Ultrasonic method and apparatus for respiration monitoring

An ultrasound apparatus for non-invasively monitoring respiration of a patient using ultrasonic waves directed onto a body of the patient, the apparatus comprising:

• at least one ultrasound transducer configured to be placed on the patient's body and configured to emit ultrasound, wherein the ultrasound transducer is coupled to the patient's body via a contact layer, and wherein the ultrasound transducer is angled such that an ultrasound beam angle formed by the ultrasound emitted from the ultrasound transducer is non-perpendicular to a motion vector of an internal structure inside the patient's body;
• and
• processing circuitry for controlling the ultrasound transducer and processing ultrasound signals received from the ultrasound transducer, wherein the processing circuitry is configured to:
• control the ultrasound transducer to emit the ultrasound which comprises a series of ultrasound pulses into a sample volume of the internal structure,
• detect ultrasound echo signals of the series of ultrasound pulses via the ultrasound transducer,
• measure phase values of the ultrasound echo signals received from the internal structure at multiple points inside the sample volume along a depth range, the phase values being measured for at least first and second echo signals, the at least first and second echo signals being received at different times,
• detect motion of the internal structure based on a difference between the measured phase values of the at least first and the second echo signals at the multiple points inside the sample volume along the depth range, and calculate an average phase value of the calculated difference in the measured phase values of the at least first and second echo signals, and
• associate the motion of the internal structure with movement caused by respiration to monitor or determine one or more respiration parameters of the patient.