Protective sheath apparatus and method for use with a heart wall actuation system for the natural heart

Abstract

An actuation system for assisting the operation of the natural heart includes a framework for interfacing with a natural heart and which is coupled with tissue of the heart. An actuator element is adapted to be coupled to the framework and is configured for extending along a portion of a heart wall exterior surface. The actuator element is operable for deforming the portion of the heart wall to effect a reduction in the volume of the heart. A protective sheath is configured to extend along the heart wall between the actuator element and the heart wall portion for protecting the heart wall portion from damage by the actuator element. The protective sheath is flexible and operable to transmit, to the heart wall portion, a force thereon by the actuator element for indenting the heart wall portion.

What is claimed is:  
     
         1 . An actuation system for assisting the operation of the natural heart, the actuation system comprising: 
 an actuator element configured for extending proximate a portion of a heart wall exterior surface and operable for indenting the portion of the heart wall to effect a reduction in the volume of the heart;    a protective sheath configured to extend along the heart wall between the actuator element and the heart wall portion for protecting the heart wall portion from damage by the actuator element;    the protective sheath being flexible and operable to transmit, to the heart wall portion, a force thereon by the actuator element for indenting the heart wall portion.    
     
     
         2 . The actuation system of  claim 1  further comprising a framework for interfacing with the heart and including elements configured for being anchored to the heart.  
     
     
         3 . The actuation system of  claim 1  wherein the protective sheath is porous.  
     
     
         4 . The actuation system of  claim 1  wherein the protective sheath comprises: 
 a plurality of interlocked elements.  
 
     
     
         5 . The actuation system of  claim 4  wherein interlocked elements of the plurality are formed of at least one of stainless steel, titanium, an abrasion-resistant polymer, a ceramic, nickel-titanium alloys, shape memory materials, and a combination of same.  
     
     
         6 . The actuation system of  claim 1  wherein the interlocked elements form ring-shaped structures.  
     
     
         7 . The actuation system of  claim 1  wherein the protective sheath comprises: 
 a fabric jacket;  
 a plurality of studs interspersed throughout the fabric and having stud surfaces generally coextensive with surfaces of the fabric.  
 
     
     
         8 . The actuation system of  claim 7  wherein said studs have rounded surfaces on at least one surface of the fabric.  
     
     
         9 . The actuation system of  claim 7  wherein the studs are formed of at least one of stainless steel, titanium, a ceramic, an abrasion-resistant polymer and a combination of same.  
     
     
         10 . The actuation system of  claim 7  wherein the fabric jacket is formed of at least one of a polyester, PTFE, a cellulose, polyethylene, and polyglycolic acid.  
     
     
         11 . The actuation system of  claim 1  wherein the protective sheath comprises: 
 a net of woven, abrasion-resistant cords.  
 
     
     
         12 . The actuation system of  claim 11  wherein the cords are formed of at least one of stainless steel, titanium, an abrasion-resistant polymer, a ceramic, nickel-titanium alloys, shape memory material, and a combination of same.  
     
     
         13 . The actuation system of  claim 1  wherein the actuator element comprises: 
 an actuator band extending along a portion of a heart wall, the actuator band being selectively movable between an actuated state and a relaxed state and operable, when in the actuated state, to assume a predetermined shape and thereby indent the protective sheath and a portion of the heart wall to effect a reduction in the volume of the heart.  
 
     
     
         14 . The actuation system of  claim 13  wherein the actuator band includes a plurality of juxtaposed blocks configured to be drawn together and to cooperate with each other, when drawn together, to assume the predetermined shape.  
     
     
         15 . The actuation system of  claim 7  wherein at least some of the cords extend in a direction; the actuator element moving in a direction generally parallel to said cord direction.  
     
     
         16 . The actuation system of  claim 2  wherein said protective sheath is anchored to said framework.  
     
     
         17 . The actuation system of  claim 1  wherein said protective sheath is anchored to said actuator element.  
     
     
         18 . The actuation system of  claim 1  wherein said protective sheath is configured for being anchored to tissue of a heart.  
     
     
         19 . The actuation system of  claim 2  wherein the actuator element is coupled to the framework.  
     
     
         20 . A method for assisting the operation of the natural heart, the method comprising: 
 positioning an actuator element to extend along a portion of a heart wall exterior surface;    positioning a flexible protective sheath along the heart wall between the actuator element and the heart wall portion for protecting the heart wall portion from damage;    indenting the sheath and portion of the heart wall to effect a reduction in the volume of the heart.    
     
     
         21 . The method of  claim 20  further comprising anchoring a framework to tissue of a natural heart and coupling the actuator element to the framework.  
     
     
         22 . The method of  claim 21  further comprising anchoring a framework having at least one internal element coupled to tissue inside of the heart and at least one external element coupled to an outside surface of the heart.  
     
     
         23 . The method of  claim 20  further comprising positioning a protective sheath having a plurality of interlocked rings along the heart wall.  
     
     
         24 . The method of  claim 20  further comprising positioning, along the heart wall, a protective sheath having a fabric jacket and plurality of studs interspersed throughout the fabric and having stud surfaces generally coextensive with surfaces of the fabric.  
     
     
         25 . The method of  claim 20  further comprising positioning a protective sheath including having a net of woven, abrasion-resistant cords along the heart wall.  
     
     
         26 . The method of  claim 20  further comprising positioning an actuator band to extend along a portion of a heart wall, and manipulating the actuator band so the band takes a predetermined shape and indent the protective sheath and a portion of the heart wall.  
     
     
         27 . The method of  claim 26  wherein the actuator band includes a plurality of juxtaposed blocks, the method further comprising drawing the blocks together to make the band assume the predetermined shape.  
     
     
         28 . The method of  claim 25  wherein at least some of the cords extend in a direction, the method comprising indenting the sheath and heart wall portion by moving the actuator element in a direction generally parallel to the cord direction.  
     
     
         29 . The method of  claim 20  further comprising anchoring the protective sheath to tissue of the heart.  
     
     
         30 . The method of  claim 21  further comprising anchoring the protective sheath to the framework.  
     
     
         31 . The method of  claim 20  further comprising anchoring the protective sheath to the actuator element.