Patent Application
20080103571
The present invention relates to medical devices and, more particularly, to delivery of implantable medical device leads.
Most commercially available cardiac pacing and defibrillation leads are placed by means of a stylet which is inserted into a central lumen through the lead, and is used to assist in pushing the lead through the vascular system and guiding it to a desired location. Leads may also be placed by a guidewire extending entirely through the lead and out its distal end. This basic approach has been adapted to cardiac pacing leads and cardioversion leads as well, as disclosed in U.S. Pat. No. 5,003,990 issued to Osypka, U.S. Pat. No. 5,755,765 issued to Hyde et al, U.S. Pat. No. 5,381,790 issued to Kenasaka and U.S. Pat. No. 5,304,218 issued to Alferness.
Aspects and features of the present invention will be appreciated as the same becomes better understood by reference to the following detailed description of the embodiments of the invention when considered in connection with the accompanying drawings, wherein:
The present invention is directed to a delivery device that assists in placement of a medical lead in the left heart of a patient. The delivery device is a hybrid of a guidewire and a stylet. The medical lead delivery device includes an elongated body, a controller, a first and second spring, and a sleeve. The elongated body includes a proximal end and a distal end. The controller is disposed at the proximal end and provides enhanced control of the distal tip of the elongated body. In particular, the delivery device can be advanced beyond the tip of the lead to provide a “rail” for the medical lead to track. The first and second springs are coupled to the distal end of the elongated body. A sleeve is coupled to the elongated body and to the first and second springs through first, second and third solder elements. The delivery device eases delivery of a medical lead to the left ventricle of the heart. Additionally, a lower manufacturing cost exists to produce the delivery device.
Lead 106 is provided with an elongated insulative lead body (e.g. insulative polymeric tube etc.), which carries a coiled conductor therein. Other lead body types may be substituted within the context of the present invention, including lead bodies employing multiple lumen tubes and/or stranded or braided conductors as disclosed in U.S. Pat. No. 5,584,873 issued to Shoberg et al, and incorporated herein by reference in its entirety. Alternatively, the lead may include additional conductors arranged either within a multi-lumen lead body or concentrically, as disclosed in U.S. Pat. No. 4,355,646 issued to Kallok et al and incorporated herein by reference in its entirety. Additional pacing electrodes, sensors, or defibrillation electrodes, may of course be added to the lead body and coupled to additional conductors.
At the proximal end of the lead body is a connector assembly (e.g. IS-1, IS-4 connector assemblies etc.) used in commercially available cardiac pacing leads. The connector assembly includes a conductive connector pin which is coupled by means of the conductor within the lead body to a tip electrode located at the distal tip of lead 106.
In one embodiment, controller 208 comprises a gripping member 210 and a tapered distal end 211 with a length of about L2. Gripping member 210 is cylindrically shaped and includes a diameter that of about D1 and a length that extends L3. During insertion of a lead into a patient, gripping member 210 is held between the thumb and the forefinger of the person attempting to place the lead in the left heart. In one embodiment, gripping member 210 includes elongated recessed regions 212 to enhance the person's ability to hold gripping member 210. At the distal end of gripping member 210 is a tapered distal end 211. Tapered distal end 211 includes a diameter D4, a length L4, and angle θ formed by first and second sides 236, 238. Tapered distal end 211 of controller 208 is configured to receive the proximal end of elongated member 202. The proximal end of elongated member 202 includes a D13.
A distal portion of elongated member 202 is surrounded by cylindrical sleeve 216 with spring 218 disposed between an inner wall of sleeve 216 and elongated member 202. Sleeve 216 provides lubricity for moving within a lead body and coil alignment between springs 218, 220. Sleeve 216 extends a length of L5 and includes an inner diameter of Dsleeve. Solder 224 (also referred to as a second solder element) connects sleeve 216 to elongated member 202, and to springs 218, 220. Solder 224 is introduced over spring 218 and sleeve 216 at a high temperature.
Elongated member 202 extends a length of L6, which is comprised of regions defined by lengths L7, L8, and L9. The L7 region includes a diameter D13 whereas the L8 region is tapered at its distal end and contacts sleeve 216. The L8 region has a diameter that ranges from about D8small to about Dlarge. The L9 region is tapered and includes regions L10, L11, L12, and L13. The L10 region includes a tapered section of elongated member 202 defined by a diameter that ranges from about D10small to about D10large. At the distal end of the L10 region is solder element 222. Solder element 222, also referred to as a third solder element, connects sleeve 216 with spring 218 and elongated member 202. Region L11 depicts spring 218 around elongated member 202. Region L11 includes a tapered section of elongated member 202 defined by a diameter that ranges from about D11small to about D11large. The L12 region extends from solder elements 224 and 214. The distal tip of elongated member 202 extends into solder 214 which increases isodymetry and body (or stiffness) to elongated member 200. Solder 214 has a diameter of D5 and is also referred to as the first solder element.
Springs 218, 220 are formed from any desired conductive material, selected based on the application of the elongated member being manufactured. Conductive material includes conductive metals or alloys, and/or conductive polymers. For example, springs 218, 220 may be formed from silver, platinum, gold, copper, a conductive alloy, or any other conductive material suitable for use in a medical lead.
Provided in Table 1 are the general dimensions for a delivery device 200 made to deliver 4 and 6 French leads.
Another embodiment of length of L1 is about 34 inches. Another embodiment of length of L1 is about 51 inches. L1 can range from about 34 inches to about 51 inches.
Various embodiments of the invention have been described. These and other embodiments are within the scope of the following claims. Presented below are additional embodiments related to delivery device 200. For example, a slideable torque tool may be employed. This embodiment is implemented through the following: side loading occurs and/or a torque-limiting (or slip clutch mechanism)—engage with lead via a connector. In another embodiment, for ease of torquing delivery device 200, proximal end is configured with square (or on-rounded) cross-section or segmented round to non-round. In yet another embodiment, the delivery device is configured with alternating floppy and stiff areas. In still yet another embodiment, a coupling and decoupling via a lead and wire mechanism. In yet another embodiment, infusion wire with injection lumen and sideport—are able to inject contrast through the lumen. In yet another embodiment, a mechanism is employed for using a temperature sensitive alloy for lead fixation. In yet another embodiment, pacing wire may be unipolar and bi-polar configuration. This may include the following: a cathode range: 1.5 mm2 to 15 mm2-5 mm2 nominal and/or an anode range: 5 mm2 to 30 mm2-10 mm2 nominal. In yet another embodiment, a telescoping delivery device is employed. In yet another embodiment, delivery device includes a centering/loading tool.
