A non-invasive blood (or compartment) pressure measurement device comprises a hand-held housing configured to fit over, or couple to, an existing ultrasound probe. At least one force sensor in or on the housing generates a signal representing the amount of force applied by the probe as a user manipulates the housing. Electronic circuitry converts the force signal into an estimate of pressure when the display shows that a particular vessel or compartment has been occluded by the force of the probe. Apparatus may be provided to grip the handle portion of the probe, with at least one force sensor is supported on or in a component disposed between the apparatus and the housing. The component may be a thin-walled tube, and a plurality of strain gages, each forming a Wheatstone bridge load cell, may be disposed circumferentially around the component. The electrically circuitry is further operative to sum the signals from the plurality of strain gages to reject non-axial moments.