Purge system for nitric oxide administration apparatus

A nitric oxide delivery system for delivering a series of therapeutic doses of nitric oxide (NO) in pulse form for administration to a patient while eliminating or lessening exposure of the patient to toxic nitrogen dioxide (NO2), said system being connectable to a source of pressurized therapy gas containing NO and having a source valve that can be opened and closed, said system comprising:

• a conduit adapted to be connected at one end to the pressurized therapy gas source, the other end of said conduit discharging therapeutic gas doses for administration to a patient;
• a dosing valve in said conduit operable to repetitiously open and close to form the pulse doses of therapy gas containing NO;
• a user input device operable by a user of the system to an inactivation condition for shutting down the nitric oxide delivery system;
• control means for automatically opening and thereafter closing said dosing valve when said user input device is operated to the inactivation condition;
• a sensor for sensing whether or not a reduction in a physical parameter of the gas in said conduit occurs as a result of an opening of said dosing valve when the system is being shut down to determine whether the source valve of the pressurized therapy gas source has been closed;
• and
• an indicator responsive to said sensor sensing that a decay in a physical parameter of the gas has not occurred for providing an indication prompting the user to close the source valve of the pressurized therapy gas source when said delivery system is being shut down.

A nitric oxide delivery system for delivering a series of therapeutic doses of nitric oxide (NO) in pulse form for administration to a patient while eliminating or lessening exposure of the patient to toxic nitrogen dioxide (NO2), said system being connectable to a source of pressurized therapy gas containing NO and having a source valve that can be opened and closed, said system comprising:

• a conduit adapted to be connected at one end to the pressurized therapy gas source, the other end of said conduit discharging therapeutic gas doses for administration to a patient;
• a dosing valve in said conduit operable to repetitiously open and close to form the pulse doses of therapy gas containing NO;
• a user input device operable by a user of the system to an activation condition upon start up of the system to render the nitric oxide delivery system operable and to an inactivation condition for shutting down the nitric oxide delivery system;
• control means for automatically opening said dosing valve when said user input device is operated to the activation condition and to the inactivation condition, the opening of the dosing valve when the user input device is operated to the activation condition passing a quantity of therapy gas along said conduit to purge the conduit when the source valve is open;
• a sensor for sensing whether a physical parameter of the gas in said conduit has been altered as a result of an operation of said dosing valve when the system is started up to determine whether said valve has been automatically opened on start up to purge the conduit, said sensor sensing whether or not a reduction in a physical parameter of the gas in said conduit has occurred as a result of an opening of said valve when the system is shut down to determine whether the source valve has been closed by the user;
• and
• an indicator responsive to said sensor and providing an indication to the user, said indicator being responsive to said sensor determining that purging of the conduit has been carried out for providing an indication to the user that the system may safety thereafter be used to administer therapeutic doses of nitric oxide to a patient, said indicator being responsive to said sensor sensing that a decay in a physical parameter of the gas has not occurred for providing an indication prompting the user to close the source valve of the pressurized therapy gas source when the delivery system is being shut down.