Suction device and dressing

Abstract

Some embodiments are directed to a system 10 for the application of topical negative pressure therapy to a site 18 on the body of a mammal. Some embodiments of the system 10 comprise a piston 22 and cylinder 24 device 12 having a self-contained power source for the generation of a reduced pressure and for aspirating the site 18. Some embodiments of the system 10 comprise a dressing 14 sealably surrounding the site 18 that can be operably connected to the device 12 by a conduit means 16 to apply the reduced pressure to the site 18.

1 - 40 . (canceled) 
     
     
         41 . An apparatus for administering negative pressure to a wound under a dressing, the apparatus comprising:
 first and second negative pressure devices configured to generate below atmospheric pressure under the dressing, the first and second negative pressure devices each comprising:
 a chamber; and 
 a piston moveably disposed within the chamber, the piston being moveable from a first position to a second position within the chamber; 
 wherein movement of the piston in a direction from the first position towards the second position generates below atmospheric pressure; and 
   a constant force spring coupled with the piston of at least one of the first and second negative pressure devices and configured to apply a force on the piston to move the piston from the first position to the second position.   
     
     
         42 . The apparatus of  claim 41 , wherein the constant force spring comprises a coiled ribbon spring. 
     
     
         43 . The apparatus of  claim 41 , wherein the first and second negative pressure devices are arranged in parallel. 
     
     
         44 . The apparatus of  claim 41 , the apparatus further comprising:
 a valve member in fluid communication with the first and second negative pressure devices;   wherein the valve member is configured to regulate a flow of fluid from the dressing.   
     
     
         45 . The apparatus of  claim 44 , wherein the valve member comprises a one-way valve and the first and second negative pressure devices are removably coupled to the valve member. 
     
     
         46 . An apparatus for administering negative pressure to a wound under a dressing, the apparatus comprising:
 a negative pressure device configured to generate below atmospheric pressure under the dressing, the negative pressure device comprising:
 a chamber; and 
 a piston moveably disposed within the chamber, the piston being moveable from a first position to a second position within the chamber; 
 wherein movement of the piston in a direction from the first position towards the second position generates below atmospheric pressure; and 
   a mechanical power source coupled with the piston and configured to apply a force on the piston to move the piston from the first position to the second position;   wherein the apparatus is configured to maintain a substantially constant level of negative pressure under the dressing as the piston travels from the first position to the second position.   
     
     
         47 . The apparatus of  claim 46 , wherein the mechanical power source comprises a spring. 
     
     
         48 . The apparatus of  claim 46 , wherein the mechanical power source comprises a constant force spring configured to apply a substantially constant force on the piston as the piston travels from the first position to the second position. 
     
     
         49 . The apparatus of  claim 48 , wherein the constant force spring comprises a coiled ribbon spring. 
     
     
         50 . The apparatus of  claim 46 , wherein the apparatus comprises a first negative pressure device and a second negative pressure device, each negative pressure device configured to generate below atmospheric pressure under the dressing and each comprising:
 a chamber; and   a piston moveably disposed within the chamber, the piston being moveable from a first position to a second position within the chamber;   wherein movement of the piston in a direction from the first position towards the second position generates below atmospheric pressure.   
     
     
         51 . The apparatus of  claim 50 , the apparatus further comprising:
 a valve member in fluid communication with the first and second negative pressure devices;   wherein the valve member is configured to regulate a flow of fluid from the dressing; and   wherein the first and second negative pressure devices are arranged in parallel.   
     
     
         52 . The apparatus of  claim 51 , wherein the valve member comprises a one-way valve and the first and second negative pressure devices are removably coupled to the valve member. 
     
     
         53 . An apparatus for administering negative pressure to a wound, the apparatus comprising:
 a negative pressure device configured to generate below atmospheric pressure, the negative pressure device comprising:
 an expandable chamber, the chamber being expandable from a first volume to a second volume; 
 wherein expansion from the first volume to the second volume generates below atmospheric pressure; and 
   a mechanical power source coupled with the expandable chamber and configured to apply a force on the expandable chamber to expand the chamber from the first volume to the second volume;   wherein the apparatus is configured to maintain a substantially constant level of negative pressure under the dressing as the expandable chamber expands from the first volume to the second volume.   
     
     
         54 . The apparatus of  claim 53 , wherein the expandable chamber comprises a syringe. 
     
     
         55 . The apparatus of  claim 53 , wherein the mechanical power source comprises a spring. 
     
     
         56 . The apparatus of  claim 53 , wherein the mechanical power source comprises a constant force spring configured to apply a substantially constant force on the expandable chamber as the expandable chamber expands from the first volume to the second volume. 
     
     
         57 . The apparatus of  claim 56 , wherein the constant force spring comprises a coiled ribbon spring. 
     
     
         58 . The apparatus of  claim 53 , wherein the apparatus comprises a first negative pressure device and a second negative pressure device, each negative pressure device configured to generate below atmospheric pressure under the dressing and each comprising:
 an expandable chamber, the chamber being expandable from a first volume to a second volume;   wherein expansion from the first volume to the second volume generates below atmospheric pressure.   
     
     
         59 . The apparatus of  claim 58 , the apparatus further comprising:
 a valve member in fluid communication with the first and second negative pressure devices;   wherein the valve member is configured to regulate a flow of fluid from the dressing; and   wherein the first and second negative pressure devices are arranged in parallel.   
     
     
         60 . The apparatus of  claim 59 , wherein the valve member comprises a one-way valve and the first and second negative pressure devices are removably coupled to the valve member.