The present disclosure is directed to apparatuses, systems and methods for measuring time-varying radar cross section (RCS) of an artery of a patient, which may be used to determine blood pressure of a patient. In some embodiments, an apparatus is provided which comprises a radio-frequency (RF) transceiver for generating RF waves, and at least one sensor configured for positioning on or adjacent the skin of a patient, and at least one of transmitting the RF waves into tissue of the patient and receiving RF wave reflections from at least one artery located within the tissue. The apparatus may further comprise a processor having computer instructions operating thereon configured to cause the processor to determine an RF arterial pulse waveform based on the received RF wave reflections. The time-varying radar cross section (RCS) comprises the RF arterial pulse waveform. This may be in turn correlated to blood pressure of the patient.
