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Abstract

An angiographic injector device for use in x-ray photography for delivering contrast media to a patient at controlled rates and pressures. A processor elicits injection parameters from an operator or a pre-programmed injection module, and on the basis of the injection parameters, calculates appropriate control signals for use in a closed-loop servo system to actuate the plunger of a syringe containing the contrast media. Injection parameters includes flow rate, volume, duration, pressure limit and rise-fall time of flow rate. The device also includes control circuits for inhibiting the injection device in response to a contrast media pressure limit, failure in the processor or injection control system, or upon reaching a predetermined volume of injected media. A mechanical stop member cooperates with the control circuit for blocking movement of the syringe plunger upon reaching the predetermined injected volume. Further, the device includes a self-test feature for checking the status of operational components thereof and a self-calibration feature for calibrating the servo system and position monitors. To improve reliability and to provide immunity from data corruption due to line power interruption, injection parameters are stored in battery-powered primary and secondary memories, and are compared and verified prior to an injection. To assist in coordinating an injection in synchronism with cardiac activity, the device monitors the ECG waveform of the patient's heart and injects a small bolus of contrast media at a given interval, such as the distolic interval. An interface also is provided for providing remote transfer of status and control information with the angiographic injector device.

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First Claim