The conductor is connected to the position sensor and has a first winding pitch over a first portion of the deformable member and a second winding pitch, different from the first winding pitch, over a second portion of the deformable member. In another embodiment, the member defines a neutral longitudinal axis extending between the proximal and distal ends. A conductor extending between the proximal and distal ends is connected to the position sensor at a connection node on the neutral axis.
1. A medical device configured for diagnosis or treatment of a tissue within a body, the medical device comprising the following:
an elongate, deformable member configured to be received within a lumen in said body, having a proximal end and a distal end, said deformable member defining a neutral longitudinal axis extending between said proximal and distal ends;
a position sensor disposed at said distal end of said deformable member; and
a conductor extending between said proximal and distal ends of said elongate, deformable member and having at least a first portion extending along said neutral axis, said conductor connected to said position sensor at a connection node on said neutral axis.
2. The medical device of claim 1 wherein said conductor is embedded within said elongate, deformable member.
3. The medical device of claim 2 wherein said conductor is embedded within a wall of said elongate, deformable member so as to be surrounded by material of said elongate, deformable member.
4. The medical device of claim 1 wherein said first portion of said conductor is straight and disposed coincident with said neutral axis.
5. The medical device of claim 4 wherein a second portion of said conductor is wound about said neutral axis.
6. The medical device of claim 5 wherein said second portion of said conductor has a constant winding pitch over an entire length of said second portion of said conductor.
7. The medical device of claim 5 wherein said second portion of said conductor has different winding pitches within an entire length of said second portion of said conductor.
8. The medical device of claim 5 wherein said second portion of said conductor is distal to said first portion of said conductor.
9. The medical device of claim 1 herein said connection node includes soldering or conductive adhesive.
10. The medical device of claim 1 wherein said connection node includes a flexible printed circuit board or wiring pad.
11. The medical device of claim 1 wherein said position sensor comprises a coil.
12. The medical device of claim 11 wherein said coil is wound about said neutral axis and embedded within said elongate, deformable member.
13. The medical device of claim 11 wherein said coil includes a core having a permeability greater than that of air.
14. The medical device of claim 1 , further comprising a wireless transmitter connected to said position sensor.
15. The medical device of claim 1 , further comprising the following:
an operational element disposed at a distal end of said elongate, deformable member; and
a handle disposed at said proximal end of said elongate, deformable member and adapted to control deflection of said distal end.