Fixation for implantable medical devices

Abstract

A fixation component includes tines extending from a base portion of the fixation component. Each tine is elastically deformable between a pre-set position and an open position. Each tine includes a hook segment extending from a proximal end near the base portion to a distal end. Each tine also includes a distal segment extending from the distal end of the hook segment to a tissue-piercing tip. When positioned in the pre-set position, the hook segment extends along a pre-set curvature that encloses an angle between 135 degrees and 270 degrees, and the distal segment extends away from a longitudinal axis of the fixation component.

What is claimed is: 
     
         1 . A fixation component for an implantable medical device, the fixation component comprising:
 a base portion; and   a plurality of tines that extend from the base portion, wherein each tine of the plurality of tines is elastically deformable between a pre-set position and an open position, wherein each tine of the plurality of tines comprises a hook segment extending from a proximal end near the base portion to a distal end, and a distal segment extending from the distal end of the hook segment to a tissue-piercing tip, wherein, when positioned in the pre-set position, the hook segment extends along a pre-set curvature that encloses an angle between 135 degrees and 270 degrees, and the distal segment extends away from a longitudinal axis of the fixation component.   
     
     
         2 . The fixation component of  claim 1 , wherein a length of the distal segment is within a range from 0.05 inch to 0.1 inch. 
     
     
         3 . The fixation component of  claim 1 , wherein a radius of the pre-set curvature of the hook segment is 0.085 inches. 
     
     
         4 . The fixation component of  claim 1 , wherein the pre-set curvature of the hook segment encloses an angle of 180 degrees. 
     
     
         5 . The fixation component of  claim 1 , wherein the pre-set curvature is defined by at least two radii and a straight segment extending between the at least a first radius and a second radius distal to the first radius, wherein the first radius is different than the second radius. 
     
     
         6 . The fixation component of  claim 1 , wherein the hook segment tapers from the proximal end to the distal end, wherein a width of the distal end of the hook segment is less than a width of the distal segment. 
     
     
         7 . The fixation component of  claim 1 , wherein the base and the plurality of tines are integrally formed. 
     
     
         8 . The fixation component of  claim 1 , wherein the target implant site is located within a right atrium of a heart of the patient. 
     
     
         9 . The fixation component of  claim 1 , wherein a length of the distal segment is configured to prevent perforation through a wall of a tissue structure at the target implant site. 
     
     
         10 . The fixation component of  claim 1 , wherein a length of the distal segment is within a range from 0.05 inch to 0.1 inch. 
     
     
         11 . The fixation component of  claim 1 , wherein the distal segment comprises a distal arch configured to, when relaxing the elastic deformation of the hook segment from the open position toward the pre-set position, at least partially cover a distal portion of the tissue-piercing tip to prevent tearing the tissue at the target implant site. 
     
     
         12 . The fixation component of  claim 1 , wherein the pre-set curvature is defined by at least two radii and a straight segment extending between the at least a first radius and a second radius distal to the first radius, wherein the first radius is different than the second radius. 
     
     
         13 . The fixation component of  claim 1 , wherein each tine of the plurality of tines is spaced apart from adjacent tines about a perimeter of a ring defined by the base. 
     
     
         14 . A method comprising:
 positioning a distal end of a delivery catheter adjacent to tissue at a target implant site within a patient, wherein the distal end of the delivery catheter comprises a wall defining a distal opening;   deploying, from the distal opening toward the tissue, an implantable medical device (IMD) comprising a fixation component coupled to a housing, wherein the fixation component comprises:
 a base portion; and 
 a plurality of tines that extend from the base portion, wherein each tine of the plurality of tines is elastically deformable between a pre-set position and an open position, wherein each tine of the plurality of tines comprises a hook segment extending from a proximal end near the base portion to a distal end, and a distal segment extending from the distal end of the hook segment to a tissue-piercing tip, wherein, when positioned in the pre-set position, the hook segment extends along a pre-set curvature that encloses an angle between 135 degrees and 270 degrees, and the distal segment extends away from a longitudinal axis of the fixation component. 
   
     
     
         15 . The method of  claim 14 , wherein the target implant site is located within a right atrium of a heart of the patient. 
     
     
         16 : The method of  claim 14 , wherein a length of the distal segment is configured to prevent perforation through a wall of a tissue structure at the target implant site. 
     
     
         17 : The method of  claim 14 , wherein a length of the distal segment is within a range from 0.05 inch to 0.1 inch. 
     
     
         18 : The method of  claim 14 , wherein the pre-set curvature of the hook segment encloses an angle of 180 degrees. 
     
     
         19 : The method of  claim 14 , wherein the pre-set curvature is defined by at least two radii and a straight segment extending between the at least a first radius and a second radius distal to the first radius, wherein the first radius is different than the second radius. 
     
     
         20 . A medical device system, comprising:
 an implantable medical device (IMD) comprising a hermetically sealed housing and a fixation component coupled to the hermetically sealed housing, the fixation component comprising:   a base portion; and
 a plurality of tines that extend from the base portion, wherein each tine of the plurality of tines is elastically deformable between a pre-set position and an open position, wherein each tine of the plurality of tines comprises a hook segment extending from a proximal end near the base portion to a distal end, and a distal segment extending from the distal end of the hook segment to a tissue-piercing tip, wherein, when positioned in the pre-set position, the hook segment extends along a pre-set curvature that encloses an angle between 135 degrees and 270 degrees, and the distal segment extends away from a longitudinal axis of the fixation component.