Hand-Activated Syringe with Vacuum Chamber for Auto Refill

Abstract

A hand-activated syringe ( 14 ) is disclosed that uses a vacuum to retract a plunger ( 54 ) of the syringe ( 14 ) to draw fluid into a syringe body ( 18 ). A first seal ( 76 ) with the plunger ( 54 ) and a second seal ( 64 ) with the plunger ( 54 ) define a vacuum chamber ( 82 ). The spacing between the first seal ( 76 ) and the second seal ( 64 ) changes in response to the plunger ( 54 ) moving relative to the syringe body ( 18 ). Advancing the plunger ( 54 ) in a direction associated with a discharge stroke creates or increases a vacuum within the vacuum chamber ( 82 ) by increasing a spacing between the first seal ( 76 ) and the second seal ( 64 ). This vacuum thereafter may be used to retract the plunger ( 54 ) by decreasing a spacing between the first seal ( 76 ) and the second seal ( 64 ), and to thereby draw fluid into the syringe ( 14 ) from a fluid source ( 86 ).

1 . A fluid delivery system, comprising:
 a fluid source;   a syringe comprising:
 a syringe body comprising a discharge port and a fill port, wherein said discharge port is connectable to a patient; 
 a plunger movable relative to said syringe body and comprising a plunger head that is disposed within said syringe body; and 
 a first seal with said plunger, wherein said plunger moves relative to said first seal; and 
   a conduit extending between said fluid source and said fill port, and including while said discharge port remains available for connection to a patient.   
     
     
         2 . The fluid delivery system of  claim 1 , wherein said plunger head moves away from said first seal and toward said discharge port for a fluid discharge stroke. 
     
     
         3 . The fluid delivery system of  claim 1 , wherein said plunger head is located between said discharge port and said first seal when said plunger is in a fully retracted position. 
     
     
         4 . The fluid delivery system of  claim 1 , wherein said syringe further comprises a discharge chamber defined by an interior of said syringe body and said plunger head, and wherein said first seal is disposed on an opposite side of said plunger head in relation to said discharge chamber. 
     
     
         5 . The fluid delivery system of  claim 4 , wherein said syringe further comprises a vacuum chamber disposed on an opposite side of said plunger head in relation to said discharge chamber. 
     
     
         6 . The fluid delivery system of  claim 1 , wherein said syringe further comprises a second seal with said plunger head, and wherein said second seal moves along with said plunger. 
     
     
         7 . The fluid delivery system of  claim 1 , wherein said syringe further comprises a vacuum chamber disposed within said syringe body and comprising first and second closed ends, and wherein said first closed end comprises said first seal, and wherein said second closed end comprises said plunger head. 
     
     
         8 . The fluid delivery system of  claim 7 , wherein said syringe further comprises a second seal fixed relative to and moveable with said plunger, and wherein said vacuum chamber extends between said first and second seals. 
     
     
         9 . A fluid delivery system, comprising:
 a fluid source;   a syringe comprising:
 a syringe body comprising a discharge port and a fill port, wherein said discharge port is connectable to a patient; 
 a plunger movable relative to said syringe body and comprising a plunger head that is disposed within said syringe body; 
 a discharge chamber on a first side of said plunger head and that fluidly communicates with said discharge port; and 
 a vacuum chamber on a second side of said plunger head and that is fluidly isolated from said discharge chamber; and 
   a conduit extending between said fluid source and said fill port and including while said discharge port remains available for connection to a patient.   
     
     
         10 . The fluid delivery system of  claim 9 , wherein a volume of said discharge chamber decreases and a volume of said vacuum chamber increases by a movement of said plunger in a direction of a fluid discharge stroke. 
     
     
         11 . The fluid delivery system of  claim 10 , wherein a pressure within said vacuum chamber decreases by a movement of said plunger in a direction of a fluid discharge stroke. 
     
     
         12 . The fluid delivery system of  claim 9 , wherein a volume of said discharge chamber decreases and a volume of said vacuum chamber increases by a movement of said plunger toward said discharge port. 
     
     
         13 . The fluid delivery system of  claim 12 , wherein a pressure within said vacuum chamber decreases by a movement of said plunger toward said discharge port. 
     
     
         14 . The fluid delivery system of  claim 9 , wherein said syringe further comprises:
 a first seal with said plunger, wherein said plunger moves relative to said first seal; and   a second seal with said plunger, wherein said second seal moves with said plunger, wherein said first and second seals are spaced from each other.   
     
     
         15 . The fluid delivery system of  claim 14 , wherein said first seal is defined by an interface between an O-ring and said plunger, wherein said O-ring is mounted to said syringe body. 
     
     
         16 . The fluid delivery system of  claim 14 , wherein said second seal is defined by an interface between said plunger head and an interior of said syringe body. 
     
     
         17 . The fluid delivery system of  claim 14 , wherein said first and second seals each define a boundary for said vacuum chamber. 
     
     
         18 . The fluid delivery system of  claim 1 , wherein said syringe further comprises:
 a first check valve associated with said discharge port.   
     
     
         19 . The fluid delivery system of  claim 18 , wherein a flow out of said syringe body is directed through said first check valve and then said discharge port. 
     
     
         20 . The fluid delivery system of  claim 18 , wherein said syringe further comprises:
 a second check valve associated with said fill port.   
     
     
         21 . The fluid delivery system of  claim 1 , wherein said syringe further comprises a spring that interacts with said plunger. 
     
     
         22 . The fluid delivery system of  claim 21 , wherein said spring biases said plunger away from said discharge port. 
     
     
         23 . The fluid delivery system of  claim 21 , wherein said spring biases said plunger toward a retracted position relative to said syringe body. 
     
     
         24 . The fluid delivery system of  claim 1 , wherein said plunger moves toward said discharge port in response to a manual force. 
     
     
         25 . The fluid delivery system of  claim 1 , wherein said syringe further comprises at least one biasing member that biases said plunger toward a fully retracted position. 
     
     
         26 - 27 . (canceled) 
     
     
         28 . The fluid delivery system of  claim 1 , wherein said fluid source is pressurized. 
     
     
         29 . The fluid delivery system of  claim 1 , further comprising:
 a pressurizing source fluidly interconnected with said fluid source.   
     
     
         30 . The fluid delivery system of  claim 1 , wherein a pressure head exists with regard to said fluid source. 
     
     
         31 . A method for operating a fluid delivery system, comprising:
 creating a vacuum within a syringe body;   exerting a biasing force on said plunger that supplements a force provided by said creating step;   executing a first moving step comprising moving a plunger relative to said syringe body in a first direction using each of said vacuum and said biasing force;   drawing fluid into said syringe body from a fluid source and through a fill port of said syringe body using said first moving step;   fluidly connecting a discharge port of said syringe body with a patient; and   executing a second moving step comprising moving said plunger relative to said syringe body in a second direction to discharge said fluid from said syringe body through said discharge port and to inject said fluid into said patient.   
     
     
         32 - 41 . (canceled)