77 results about "Active fixation" patented technology

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 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.

A stent graft includes a stent graft material of tubular shape and annular shaped stent elements coupled to the stent graft material. The stent graft further includes hooked fixation elements, having hook-end portions and coupling-end, circumferentially spaced about an annular shaped spring attachment element, and coupled to the stent graft at apexes of the spring attachment element. Before deployment the hook-end portions of the apexes of the attachment element and the hooked fixation elements attached thereto are compressed within the space bounded by the interior and exterior sides of the spring attachment element and angled laser cut strut inner surfaces under each apex of the spring attachment element are cut at an angle to cause apex and hook rotation at expansion and deployment. At deployment, the apex and hook-end portions rotate outwardly from the stent graft, partially penetrating the body vessel walls in which the stent graft is deployed and actively fixing the stent graft at the position of deployment.

A cardiac stimulator lead is provided that includes a connector for connecting to a cardiac stimulator and an insulating sleeve that has a first end coupled to the connector and a second end. The second end has an opening therein. An electrode is positioned in the insulating sleeve and has a piercing member. The electrode is moveable axially from a retracted position to an extended position wherein the piercing member projects from the opening. A conductor wire is disposed in the sleeve and coupled between the connector and the electrode for transmitting electric signals between the cardiac stimulator and the electrode. A lubricant is provided inside the insulating sleeve for lubricating the movement of the electrode. The lubricant reduces the potential for sticking, particularly for silicone lead sleeves.

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.

Electrical medical leads having active fixation electrodes, particularly helix electrodes intended to be screwed into body tissue, e.g., the heart, are disclosed having selectively applied insulation to optimize exposed electrode surface area and dispose the exposed electrode surface area toward tissue that is less traumatized by injury caused by screwing in the fixation helix. In a preferred fabrication method, an outer helical surface is masked by contact with a masking tube while a dielectric coating is applied to the inner helical surface of the coil turns of the helix, and the masking tube is removed when the dielectric coating has set. In one variation, at least one aperture is formed through the masking tube sidewall exposing an area of the outer helical surface thereby interrupting the uninsulated outer helical electrode.