System and method for ventilating lungs

A system for ventilating lungs of a subject, the system comprising:

• a control unit configured to control operation of the system;
• a machine ventilator circuit configured to assist breathing functions of the subject, the machine ventilator circuit comprising an inspiration delivery unit for delivering gas flow along an inspiration branch and an expiration circuit for discharge of an expiration gas along an expiration branch, the expiration circuit comprising an expiration valve;
• and
• a manual ventilation circuit in flow connection with the expiration branch, the manual ventilation circuit comprising:
• a manual bag, wherein a first gas flow is guided out from the manual bag to the expiration branch to assist an inspiration phase, a second gas flow is received to fill the manual bag during an expiration phase;
• and
• a first sensor, wherein the first sensor is configured to detect a flow direction inside the manual ventilation circuit and to provide a first signal to the control unit based on the detected flow direction;
• and
• wherein the machine ventilator circuit comprises a second sensor, wherein the second sensor is configured to detect the pressure inside the machine ventilation circuit and to provide a second signal to the control unit based on the pressure inside the machine ventilation circuit;
• wherein the control unit controls the inspiration delivery unit and the expiration circuit in response to the first and second signals and is configured to identify whether the inspiration phase or the expiration phase is active and to guide the expiration valve, when the expiration phase is active, to be in a close position allowing the gas flow towards the manual bag filling it until the second signal indicates to the control unit that the pressure of the manual bag achieves a predetermined pressure after which the control unit is configured to guide the expiration valve to an open position to allow extra gas flow out in order to maintain the predetermined pressure.

A method for ventilating lungs of a subject with a system comprising a control unit configured to control operation of the system;

• a machine ventilator circuit configured to assist breathing functions of the subject and comprising an inspiration delivery unit, an expiration circuit for controlling a discharge of expiration gas, wherein expiration circuit includes an expiration valve and a pressure sensor configured to detect the pressure inside the mechanical ventilation circuit;
• and a manual ventilation circuit comprising a manual bag and a flow direction sensor, the method comprising:
• increasing pressure to guide a first gas flow to assist an inspiration phase during compression of the manual bag;
• guiding, with the control unit, a second gas flow that at least partially comprises the gas flow guided to assist the inspiration phase to fill the manual bag during an expiration phase;
• detecting a flow direction inside the manual ventilation circuit with the flow direction sensor;
• providing a signal to the control unit with the flow direction sensor based on the detected flow direction to indicate the inspiration phase or the expiration phase;
• controlling, with the control unit, the inspiration delivery unit, the expiration circuit and the expiration valve of the system in response to the signal;
• and
• guiding, with the control unit, a discharge of extra gas volume based on the detected flow direction, when the expiration phase is active, such that the expiration valve is in a closed position allowing gas to flow towards the manual bag filling it at least partly with the extra gas volume if the pressure sensor has not indicated to the control unit that the pressure of the manual bag has achieved a predetermined pressure after which the expiration valve is in an open position to allow the extra gas volume out in order to maintain the predetermined pressure, wherein the extra gas volume is discharged during the expiration phase in order to reach a pressure level of an expiratory pressure,