blood transfusion protocol

I am on a nursing commitee and we are discussing the blood transfusion policy in our hospital. At this time our tubing for blood tansfusion is free flow, no controllers to regulate rate of flow, just the ball on tubing. The only machine I have seen for blood transfusions are the blood warmers. Does anyone have any insight on the use of IV controllers for blood transfusions?, Or know of any research articles on this particular subject, as I am on the Nurse Practice Consul, and we are basing our findings on Nurse Research.
Also, when transferring a patient from one unit to another, does an RN have to be present when blood products are hanging? Our policy is vague, but it is the practice of our hospital to always have an RN present.
thanks for any input.