Details for Patent: 6,581,592
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| Title: | Purge system for nitric oxide administration apparatus |
| Abstract: | A nitric oxide delivery system is disclosed that delivers a pulsed volume of NO containing therapeutic gas to a patient upon each inhalation of the patient. The NO delivery system includes certain functions to provide protection against the inadvertent inclusion of NO.sub.2 in the therapeutic gas administered to the patient. One of the functions is to provide a purge upon start up of the delivery system apparatus that clears the regulator and conduits of any NO.sub.2 that may have formed during the prior idle period of the system. A detector determines the start-up and may automatically carry out the purge cycle or may cause a prompt that is visual or audible to remind the user to carry out the purge cycle manually. As a further function, when the NO apparatus is terminated with respect to a patient, the system can, again, sense the termination or cessation of the therapy and automatically shut off the supply of NO containing gas at the source or provide an audible or visual prompt to remind the user to shut off the supply of the NO containing gas manually. |
| Inventor(s): | Bathe; Duncan P. L. (Madison, WI), Montgomery; Frederick J. (Sun Prairie, WI) |
| Assignee: | Datex-Ohmeda, Inc. (Madison, WI) |
| Filing Date: | Jun 21, 2000 |
| Application Number: | 09/598,584 |
| Claims: | 1. 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 (NO.sub.2) said system being connectable to a source of pressurized therapy gas containing NO, 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; control means responsive to the user input device being operated to the activation condition for automatically opening and thereafter closing said dosing valve to pass a quantity of therapy gas along said conduit to purge the conduit; 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; and an indicator 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 safely thereafter be used to administer therapeutic doses of nitric oxide to a patient. 2. A nitric oxide delivery system as defined in claim 1 wherein said sensor comprises a flow sensor. 3. A nitric oxide delivery system as defined in claim 1 wherein said sensor comprises a pressure sensor. 4. A nitric oxide delivery system as defined in claim 1 wherein said sensor senses a physical parameter of the gas in said conduit downstream of said dosing valve. 5. A nitric oxide delivery system as defined in claim 1 wherein said indicator is an audio alarm. 6. A nitric oxide delivery system as defined in claim 1 wherein said indicator is a visual display. 7. 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 (NO.sub.2), 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. 8. A nitric oxide delivery system as defined in claim 7 wherein said indicator is further defined as providing an indication prompting the user to close the source valve of the pressurized therapy gas source when the user input device is operated to the inactivation condition. 9. A nitric oxide delivery system as defined in claim 7 wherein said sensor comprises a flow sensor. 10. A nitric oxide delivery system as defined in claim 7 wherein said sensor comprises a pressure sensor. 11. A nitric oxide delivery system as defined in claim 7 wherein said sensor senses a physical parameter of the gas in said conduit downstream of said dosing valve. 12. A nitric oxide delivery system as defined in claim 7 wherein said indicator is an audio alarm. 13. A nitric oxide delivery stem as defined in claim 7 wherein said indicator is a visual display. 14. 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 (NO.sub.2), 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. 15. A nitric oxide delivery system as defined in claim 14 wherein said indicator is further defined as providing an indication prompting the user to close the source valve of the pressurized therapy gas source when the user input device is operated to the inactivation condition. 16. A nitric oxide delivery system as defined in claim 14 wherein said sensor comprises a flow sensor. 17. A nitric oxide delivery system as defined in claim 14 wherein said sensor comprises a pressure sensor. 18. A nitric oxide delivery system as defined in claim 14 wherein said sensor senses a physical parameter of the gas in said conduit downstream of said dosing valve. 19. A nitric oxide delivery system as defined in claim 14 wherein said indicator is an audio alarm. 20. A nitric oxide delivery system as defined in claim 14 wherein said indicator is a visual display. |
