Device for reducing mri rf-induced heating in active implanted medical device leads

A method of implanting an anchor device, for an electrode lead, to a bodily structure, the electrode lead configured to deliver electrical stimulation to a patient, comprising:

• providing the anchor device with a toroidal base, adapted to receive a locking cap;
• pressing the electrode lead into a circumferential slot of the toroidal base, such that the electrode lead forms a primary coil of an air-core transformer;
• providing the toroidal base with an axially located electrical coil, interior to the circumferential slot, such that the axially located electrical coil forms a secondary coil of the air-core transformer;
• fixing the locking cap to the toroidal base, such that the locking cap prevents escape of the electrode lead from the toroidal base;
• and
• anchoring the toroidal base and the locking cap to the bodily structure.

An anchor device configured to anchor an electrode lead to a bodily structure, the electrode lead configured to deliver electrical stimulation to a patient, the anchor device comprising:

• a rounded anchor body;
• a clamping means for securing the electrode lead in the rounded anchor body;
• a set of retaining pins projecting from the rounded anchor body;
• and
• whereby the set of retaining pins is comprised of a shape memory alloy having a transition temperature between about 35° C. and about 60° C.

A method of preparing a retaining pin for an anchor device, the anchor device for use in securing an electrode lead to a bodily structure of a patient, the method comprising:

• forming the retaining pin from a shape memory alloy;
• mechanically bending the retaining pin into an anchor shape while the shape memory alloy is in a martensite phase;
• fixing the retaining pin in the anchor shape using a mechanical clamp;
• heating the retaining pin above a stress relief temperature for a finite time;
• quenching the retaining pin thereby fixing it in an austenite phase;
• removing the retaining pin from the mechanical clamp;
• and
• mechanically bending the retaining pin into a deployment shape for piercing the bodily structure while the shape memory alloy is in the austenite phase.