O2 concentrator with sieve bed bypass and control method thereof

Inventors

Westfall, Tom • Brambilla, Enrico

Assignees

Breathe Technologies Inc

Abstract

An oxygen concentrator includes one or more adsorbent sieve beds operable to remove nitrogen from air to produce concentrated oxygen gas at respective outlets thereof, a product tank fluidly coupled to the respective outlets of the sieve bed(s), a compressor operable to pressurize ambient air, one or more sieve bed flow paths from the compressor to respective inlets of the sieve bed(s), a bypass flow path from the compressor to the product tank that bypasses the sieve bed(s), and a valve unit operable to selectively allow flow of pressurized ambient air from the compressor along the one or more sieve bed flow paths and along the bypass flow path in response to a control signal. The valve unit may be controlled in response to a command issued by a ventilator based on a calculated or estimated total flow of gas and entrained air or % FiO2 of a patient.

Core Innovation

The invention relates to estimating a fraction of inspired oxygen %FiO2 of a patient receiving ventilatory support from a ventilator by using a patient ventilation interface having one or more nozzles that expel a flow of gas and one or more apertures for the entrainment of additional ambient air. The interface is connected to the ventilator, and the method stores, for each of a plurality of measurements of a flow rate expelled by the one or more nozzles, corresponding measurements of %FiO2 in correspondence with measurements of pressure in the patient ventilation interface.

During use, a flow rate of gas expelled by the one or more nozzles is measured and a pressure in the patient ventilation interface is measured. The %FiO2 is then estimated by comparing the measured pressure to the stored plurality of measurements of %FiO2 for the measured flow rate. The same estimation concept is supported by a controller and data storage that perform the comparison between measured pressure and stored %FiO2 values.

In a ventilation system context, the estimated %FiO2 is used to control an oxygen concentrator connected to the ventilator. A non-transitory program storage medium and controller operations store the plurality of measurements and execute operations to estimate %FiO2, and then transmit signals to the oxygen concentrator based on the estimated %FiO2. The oxygen concentrator includes a controller that selectively permits pressurized ambient air to flow into a product tank, operates a valve unit to maintain a preset oxygen concentration in the product tank, and may operate a valve unit to permit pressurized ambient air to bypass one or more sieve beds.

Claims Coverage

The independent claims cover three inventive features: storing pressure/%FiO2 correspondences for measured nozzle flow rates, estimating %FiO2 from measured interface pressure and measured nozzle flow rate, and controlling an oxygen concentrator based on the estimated %FiO2.

Across the independent claims, the core claim coverage is directed to estimating patient %FiO2 by storing and using correspondences between nozzle-expelled gas flow, interface pressure, and %FiO2, and in system or program contexts using the estimated %FiO2 to control an oxygen concentrator. The concentrator control features include transmitting a signal based on the estimated %FiO2, operating a valve unit to maintain a preset oxygen concentration in a product tank, and permitting pressurized ambient air to bypass one or more sieve beds.

Stated Advantages

Documented Applications