Magnetically navigable telescoping catheter and method of navigating telescoping catheter
View Patent ↗A magnetically navigable catheter includes a sheath having a proximal end and a distal end, and an extension member having a proximal end and a distal end, slidably mounted in the sheath so that the distal end portion of the extension member telescopes from the distal end of the sheath. The distal end portion of the extension member being relatively more flexible than the distal end of the sheath. There may be one or more electrodes on the distal end of the extension member. There is also at least one magnet, and preferably more than one magnet, on the distal end portion of the extension member to allow the distal end of extension member to be oriented by the application of an externally applied magnetic field. The catheter preferably also includes a sleeve, having a proximal end and a distal end, the sleeve being slidably mounted in the sheath so that the distal end portion of the sleeve telescopes from the distal end of the sheath, so that the sleeve can be selectively extended and retracted relative to the sheath, and the extension member can be selectively extended and retracted relative to the sleeve. According to the method of this invention, the distal end of the electrode catheter is introduced into the part of the body where the electrode will be used to contact the specific body structures, and the electrode is moved into contact with the body structure by applying an external magnetic field and selectively telescoping the extension member relative to the sheath to bring the electrode on the distal end of the extension member into contact with the specific body structure.
1. A method of mapping the electrical characteristics of the left atrium of the heart comprising:
providing a magnetically navigable electrode catheter comprising a sleeve having a proximal end and a distal end, an extension member having a proximal end and a distal end, the extension member being slidably mounted in the sleeve so that the distal end portion telescopes from the distal end of the sleeve, the distal end portion of the extension member being relatively more flexible than the distal end of the sleeve;
providing at least one electrode on the distal end of the extension member; and at least one magnet on the distal end of portion of the extension member, wherein the distal end portion of the extension member containing the at least one magnet is relatively rigid and the portion of the extension member just proximal to the at least one magnet is flexible;
introducing the distal end of the magnetically navigable electrode catheter into left atrium;
moving the electrode into contact with a selected point on the surface of the left atrium by applying an external magnetic field, such that the catheter bends at a point proximal to the distal end portion having the at least one magnet, and selectively telescoping extension member relative to the sleeve to bring the electrode on the distal end of the extension member into contact with the specific point on the surface of the left atrium;
measuring the electrical characteristics of the left atrium between the electrodes.
2. The method according to claim 1 wherein the magnetically navigable electrode catheter further comprises a sheath having a proximal end and a distal end, the sleeve being slidably mounted in the sheath so that the distal end portion of the sleeve telescopes from the distal end of the sheath, and wherein the step of moving the electrode into contact with a selected point on the surface of the left atrium includes selectively telescoping the sleeve relative to the sheath.
3. The method according to claim 1 wherein the extension member has a lumen extending at least partly therethrough, the method comprising inserting a stylette into the lumen in the extension member to stiffen the extension member.
4. The method according to claim 1 wherein the extension member has a lumen extending at least partly therethrough, the method comprising inserting a pre-shaped stylette into the lumen in the extension member to shape the extension member to facilitate navigation of the extension member.
5. The method according to claim 1 wherein the extension member has a lumen extending at least partly therethrough, the method comprising inserting a stylette into the lumen in the extension member and pushing the stylette to push the extension member.
6. A method of therapeutically ablating tissue in the left atrium of the heart comprising:
providing a magnetically navigable electrode catheter comprising a sleeve having a proximal end and a distal end, an extension member having a proximal end and a distal end, the extension member being slidably mounted in the sleeve so that the distal end portion telescopes from the distal end of the sleeve, the distal end portion of the extension member being relatively more flexible than the distal end of the sleeve;
providing at least one electrode on the distal end of the extension member; and at least one magnet on the distal end portion of the extension member;
introducing the distal end of the magnetically navigable electrode catheter into left atrium;
moving the electrode into contact with a selected point on the surface of the left atrium by applying an external magnetic field and selectively telescoping extension member relative to the sleeve to bring the electrode on the distal end of the extension member into contact with the specific point on the surface of the left atrium; and
applying an RF signal to the tissue in contact with the electrode to ablate the tissue, wherein the extension member has a lumen extending at least partly therethrough, the method comprising inserting a stylette into the lumen in the extension member to stiffen the extension member.
7. A method of therapeutically ablating tissue in the left atrium of the heart comprising:
providing a magnetically navigable electrode catheter comprising a sleeve having a proximal end and a distal end, an extension member having a proximal end and a distal end, the extension member being slidably mounted in the sleeve so that the distal end portion telescopes from the distal end of the sleeve, the distal end portion of the extension member being relatively more flexible than the distal end of the sleeve;
providing at least one electrode on the distal end of the extension member; and at least one magnet on the distal end portion of the extension member;
introducing the distal end of the magnetically navigable electrode catheter into left atrium;
moving the electrode into contact with a selected point on the surface of the left atrium by applying an external magnetic field and selectively telescoping extension member relative to the sleeve to bring the electrode on the distal end of the extension member into contact with the specific point on the surface of the left atrium; and
applying an RF signal to the tissue in contact with the electrode to ablate the tissue, wherein the extension member has a lumen extending at least partly therethrough, the method comprising inserting a pre-shaped stylette into the lumen in the extension member to shape the extension member to facilitate navigation of the extension member.
8. A method of therapeutically ablating tissue in the left atrium of the heart comprising:
providing a magnetically navigable electrode catheter comprising a sleeve having a proximal end and a distal end, an extension member having a proximal end and a distal end, the extension member being slidably mounted in the sleeve so that the distal end portion telescopes from the distal end of the sleeve, the distal end portion of the extension member being relatively more flexible than the distal end of the sleeve;
providing at least one electrode on the distal end of the extension member; and at least one magnet on the distal end portion of the extension member;
introducing the distal end of the magnetically navigable electrode catheter into left atrium;
moving the electrode into contact with a selected point on the surface of the left atrium by applying an external magnetic field and selectively telescoping extension member relative to the sleeve to bring the electrode on the distal end of the extension member into contact with the specific point on the surface of the left atrium; and
applying an RF signal to the tissue in contact with the electrode to ablate the tissue, wherein the extension member has a lumen extending at least partly therethrough, the method comprising inserting a stylette into the lumen in the extension member and pushing the stylette to push the extension member.