Patent ID: 11865255
Assignee: INVENT MEDICAL CORPORATION
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A ventilator system comprising:
an air inlet connected to a first gas line;
an oxygen inlet connected to a second gas line;
a mixing chamber connected to both the first gas line and the second gas line;
an air pump and an air flow sensor both connected to the first gas line downstream of the air inlet and upstream of the mixing chamber;
an oxygen control valve and an oxygen flow sensor both connected to the second gas line upstream of the mixing chamber and downstream of the oxygen inlet;
a mixed gas pressure sensor connected to a third gas line downstream of the mixing chamber and upstream of a patient interface;
a mixing chamber oxygen sensor connected to the mixing chamber; and
a controller operably connected to the air pump and the oxygen control valve, and further configured to receive measurement signals from the air flow sensor, the oxygen flow sensor, the mixed gas pressure sensor and the mixing chamber oxygen sensor, and to implement a cascaded feedback loop that commands a flow target of a mixture of oxygen to air to achieve a target pressure, wherein the cascaded feedback loop comprises an outer, pressure feedback loop and dual inner feedback loops, comprising an oxygen flow control feedback loop and an air flow control feedback loop, and wherein the controller is further configured to:
obtain a target mixed gas pressure and a target mixed gas oxygen content;
determine, via the mixed gas pressure sensor and the mixing chamber oxygen sensor, current mixed gas pressure and current mixed gas oxygen content;
based on the current mixed gas pressure and current mixed gas oxygen content, determine a target air flow and a target oxygen flow that collectively achieve the target mixed gas pressure and the target mixed gas oxygen content;
determine, via the air flow sensor and the oxygen flow sensor, current air flow and current oxygen flow; and
based on the current air flow and the current oxygen flow, control the air pump and the oxygen control valve to obtain the target air flow and the target oxygen flow.