Injection System with Capacitive Sensing

Abstract

A powerhead ( 50 ) of a power injector is disclosed that includes a syringe housing ( 110 ) that contains a capacitive fluid detector ( 112 ). The capacitive fluid detector ( 112 ) may be operable to detect fluid within a syringe ( 116 ) installed on the syringe housing ( 110 ). The output of the capacitive fluid detector ( 112 ) may be used to estimate the volume of fluid within the syringe ( 116 ). The capacitive fluid detector ( 112 ) may include a plurality of discrete capacitors ( 118 a - 118 h ) arranged serially along a longitudinal axis ( 120 ) of the syringe ( 116 ). Each of the plurality of capacitors ( 118 a - 118 h ) may be operable to produce an electric field extending into the syringe ( 116 ). Each of the plurality of capacitors ( 118 a - 118 h ) may be formed on a printed circuit board ( 130 ).

1 - 38 . (canceled) 
     
     
         39 . An injection system comprising:
 an injection device;   a syringe barrel zone, wherein said injection device is operable to hold a syringe such that a syringe barrel of said syringe is coextensive with said syringe barrel zone, wherein said syringe barrel zone comprises a syringe barrel zone length coinciding with a syringe barrel length of said syringe when said syringe is held by said injection device; wherein said syringe barrel zone comprises a syringe barrel zone longitudinal axis coinciding with a syringe barrel longitudinal axis of said syringe when said syringe is held by said injection device, said injection device comprising a capacitive detector, wherein an electric field of said capacitive detector penetrates a first region adjacent to said syringe barrel zone; and   user input determination logic operable to determine a user input at least partially based on output from said capacitive detector.   
     
     
         40 . The injection system of  claim 39 , wherein said electric field of said capacitive detector penetrates a second region adjacent to said syringe barrel zone, wherein said second region is on an opposite side of said syringe barrel zone than said first region. 
     
     
         41 . The injection system of  claim 40 , wherein said user input determination logic is operable to distinguish a user input within said first region from a user input within said second region. 
     
     
         42 . The injection system of  claim 40 , wherein said first and second regions each extend along substantially an entirety of said syringe barrel zone length. 
     
     
         43 . The injection system of  claim 42 , wherein said user input determination logic is operable to detect fingers of a user moving in said first and second regions along said syringe barrel zone length. 
     
     
         44 . The injection system of  claim 39 , wherein said capacitive detector comprises a first capacitor set, wherein said first capacitor set comprises a plurality of first capacitors that are spaced along said syringe barrel zone length and coincides with said first region, and wherein said electric field of said capacitive detector that corresponds with said first capacitor set penetrates said first region adjacent to said syringe barrel zone. 
     
     
         45 . The injection system of  claim 44 , wherein each said first capacitor comprises a pair of substantially coplanar plates. 
     
     
         46 . The injection system of  claim 44 , wherein said first capacitor set extends along substantially an entirety of said syringe barrel zone length. 
     
     
         47 . The injection system of  claim 44 , wherein each said first capacitor is of a first value when a user's finger is in its corresponding said electric field, and wherein each said first capacitor is of a second value when a user's finger is absent from its corresponding said electric field. 
     
     
         48 . The injection system of  claim 44 , wherein said capacitive detector further comprises a second capacitor set, wherein said second capacitor set comprises a plurality of second capacitors that are spaced along said syringe barrel zone length and coincides with a second region that is adjacent to said syringe barrel zone, wherein said second region is spaced from said first region, and wherein said electric field of said capacitive detector that corresponds with said second capacitor set penetrates said second region adjacent to said syringe barrel zone. 
     
     
         49 . the injection system of  claim 48 , wherein each said first capacitor comprises a pair of substantially coplanar plates and each said second capacitor comprises a pair of substantially coplanar plates. 
     
     
         50 . The injection system of  claim 48 , wherein said second region is on an opposite side of said syringe barrel zone than said first region. 
     
     
         51 . The injection system of  claim 48 , wherein said user input determination logic is operable to distinguish a user input within said first region from a user input within said second region. 
     
     
         52 . The injection system of  claim 48 , wherein said first and second regions each extend along substantially an entirety of said syringe barrel zone length. 
     
     
         53 . The injection system of  claim 48 , wherein each of said first capacitor set and said second capacitor set extends along substantially an entirety of said syringe barrel zone length. 
     
     
         54 . The injection system of  claim 48 , wherein each said first capacitor and each said second capacitor is of a first value when a user's finger is in its corresponding said electric field, and wherein each said first capacitor and each said second capacitor is of a second value when a user's finger is absent from its corresponding said electric field. 
     
     
         55 . The injection system of  claim 48 , further comprising a central capacitor located between said first capacitor set and said second capacitor set, wherein said central capacitor extends along substantially an entirety of said syringe barrel zone length. 
     
     
         56 . The injection system of  claim 55 , wherein said central capacitor comprises a pair of substantially coplanar plates arranged side by side. 
     
     
         57 . A method of operating an injection system comprising a syringe, said method comprising:
 capacitively sensing a finger of a user proximate to said syringe; and   interpreting said capacitive sensing as a user input to said injection system, wherein said capacitively sensing and interpreting steps are executed by said injection system.   
     
     
         58 . The method of  claim 57 , further comprising said user advancing said finger along a length of said syringe, wherein said capacitively sensing step senses said finger during said advancing step and which is used as said user input to said injection system.