Patent ID: 8210169
Filing Date: 2012-07-03
Classification: A61M

Abstract:
1. A delivery apparatus for pressurized medical liquids comprising: a primary reservoir and a primary pressurizer that pressurizes medical liquid in the primary reservoir to a driving pressure; a secondary reservoir having an inlet connected to receive pressurized liquid from the primary reservoir via a controllable intermediate valve, and a secondary pressurizer that supplies a maintaining pressure to the received pressurized liquid to maintain the pressurized liquid at substantially the delivered pressure, and an outlet for discharge of the received medical liquid via a controllable dosing valve adapted to communicate with a patient to supply said medical liquid to the patient; a pressure measuring unit that measures the pressure in the secondary reservoir; a control unit that controls the intermediate valve and that controls the dosing valve to open the dosing valve to permit a controlled discharged of said received medical liquid from said outlet to the patient; said control unit monitoring operation of the intermediate valve and the dosing valve dependent on measured pressure values from the pressure measuring unit and generating a status signal dependent on predetermined rules for measured pressure changes compared with calculated pressure changes; and said control unit being configured to automatically determine, from said measured pressure values, when refilling of said secondary reservoir is needed and to thereupon open said intermediate valve to refill said the secondary reservoir, but to always maintain said intermediate valve closed when said dosing valve is open in order to prevent an uncontrolled discharge of said medical liquid to the patient via the open dosing valve; thereby, improving the safety of the delivery apparatus.