Hydraulic reducer for injector

Abstract

A medical device is provided having a needle or a catheter, insertable into a living body, which defines a plurality of holes in fluid communication with a central lumen. The holes may be of various patterns located and angled to create a desired injectate cloud pattern when an injectate is forced through the central lumen and through the plurality of holes. One embodiment provides various designs including a moveable sheath or stylet used to selectively occlude one or more of the holes while in use, thereby providing an operating physician a way to manipulate the cloud pattern anytime during the introduction of the injectate. A reducer may be used in conjunction with these needles which provides an increased degree of control when injecting very small quantities of fluid.

1 . An in-line volumetric reducer useable to advance a predetermined volume of liquid to an open end of a fluid-delivery catheter comprising: 
 a rigid housing defining:    a proximal opening attachable to a distal end of a hydraulic pressure line, said line having a proximal end in fluid communication with a plunger, whereby said proximal opening is in fluid communication with said pressure line when attached thereto;    a first inner chamber extending distally from said proximal opening and having a predetermined, substantially uniform, cross-sectional area along a predetermined linear axis;    a distal opening attachable to a proximal end of a catheter such that said distal opening is in fluid communication with said catheter when attached thereto; and,    a second inner chamber extending proximally from said distal opening and having a predetermined, substantially uniform cross-sectional area along a predetermined linear axis, wherein said cross-sectional area of said second inner chamber is smaller than said cross-sectional area of said first inner chamber;    a piston assembly including:    a first piston operably disposed within said first inner chamber and having a proximal side and a distal side, said first piston forming a substantially liquid-tight seal with said rigid housing such that pressurized liquid on said proximal side of said first piston is not able to pass around said first piston to said distal side of said first piston; and,    a second piston operably disposed within said second inner chamber and having a proximal side and a distal side, said second piston forming a substantially liquid-tight seal with said rigid housing such that liquid on said distal side of said second piston is not able to pass around said second piston to said proximal side of said second piston;    wherein said first piston is operably attached to said second piston such that when said first piston is moved linearly a predetermined distance, said second piston moves linearly an equal distance to said predetermined distance.    
   
   
       2 . The reducer of  claim 1  wherein said first piston is rigidly connected to said second piston.  
   
   
       3 . The reducer of  claim 1  wherein said housing is constructed and arranged such that a portion of said housing that defines said first inner chamber is integral with a portion of said housing that defines said second inner chamber and said housing further defines at least one vent constructed and arranged to allow a fluid to escape from said first inner chamber when said first piston is moved distally.  
   
   
       4 . The reducer of  claim 1  wherein said predetermined second chamber linear axis is aligned with said predetermined first chamber linear axis.  
   
   
       5 . The reducer of  claim 1  further comprising a stop extending inwardly from said housing constructed and arranged to limit said predetermined linear distance which said pistons may move.  
   
   
       6 . The reducer of  claim 1  wherein said housing further defines a threaded connector surrounding said proximal opening connectable to a complimentarily threaded fitting on said distal end of said hydraulic pressure line.  
   
   
       7 . The reducer of  claim 1  wherein said housing further defines a threaded connector surrounding said distal opening connectable to a complimentarily threaded fitting on said proximal end of said catheter.  
   
   
       8 . The reducer of  claim 1  wherein said housing further defines a luer lock connector surrounding said proximal opening connectable to a complimentary connector on said distal end of said hydraulic pressure line.  
   
   
       9 . The reducer of  claim 1  wherein said housing further defines a luer lock connector surrounding said distal opening connectable to a complimentary connector on said proximal end of said catheter.  
   
   
       10 . The reducer of  claim 1  further comprising a base plate to which said first cylinder is operably attached and to which said second cylinder is operably attached, said base plate fixing said first cylinder and said second cylinder relative to each other.  
   
   
       11 . The reducer of  claim 1  further comprising a bleed valve operably attached to said second cylinder and useable to vent air therefrom.  
   
   
       12 . The reducer of  claim 1  further comprising a vial attachment port operably attached to said second cylinder, and in fluid communication therewith, constructed and arranged to receive a vial of medicament.  
   
   
       13 . An in-line volumetric reducer useable to advance a predetermined volume of liquid to an open end of a fluid delivery lumen comprising: 
 a first cylinder having a proximal end defining a proximal opening and a distal end defining a distal opening;    a second cylinder having a proximal end defining a proximal opening and a distal end defining a distal opening, said second cylinder having a smaller diameter than said first cylinder;    a first piston operably disposed in said first cylinder;    a second piston operably disposed in said second cylinder;    wherein said first cylinder distal end is operably connected to said second cylinder proximal end;    wherein said first piston is operably connected with said second piston such that when said first piston travels a predetermined distance within said first cylinder, said second piston travels a distance within said second cylinder which is substantially equal to said predetermined distance.    
   
   
       14 . The reducer of  claim 13  wherein said first cylinder distal end is integral with said second cylinder proximal end and said first cylinder further defines at least one vent constructed and arranged to allow a fluid to escape from inside said first cylinder when said first piston is moved distally.  
   
   
       15 . The reducer of  claim 13  wherein said first cylinder comprises a stop extending inwardly constructed and arranged to limit said predetermined linear distance which said pistons may travel.  
   
   
       16 . The reducer of  claim 13  wherein said second cylinder is removably attachable to said first cylinder.  
   
   
       17 . The reducer of  claim 16  wherein said first piston comprises a distal end and a member extending distally from said distal end and constructed and arranged to abut against a proximal end of said second piston when said second cylinder is attached to said first cylinder.  
   
   
       18 . The reducer of  claim 16  wherein said second piston comprises a proximal end and a member extending proximally from said proximal end and constructed and arranged to abut against a distal end of said first piston when said second cylinder is attached to said first cylinder.  
   
   
       19 . A method of releasing a predetermined output volume from an output of a lumen of a catheter for a given input volume introduced to an input of said lumen comprising: 
 providing a flow reducer in line with said catheter between said input and said output, said reducer having a first piston distal said input and a second piston proximal said output, said first piston constructed and arranged such that when said first piston travels a predetermined distance, said second piston travels a distance substantially equal to said predetermined distance, said first piston having a first diameter and said second piston having a second diameter;    filling that portion of said catheter which extends from said second piston to said output with a desired output fluid;    injecting a predetermined amount of input fluid into said catheter input, thereby moving said first piston a predetermined distance and second piston a distance substantially equal to said predetermined distance;    thereby causing said predetermined output volume of output fluid to exit said catheter output, said output volume equal to the squared ratio of the second diameter to the first diameter.    
   
   
       20 . A method of injecting a predetermined quantity of injectate comprising: 
 providing a catheter having a proximal end attached to a supply of pressurized fluid and a distal end in fluid communication with a first component operably containing a first piston;    attaching a second component to a distal end of the first component, the second component operably containing a second piston which is constructed and arranged to move with the first piston, said second piston having a smaller cross sectional area than the first piston, said second component defining a chamber on a distal side of said second piston containing said predetermined quantity of injectate, said second component having a distal end which is operably attached to a hypodermic device;    forcing a predetermined quantity of said pressurized fluid through said catheter to cause said first piston and said second piston to move a predetermined linear distance in a distal direction, thereby forcing said predetermined quantity of injectate out of said hypodermic device.    
   
   
       21 . An in-line volumetric amplifier useable to advance a predetermined volume of liquid to an open end of a fluid delivery lumen comprising: 
 a first cylinder having a proximal end defining a proximal opening and a distal end defining a distal opening;    a second cylinder having a proximal end defining a proximal opening and a distal end defining a distal opening, said second cylinder having a larger diameter than said first cylinder;    a first piston operably disposed in said first cylinder;    a second piston operably disposed in said second cylinder;    wherein said first cylinder distal end is operably connected to said second cylinder proximal end;    wherein said first piston is operably connected with said second piston such that when said first piston travels a predetermined distance within said first cylinder, said second piston travels a distance within said second cylinder which is substantially equal to said predetermined distance.    
   
   
       23 . A method of introducing precise amounts of medical substance into a human comprising: 
 providing an injecting device containing fluid;    providing a hydraulic reducer;    providing said medical substance at an output end of said hydraulic reducer;    connecting said injecting device to said hydraulic reducer;    urging a volume fluid out of said injecting device into a hydraulic reducer such that a volume of medical substance urged out of said reducer to said human is a fraction of said volume of fluid urged into said hydraulic reducer;    
   
   
       24 . A device for deliverying precise amounts of a medical fluid to a human comprising: 
 injector device having a working fluid and an outlet;    a reducing device having an inlet connected to said outlet of said injector device, said reducing device having an outlet in fluid communication with a human;    said medical fluid disposed in said reducing device at said outlet;    said reducing device having a reduction element movable according to an introduction of working fluid into said reducing device, said movement of said reduction element causing a discharge of medical substance from said outlet of said reducing device, said discharge being a fraction in volume of a volume of said working fluid introduced into said reducing device.