Breast implant with internal flow dampening

Abstract

An implantable prosthesis is provided having a membrane which holds a flowable substance. The membrane is separated into a first chamber and a second chamber with the first and second chambers being fluidly coupled via an orifice. The orifice has a size which may be adjusted by the user after implanting the prosthesis into the patient.

1 . An implantable prosthesis, comprising:
 a soft, flexible outer membrane;   a flowable substance contained within the membrane;   an open cell structure positioned inside the membrane, the open cell structure being filled with the flowable substance so that the open cell structure dampens motion of the flowable substance within the membrane.   
   
   
       2 . The implantable prosthesis of  claim 1 , wherein the membrane includes a first chamber and a second chamber and a flow restricting orifice which fluidly couples the first chamber to the second chamber. 
   
   
       3 . The implantable prosthesis of  claim 2 , wherein an adjustable flow restricting orifice which fluidly couples the first chamber to the second chamber, the adjustable flow restricting orifice having a control element which permits the user to change a size of the orifice thereby altering a flow resistance between the first and second chambers. 
   
   
       4 . The implantable prosthesis of  claim 2 , wherein the control element is configured to extend out of the patient when the membrane has been implanted into a patient so that the size of the orifice may be altered after the membrane has been implanted into the patient. 
   
   
       5 . The implantable prosthesis, of  claim 1 , further comprising: a tension element coupled to the membrane at a first location and a second location; and a control element coupled to the tension element, the control element being configured to increase tension on the tension element so that the tension element draws the first and second locations toward one another. 
   
   
       6 . The prosthesis of  claim 5 , wherein the control element is configured to extend out of the patient when the membrane has been implanted into a patient so that tension on the tension element may be altered after the membrane has been implanted into the patient. 
   
   
       7 . The prosthesis of  claim 5 , wherein the membrane has a posterior wall and an anterior wall; and the first location being on the posterior wall and the second location being on the anterior wall. 
   
   
       8 . The prosthesis of  claim 5 , further comprising a plurality of tension elements extending within the membrane, each of the tension elements being configured to be tensioned independently by the user after introduction of the membrane into the patient. 
   
   
       9 . The implantable prosthesis of  claim 1 , further comprising a plurality of elastic tension elements extending through the open-cell structure coupled to the membrane, each tension element having a first end and a second end which are both attached to the membrane. 
   
   
       10 . The implantable prosthesis of  claim 9 , wherein the membrane has a round posterior wall; and the plurality of tension elements extend from one side of the membrane to a diametrically opposed side relative to the circular posterior wall. 
   
   
       11 . The implantable prosthesis of  claim 10 , wherein the plurality of tension elements are coupled together at a junction which is between the first and second ends of the tension elements. 
   
   
       12 . The implantable prosthesis of  claim 1 , further comprising a plurality of voids in the open-cell structure which are substantially larger than the cells of the open-cell structure. 
   
   
       13 . The prosthesis of  claim 12 , wherein the plurality of voids are organized in a symmetrical pattern relative to the axis of symmetry. 
   
   
       14 . The prosthesis of  claim 12 , wherein the plurality of voids are elongate channels which extend through the open-cell structure. 
   
   
       15 . The implantable prosthesis of  claim 1 , further comprising a cover material;
 the membrane having an outer surface, a posterior wall, an anterior wall and a waist, the waist being an outer ring which is positioned between the anterior wall and the posterior wall when the membrane is supported by the posterior wall;   the cover material extending over the membrane and being made of expanded PTFE, wherein at least 80 percent of the expanded ePTFE which covers the membrane is positioned no more than one centimeter from the waist of the membrane.   
   
   
       16 . The prosthesis of  claim 15 , wherein the outer surface of the membrane is exposed to tissue when implanted into the patient except for the portion of the outer surface covered by the cover material. 
   
   
       17 . The prosthesis  claim 15 , wherein the cover material is a strip of expanded PTFE which wraps around the membrane in a direction which is parallel to the waist so that the strip covers the outer surface of the membrane along the waist. 
   
   
       18 . The implantable prosthesis of  claim 1 , wherein the open cell structure has a natural, unbiased shape which is larger than the membrane, the membrane holding the open cell structure in a compressed state which is smaller than the natural unbiased shape. 
   
   
       19 . The implantable prosthesis of  claim 1 , wherein the membrane includes an inner surface which is exposed to the flowable substance; and the open cell structure includes a channel extending along an outer surface of the open cell structure adjacent to the inner surface of the membrane. 
   
   
       20 . The implantable prosthesis of  claim 19 , wherein the membrane includes a posterior wall and an anterior wall, the anterior wall having an apex; and the open cell structure includes a plurality of channels which intersect at along the inner surface of the membrane below the apex. 
   
   
       21 . The implantable prosthesis of  claim 20 , wherein the membrane includes a posterior wall and an anterior wall, the anterior wall having an apex; and the open cell structure includes a plurality of channels which extend radially relative to the apex of the membrane. 
   
   
       22 . The implantable prosthesis of  claim 20 , wherein the plurality of channels in the open cell structure do not intersect one another. 
   
   
       23 . The implantable prosthesis of  claim 19 , wherein the channel in the open cell structure extends circumferentially about an external surface of the open cell structure. 
   
   
       24 . The implantable prosthesis of  claim 1  wherein the membrane has a posterior wall, an anterior wall and an inner surface which is exposed to the flowable substance; and the open cell structure being selectively attached to the membrane at discrete locations. 
   
   
       25 . The implantable prosthesis of  claim 24 , wherein the open cell structure is selectively attached at a plurality of locations separated by portions of the open cell structure which are free to move relative to the inner surface of the membrane. 
   
   
       26 . The implantable prosthesis of  claim 24 , wherein the open cell structure is attached to the posterior wall of the membrane at a plurality of locations separated by portions of the open cell structure which are free to move relative to the inner surface of the membrane along the posterior wall. 
   
   
       27 . The implantable prosthesis of  claim 24 , wherein the open cell structure is attached to the anterior wall of the membrane at a plurality of locations separated by portions of the open cell structure which are free to move relative to the inner surface of the membrane along the anterior wall. 
   
   
       28 . The implantable prosthesis of  claim 25 , wherein the open cell structure is selectively attached to the membrane along a strip of the inner surface of the membrane. 
   
   
       29 . The implantable prosthesis of  claim 1 , further comprising a plurality of spacing elements positioned between the membrane and the open cell structure, the spacing elements forming a space between the membrane and the open cell structure to promote flow of the flowable substance in the space between the membrane and the open cell structure. 
   
   
       30 . The implantable prosthesis of  claim 29 , wherein the membrane has an inner surface which is the open cell structure has an outer surface; and the plurality of spacing elements cover less than 20% of the outer surface of the open cell structure so that at least 80% of the outer surface is exposed and free to move relative to an inner surface of the membrane. 
   
   
       31 . The implantable prosthesis of  claim 18 , wherein the open cell structure has a volume in its natural unbiased shape that is 5% to 20% larger than the volume of the membrane. 
   
   
       32 . The implantable prosthesis of  claim 18 , wherein the open cell structure has a height in its natural unbiased shape that is 5% to 20% larger than the maximum length between an anterior wall and a posterior wall of the membrane. 
   
   
       33 . The implantable prosthesis of  claim 18 , wherein the open cell structure has a width in its natural unbiased shape that is 5% to 20% larger than the maximum width or diameter of a posterior wall of the membrane.