Systems, apparatuses and methods for determining blood pressure

An apparatus for measuring time-varying radar cross section (RCS) of an artery of a patient, comprising:

• a radio-frequency (RF) transceiver for generating RF waves;
• a first sensor and a second sensor configured for positioning on or adjacent to skin of the patient;
• wherein the first sensor is configured for sensing RF wave reflections corresponding to a first arterial-pulse-arrival-time (PAT) at a first arterial tree location, and the second sensor is configured for sensing signals corresponding to a second PAT at a second arterial tree location, which is located on a different arterial tree than the first arterial tree location;
• and
• a processor having computer instructions operating thereon configured to cause the processor to:
• receive a first signal representative of the RF wave reflections detected by the first sensor;
• choose a first artery of the first arterial tree for observation located at a first depth;
• filter the received first signal to isolate reflections from the first artery at the first depth;
• determine the first PAT at the first arterial tree location based on the filtered first signal;
• receive a second signal representative of the RF wave reflections detected by the second sensor;
• choose a second artery of the second arterial tree for observation located at a second depth, which is different than the first depth;
• filter the received second signal to isolate reflections from the second artery at the second depth;
• determine, based on the filtered second signal, the second PAT at the second arterial tree location on the different arterial tree than the first arterial tree location;
• and
• determine the difference between the first PAT at the first arterial tree location and the second PAT at the second arterial tree location so as to determine an arterial-pulse-travel-time (PTT), wherein the arterial PTT comprises a travel time for the pulse to travel from the ventricle to the first arterial tree location or the second arterial tree location.