Steerable Stylet

• US 20110106101A1
• Filed: 10/29/2010
• Published: 05/05/2011
• Est. Priority Date: 10/30/2009
• Status: Active Grant

• Current Assignee: Advanced Bionics LLC (Sonova Holding AG)
• Original Assignee: Advanced Bionics LLC (Sonova Holding AG)
• Inventors: Tortonese, Marco, Beerling, Timothy, Haller, Matthew I.
• Granted Patent: US 9,211,403 B2
• Time in Patent Office: Days
• US Class Current: 606/129
• CPC Class Codes: A61M 25/0102 Insertion or introduction using an inner stiffening member, e.g. stylet or push-rod
• CPC Class Codes: A61M 25/0147 with movable mechanical means, e.g. pull wires
• CPC Class Codes: A61N 1/0541 Cochlear electrodes

Abstract

A stylet for inserting an electrode array into a cochlea includes a first sensor insertable within a lumen of the electrode array and sensitive to force applied by a lumen wall to the first sensor and a first actuator adapted to move the electrode array in response to the force sensed by the first sensor.

Claims

1. A stylet for inserting an electrode array into a cochlea, comprising:

a first sensor insertable within a lumen of the electrode array and sensitive to force applied by a lumen wall to the first sensor; and

a first actuator adapted to move the electrode array in response to the force sensed by the first sensor.

2. The stylet of claim 1, in which the first sensor comprises a piezoresistive sensor.

3. The stylet of claim 2, in which the piezoresistive sensor comprises a silicon strain gauge configured to detect bending of the stylet around two orthogonal axes of rotation.

4. The stylet of claim 3, in which the silicon strain gauge comprises two active portions, in which differential measurements between the two active portions measure bending of the stylet in a first axis and summed measurements of the two active portions measure bending of the stylet about a second axis.

5. The stylet of claim 1, in which the first sensor comprises a fiber optic sensor.

6. The stylet of claim 5, in which the fiber optic sensor comprises at least one of:

a Fiber Bragg grating and a Fabry-Perot sensor.

7. The stylet of claim 6, in which the fiber optic sensor comprises a single optical fiber with a series of Fiber Bragg gratings spaced along a portion of a length of the fiber, each Fiber Bragg grating being tuned to a different wavelength range.

8. The stylet of claim 5, in which the first sensor comprises a pressure sensor.

9. The stylet of claim 6, in which the pressure sensor is a Fabry-Perot sensor disposed on a distal end of the fiber.

10. The stylet of claim 1, in which the first sensor is sensitive to force of less than 1 micronewton.

11. The stylet of claim 1, in which the first actuator comprises a pull wire.

12. The stylet of claim 11, in which the pull wire substantially comprises a material chosen from the group consisting of:

silicon, stainless steel, and a platinum iridium alloy.

13. The stylet of claim 11, in which the pull wire has a diameter of less than 50 microns.

14. The stylet of claim 1, in which the first actuator comprises a plurality of pull wires.

15. The stylet of claim 1, further comprising a multi-lumen polymer body;

the actuator being inserted into a first lumen of the multi-lumen polymer body and the sensor being positioned in the multi-lumen polymer body within a second lumen.

16. The stylet of claim 15, in which the multi-lumen polymer body comprises at least 4 lumens and has a diameter of less than 0.5 millimeters.

17. The stylet of claim 16, in which the multi-lumen polymer body comprises a silicone core with an outer parylene coating.

18. The stylet of claim 16, in which the multi-lumen extruded polymer body comprises one of:

a fluoropolymer, polyurethane, and silicone.

19. The stylet of claim 16, in which the actuator comprises at least three pull wires, the at least three pull wires being positioned in lumens in the multi-lumen extruded polymer body.

20. The device of claim 1, in which the stylet is configured to be extracted from the electrode array after insertion of the electrode array into the cochlea.

21. The device of claim 2, in which the stylet has a diameter of less than 0.5 millimeters.

22. The stylet of claim 1, in which the stylet is configured to be inserted into a lumen of an electrode array and sense contact of the electrode array with a cochlear wall during insertion of the electrode array into a cochlea.

32. The system of claim 1 in which the sensor is removably insertable into the lumen of the electrode array.

33. The system of claim 1 in which the sensor is integral to the electrode array.

23. A method for inserting an electrode array into a cochlea comprising:

inserting a stylet into a lumen of the electrode array;

inserting a first portion of the electrode array into the cochlea;

activating a first actuator in the stylet;

receiving an output from a sensor within the stylet;

comparing the output to an anticipated output; and

if the output is substantially similar to the anticipated output, no contact of the electrode array with a cochlear wall is detected;

if the output is not substantially similar to the anticipated output, detecting contact of the electrode array with a cochlear wall.

24. The method of claim 23, further comprising:

if contact of the electrode array with the cochlear wall is detected, activating the first actuator in the stylet to move the electrode array away from the cochlear wall.

25. The method of claim 24, further comprising, after moving the electrode array away from the cochlear wall, continuing to insert the electrode array into the cochlea.

26. The method of claim 23, further comprising:

inserting the electrode array into a desired position; and

removing the stylet from the lumen in the electrode array.

27. The method of claim 26, in which removing the stylet from the lumen comprises:

relaxing the first actuator; and

pulling the stylet from the lumen.

28. The method of claim 27, in which the first actuator comprises a plurality of pull wires and relaxing the first actuator comprises releasing the pull wires.

29. The method of claim 26, in which removing the stylet from the lumen comprises:

recording the activation sequence of the plurality of actuators during insertion; and

reversing activation of the plurality of actuators while withdrawing the stylet.

30. A method of mapping the geometry of a cavity in a body comprises:

activating an actuator in a lead inserted into the cavity;

receiving an output from a sensor within the lead;

comparing the output to an anticipated output; and

if the output is substantially similar to the anticipated output, no contact of the lead with a cavity wall is detected;

if the output is not substantially similar to the anticipated output, detecting contact of the lead with the cavity wall.

31. A system for inserting an electrode array into a cochlea comprising:

a sensor sensitive to the proximity of at least a portion of the electrode array to the cochlea; and

an actuator removably insertable into a lumen of the electrode array and responsive to the proximity sensed by the sensor.