Chameleon Scientific Corporation (Plymouth, MN) Chief Technology Officer Daniel M Storey invented thin conductive metal coatings suitable for flexible nonmetal fine wires and leads used in pacemakers and other implantable medical devices.
According to U.S. Patent Application 20100057179, polymer clad silica fiber cores are produced by plasma coating with dual layers of metals such as silver, gold or titanium to provide micro thin leads such as those used for pacemakers that are resistant to flexing breakage, and are conductive. The metal surfaces can be engineered to promote cell adhesion so that tissue scarring in vivo is greatly reduced. Nanostructure and thickness of the metal coating can be controlled to provide radiopaque surfaces on nonmetal medical devices and lead wires.
Cardiac pacing is a proven means of maintaining heart function for patients with various heart conditions. Over 650,000 pacemakers are implanted annually in patients worldwide, including over 280,000 in the United States. Over 3.5 million people in the developed world have implanted pacemakers. Another approximately 900,000 people have an implantable cardioverter defibrillator (ICD) or cardiac resynchronization (CRT) device. Pacemakers use an average of about 1.4 implanted conductive leads during their service life and ICD and CRT devices use an average of about 2.4 leads.
Lead failure is a serious and in some situations life threatening problem for pacemakers and ICD and CRT devices. The average number of leads used per unit indicates the high incidence of lead failure, which is due to two main failure modes for current leads.
Failure of a lead body may occur due to cracking or breaking of the conductor in the lead. This often arises due to repeated flexing from the beating of the heart and associated muscular movements that stress the pathway from the pacemaker to the heart. This subjects the lead at a series of points along its length to tens of millions of cycles per year over a lead's lifetime. Currently available wire leads have not been durable enough to withstand this rigorous environment and many have experienced failure due to conductor fatigue.
A second cause of lead failure is dislodgment or fouling of the distal end, thereby rendering the lead inoperable. The distal end can become non-functional in two distinct ways. Dislodgment of the end from the muscle may occur. While not common, the heart muscle in constant motion can unseat the tine, causing lost contact with the area that needs the voltage for correct pacing. A more common occurrence is the buildup of scar tissue around the insertion point due to the body's natural foreign body response and the healing response initiated from insertion of the electrode into the heart. Buildup of scar tissue may also occur from abandoned leads that have not been removed. Increased resistance of an active connection causes a larger draw of power from the generator in order to correctly pace the heart. Both failure modes can be fatal.
Lead failure is a serious and in some situations life threatening problem for pacemakers and ICD and CRT devices. The average number of leads used per unit indicates the high incidence of lead failure, which is due to two main failure modes for current leads.
Failure of a lead body may occur due to cracking or breaking of the conductor in the lead. This often arises due to repeated flexing from the beating of the heart and associated muscular movements that stress the pathway from the pacemaker to the heart. This subjects the lead at a series of points along its length to tens of millions of cycles per year over a lead's lifetime. Currently available wire leads have not been durable enough to withstand this rigorous environment and many have experienced failure due to conductor fatigue.
A second cause of lead failure is dislodgment or fouling of the distal end, thereby rendering the lead inoperable. The distal end can become non-functional in two distinct ways. Dislodgment of the end from the muscle may occur. While not common, the heart muscle in constant motion can unseat the tine, causing lost contact with the area that needs the voltage for correct pacing. A more common occurrence is the buildup of scar tissue around the insertion point due to the body's natural foreign body response and the healing response initiated from insertion of the electrode into the heart. Buildup of scar tissue may also occur from abandoned leads that have not been removed. Increased resistance of an active connection causes a larger draw of power from the generator in order to correctly pace the heart. Both failure modes can be fatal.
Chameleon Scientific coating methods provide conductive, flexible metal coatings on polymer or composite surfaces of medical devices and are ideally suited for coating thin wire or fiber leads such as those used in pacemakers. The deposited coatings are thick enough to prevent x-ray transmission, i.e., are radiopaque, yet do not affect polymer qualities such as flexibility which may interfere with medical procedures. A particular advantage of wires and leads coated in this manner is the ability to manufacture metal coated leads having overall diameters as small as 100 nm.
Pacemaker leads manufactured by Chameleon Scientific have notable advantages over currently used metal wire conductors used by medical device manufacturers. It is well recognized that currently marketed leads experience plastic deformation fatigue due to repeated flexing after implantation. In contrast, the coated fine wires developed by Chameleon Scientific are good conductors and retain flexibility, radiopacity, and resistance to flaking over tens of thousands of flexing cycles.
Pacemaker leads manufactured by Chameleon Scientific have notable advantages over currently used metal wire conductors used by medical device manufacturers. It is well recognized that currently marketed leads experience plastic deformation fatigue due to repeated flexing after implantation. In contrast, the coated fine wires developed by Chameleon Scientific are good conductors and retain flexibility, radiopacity, and resistance to flaking over tens of thousands of flexing cycles.
Leads made by Chameleon Scientific’s process do not require additional wires as are used in the multifilar coiled designs; rather a thin, flexible single wire is small enough to be effectively implanted and used in left-heart CRT, and neurological and spinal applications where small size is critical for proper performance and minimization of side effects.
Additionally, Chameleon Scientific’s leads are significantly less expensive to manufacture than coiled, multifilar designs. A simple manufacturing fixturing process utilizes metal ion plasma deposition in a chamber equipped to rotate a wire and allow even coatings.
Chameleon Scientific’s metal coatings are extremely thin, on the order of 1-20 microns, radiopaque, and conductive as well as having high flexibility. Radiopacity allows visualization by fluoroscope or X-radiation so that placement and tracking in vivo can be enhanced for medical device components.
Additionally, Chameleon Scientific’s leads are significantly less expensive to manufacture than coiled, multifilar designs. A simple manufacturing fixturing process utilizes metal ion plasma deposition in a chamber equipped to rotate a wire and allow even coatings.
Chameleon Scientific’s metal coatings are extremely thin, on the order of 1-20 microns, radiopaque, and conductive as well as having high flexibility. Radiopacity allows visualization by fluoroscope or X-radiation so that placement and tracking in vivo can be enhanced for medical device components.
Chameleon Scientific
13355 10th Avenue North, Suite 108
Plymouth, MN 55441
Office (763) 519-2716
Fax (763) 559-0481
Plymouth, MN 55441
Office (763) 519-2716
Fax (763) 559-0481
www.chameleonscientific.com/
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