Powerhead of a power injection system
View Patent ↗A contrast media injection system detects the absolute position of the syringe ram using a non-contact sensor. A series of magnets and Hall-Effect sensors may be used or an opto-reflective system. Illuminated knobs that are connected to the drive mechanism for the syringe ram rotate with the drive and provide visual feedback on operation through the illumination. Analog Hall-Effect sensors are used to determine the presence or absence of magnets that identify the type of faceplate being used. The faceplates include control electronics, connected to the powerhead through connectors, which may be interchangeably used by the two faceplates. The faceplate electronics include detectors for automatically detecting the capacity of pre-filled syringes. Additional features include using historical data to provide optimum pressure limit values during an injection protocol, a removable memory device for storing and transferring information such as injection protocols and injector statistics, and password protection of such protocols.
1. A contrast media injector system comprising:
a faceplate mounting region at which magnetic sources of a faceplate may be located;
a Hall effect sensor associated with a location of said faceplate mounting region at which a magnetic source of a faceplate may be located;
an analog circuit configured for measuring an analog signal representative of magnetic flux impinging upon said Hall effect sensor;
a stored threshold analog signal value that is of an analog magnitude that is between first and second signal levels, said first signal level being from a first analog signal output by said Hall effect sensor when a faceplate is attached to said faceplate mounting region, and said second signal level being from a second analog signal output by said Hall effect sensor when the same faceplate is detached from said faceplate mounting region; and
a control circuit coupled to said analog circuit for determining whether a magnetic source of a faceplate has one of at least three states based upon said analog signal and said stored threshold analog signal value.
2. The system of claim 1 , wherein said faceplate mounting region is configured to attach to a faceplate having one or more magnets each associated with a respective magnetic conductor such that a presence, absence, and/or polarity of at least one of said one or more magnets on the faceplate is detected by a respective Hall effect sensor.
3. The system of claim 1 , further comprising:
a memory configured to store, for each of a plurality of faceplates, a respective state representing an analog signal representative of magnetic flux impinging on said Hall effect sensor.
4. Within a contrast media injector system, a method comprising:
attaching a faceplate to a powerhead of a contrast media injector system, wherein said faceplate comprises one or more magnets;
acquiring with a Hall effect sensor a first analog signal representative of magnetic flux impinging on said Hall effect sensor with said faceplate attached;
acquiring with said Hall effect sensor a second analog signal representative of magnetic flux impinging on said analog Hall effect sensor with said faceplate detached; and
storing a signature for said faceplate based on each of said first and second analog signals, wherein said signature comprises a stored threshold analog signal value that is between first and second signal levels from said first and second analog signals, respectively.
5. The method of claim 4 , wherein said stored threshold analog signal value is approximately halfway between said first and second signal levels from said first and second analog signals, respectively.
6. The method of claim 4 , further comprising:
storing a respective signature for each of a plurality of faceplates.
7. The method of claim 6 , further comprising:
attaching an unknown faceplate to said powerhead;
determining a detected analog signal level and/or polarity for said Hall effect sensor; and
identifying said unknown faceplate based on said detected signal levels and said stored signatures.
8. The system of claim 1 , wherein said control circuit utilizes said stored threshold value to determine whether a faceplate attached to said faceplate mounting region includes a corresponding magnetic source.
9. The system of claim 1 , further comprising:
a plurality of said Hall effect sensors; and
a memory comprising a plurality of faceplate identifiers, wherein each of said plurality of faceplate identifiers is associated with a unique combination of states derived from said analog signal from each of said plurality of Hall effect sensors.
10. A contrast media injector system comprising:
a faceplate mounting region at which one or more magnetic sources of a faceplate may be located;
a plurality of Hall effect sensors each associated with a location of said faceplate mounting region at which a magnetic source of a faceplate may be located;
an analog circuit configured for measuring an analog signal representative of magnetic flux impinging upon said each said Hall effect sensor;
a stored threshold analog signal value associated with each said Hall effect sensor, wherein each said stored threshold analog signal value is of a magnitude that is between first and second signal levels, said first signal level being from a first analog signal output by the corresponding said Hall effect sensor when a faceplate is attached to said faceplate mounting region, said second signal level being from a second analog signal output by the corresponding said Hall effect sensor when the same faceplate is detached from said faceplate mounting region;
a control circuit coupled to said analog circuit for determining a state from said analog signal from each said Hall effect sensor and utilizing the corresponding said threshold analog signal value; and
a stored faceplate identifier that is associated with a first combination of said states.