A method comprising: at a processor, determining an in vivo transit distance for an arterial pulse between a first arterial pulse point and a second arterial pulse point using a first distance measured to the first arterial pulse point and a second distance measured to a second arterial pulse point and at the processor, determining a transit time for an arterial pulse between the first arterial pulse point and the second arterial pulse point, based on one or more transmitted detecting and ranging wave pulses reflected from the first arterial pulse point and from one or more transmitted detecting and ranging wave pulses reflected from the second arterial pulse point.
