Method for making implantable medical devices having carbon nanotube-based Anti-electrostatic coatings

Abstract

A method of fabricating an implantable medical device having a receptacle adapted to receive a connector assembly attached to a proximal end of an implantable lead. A distal end portion of the implantable lead carries at least one electrode electrically connected with a terminal contact on the connector assembly. The receptacle contains at least one internal insulative sealing surface. An anti-static coating comprising carbon nanotubes is applied to the at least one internal insulative sealing surface.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional of copending U.S. patent application Ser. No. 11 / 133,921, filed May 19, 2005, titled “Implantable Medical Leads and Devices Having Carbon Nanotube-Based Anti-Electrostatic Coating and Methods for Making Such Leads and Devices” (Attorney Docket No. A05P1040).FIELD OF THE INVENTION[0002]The present invention relates generally to implantable medical devices, and particularly to implantable medical devices having one or more surfaces treated to prevent the accumulation of electrostatic charges or to dissipate such charges.BACKGROUND OF THE INVENTION[0003]Body implantable electrical leads form the electrical connection between an implantable medical device (IMD), such as a cardiac pacemaker and / or implantable cardioverter-defibrillator (ICD), and body tissue, such as that of the heart, which is to be electrically stimulated. As is well known, the leads connecting IMDs with the heart may be used for pacing or fo...

AI Technical Summary

Benefits of technology

The patent describes an implantable medical lead for transmitting electrical signals between an implantable medical device and body tissue. The lead has a coating that helps to dissipate electrostatic charges, which can accumulate on the surface of the lead during use. The coating is made of carbon nanotubes and is applied to the lead's housing. The lead also has a connector assembly with an insulating sealing surface that also helps to dissipate electrostatic charges. The technical effects of this invention include reducing the risk of electrostatic charge accumulation on the lead, improving the stability of the electrical connection between the lead and the implantable medical device, and reducing the risk of damage to the lead during use.

Problems solved by technology

Voltage levels generated by these insulating sources can be extremely high since their charges are not readily dissipated or distributed over their surfaces or conducted to other objects.

The accumulation of electrostatic charge in the form of rubbing, friction-induced triboelectric charge has been a persistent problem with endocardial leads.

Static charges tend to build up on the insulation between and adjacent to the ring terminal contacts on the connector assembly as a result of the high voltage spikes during defibrillation.

The electrical insulation may slowly degrade (similar to being electrically burned) due to the voltage build-up.

Similarly, static charges tend to build up on the surfaces of the internal insulating seals between the contact elements within the connector assembly-receiving cavity in the IMD and to progressively burn away these seals.

The dissipation of electrostatic charges is a particular problem in leads carrying cardiomechanical sensors (CMES) such as pressure transducers or accelerometers that generate very low amplitude output signals that are easily lost in the noise produced by the static charges.

Thus, these coatings tend to be relatively thick and therefore unacceptable for use with leads having small diameters, and with connector assemblies such as the aforementioned DF-4 connector assembly that is small and has tight design tolerances.

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