Abstract: Neutralized surface of a polymer of perfluoro-3,6-dioxa-4-methyl-7-octene sulphonyl fluoride for attachment and growth of animal cells in vivo or in vitro, the comonomer preferably being tetrfluorethylene.

Abstract: A surface for the attachment and growth of cells is prepared by first grafting polyacrylic acid chains to a fluorocarbon polymer substrate so that its weight increases by between 0.1 % and 20%. The surface is then treated with concentrated sulphuric acid under such conditions that will separately decarboxylate, aromatize and sulphonate an effective proportion of the grafted polyacrylic acid chains before being dried, soaked in a concentrated acid and brought to a substantially neutral pH for cell attachment and growth thereupon. The surface may also be used as a human tissue implant.

Abstract: An external connection assembly for a conductor insulated by a compressible sleeve. The external conductor is in the form of a ring which is a compressingly fit on to the insulating sleeve and which is so dimensioned with respect to the sleeve that there is no discontinuity in the profile of the sleeve at the ring. Electrical continuity from the conductor to the ring is provided by a bridging wire which passes through the sleeve, the ends of the bridging wire being respectively clamped by compression fit between the conductor and the sleeve, and between the sleeve and the ring.

Abstract: A J-shaped atrial electrode lead having a pliant tube encasing a spiral wound conductor. A curved, resilient reinforcing member surrounding a portion of the conductor curves the conductor to conform with the shape of the origin of the crista terminalis of the right atrium to position an electrode tip in electrical contact with the junction of the crista terminalis and the superior margin of the right atrial appendage. The lead can be electrically bipolar or unipolar and includes tines adapted for engagement in the right atrial appendage, and an improved proximal portion for connection with a pacemaker circuit module.

Abstract: A current-limiter device is placed in series circuit between a pacemaker and the proximal end of an electrode to prevent tissue damage adjacent the distal end of the electrode which otherwise may have occurred during defibrillation, cardioversion, or diathermy.

Abstract: A medically implantable electrode lead for muscle stimulation comprising an electrode assembly with an exposed conductive distal tip which is coupled by an electrical conductor to a source of electrical pulses. The electrode assembly and electrical conductor are encased in an electrical insulator. The insulator has extending from it a plurality of flexible tines which are adapted to hold the exposed distal tip into position. To facilitate insertion of the distal tip into the desired location, especially when inserting the distal tip through a small opening such as a small vein, the insulator includes a transitional, truncated cone section between the distal tip and the tines. The outside diameter of the distal end of the cone section equals the outside diameter of the distal tip and the outside diameter of the proximal end of the cone section equals the outside diameter of the tines when they are folded into a closed position.

Abstract: A heart pacer providing heart stimulating electrical impulses in the absence of naturally occurring heartbeats, together with means to prevent inhibition of the electrical impulse in the presence of electrical interference signals of either physiological or nonphysiological origin. Logic functions are incorporated to detect the presence of any sensed signal occurring after a first predetermined time but earlier than a second predetermined time, both measured from the preceding detected signal which may be either a natural heartbeat, a stimulating electrical impulse, or an interference signal. The first predetermined time interval is greater than the time duration of the electrical manifestations of a single heartbeat while the second predetermined time interval is less than the interval between two natural heartbeats. Sensed signals are delayed before triggering the demand function.

Abstract: An improved muscle stimulator, particularly suited to long term rhythmic stimulation for the selective development of musculature otherwise asymmetric or retarded in relative development. To minimize the subjects' awareness of stimulation, to permit nocturnal use, and to minimize battery consumption, the energy content of each pulse train is modulated by a progressive increase of pulse width up to a maximum, followed by a progressive decrease of pulse width, thus yielding a gradual contraction and relaxation of the muscle.

Abstract: A heart pacer providing heart stimulating electrical impulses in the absence of naturally occurring heartbeats, including two electrical impulse generating time bases each capable of emitting heartbeat stimulating impulses. A sensed signal, accepted against criteria preceding it in time, as a valid heartbeat signal rather than an interference signal, serves to reset one time base while a second time base continues its cycle on the assumption that the sensed signal is an invalid or interference signal. If further signals are sensed, within criteria indicating that the original sensed signal was, in fact, invalid, the second time base continues its cycle until it emits a heart stimulating impulse at which time the first time base timing cycle is cancelled. If, however, the original sensed signal is not shown to be invalid the output of the second time base is suppressed and the reset timing cycle of the first time base continues.

Abstract: An implantable cardiac pacemaker which is enclosed in a titanium or titanium alloy housing with at least a portion of the housing coated with a silicone elastomer which both electrically and physiologically isolates the metal surface from the body while at the same time permitting the body tissue to act on the elastomer itself to provide a form of adhesion thereby to assist in stabilizing the pacemaker position within the body.

Abstract: The disclosure relates to a bone prosthesis having a keying electrode. The electrode is provided with key formations into which bone may grow for locking engagement therewith.