Trauma nail accumulator

Abstract

Provided is an accumulator that may store energy within a pressurized inflatable nail to compensate for small changes or losses in a system volume. Alternatively, the accumulator may be external to a pressurized inflatable nail and attached to the nail after the nail is implanted. The accumulator may be comprise a piston or a pressurized bladder. The energy may be stored in a spring, compressed air, or other pressure source. The accumulator may stabilize a system pressure by supplying fluid to the closed system. Alternatively, the accumulator may stabilize a system pressure by replacing the volume of the lost fluid.

1 . An apparatus for maintaining a pressure level in a closed system, the apparatus comprising:
 an accumulator, the accumulator comprising a system energy source coupled to a piston, the system energy source moveable between a first position and a second position in response to an outside force, wherein movement of the system energy source from the first position to the second position moves the piston to maintain a system pressure level in the closed system.   
     
     
         2 . The apparatus of  claim 1 , further comprising a means for adjusting fluid flow in the apparatus. 
     
     
         3 . The apparatus of  claim 2 , wherein the means for adjusting fluid flow is a mechanism selected from the group consisting of an adjustable valve and a coupler. 
     
     
         4 . The apparatus of  claim 1 , wherein the accumulator is coupled with a device comprising at least one inflatable balloon, the device being insertable into a bone cavity. 
     
     
         5 . The apparatus of  claim 4 , wherein the accumulator is externally coupled with the device. 
     
     
         6 . The apparatus of  claim 4 , wherein the accumulator is internally coupled with the device. 
     
     
         7 . The apparatus of  claim 4 , wherein the system energy source is selected from the group consisting of a spring and a volume of compressed air. 
     
     
         8 . The apparatus of  claim 1 , wherein the first position is a contracted state and the second position is an expanded state. 
     
     
         9 . An inflatable device that maintains a system pressure in a bone cavity, the inflatable device comprising:
 at least one inflatable balloon; and   an accumulator device in fluid communication with the at least one inflatable balloon, the accumulator device comprising
 a source of energy moveable between a first state and a second state, wherein moving the source of energy from the first position to the second position causes an increase in the system pressure. 
   
     
     
         10 . The inflatable device of  claim 9 , wherein the device is an inflatable nail. 
     
     
         11 . The inflatable device of  claim 10 , wherein the device is an inflatable intramedullary nail. 
     
     
         12 . The inflatable device of  claim 9 , wherein the accumulator is positioned in a housing external to the at least one inflatable balloon. 
     
     
         13 . The inflatable device of  claim 9 , wherein the at least one inflatable balloon is positioned within a housing, and wherein the accumulator is positioned in the housing. 
     
     
         14 . The inflatable device of  claim 13 , wherein the device is an inflatable nail having an inner shaft, and wherein the accumulator is positioned within the inner shaft. 
     
     
         15 . The inflatable device of  claim 9 , further comprising a flexible lumen. 
     
     
         16 . A method of maintaining a pressurized system in a bone cavity, comprising:
 inserting the inflatable device into a bone cavity, the inflatable device comprising at least one inflatable balloon and an accumulator device in fluid communication with the at least one inflatable balloon, the accumulator device comprising a source of energy moveable between a contracted state and an expanded state; and piston that is moveable between in a first position and a second position, wherein moving the piston from the first position to the second position causes the source of energy to move to maintain a pressure level;   inflating the at least one inflatable balloon to a pressure level, wherein inflating the at least one balloon moves the piston from a first position to a second position to store energy within the source of energy; and   releasing the energy stored within the source of energy to maintain the certain pressure in the bone cavity.   
     
     
         17 . The method of  claim 16 , wherein the inflatable device is an intramedullary nail.