Calibrated pushrod for injection volume control in prefilled syringes
A pushrod for use with a prefilled syringe containing a known amount of a medical fluid and having a volume, including a shaft having a scale corresponding to the cross-sectional area of the prefilled syringe, a stop configured for location along the shaft, the stop located using the scale in correspondence with a prescribed dosage injected from the prefilled syringe.
1 . A pushrod for use with a prefilled syringe containing a known amount of a medical fluid and having a cross-sectional area, comprising:
a shaft including a scale corresponding to the volume of the prefilled syringe; and,
a stop configured for location along the shaft;
the stop located using the scale in correspondence with a prescribed dosage injected from the prefilled syringe.
2 . The pushrod of claim 1 , the shaft and the stop including corresponding threads, the threads used for locating the stop along the shaft.
3 . The pushrod of claim 1 , the shaft including a thumb rest.
4 . The pushrod of claim 1 , the shaft made of a molded material.
5 . The push rod of claim 1 , the prefilled syringe including a barrel with a flange, the stop abutting the flange when the prescribed dosage has been injected.
6 . A hand-held syringe assembly comprising:
a prefilled syringe containing a known amount of a medical fluid and having a cross-sectional area; and,
a pushrod configured for use with the prefilled syringe and including:
a shaft having a scale corresponding to the volume of the prefilled syringe; and,
a stop configured for location along the shaft;
the stop located using the scale in correspondence with a prescribed dosage injected from the prefilled syringe.
7 . The assembly of claim 6 , the shaft and the stop including corresponding threads, the threads used for locating the stop along the shaft.
8 . The assembly of claim 6 , the shaft including a thumb rest.
9 . The assembly of claim 6 , the shaft made of a molded material.
10 . The assembly of claim 6 , the prefilled syringe including a barrel with a flange, the stop abutting the flange when the prescribed dosage has been injected.
11 . A method of injecting a medical fluid from a prefilled syringe containing a known amount and having a cross-sectional area, comprising:
coupling a calibrated pushrod to the prefilled syringe;
setting a stop on the pushrod to a prescribed dosage; and,
administering the dosage through injection.