Various medical procedures require that one or more medical fluids be injected into a patient. For example, medical imaging procedures oftentimes involve the injection of contrast media into a patient, possibly along with saline and/or other fluids. Other medical procedures involve injecting one or more fluids into a patient for therapeutic purposes. Power injectors may be used for these types of applications.
A power injector generally includes what is commonly referred to as a powerhead. One or more syringes may be mounted to the powerhead in various manners (e.g., detachably; rear-loading; front-loading; side-loading). Each syringe typically includes what may be characterized as a syringe plunger, piston, or the like. Each such syringe plunger is designed to interface with (e.g., contact and/or temporarily interconnect with) an appropriate syringe plunger driver that is incorporated into the powerhead, such that operation of the syringe plunger driver axially advances the associated syringe plunger inside and relative to a barrel of the syringe. One typical syringe plunger driver is in the form of a ram that is mounted on a threaded lead or drive screw. Rotation of the drive screw in one rotational direction advances the associated ram in one axial direction, while rotation of the drive screw in the opposite rotational direction advances the associated ram in the opposite axial direction.
The syringes used by the power injector may be pre-filled and/or bulk fluid containers may be used to fill the syringes of the power injector. Where bulk fluid containers are utilized, the syringes may be filled by retracting the plunger of the syringe while the bulk fluid container is fluidly interconnected with the syringe. This may be desirable since bulk fluids (e.g., multiple doses of fluids supplied in a single bulk container) may be less expensive to use than individually filled, one time use syringes.
One example of a medical procedure involving the injection of fluids is an imaging procedure such as a radiological procedure used to image the internal structure of a patient (e.g., computed tomography or CT imaging; magnetic resonance imaging or MRI; SPECT imaging; PET imaging; X-ray imaging; angiographic imaging; optical imaging; ultrasound imaging). To aid in the imaging, contrast may be injected into the patient. Typically, contrast is supplied in individual syringes of a predetermined volume.