Methods and apparatus for selectively occluding the lumen of a needle

A method for transferring fluid to or from a patient using a parenteral transfer device, the device including a housing defining a fluid flow path, a needle having a lumen in fluid communication with the fluid flow path and being configured for insertion into the patient, and an occlusion mechanism operable to selectively control fluid flow to or from a patient through the needle lumen and the fluid flow path, the occlusion mechanism includes an occlusion member disposed about at least a portion of the needle and configured to selectively obstruct the lumen of the needle during insertion into the patient, the method comprising:

• disposing the occlusion member in a first position relative to the needle prior to insertion into the patient to place the occlusion mechanism in a first configuration in which the lumen of the needle is obstructed to prevent at least one of tissue, bodily fluid, and contaminants from entering the lumen;
• inserting the needle into the patient, the occlusion mechanism being in the first configuration as the needle is inserted into the patient;
• after the needle has been inserted into the patient, rotating the occlusion member from the first position to a second position to place the occlusion mechanism in a second configuration in which the lumen of the needle is unobstructed and the occlusion member is disposed outside of the fluid flow path;
• and
• transferring a volume of a fluid substantially free of tissue and contaminants between the patient and a fluid reservoir in fluid communication with the fluid flow path when the occlusion mechanism is in the second configuration.