Abstract: Disclosed is an implantable catheter-type cardioverting electrode whose conductive discharge surface is comprised of coils of wound spring wire. An electrically conductive lead extends through the wound wire section of the electrode and has its distal end connected to the discharge coil at two locations. The proximal end of the conductive lead is adapted for connection to an implanted pulse generator. A pliable elastomeric material such as a medical-grade adhesive fills the conductive coils in the wound wire section of the spring wire electrode so that only the outer periphery of the wound section is exposed to the body. The catheter electrode is flexible, allowing easy implantation and avoiding trauma after implantation, and provides a large discharge surface for effecting defibrillation. The electrode is designed to reside in or about the heart, as in the superior vena cava or in the coronary sinus, and acts against another implanted electrode such as a conformal electrode residing at the apex of the heart.

Abstract: A method for preparing iron electrodes is provided which includes mixing particulate iron such as iron powder, iron oxide or iron hydroxide with an organic moldable resin and, preferably, carbon black. The mixture is molded into the desired electrode configuration and the molded electrode is heated in an inert atmosphere to at least 950.degree. C. to carbonize said resin. The electrode may be thereafter activated by use of sulfur compound or the like.

Abstract: Disclosed are several embodiments of an electrode system for ventricular defibrillation, and the methods of using and implanting the electrode system. In one embodiment, the electrodes are in a generally base-apex configuration having a split conformal base electrode residing above the base of the ventricles (a transecting plane separating the atria from the ventricles) in the region of the atria and a conformal apex electrode in the form of a rotated conic section residing at the apex of the heart. In another embodiment, defibrillation is accomplished by the apex electrode acting against a catheter electrode situated high in the heart or in the superior vena cava.The electrodes themselves are in the form of planar metallic mesh elements adapted to lie in contact with body tissue on an active surface, insulated on the opposite surface. In another embodiment, the conductive portions of the respective electrodes are developed from metallic plates, exposed on one surface and insulated on the other.

Abstract: A flexible substrate having a caustic resistant support and at least one membrane comprising a solid polymeric matrix containing a network of interconnected pores and interdispersed inorganic filler particles with a ratio of filler: polymer in the polymeric matrix of between about 1:1 to 5:1, is made by coating at least one side of the support with a filler:coating formulation mixture of inorganic filler particles and a caustic resistant, water insoluble polymer dissolved in an organic solvent, and removing the solvent from the mixture to provide a porous network within the polymeric matrix.

Abstract: An externally controlled implantable electronic device for delivering a cardioverting pulse of energy to the atrium of an ailing heart. In one embodiment, the device is particularly suited for use when the patient visits the office of his physician, and contemplates the transmission of both information and powering energy through the skin of the patient. In another embodiment, the device can be readily operated at home, by the patient, and without the intervention of the physician. Here, the source of energy is permanently implanted.