Patent ID: 7458962

Claim:
A method for injecting medication, the method comprising: providing a medical device that includes a displaceable housing and a barrel, wherein the housing is connected to a needle that defines a sharpened tip; piercing a patient with the needle; injecting fluid into the patient; retracting the needle so that the sharpened tip is shielded against inadvertent contact; releasably locking the needle in the retracted position; re-extending the needle to the extended position by displacing the housing relative to the barrel while substantially preventing rotation of the housing relative to the barrel such that the needle moves from the extended position to the retracted position and back to the extended position again substantially without rotation of the housing relative to the barrel; piercing the patient a subsequent time with the needle; retracting the needle a subsequent time so that the sharpened tip is shielded against inadvertent contact; and permanently locking the needle in a retracted position to prevent further axial displacement of the needle after the needle is retracted the subsequent time.