bild

Blood pressure monitors. Automated (left) and manual (right) sphygmomanometers. These devices are used to measure a patient's blood pressure. A cuff (grey, centre left, and blue, lower right) is placed around the patient's arm. The automated device self-inflates the cuff, while the cuff of the manual device must be inflated with a hand- pump (lower right). The cuff stops the flow of blood in the arm. As the cuff is gradually deflated, a blood pressure reading is taken. The automated device calculates the blood pressure and displays it digitally, whereas a doctor must listen with a stethoscope while using the manual device and read the values from a gauge. (KEYSTONE/SCIENCE PHOTO LIBRARY/GUSTOIMAGES)