System, ventilator and method for real-time determination of a local strain of a lung during artificial ventilation

A system for real-time determination of a local strain of a lung during artificial ventilation using a ventilator, wherein the system comprises a device for electrical impedance tomography (EIT), which device is configured to capture an electrical impedance distribution along at least one two-dimensional section through a human thorax, and further comprises a device for assigning the captured electrical impedance distribution, dividing the captured electrical impedance distribution at different times during the artificial ventilation into a multiplicity of EIT pixels and assigning a specific value of the electrical impedance at a specific time to a specific EIT pixel;

• wherein the system further comprises a device for determining a local strain value which device is configured to determine at least one end-inspiratory electrical impedance (ZINSP) of the specific EIT pixel and an end-expiratory electrical impedance (ZEXSP) of the specific EIT pixel, to form a local tidal volume reference value (ΔZ) of the specific EIT pixel as a difference between the end-inspiratory electrical impedance (ZINSP) and the end-expiratory electrical impedance (ZEXSP), in particular by subtracting the end-expiratory electrical impedance (ZEXSP) from the end-inspiratory electrical impedance (ZINSP), and
• to form a preliminary strain value (STRVORL) of the specific EIT pixel by dividing the local tidal volume reference value (ΔZ) by the end-expiratory electrical impedance (ZEXSP);
• and wherein the device for determining a local strain value is further configured to form a relative strain value (STRRELATIV) of the specific EIT pixel by normalizing the preliminary strain value (STRVORL) to a reference strain value (STRREF).