Patent ID: 7553304

Claim:
A method for injecting liquid under pressure to a patient, the method comprising: providing liquid under pressure to a patient through a length of tubing, the tubing including a pressurizing system, a first occlusion system and a regulation system located upstream from the first occlusion system, the first occlusion system and the regulation system defining an intermediate segment having an intermediate pressure, the tubing also including a segment downstream of the first occlusion system having a downstream pressure; wherein due to the action of the pressurizing system, there is a positive pressure during the injection in the intermediate segment and the downstream segment; and when injection to the patient is desired to be stopped, closing the regulation system and the first occlusion system in such a manner that the first occlusion system closes when the pressure in the intermediate segment falls below an opening pressure of the first occlusion system, said opening pressure of the first occlusion system being greater than a venous pressure of the patient which corresponds to a maximum pressure of the downstream segment in the absence of injection, so that part of said positive pressure is maintained in the intermediate segment, while the pressure in the downstream segment is not maintained at such positive pressure, at least until the patient is disconnected from the tubing, in order to direct leakage of fluid from the first occlusion system to the patient.