Respiratory assist device and method of providing respiratory assistance

The device as claimed in any one of the preceding claims, further including one or more of:

• a circuit pressure monitor and associated alarm;
• an Oxygen analyser;
• a Carbon Dioxide analyser;
• a safety valve adapted to open the circuit to atmosphere upon sensing that the fresh gas supply is exhausted;
• and a device adapted to servo control the fresh gas flow delivery.

A method of providing respiratory assistance adapted for a transport environment, the method including performing the following steps in a gas circuit having at least a breathable gas mixture of fresh gas and Carbon Dioxide depleted gas travelling therethrough:

• entraining fresh gas into the circuit, thereby increasing the velocity of the gas mixture in the circuit;
• delivering the gas mixture, downstream of the fresh gas entrainment, from the circuit to a patient's airways and returning the patient's exhaled gas to the circuit;
• and
• absorbing Carbon Dioxide from the circuit downstream of the patient's airways and upstream of the entrainment.

A respiratory assist device, the device comprising the following components in a gas circuit having at least a breathable gas mixture of fresh gas and Carbon Dioxide depleted gas travelling therethrough:

• a venturi for receiving fresh gas from a fresh gas source and entraining the fresh gas into the gas mixture in the circuit, thereby increasing the velocity of the gas mixture in the circuit;
• an airway gas delivery assembly downstream of the venturi for delivering the gas mixture from the circuit to a patient's airways and returning the patient's exhaled gas to the circuit;
• and
• a Carbon Dioxide absorber downstream of the mask, and upstream of the venturi, for removing Carbon Dioxide from the breathable gas mixture in the circuit.

A method of providing respiratory assistance in a gas circuit having at least a breathable gas mixture of fresh gas and Carbon Dioxide depleted gas travelling therethrough, the method comprising the following steps:

• entraining fresh gas into the circuit to increase the velocity of the gas mixture in the circuit;
• delivering the gas mixture, downstream of the fresh gas entrainment, from the circuit to a patient's airways and returning the patient's exhaled gas to the circuit;
• and
• absorbing Carbon Dioxide from the circuit downstream of the patient's airways and upstream of the entrainment.

A respiratory assist device comprising:

• a gas circuit having at least a breathable gas mixture of fresh gas and Carbon Dioxide depleted gas travelling therethrough;
• a venturi for receiving fresh gas from a fresh gas source and entraining the fresh gas into a gas mixture in the circuit, thereby increasing the velocity of the gas mixture in the circuit;
• an airway gas delivery assembly downstream of the venturi for delivering the gas mixture from the circuit to a patient's airways and returning the patient's exhaled gas to the circuit;
• and
• a Carbon Dioxide absorber downstream of the mask, and upstream of the venturi, for removing Carbon Dioxide from the breathable gas mixture in the circuit.

A method of providing respiratory assistance in a gas circuit, the method comprising the following steps:

• entraining fresh gas into the circuit to increase the velocity of a breathable gas mixture in the circuit, the gas mixture having the fresh gas and also Carbon Dioxide depleted gas travelling therein;
• delivering the gas mixture, downstream of the fresh gas entrainment, from the circuit to a patient's airways and returning the patient's exhaled gas to the circuit;
• and
• absorbing Carbon Dioxide from the circuit downstream of the patient's airways and upstream of the entrainment.