Syringe with multi-stage filling and dispensing

Abstract

The syringe includes a hollow body with at least one free-floating piston and a plunger within the body, with the piston between the plunger and a proximal end of the body. A manifold is provided lateral to the body. The manifold leads to an input/output tip. The manifold includes a front port located between the piston and the proximal end of the body and a rear port spaced from the proximal end of the body. The manifold includes at least one flow path leading from the input/output tip to at least one of the front port and/or the rear port. A first fluid fills a rear chamber distal to the piston and then the manifold is adjusted to fill second fluid into a front chamber proximal of the piston, and then the manifold is adjusted to allow sequential delivery of the second fluid and the first fluid.

What is claimed is: 
     
         1 . A method for sequential delivery of at least two separate fluids from a syringe, including the steps of:
 loading a first fluid into a syringe, the syringe having a hollow body having a proximal end opposite a distal end, a plunger extending into the distal end of the hollow body and adapted to translate linearly within the hollow body, a piston movable within the hollow body and between the plunger and the proximal end of the hollow body, a front port accessing a space within the hollow body between the piston and the proximal end of the hollow body, a rear port accessing a space within the hollow body and on a distal side of the piston when the piston is adjacent to the proximal end of the hollow body, and at least one flow path extending from an input/output tip of the syringe and selectively connectable and disconnectable to the front port and/or rear port;   said loading a first fluid step including retracting the plunger away from the proximal end while the flow path is connected to the rear port;   loading a second fluid into the syringe by retracting the plunger away from the proximal end while the flow path is connected to the front port; and   delivering the second fluid followed by the first fluid by pushing the plunger toward the proximal end of the syringe while the flow path is connected to both the front port and the rear port.   
     
     
         2 . The method of  claim 1  wherein said loading a first fluid step occurs before said loading a second fluid step. 
     
     
         3 . The method of  claim 1  wherein said fluids are each liquid medicaments. 
     
     
         4 . The method of  claim 1  wherein said first fluid is a saline flush. 
     
     
         5 . The method of  claim 1  including the further step of coupling the input/ output tip to medical tubing leading to a body lumen of a patient, the medical tubing having a volume associated therewith, the saline flush having a volume larger than the volume of the medical tubing, so that the second fluid is fully delivered out of the medical tubing and into the patient. 
     
     
         6 . The method of  claim 1  wherein said loading a first fluid step includes at least a portion of the flow path located upon a manifold adjacent to the hollow body and including a front path, a rear path and a staged delivery path, the front path selectively alignable with the front port, the rear path selectively alignable with the rear port, and the staged delivery path selectively alignable simultaneously with both the front port and the rear port. 
     
     
         7 . The method of  claim 6  including the further step of adjusting the manifold to align one of the paths of the manifold with at least one of the ports of the syringe. 
     
     
         8 . The method of  claim 7  wherein said adjusting step includes rotating the manifold. 
     
     
         9 . The method of  claim 7  wherein said adjusting step includes linearly translating the manifold. 
     
     
         10 . The method of  claim 7  wherein said loading a first fluid step and said loading a second side step each include the hollow body of the syringe being at least partially transparent and with graduation marks provided on the hollow body, with indicia visible adjacent to at least one of the graduation marks, the graduation marks beginning on a portion of the hollow body spaced from the proximal end by distances similar to a length of the piston within the body. 
     
     
         11 . A method for delivering two separate fluids from a single syringe, including the steps of:
 pushing a plunger of the syringe to move toward an end of a hollow body of the syringe that is opposite the plunger, the hollow body including a piston between the plunger and the end of the hollow body, and with a first fluid between the piston and the end of the hollow body and with a second fluid between the piston and the plunger;   sequentially discharging the two separate fluids through a common output during said pushing step, the output open to a first port between the piston and the end of the hollow body where the first fluid is located and initially closed to a second port closer to the plunger than to the first port; and   flow of the second fluid through the second port being blocked until after the piston has moved at least partially, after which piston movement the output is open to the second port.   
     
     
         12 . The method of  claim 11  wherein said discharging of each of the fluid occurs without manipulation of any valves during said pushing step. 
     
     
         13 . The method of  claim 11  wherein the second fluid is sequentially delivered after the first fluid. 
     
     
         14 . The method of  claim 13  wherein a burst disk blocks flow through the second port until the burst disk is fractured by plunger pushing force causing the second fluid pressure to exceed a fracture threshold for the burst disk, followed by fracture of the burst disk and flow of the second fluid to the output. 
     
     
         15 . The method of  claim 13  wherein the piston blocks the second port when the piston is spaced away from the end of the hollow body. 
     
     
         16 . The method of  claim 15  wherein manifold includes a shaft therein with at least two positions of the manifold provided by rotationally adjusting the shaft to bring separate pathways on the shaft leading to the output selectively into and out of alignment with the first port and/or the second port. 
     
     
         17 . The method of  claim 16  wherein the manifold is adjustable between at least three positions including a position where the output is open to only the first port, a position where the output is open only to the second port, and a position where the output is open to both the first port and the second port. 
     
     
         18 . The method of  claim 11  wherein said pushing step is preceded by the step of loading the first fluid by retracting the plunger away from the end of the hollow body. 
     
     
         19 . The method of  claim 18  wherein the second fluid is pre-loaded into a space between the piston and the plunger before said loading the first fluid step. 
     
     
         20 . The method of  claim 18  including the step of loading the second fluid after said loading the first fluid step.