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US 5,259,394 AGranted
Endocardiac lead having an active fastening means
AssigneeELA Medical S.A.
InventorJean-Luc Bens
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AssigneeELA Medical S.A.
InventorJean-Luc Bens
Estimating the term…
An endocardiac lead of the type including a conductive spiral winding 2 placed inside a sheath 1 made of a flexible material being insensitive to body fluids. This spiral winding 2 is electrically connected to an electrode 3 intended for being brought into contact with the inner wall of the heart. The electrode 3 is hollow and accommodates along its centerline a deformable helix 6 intended for fastening the lead into the heart muscle. The inner diameter of the electrode 3 is smaller than the outer diameter of the undeformed helix 6. The helix 6 presents a sufficient longitudinal elasticity modulus for being retractable inside the electrode 3 with a mechanical deformation, while the helix will substantially recover its initial shape during its extraction out of the electrode and secure the electrode to the tissue. The helix 6 may be made of a nickel-titanium based alloy. The inner wall of the electrode 3 presents a deformation having the shape of a notch 13 against which the helix 6 will abut during its extraction.
An endocardiac lead of the type comprising a sheath (1), an electrode (3), a helix (6), a conductive spiral winding (2) placed inside the sheath (1) made of a flexible insulating material which is insensitive to body fluids, the spiral winding (2) being electrically connected to the electrode (3) intended for being brought into contact with the inner wall of the heart, said electrode (3) being hollow and receiving along its centerline the helix (6) for fastening the lead into the heart muscle, characterized in that the internal diameter of the electrode (3) is smaller than the external diameter of the helix (6), and in that the helix (6) presents a sufficient modulus of longitudinal elasticity for being retractable within the electrode (3) with a mechanical deformation, and in that the helix (6) will substantially recover its initial shape when being extracted out of the electrode.
Apparatus for securing a body to tissue comprising:
An endocardiac lead comprising:
A method for securing a body having a tissue contacting surface to tissue comprising:
Dependencies are inferred from the claim text.
No related US applications are recorded in the indexed filing history.
Anchoring means; Means for fixing the head inside the heart: chacterised by means penetrating the heart tissue, e.g. helix needle or hook
Electrotherapy
Term ended 23 Dec 2011 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to endocardiac leads for cardiac pacemakers, more particularly to leads of the type having their distal end provided with an active fastening means which penetrates into the heart muscle.
It is known to use endocardiac leads, also called catheters, for stimulating a heart and for sensing electrical signals therefrom.
An endocardiac lead presents two ends. One end is called the proximal end and is connected within the connector head of a pacemaker to a source of electrical energy. The other end is called the distal end and is typically brought into contact with the internal wall of the heart muscle. The distal end includes a conductive electrode that is connected to an electrically conductive part, such as a coiled conductive wire, encased in a flexible sheath. The sheath may be made, for instance, of silicone rubber.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the invention, in which like reference numerals refer to like elements, and in which:
FIG. 1 is a longitudinal cross-section of the distal end of a lead in accordance with an embodiment of the present invention, showing the helix in a retracted position; and
FIG. 2 is a longitudinal cross-section of the distal end of the lead of FIG. 1 showing the helix during its extraction out of the lead.
Referring to FIGS. 1 and 2, the distal end of an endocardiac lead according to a preferred embodiment of the present invention is shown. The lead comprises a sheath 1 made of a material, such as a silicone elastomer, that is flexible, insulating and insensitive to the body fluids. Sheath 1 surrounds a helically shaped conductive winding 2. At distal end D, winding 2 is connected to a hollow electrode 3 intended to abut an internal wall of the heart muscle. At proximal end P, winding 2 is connected to a pulse generator constituting the heart stimulator or cardiac pacemaker (not shown). The pulse generator, the cardiac pacemaker and their connection to the endocardiac lead of the described embodiment forms no part of the present invention.
In a preferred embodiment, electrode 3 is substantially annular and comprises a tubular extension 4 which extends inwardly inside the lead so that it will contact a certain number of turns of winding 2, e.g., 8 triple turns, for ensuring the transfer to electrode 3 of the electrical pulses received from the pacemaker. Electrode 3 is fixed to the distal end of the sheath 1 by means of an adhesive 5, for example, silicone adhesive.
The lead has in its distal end D, a fastening means in the form of a helix 6 extending coaxially to electrode 3. The proximal part of helix 6 forms a straight stem 7 which extends through a cylindrical seal 8 made of an electrically insulating material, for example silicon rubber or polyurethane elastomer. The tip of this proximal part is connected to a driving end piece 9 is a conventional manner which is also cylindrical and made of steel and other metallic material, e.g., chrome and cobalt alloy. Preferably, the stem tip is inserted and clamped in a bore 10 formed in driving end piece 9 and the opposite end of driving end piece 9 presents a radial slit 11 for receiving the tip 12 of a conventional stylet.