Abstract: A tine portion of an implantable medical device includes a hook segment and a distal segment terminated by a tissue-piercing tip, wherein the distal segment extends from a distal end of the hook segment to the tip. The hook segment, which is elastically deformable from a pre-set curvature, for example, defined by a single radius, preferably tapers from a first width thereof, in proximity to a proximal end thereof, to a smaller, second width thereof, in proximity to the distal end thereof, wherein the tip has a width that is greater than the second width of the hook segment. Alternately, the tine portion may include a hook segment that is defined by two radii and a straight section extending therebetween.

Abstract: A tine portion for an implantable medical device includes a hook segment and a distal segment terminated by a tissue-piercing tip, wherein the distal segment extends from the hook segment to the tip. The hook segment, which is elastically deformable from a pre-set curvature, has one of: a round cross-section and an elliptical cross-section, while the distal segment has a flattened, or approximately rectangular cross-section. One or a pair of the tine portions may be integrally formed, with a base portion, from a superelastic wire, wherein the base portion is configured to fixedly attach to the device, for example, being captured between insulative members of a fixation subassembly.

Abstract: A tine portion of an implantable medical device includes a hook segment and a distal segment extending therefrom, wherein the hook segment is pre-set to extend along a curvature and is elastically deformable therefrom to an open position. The distal segment includes a tooth and an end that surrounds the tooth, wherein the end includes a pair of legs and a distal arch. The legs extend along a length of, and on opposing sides of the tooth, and the distal arch extends between the legs, distal to a tissue-piercing tip of the tooth. When the hook segment is in the open position, and a force is applied along a longitudinal axis of the device, to push the distal arch of the distal segment against tissue, for initial tissue penetration, the legs of the end of the distal segment bend in elastic deformation to expose the tissue-piercing tip to the tissue.