Suspension device and method

Abstract

A device and method for providing a suspended agent such as a contrast agent without mechanical resuspension. A volume of agent is divided into sub-volumes in a network configured to suspend and deliver the sub-volumes of agent to a patient when a propellant fluid flows through the network. The invention reduces sedimentation of agents into one or a few aggregates and eliminates a mechanical mixing step. The invention thus provides a uniformly suspended agent, improving patient health and safety and increasing cost and time savings.

What is claimed is:  
     
         1 . A method for providing a volume of a suspendable agent using a propellant fluid, the method comprising: 
 operably engaging a charging container containing a pressurized propellant fluid to the inlet of the tubular network having a plurality of helices containing a plurality of sub-volumes of a suspendable contrast agent with at least two helices compressibly secured and fastened together, an inlet to the tubular network, and an outlet from the tubular network; and    depressurizing the charging container and providing propellant pressure to the tubular network effective to suspend and deliver the plurality of sub-volumes of the suspendable agent through the outlet.    
     
     
         2 . The method of  claim 1  wherein the pressurized fluid is a gas.  
     
     
         3 . The method of  claim 2  wherein the gas is selected from the group consisting of helium, neon, argon, hydrogen, octafluoropropane, air, carbon dioxide, oxygen, and combinations thereof  
     
     
         4 . The method of  claim 1  wherein the tubular network is positioned inside a syringe.  
     
     
         5 . The method of  claim 1  wherein the suspendable agent is selected from the group consisting of a colloid, a microbubble preparation, an imaging contrast agent.  
     
     
         6 . The method of  claim 1  wherein the suspendable agent is a contrast agent having a microbubble formulation in which microbubbles are formed by the method.  
     
     
         7 . A suspension device for a suspendable agent, comprising: 
 a tubular network for containing a plurality of sub-volumes of the agent, said tubular network including inflow and outflow ports for flow of a fluid to suspend and propel the agent from said tubular network, said tubular network having a first cross-sectional internal geometrical configuration along a first length and a second cross-sectional internal geometrical configuration along a second length, the second cross-sectional internal geometrical configuration differing from the first cross-sectional internal geometrical configuration.    
     
     
         8 . The suspension device of  claim 7  wherein said first cross-sectional internal geometrical configuration is circular, and said second cross-sectional internal geometrical configuration is selected from the group consisting of circular, square, elliptical, triangular, rectangular, and wedge-shaped.  
     
     
         9 . The suspension device of  claim 7  wherein at least one of said first cross-sectional internal geometrical configuration or said second cross-sectional internal geometrical configuration includes a plurality of lumens.  
     
     
         10 . The suspension device of  claim 7  wherein said first internal cross-sectional geometrical configuration and said second internal cross-sectional geometrical configuration are each selected from the group consisting of circular, square, elliptical, triangular, rectangular, and wedge-shaped.  
     
     
         11 . The suspension device of  claim 7  wherein at least one of said first internal cross-sectional geometrical configuration or said second internal cross-sectional geometrical configuration is non-circular.  
     
     
         12 . The suspension device of  claim 7  wherein said first and second geometrical configurations are contiguous along said network path.  
     
     
         13 . The suspension device of  claim 7  wherein said first and second geometrical configurations are non-contiguous along said network path.  
     
     
         14 . The suspension device of  claim 7  wherein said first and second geometrical configurations are symmetrical along said network path.  
     
     
         15 . A suspension device for a suspendable agent, comprising: 
 a helical tubular network for containing a plurality of sub-volumes of the agent, said helical tubular network having a non-uniform radius of curvature, a columnar arrangement, a non-uniform network density, or a combination thereof; and    inflow and outflow ports in said helical tubular network for flow of a fluid to suspend the suspendable agent and propel the suspended agent from said helical tubular network.    
     
     
         16 . The suspension device of  claim 15  wherein said tubular network has a radius of curvature that varies symmetrically.  
     
     
         17 . The suspension device of  claim 15  wherein said tubular network has a radius of curvature that varies non-symmetrically.  
     
     
         18 . The suspension device of  claim 15  wherein said tubular network includes at least two parallel columns, each of said at least two parallel columns being independently operatively connected in said suspension device.  
     
     
         19 . A method of decreasing escape of a gaseous agent contained within a device for suspending a volume of said agent, the network comprising a network to contain a plurality of sub-volumes of said agent and ports for an inflow and an outflow of a fluid to propel said agent from said network, said method comprising: 
 providing said device within a container comprising a material having a permeability to said gaseous agent that is less than a permeability of said network to said gaseous agent.    
     
     
         20 . The method of  claim 19  wherein a plurality of said devices are provided within said container.  
     
     
         21 . An apparatus to decrease escape of a gaseous agent contained within a suspension device for a volume of said agent, the device comprising a network to contain a plurality of sub-volumes of said agent and ports operatively connected to said network at an inflow site and an outflow site for a fluid to propel said agent from said network, said apparatus comprising: 
 a container made of a material that is less permeable to said gaseous agent than the permeability of said network and containing at least one of said device.    
     
     
         22 . The apparatus of  claim 21  wherein said material is selected from the group consisting of glass and thick walled plastic.  
     
     
         23 . The apparatus of  claim 22  wherein said thick walled plastic is selected from the group consisting of polypropylene and polyvinyl chloride.  
     
     
         24 . A method of manufacturing a device for delivering a suspendable agent, comprising: 
 forming a tubular network having a plurality of helices, an inlet adapted to receive a pressurized propellant fluid and an outlet;    compressibly securing and fastening together at least two helices; and    filling the tubular network with a plurality of sub-volumes of a suspendable agent.