A Microprocessor-Based Tilting Bed for Blood Pressure Control

An automated system has been developed for unattended regulation of arterial pressure in patients with intracranial anneurysm or hemmorhage. A microprocessor continously samples arterial pressure from a superficial temporal artery. When pressure exceeds desired bounds, the patient's bed is tilted in a direction to restore the desired pressure. In determining the extent and direction of tilt, a programmable algorithm in the processor considers such factors as short and long-term averages of systolic and diastolic pressures, cardiac rate, present bed angle, time since last angle change, and others. Monitored values and system status are easily viewed on a color graphics display. Each control event, along with physiological data, are logged in a flexible diskette. This system has been used successfully to stabilize blood pressure fluccuations in patients with intracranial hemmorhage. Such patients frequently exhibit unstable pressure due to loss of normal physiological control. Tilting reduces both the magnitude and duration of these fluccuations.