Patent Application
20090276020
The present invention relates to medical devices designed to operate with navigation and visualization systems. More specifically, the present invention relates to tools for delivering implantable medical leads, wherein the tools are designed to be tracked via navigation and visualization systems.
Currently, physicians use fluoroscopy for navigation and guidance when implanting leads for pacing, defibrillation, or cardiac resynchronization therapy (“CRT”). Fluoroscopy has some significant drawbacks. For example, fluoroscopy exposes the patient and medical staff to radiation, and special clothing and equipment is needed in an attempt to protect against the radiation. Also, fluoroscopy equipment is expensive. Finally, the images provided by fluoroscopy are often less than desirable.
Navigation and imaging systems such as the St. Jude Medical, Inc. Ensite Array™ multi-electrode array catheter system and Ensite NavX™ system allow visualization and tracking of electrode equipped medical devices, such as electrophysiology (“EP”) catheters, within a patient without employing fluoroscopy. In order to ensure adequate signal emanation and detection to perform the primary sensing and/or treatment purposes of an EP catheter, pacing lead, or other electrode equipped medical device, material conductivity and component connections are critical to the design of such devices and their electrodes. Such electrodes and their electrical connections are expensive to manufacture. As a result, providing such electrodes to a lead delivery tool, such as an introducer sheath, catheter, etc., simply for the purposes of visualization and tracking the delivery tool via a non-fluoroscopy visualization and tracking system is unnecessarily expensive.
There is a need in the art for a delivery tool usable with a non-fluoroscopy visualization and tracking system that is cost effective to manufacture. There is also a need in the art for methods of using and manufacturing such a tool.
Disclosed herein is a tool for implanting a medical lead. In one embodiment, the tool includes a body, an electrode, and a conductor. The body includes a distal end and a proximal end. The electrode is supported by the body. The conductor is in electrical contact with the electrode and extends along the body from the electrode to the proximal end. The electrode and conductor form an electrically conductive path that extends from a surface of the electrode to a proximal most point of the conductor on the body. The electrical resistance of the electrically conductive path is at least approximately 100 Ohms.
Disclosed herein is a tool for implanting a medical lead. In one embodiment, the tool includes a distal end, a proximal end, a first layer, a conductor, a second layer and an electrode. The conductor extends along an outer surface of the first layer. The second layer extends over the outer surface of the first layer. The electrode extends over the outer surface of the first layer, forms a portion of the second layer and is in electrical contact with an electrically conductive portion of the conductor.
Disclosed herein is a tool for implanting a medical lead. In one embodiment, the tool includes a distal end, a proximal end, a first layer, a conductor, a second layer, and an electrode. The conductor forms a portion of the first layer. The second layer extends over the outer surface of the first layer. The electrode extends over the outer surface of the first layer, forms a portion of the second layer and is in electrical contact with the conductor.
Disclosed herein is a tool for implanting a medical lead. In one embodiment, the tool includes a distal end, a proximal end, a first layer, a conductor, and an electrode. The conductor extends along the surface of the first layer. The electrode extends over the outer surface of the first layer and is in electrical contact with the conductor. The conductor and/or the electrode are formed of an electrically conductive ink.
Disclosed herein is a system for implanting a medical lead. In one embodiment, the system includes an imaging system (e.g., an Ensite™ system as manufactured by St. Jude Medical, Inc.) and a tool for delivering a medical lead. The imaging system includes a power and imaging device and surface electrode pairs electrically coupled to the device. The imaging system generates generally orthogonal electric fields via the electrodes pairs. The tool includes a tubular body having a conductor extending from a proximal end of the body to an electrode supported on the body. The conductor is electrically coupled at the proximal end of the body to the device. The electrode is visible via the imaging system but generally inadequate for sensing or treatment purposes due to the high electrical resistance of an electrically conductive path extending from a surface of the electrode to a proximal most point of the conductor on the body.
Disclosed herein is a method of delivering an implantable medical lead. In one embodiment, the method includes: electrically coupling a tool to an imaging system (e.g., an Ensite™ system as manufactured by St. Jude Medical, Inc.); generating generally orthogonal electric fields in a patient with the imaging system; tracking the tool to a lead implantation site, wherein the tool includes an electrode that is visible within the patient via the imaging system, but the electrode is generally inadequate for sensing or treatment purposes due to the high electrical resistance of an electrically conductive path extending from a surface of the electrode to a proximal most point of the conductor on the body; and delivering the lead to the implantation site through the tool.
Disclosed herein is a method of manufacturing a tool for delivering an implantable medical lead. In one embodiment, the method includes: providing a inner tubular layer, extending an jacketed conductor along a surface of the inner tubular layer; exposing a conductive core of the jacketed conductor along a region of the inner tubular layer; providing an outer tubular layer over the inner tubular layer and jacketed conductor, wherein an electrode region of the outer tubular layer is impregnated with an electrically conductive material; aligning the electrode region with the region of the inner tubular layer corresponding to the exposed conductive core; and causing the outer tubular layer to adhere to the inner tubular layer.
Disclosed herein is a method of manufacturing a tool for delivering an implantable medical lead. In one embodiment, the method includes: providing a inner tubular layer including a conductor region forming a portion of the inner tubular layer, wherein the conductor region is impregnated with an electrically conductive material; and providing an electrode in electrical communication with the conductor region.
Disclosed herein is a method of manufacturing a tool for delivering an implantable medical lead. In one embodiment, the method includes: providing a tubular layer; supporting a conductor on the tubular layer; and providing an electrode in electrical communication with the conductor, wherein at least one of the conductor or electrode is an electrically conductive ink.
While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. As will be realized, the invention is capable of modifications in various aspects, all without departing from the spirit and scope of the present invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
Disclosed herein are delivery tools 10 for delivering an implantable medical lead, wherein the delivery tools include at least one visualization electrode 15 that facilitates the tool being tracked by a mapping system 20 such as, or similar to, one of the St. Jude Medical, Inc. Ensite™ systems. The electrode and conductor configurations employed on the delivery tools 10 result in economical delivery tools 10 that are trackable via mapping systems 20 such as the Ensite™ systems.
For a general overview of a mapping system 20 similar to an Ensite™ system, reference is made to
In one embodiment, the mapping system 20 is an Ensite NavX™ imaging and mapping system as marked by St. Jude Medical, Inc. In other embodiments, the mapping systems 20 are other non-fluoroscopy type imaging and mapping systems similar to the Ensite NavX™ system and capable of tracking an electrode of a medical device, such as an electrode equipped lead delivery tool, within a patient. In one embodiment, the mapping system 20 is an imaging and mapping system similar to those disclosed in U.S. Pat. Nos. 5,291,549; 5,553,611; 5,662,108; 6,240,307; 6,939,309; 6,978,168; and 6,990,370, which are incorporated herein by reference in their entireties.
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For a discussion regarding a first embodiment of tool 10 for delivering an implantable medical lead, reference is made to
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In other embodiments, as discussed later in this detailed description in reference to
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In one embodiment, the conductors 40a, 40b have a diameter of between approximately 0.001″ and approximately 0.025″. In one embodiment, the conductors 40a, 40b have a conductive core 140a, 140b formed of a metal material (e.g., stainless steel, Nitinol, MP35N, copper, silver, gold, etc.) and an electrical insulation jacket 135a, 135b formed of a polymer material (e.g., nylon, polytetrafluoroethylene (“PTFE”), polyimide, etc.).
In one embodiment, the reinforcement wires 98a, 98b have a diameter of between approximately 0.001″ and approximately 0.025″. In one embodiment, the reinforcement wires 98a, 98b have a core formed of a metal material (e.g., stainless steel, Nitinol, MP35N, copper, silver, gold, etc.) and may or may not be insulated with an electrical insulation jacket 135a, 135b formed of a polymer material (e.g., nylon, PTFE, polyimide, etc.). In one embodiment, the reinforcement wires 98a, 98b are formed of carbon fiber or a polymer material (e.g., Dacron, nylon, PTFE, etc.).
In one embodiment, the inner layer 100 has a radial thickness of between approximately 0.001″ and approximately 0.025″, and the inner layer 100 is formed of a polymer material (e.g., “PTFE”, etc.). In one embodiment, the outer layer 90 has a radial thickness of between approximately 0.002″ and approximately 0.010″, and the outer layer 90 is formed of a polymer material (e.g., poly-block amides (“PEBAX”), nylon, silicone rubber, silicone rubber—polyurethane—copolymer (“SPC”), etc.). In one embodiment, the lumen 70 has a diameter of between approximately 0.016″ and approximately 0.099″, and the tool body 45 has an outer diameter of between approximately 0.039″ and approximately 0.122″.
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In various embodiments, the electrodes 15 and/or contact rings 80 will be formed of metal materials (e.g., platinum-iridium alloy, stainless steel, MP35N, etc.). Such electrodes 15 and/or contact rings 80 will be formed about the braid layer 95 via commonly used methods, and the outer layer 90 will be reflowed about the braid layer 95 between the electrodes and/or contact rings 80 to complete the outer circumferential surface 120 of the tool body 45.
In one embodiment, the electrodes 15 and/or contact rings 80 are formed of a ceramic material loaded with an electrically conductive material. The electrically conductive material of the loaded ceramic material constitutes is of types and in amounts as known in the art to enable a ceramic material to be electrically conductive. The ceramic electrodes and/or contact rings are placed over and adhered to the braid layer (e.g., via an adhesive or brazing). The outer layer 90 is then reflowed about the braid layer 95 between the electrodes and/or contact rings 80 to complete the outer circumferential surface 120 of the tool body 45.
In one embodiment, the electrodes 15 and/or contact rings 80 are formed of a hydrogel material or a polymer material (e.g., PEBAX, silicone rubber, SPC, etc.) loaded with an electrically conductive material (e.g., nickel-coated graphite powder, nickel-coated graphite fibers, etc.). In one embodiment where the loaded polymer material is PEBAX, the electrically conductive material of the loaded PEBAX material constitutes between approximately 10 percent and approximately 50 percent of the total weight of the loaded PEBAX material.
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In one such embodiment, the ink-formed conductors 240a, 240b are deposited on the surfaces of the respective layers 100a, 100b via such methods as screen printing, pad printing, etc. After application of an ink-formed conductor 240a, 240b to its respective substrate, the respective next outer layer is applied over the ink-formed conductor and its respective substrate via such methods as spray deposition, extrusion, reflow, etc., as the case may be. In such embodiments, the electrodes 15a, 15b may be formed of electrically conductive inks in a manner similar to that employed for the ink-formed conductors 240a, 240b, or the electrodes 15a, 15b could be formed of materials similar to those described above with respect to
In some embodiments, the electrically conductive inks are used to form electrical conductors or traces 240 on the outer circumferential surface of the outer layer 90. An electrical insulation material is then sprayed or otherwise deposited over the ink-formed traces 240 in areas of the traces 240 wherein electrical isolation from the surrounding environment is desired. Electrically conductive inks are used to form electrodes 15 on the outer circumferential surface of the outer layer, and these electrodes 15 are placed in electrical contact with the in-formed traces 240.
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Similarly, the second conductor 240b is a longitudinally extending strip of the middle layer 100b. In such an embodiment, the second conductor 240b is formed of the same polymer material as the rest of the middle layer 100b, or is at least compatible with or otherwise joinable to the rest of the middle layer 100b such that the middle layer 100b ends up being an integral whole that includes the second conductor 240b. In such an embodiment, the conductors 240 are formed in their respective layers 100 via such methods as co-extrusion, and the conductors 240 are formed of polymer materials loaded with an electrically conductive material in a manner similar to that discussed above with respect to the electrodes 15 of
Regardless of whether the conductors 240 are formed of ink or a polymer material loaded with an electrically conductive material, in some embodiments, the conductors 240 are highly flexible, which assists in providing highly flexible tool bodies 45. Additionally, in some embodiments, such conductors 240 do not significantly add to the overall diameter of the tool body 45.
In some of the versions of the above-discussed embodiments depicted in
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In one embodiment, the electrical resistance of the tool 10, as measured from the exterior contact surface of an electrode 15 to the exterior contact surface of its corresponding contact ring 80 is at least approximately 200 Ohms. In one embodiment, the electrical resistance of the tool 10, as measured from the exterior contact surface of an electrode 15 to the exterior contact surface of its corresponding contact ring 80 is at least approximately 300 Ohms. In one embodiment, the electrical resistance of the tool 10, as measured from the exterior contact surface of an electrode 15 to the exterior contact surface of its corresponding contact ring 80 is at least approximately 400 Ohms. In one embodiment, the electrical resistance of the tool 10, as measured from the exterior contact surface of an electrode 15 to the exterior contact surface of its corresponding contact ring 80 is at least approximately 500 Ohms. In one embodiment, the electrical resistance of the tool 10, as measured from the exterior contact surface of an electrode 15 to the exterior contact surface of its corresponding contact ring 80 is between approximately 100 Ohms and approximately 6000 Ohms. In one embodiment, the electrical resistance of the tool 10, as measured from the exterior contact surface of an electrode 15 to the exterior contact surface of its corresponding contact ring 80 is between approximately 100 Ohms and approximately 7000 Ohms.
While such high resistances would make an electrode of the tool generally unacceptable for purposes of electrograms or pacing or similar sensing or treatment functions, the high resistance electrodes 15 are adequate for use with a non-fluoroscopy imaging and tracking system (e.g., a St. Jude Medical, Inc. Ensite™ system) to generate cardiac anatomy, potential maps and to track the tool 10.
Where electrode configuration has been optimized for the specific non-fluoroscopy imaging and tracking system, tool electrical resistances exceeding 7000 Ohms can even be useful for purposes of generating cardiac anatomy, potential maps and to track the tool 10.
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In one embodiment, one or more of the electrodes 15 will have a surface area common for electrodes used for electrograms or pacing, for example, a surface area for an individual electrode of between approximately 4.8 mm2 and approximately 14.6 mm2. While such small surface areas are generally inadequate for electrogram or pacing or similar sensing or treatment functions, the surface area is not so small as to be insufficient for use with a non-fluoroscopy imaging and tracking system (e.g., a St. Jude Medical, Inc. Ensite™ system) to generate cardiac anatomy, potential maps and to track the tool 10. Such small electrode surface areas may facilitate the creation of tools 10 having complicated geometry, extremely tight bend radius, the location of additional features on the tool, increased tool body flexibility, reduced electrode material costs, etc., than would otherwise be possible with typical electrode surface areas used for electrogram or pacing.
While the some of the above-discussed embodiments may have electrodes, contact rings and conductors that result in tools with electrical resistances that are excessively high for electrogram, pacing and similar functions, the embodiments are still advantageous at least because: (1) the tools'electrical resistances are adequate for imaging and tracking purposes when used with a non-fluoroscopy imaging and tracking system (e.g., a St. Jude Medical, Inc. Ensite™ system); and (2) the electrode, contact ring and conductor configurations disclosed herein are inexpensive to manufacture.
Similarly, while the some of the above-discussed embodiments may have electrodes with small spacing and/or small surface areas that make the electrodes inadequate for electrogram, pacing and similar functions, the embodiments are still advantageous at least because the small spacing between electrodes and/or small electrode surface areas: (1) are adequate for imaging and tracking purposes when used with a non-fluoroscopy imaging and tracking system (e.g., a St. Jude Medical, Inc. Ensite™ system); and (2) allow a tool to be constructed with a tighter bending curve and/or greater flexibility; and (3) can result in a less expensive tool to manufacture.
By employing the concepts disclosed in this Detailed Description, visualization electrodes 15 can be economically provided to delivery tools 10 purely for imaging and tracking purposes within a non-fluoroscopy imaging and tracking system (e.g., a St. Jude Medical, Inc. Ensite™ system), thereby enabling such imaging and tracking systems to be used for medical lead implantation and substantially, if not completely, eliminating the need for fluoroscopy during lead implantation.
Although the present invention has been described with reference to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
