Patent ID: 8870785

Claim:
A method for detection of respiration of a patient comprising the following steps: emitting using a two-channel Doppler radar sensor an electromagnetic signal towards the patient; receiving a reflected electromagnetic signal reflected from the patient using the two-channel Doppler radar sensor; converting using the two-channel Doppler radar sensor the reflected electromagnetic signal to a first signal; phase-shifting using the two-channel Doppler radar sensor the reflected electromagnetic signal and converting the phase-shifted reflected electromagnetic signal to a second signal; determining using a calculating device a first vector by taking time derivatives of the first signal and the second signal, for a common first point in time; determining using the calculating device a second vector by taking the time derivatives of the first signal and the second signal, for a common second point in time; normalizing using the calculating device the first and second vectors; calculating using the calculating device the scalar product of the normalized first vector and the normalized second vector as an indicator value for a change from expiration to inspiration of the patient or vice versa; and controlling a display to display a respiration value based on the indicated changed from expiration to inspiration of the patient or vice versa.