Abstract: An implantable medical device having at least one lead connector. The lead connector has a collet-type mechanism. A bolt is securely affixed within the header of the implanted device. The bolt means has a central bore for receiving a pin of a lead, and fingers for contacting the end of the lead. Initial electrical contact is achieved by the bolt when the lead is inserted therein. A nut threadedly engages the bolt to compress the fingers against the lead. The nut is rotatably received within the header of the implanted device so that it can both tighten on the bolt and loosen therefrom. The nut is manipulated through a piercable septum.

Abstract: A connector terminal in a cardiac stimulator for receiving a connector pin of an associated lead includes a hollow box member having opposite end walls defining a first bore for receipt of the connector pin. A ring member movably disposed within the box member defines a second bore generally aligned with the first bore for also receiving the connector pin. A threaded neck connected to the ring member extends perpendicular to the second bore and is received within a through bore of the box member that is disposed perpendicular to the first bore. An internally threaded cap threadedly engages the threaded neck and bears in a thrust bearing relationship on the box portion. As the cap is rotated, the ring portion is drawn upwardly as the cap presses downwardly on the box portion, causing the second bore to be moved transversely out of alignment with the first bore. A connector pin received through both first and second bores is clamped therebetween and retained against axial withdrawal from the connector terminal.

Abstract: An implantable endocardial lead with retractable fixation apparatus. The fixation apparatus comprises a sharpened helix which can be repeatedly both retracted within an electrode at a distal end of the lead and displaced outside the electrode by action of a flexible, tubular lanyard. The lanyard passes through a lumen from a proximal end of the lead to the distal end of the lead, where the lanyard is attached to a piston supporting the helix. At the proximal end of the lead, a jig moves the lanyard with respect to a longitudinal axis of the lead. When the helix is in an exposed position, torque can be transmitted from the proximal end of the lead to the distal end thereof, through the electrode to the piston and then to the helix to screw the helix into the endocardial tissue. To stiffen the lead during implantation, a stylet can be inserted into a lumen in the lanyard.

Abstract: An implantable lead for a cardiac stimulator has an electrode at its distal end, and resilient, non-penetrating, tissue-contacting elements integral with the lead in the vicinity of the electrode. The resilient elements are movable from a first unextended position for ease of insertion or withdrawal of the lead through the vein of a patient to a second extended position for contacting tissue to retain the electrode in a selected location in the heart of the patient. A device operable along the lead serves to selectively move the resilient elements from the unextended to the extended position or vice versa.

Abstract: An active fixation mechanism for a pacemaker lead with a tissue-stimulating electrode has a rigid hook for engaging tissue pivotally fastened to the lead in the vicinity of the electrode. The tip of the hook is normally resiliently urged into a recess in the lead adjacent to the electrode. A mechanism is coupled to the lead to permit the normal bias on the hook tip to be selectively overcome to position the hook outwardly of the lead. In this position, the hook is deployed to engage tissue in the vicinity of the electrode. The force applied to deploy the hook may be removed to allow the hook to move back into the recess under the normal bias. Sufficient force applied to the hook while deployed, along the axis of the lead, will cause the hook to assume a position beyond the distal end of the lead, in which it is precluded from engaging tissue.

Abstract: An improved connection assembly for connecting a burn-in component board located within a burn-in chamber to control circuitry located outside the chamber is disclosed. The assembly includes a connecting device for connecting the component board to the control circuitry. The improvement includes an isolation apparatus for isolating the connecting device from the chamber, the isolation apparatus including (i) a cavity extending through at least a portion of the wall of the chamber and defining a cavity base disposed between the inner surface of such wall and the exterior of such chamber and (ii) a cavity cover disposed between the cavity base and the interior of the chamber such that contact between the air of the chamber and the connecting device is substantially reduced and the flow of air between the inside and outside of the chamber adjacent the connector is substantially inhibited.