This disclosure provides a personal hand-held monitor (PHHM) which comprises a signal acquisition device for acquiring signals which can be used to derive a measurement of a subject's blood pressure (BP), the signal acquisition device being integrated with a personal hand-held computing device (PHHCD). The signal acquisition device comprises a blood flow occlusion means adapted to be pressed against one side only of a body part or to have one side only of a body part pressed against it, a means for measuring the pressure applied by or to the body part, and a means for detecting the flow of blood through the body part in contact with the blood flow occlusion means. The blood flow occlusion means comprises at least part of an external surface of the PHHM and wherein the pressure is sensed by means of a flexible and essentially incompressible gel in which is immersed a pressure sensor. The pressure sensor is adapted to provide electrical signals to the processor of the PHHCD.