Neonatal oxygen consumption monitor
First Claim
1. An oxygen consumption monitor system suitable for use in measuring oxygen uptake in neonates, comprising:
- (a) a respirator for supplying a high volume, controlled flow of oxygen;
(b) a flow duct for conducting said oxygen from the respirator, said flow duct having a primary flow line and a secondary outlet communicating with said primary flow line;
(c) a respiration duct having one end adapted for communication with the lungs of said neonate;
(d) an expiration duct for receiving expired gas from the neonate;
(e) an inlet and outlet check valve combination coupled jointly on one side of said valves to said respiration duct and on the other side respectively to said secondary outlet and said expiration duct, said valve combination coupling providing an intermittent inspiration passageway from said primary flow line, through said inlet check valve and into the respiration duct and lung region, and an exiration passageway through said respiration duct and outlet check valve to said expiration duct, each of said inlet and outlet valves being biased in a closed position, the valve combination coupling having minimal deadspace; and
(f) means coupled to said primary flow line and said expiration duct for comparing the oxygen concentration of inspired gas versus that of corresponding expired gas for a determination of the amount of oxygen consumed.
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Accused Products
Abstract
An oxygen consumption monitor system suitable for use in measuring oxygen uptake in neonates wherein the system includes a check valve system in combination with a high flow, positive-end-expiratory-pressure respirator for supplying a high volume, controlled flow of oxygen through a flow circuit which includes (1) a primary flow line for carrying most of the oxygen supply through a respirator circuit maintained at a positive pressure, and (2) a secondary outlet communicating from said primary flow line through the check valve combination to permit inspiration of oxygen from the respirator circuit and expiration to a separate chamber for measurement of oxygen consumption. Minimal deadspace is developed in the check valve combination to insure fresh oxygen supply with each inspiration by the neonate. The use of opposing oneway valves at inlet and outlet locations of the valve combination permits use of a single opening for coupling to an endotrachael tube. The reduced deadspace also enables accurate oxygen consumption measurement by cumulating the amounts of oxygen required to replenish the expired air to an oxygen concentration measured in the primary flow line.
82 Citations
12 Claims
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1. An oxygen consumption monitor system suitable for use in measuring oxygen uptake in neonates, comprising:
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(a) a respirator for supplying a high volume, controlled flow of oxygen; (b) a flow duct for conducting said oxygen from the respirator, said flow duct having a primary flow line and a secondary outlet communicating with said primary flow line; (c) a respiration duct having one end adapted for communication with the lungs of said neonate; (d) an expiration duct for receiving expired gas from the neonate; (e) an inlet and outlet check valve combination coupled jointly on one side of said valves to said respiration duct and on the other side respectively to said secondary outlet and said expiration duct, said valve combination coupling providing an intermittent inspiration passageway from said primary flow line, through said inlet check valve and into the respiration duct and lung region, and an exiration passageway through said respiration duct and outlet check valve to said expiration duct, each of said inlet and outlet valves being biased in a closed position, the valve combination coupling having minimal deadspace; and (f) means coupled to said primary flow line and said expiration duct for comparing the oxygen concentration of inspired gas versus that of corresponding expired gas for a determination of the amount of oxygen consumed. - View Dependent Claims (2, 3, 4, 5, 7, 8, 9, 10, 11)
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6. An oxygen consumption monitor as defined in chaim 1, wherein the volume of said third chamber is less than 2 cc.
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12. A method for measuring oxygen uptake in neonates ventilated by a positive-end-expiratory-pressure respiratory system, comprising the steps of:
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a. interposing a one way inlet check valve at a secondary opening to a primary oxygen flow line, thereby permitting flow therethrough from said primary flow line; b. coupling said inlet valve to a low volume chamber having a first outlet means to a respiratory duct communicating with the lungs of said neonate and a second outlet means coupled to an expiration duct for conducting expired air to an oxygen comparison sensing system for effecting replenishment of said expired air, said second outlet means including one way valve means for precluding flow therethrough except during expiration by the neonate, said inlet check valve being biased in the closed position during such expiration; c. analyzing respective samples of inspired and expired air within the system for oxygen concentration; d. replenishing depleted oxygen to the expired air based on the difference of oxygen concentration detected with respect to the inspired sample; and e. returning the replenished air to the respirator to maintain a constant positive-pressure system.
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Specification