Patent ID: 6955171
Filing Date: 2005-10-18
Classification: A61M,Y10T

Abstract:
1. A system for administering NO to a mammal through an external breathing circuit comprising: A) a tube having an outlet end fluidically connected to a respiratory system of a mammalian patient and conducting fluid to the respiratory system of the mammalian patient, and an inlet end; B) a total flow sensor which includes C) a breathing gas supply; D) a fluid connection fluidically connecting said breathing gas supply to the first inlet on the housing of said total flow sensor; E) breathing gas from said breathing gas supply being conducted to said total flow sensor at a breathing gas flow rate; F) an NO gas source; G) a proportioning orifice valve having an inlet and an outlet; H) a fluid connection fluidically connecting said NO gas source to the inlet of said proportioning orifice valve and conducting NO gas to said proportioning orifice valve; I) said proportioning orifice valve including a flow adjusting element which is movable between a first configuration permitting full flow of NO from the inlet of said proportioning orifice valve to the outlet of said proportioning orifice valve and a second configuration preventing flow of NO from the inlet of said proportioning orifice valve to the outlet of said proportioning orifice valve; J) an NO flow sensor having an inlet and an outlet; K) a fluid connection fluidically connecting the outlet of said proportioning orifice valve to the inlet of said NO flow sensor and conducting NO from the outlet of said proportioning orifice valve to the inlet of said NO flow sensor; L) a fluid connection fluidically connecting the outlet of said NO flow sensor to the second inlet of the housing of said total flow sensor; M) a signal generator in said NO flow sensor which generates a signal corresponding to the flow of NO from the outlet of said proportioning orifice valve to the second inlet of the housing of said total flow sensor; N) a valve actuator connected to the flow adjusting element of said proportioning orifice valve; O) a signal divider having an electrical input signal connection and an electrical output signal connection and a signal proportioning element electrically connecting the input signal connection of said signal divider to the output signal connection of said signal divider to adjust an output signal at the output signal connection to correspond to a signal corresponding to a fraction of the total fluid flow through the housing of said total flow sensor, the fraction being equal to or greater than zero and less than or equal to unity; P) a control element on said signal divider; Q) an electrical connection between the signal generator in said total flow sensor and the input signal connection of said signal divider whereby the signal corresponding to the total fluid flow through the housing of said total flow sensor is the input signal at the input signal connection of said signal divider; R) an error amplifier circuit having S) an electrical connection between the output signal generator of said error amplifier circuit and said valve actuator and which conducts the output signal of said error amplifier circuit to said valve actuator; and T) said valve actuator having a circuit which converts the output signal received from said error circuit amplifier circuit to a positioning signal for the flow adjusting element of said proportioning orifice valve.