Wound dressing with micropump

Abstract

A composite wound dressing apparatus promotes healing of a wound via the use of a micropump system. The micropump system includes a micropump that applies a subatmospheric pressure to the wound to effectively draw wound fluid or exudate away from the wound bed, or deliver fluids to the wound bed, without the need for a cumbersome external pressure (e.g. vacuum) source. Hence, the wound dressing and micropump system is portable which allows the patient mobility that is unavailable when an external vacuum source is used.

1 .- 74 . (canceled) 
     
     
         75 . A wound dressing apparatus, which comprises:
 a wound dressing member dimensioned for positioning relative to a wound bed; and   a micropump system including a micropump for applying subatmospheric pressure to at least the wound dressing member to facilitate removal of fluid from the wound bed, the micropump being placed in the wound or mounted to the wound dressing member;   wherein fluid enters an inlet side of the micropump from the wound dressing member and exits a fluid accumulation device under positive pressure.   
     
     
         76 . The wound dressing apparatus according to  claim 75  wherein the wound dressing member includes a backing, an adhesive coated on the backing, and a wound packing layer. 
     
     
         77 . The wound dressing apparatus according to  claim 76  wherein the adhesive coated backing is secured about the periphery of the wound to provide a seal between the wound dressing member and tissue surrounding the wound bed. 
     
     
         78 . The wound dressing apparatus according to  claim 75  wherein the wound dressing apparatus further includes an exudate collection line and an exudate collection device. 
     
     
         79 . The wound dressing apparatus according to  claim 78  wherein the exudate collection device is a flexible disposable pouch. 
     
     
         80 . The wound dressing apparatus according to  claim 75  wherein the vacuum applied by the micropump is self limiting and incapable of creating a vacuum in excess of 200 mmHg below atmospheric pressure. 
     
     
         81 . The wound dressing apparatus according to  claim 75  wherein the micropump comprises an electroactive actuator member. 
     
     
         82 . The wound dressing of  claim 75 , wherein
 the backing comprises an interior surface and an external surface;   an adhesive on at least a portion of the interior surface, wherein the adhesive extends around a perimeter of the interior surface of the backing to adhere the medical dressing to a subject over a wound;   wherein, when the medical dressing is attached over the wound, the medical dressing defines a sealed environment over the wound, and further wherein operation of the micropump causes fluid within the sealed environment to be moved through at least one opening in the backing   
     
     
         83 . The wound dressing of  claim 75 , wherein the micropump is rotorless and located proximate the backing 
     
     
         84 . The medical dressing of  claim 75 , wherein the dressing further comprises a normally-closed valve attached to the backing over an opening formed through the backing, wherein fluid flow through the opening is controlled by the valve, and wherein a dead volume between the normally-closed valve and the backing is 10 mm 3  or less. 
     
     
         85 . A medical dressing according to  claim 84 , wherein the valve comprises a one-way valve that permits fluid flow out of the sealed environment when in an open configuration and restricts fluid flow into the sealed environment when in a closed configuration. 
     
     
         86 . A medical dressing according to  claim 84 , wherein the valve comprises a plurality of polymeric film layers aligned with the backing, wherein the plurality of polymeric film layers comprises a flap layer comprising a flap formed therein. 
     
     
         87 . A medical dressing according to  claim 75 , wherein the medical dressing further comprises a stand-off element, wherein the stand-off element defines plurality of fluid pathways to the opening on the interior surface of the backing when the stand-off element is positioned proximate the interior surface of the backing in the sealed environment.