Abstract: Radar is used to measure internal body motion. Radar reflections from the body are measured using a range of frequencies that includes a higher frequency band and a lower frequency band. In the higher frequency band, e.g. above 24 GHz, the radar signal hardly penetrates the skin, whereas it penetrates deeper into the chest in the lower frequency band e.g. below 10 GHz. Chest surface motion is estimated by means of the measurements using the higher frequency band. Effects of the estimated chest surface movement are subtracted from the measurements from the lower frequency band. The resulting response after removal is used to fit a model of a heart.

Abstract: The invention relates to a method for estimating an object motion characteristic from a radar signal. The method comprises the step of receiving radar data of an object from a multiple beam radar system. Further, the method comprises the steps of associating radar data with estimated height and/or cross-range information of object parts causing the corresponding radar data and fitting an object model with radar data being associated with a selected estimated height and/or cross-range information interval. The method also comprises the step of determining an object motion characteristic from the fitted object model.

Abstract: The invention relates to a method for estimating an object motion characteristic from a radar signal. The method comprises the step of receiving radar data of an object from a multiple beam radar system. Further, the method comprises the steps of associating radar data with estimated height and/or cross-range information of object parts causing the corresponding radar data and fitting an object model with radar data being associated with a selected estimated height and/or cross-range information interval. The method also comprises the step of determining an object motion characteristic from the fitted object model.