Methods and apparatus to generate liquid ambulatory oxygen from an oxygen concentrator

An ambulatory liquid oxygen system where liquid oxygen is formed from gaseous oxygen obtained from an oxygen concentrator comprising:

• (a) an oxygen concentrator which separates oxygen gas from the air line;
• (b) a first output line from said oxygen concentrator for delivering oxygen gas from said concentrator;
• (c) a first valve placed in said first output line to control the output flow of oxygen;
• (d) a condenser in cooperation with a cryocooler for providing cooling for said condenser;
• (e) a second output line in communication between the first valve and the condenser for delivering the oxygen gas from the concentrator output to the condenser for cooling to form liquid oxygen;
• (f) a storage dewar for storing liquid oxygen liquefied by the condenser;
• (g) a third output line in communication between said condenser and storage dewar for delivering liquid oxygen from the condenser to the storage dewar;
• (h) a heater for heating liquid oxygen in said dewar;
• (i) an oxygen sensor to measure the oxygen concentration of flow from said concentrator;
• (j) a liquid level sensor in said dewar;
• (k) a temperature sensor in said dewar;
• (l) a pressure sensor in communication with said dewar;
• and
• (m) a controller for receiving output from the oxygen sensor, liquid level sensor, temperature sensor and pressure sensor, and for controlling the flow of input gaseous oxygen to the condenser and for controlling liquefaction and transfer from the storage dewar in accordance with the sensed conditions.

A method for controlling an ambulatory oxygen generator and oxygen liquefier having an oxygen concentrator, a condenser, a storage dewar and a controller comprising the following steps:

• (a) generating a gaseous supply of oxygen using the oxygen concentrator for supplying oxygen to a patient;
• (b) splitting off a portion of the gaseous supply to be liquefied;
• (c) cooling said split-off supply of oxygen using the condenser to transform the oxygen from gaseous phase to liquid phase;
• (d) storing the liquid oxygen in the storage dewar;
• (e) sensing a concentration of oxygen being supplied by the oxygen concentrator, the level of liquid oxygen in said dewar and the temperature and pressure in said dewar;
• and
• (f) the controller calculating conditions and controlling the operation of the above system to allow for liquefaction and operative transfer of liquid oxygen to a portable dewar.

A method for controlling a home ambulatory liquid oxygen system comprised of an oxygen generator, a controller having a microprocessor, a condenser, a cryocooler and a storage dewar, where all or only a portion of the oxygen flow is utilized for liquefaction, comprising:

• (a) providing the microprocessor with a database and control functions;
• (b) sensing the parameters relating to the concentration and supply of gaseous oxygen, the level of liquid oxygen in the dewar, and the pressure of the condenser;
• (c) providing the microprocessor with these sensed parameters and having the microprocessor calculate optimal conditions;
• (d) controlling servomechanisms to regulate the system so that optimal conditions are realized as a function of said calculations.

A controller for a home ambulatory liquid oxygen system having a computer, an oxygen concentrator, condenser, and storage dewar comprising:

• (a) means for sensing the oxygen pressure of flow out of the concentrator;
• (b) means for sensing the oxygen concentration of flow out of the concentrator;
• (c) means for sensing the liquid level in the dewar;
• (d) means for sensing flow parameters at the condenser;
• (e) means for sensing the temperature at the dewar;
• (f) means for controlling input of gaseous oxygen to the condenser;
• (g) means for initiating and controlling the output of liquid oxygen from the storage dewar;
• (h) a programmable control means coupled to each means for sensing, said programmable control means to be used for storing at least one required input/output control schedule, for processing the inputted signals and for actuating one or more control means.

A system for liquefying oxygen utilizing an oxygen concentrator, condenser, cryocooler and storage dewar comprising:

• (a) a first flow control means for channeling off gaseous fluid flow from an oxygen concentrator;
• (b) a second flow control means for advancing said gaseous fluid to a condenser;
• (c) means for cooling said condenser to change the phase of said oxygen flow from gas to liquid;
• (d) a conduit for transferring the liquid oxygen from the condenser to a storage dewar;
• (e) a third flow control means for advancing the flow of liquid oxygen out of the storage dewar;
• (f) a controller for sensing the oxygen concentration of flow into the condenser, for sensing the liquid level in the storage dewar, and for controlling said first, second, and third flow control means;
• (g) programmable control means in said controller coupled to each of said flow control means, for storing flow delivery and liquefaction parameters for use by the controller in optimizing liquefaction of oxygen.

A home liquefaction system including an oxygen concentrator, controller with a programmable control means, condenser, cryocooler and storage dewar comprising:

• (a) an oxygen concentrator which separates oxygen gas from the air;
• (b) a first flow line from said oxygen concentrator for delivering oxygen gas from said concentrator;
• (c) a first valve placed in said first flow line to control the output flow of oxygen;
• (d) a condenser in cooperation with a cryocooler for providing cooling for said condenser;
• (e) a second flow line in communication between the first valve and the condenser for delivering the oxygen gas from the concentrator output to the condenser for cooling to form liquid oxygen;
• (f) a storage dewar for storing liquid oxygen liquefied by the condenser;
• (g) a third flow line in communication between said condenser and storage dewar for delivering liquid oxygen from the condenser to the storage dewar;
• (h) a heater for heating liquid oxygen in said dewar;
• (i) an oxygen sensor to measure the oxygen concentration of flow from said concentrator;
• (j) a liquid level sensor in said dewar;
• (k) a temperature sensor in said dewar;
• (l) a pressure sensor for sensing pressure in said dewar;
• (m) a second valve for regulating flow of liquid oxygen from said dewar;
• (n) a controller for receiving output from the oxygen sensor, liquid level sensor, temperature sensor and pressure sensor, and having means for storing at least one parameter from the Optimum Liquefaction Schedule, for controlling the flow of input gaseous oxygen to the condenser, and for optimizing liquefaction and transfer from the storage dewar in accordance with the sensed conditions.

An oxygen liquefaction system utilizing a concentrator to increase the oxygen concentration of an oxygen enriched product gas comprising:

• (a) a first output line for transporting said product gas from said concentrator;
• (b) a first valve for selectively withdrawing all or a portion of said product gas from said conduit to be liquefied;
• (c) flow rate sensor independent of said first valve for sensing the rate of withdrawal of the product gas from said conduit to be liquefied and for communicating the sensed rate of withdrawal of said product gas to a modem;
• (d) an oxygen sensor for sensing the oxygen concentration in said oxygen enriched product gas selectively withdrawn for liquefaction and for communicating the sensed oxygen concentration in said product gas to a first modem;
• (e) a condenser for receiving the product gas withdrawn from said first flow control means;
• (f) a second output line from said first flow control means oxygen concentrator for delivering oxygen gas from said concentrator for a first use;
• (g) a second flow rate sensor in said second output line;
• (h) a second oxygen sensor in said second output line;
• (i) a cryocooler for providing cooling for said condenser;
• (j) a storage dewar for storing liquid oxygen liquefied by the condenser;
• (k) a third output line in communication between said condenser and storage dewar for delivering liquid oxygen from the condenser to the storage dewar;
• (l) a heater for heating liquid oxygen in said dewar;
• (m) a liquid level sensor for sensing the level in said dewar;
• (n) a temperature sensor for sensing the temperature in said dewar;
• (o) a pressure sensor for sensing the pressure in said dewar;
• (p) a second modem for receiving quantitative signals communicated from said flow rate sensing means and said oxygen sensing means and for transmitting said signals to a remote controller;
• and
• (q) a remote controller in telephonic communication with said first and second modems for receiving transmitted signals from said modems and having means for displaying the liquefaction parameters in the liquefaction process.

An ambulatory liquid oxygen system where liquid oxygen is formed from gaseous oxygen obtained from an oxygen concentrator comprising:

• (a) an oxygen concentrator which separates oxygen gas from the air;
• (b) a first output means from said oxygen concentrator for delivering oxygen gas from said concentrator;
• (c) a first valve placed in said first output means to control the output flow of oxygen;
• (d) a condenser in cooperation with a cryocooler for providing cooling for said condenser;
• (e) a second output line in communication between the first valve and the condenser for delivering the oxygen gas from the concentrator output to the condenser for cooling to form liquid oxygen;
• (f) a storage dewar for storing liquid oxygen liquefied by the condenser;
• (g) a third output line in communication between said condenser and storage dewar for delivering liquid oxygen from the condenser to the storage dewar;
• (h) a heater for heating liquid oxygen in said dewar;
• (i) an oxygen sensor to measure the oxygen concentration of flow from said concentrator;
• (j) a liquid level sensor in said dewar;
• (k) a temperature sensor in said dewar;
• (l) a pressure sensor in communication with said dewar;
• (m) a controller for receiving output from the oxygen sensor, liquid level sensor, temperature sensor and pressure sensor, and for controlling the flow of input gaseous oxygen to the condenser and for optimizing liquefaction and transfer from the storage dewar in accordance with the sensed conditions.

An ambulatory home oxygen concentrator liquefaction system comprising:

• (a) an oxygen concentrator which can isolate oxygen gas from the air;
• (b) a first output means from the concentrator to channel the oxygen which is isolated;
• (c) a second means to split off all or a portion of the gaseous oxygen from the output means of said concentrator for liquefaction;
• (d) a condenser which can cause gaseous oxygen to change phase into liquid oxygen;
• (e) means to channel the oxygen stream from said output means to a condenser;
• (f) means to liquefy said oxygen stream in said condenser using a cryocooler;
• (g) means to collect the condensed liquid oxygen using a dewar;
• (h) wherein said dewar includes a heater which can be used to effectuate the transfer of liquid oxygen from the dewar for storing a quantity of liquid oxygen from which smaller quantities can be transferred for moveable oxygen treatment.

A system for liquefying oxygen utilizing an oxygen concentrator, condenser, cryocooler and storage dewar comprising:

• (a) a first flow control means for channeling off gaseous fluid flow from an oxygen concentrator;
• (b) a second flow control means for advancing said gaseous fluid to a condenser;
• (c) means for cooling said condenser to change the phase of said oxygen flow from gas to liquid;
• (d) a conduit for transferring the liquid oxygen from the condenser to a storage dewar;
• (e) a third flow control means for advancing the flow of liquid oxygen out of the storage dewar;
• (f) a controller for sensing the oxygen concentration of flow into the condenser, for sensing the liquid level in the storage dewar, and for controlling said first, second, and third flow control means;
• (g) programmable control means in said controller coupled to each of said flow control means, for storing flow delivery and liquefaction parameters for use by the controller in optimizing liquefaction of oxygen.