Chronically-implantable active fixation medical electrical leads and related methods for non-fluoroscopic implantation

Abstract

Bio-impedance may be used for navigation systems to chronically implant pacing and defibrillation leads in the heart using a non-fluoroscopic position sensing unit (PSU), such as a modified LocaLisa TM system from Medtronic Inc., which allows for variable frequency sampling of the position of electrode of a catheter. The PSU injects small AC signals via surface electrodes in three orthogonal axes, each on a slightly different frequency (e.g., near 30 KHz). Indwelling electrodes electrically connected to the PSU resolves the magnitude of induced voltage for each of the three frequencies, thus measuring voltage for each of the three axes. Voltages are divided by induced current to yield impedance in each axis for each electrode. Impedance is proportional to position within the body. Such a system requires that a conductive material, such as a retractable helical tip-electrode, be exposed during implantation. Since the tip is retracted during implantation, this disclosure provides a modified distal portion employing at least one aperture (or 'window') for fluid exposure of the helix-electrode and a deployable internal sleeve for covering the aperture(s) when the helix-electrode is extended.

Description

[0001] statement incorporated by reference [0002] This non-provisional U.S. patent application claims priority to the filing of the following provisional U.S. patent applications, Ser. Each of said applications is hereby incorporated by reference in its entirety as if fully set forth herein. technical field [0003] The present invention relates generally to implantable medical devices (IMDs), and more particularly to electronic medical lead structures, systems and methods for acquiring at least Part of the anatomical data, so that long-term implantable medical electronic leads (eg, cardiac pacing leads, etc.) can be implanted. Background technique [0004] Prior art directly pertinent to the present invention includes US Patent Nos. 5,983,126 and 5,697,377 to Wittkampf, the contents of which are incorporated herein by reference. Wittkampf's work is based on orthogonal electric fields created by applying electrical energy to connected pieces placed on the body. System d...

AI Technical Summary

Problems solved by technology

However, neither this system nor short-term implantable leads provide the ability to accurately locate and long-term implant medical electronic leads such as cardiac pacing leads

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