Siemens Elema Ab

G&ouml;ran Rydin

Johan Bennarsten

Christer Str&ouml;m

In a method and arrangement for evaluating effective flow resistance of a patient breathing circuit connected to a mechanical breathing assist device, a flow controller is operable to temporarily introduce an occlusion to the gas flow within the breathing circuit at a time after the end of an inspiration phase of a breathing cycle provided by the breathing assist device. A sensor unit has a flow sensor for measuring gas flow within the circuit and a pressure sensor for measuring gas pressures within the circuit. An evaluating unit receives measurements from the sensor unit, to determine for a measured gas flow a value of a pressure drop within the breathing circuit after the introduction of the occlusion, and establishes a relationship between the calculated pressure drop and the measured gas flow, such as based on the known Blasius formula.

Method and arrangement for evaluating effective flow resistance of patient breathing circuit

A valve for regulating a gas flow has a valve seat and a valve body, movable against the valve seat. The valve achieves high accuracy, a wide dynamic range and high operating reliability by causing the valve body substantially only to move axially against the valve seat and by using a stepper motor to actuate the valve body's axial movement against the valve seat with a non-linearly threaded engagement between the stepper motor and valve body so that the valve body performs continuous, non-linear, axial movement against the valve seat.

Growing community of inventors

Täby, Sweden

Göran Rydin

Growing community of inventors

Täby, Sweden

G&ouml;ran Rydin

Göran Rydin