GB978073A - Automatically operating sphygmomanometer - Google Patents

Abstract

978,073. Sphygmomanometers. SIEMENS-REINIGER-WERKE A.G. April 30, 1963 [May 5, 1962 (2)], No. 17034/63. Heading A5K. An automatically operating sphygmomanometer having means for increasing the pressure in a cuff above systolic pressure, after determination of the diastolic pressure, has control means for exhausting the cuff if no diastolic reading has been obtained and / or further control means for exhausting the cuff if no systolic pressure is recorded. Functioning of the equipment is controlled by a unit 11, initially switched on by a control button 12. This closes a switch 18 to energise a motor 19 which drives a compressor 20 and so, through a pressure accumulator 21, inflates a cuff 2 on the patient's arm 1. A microphone 3, receiving pulse sounds from the artery, passes its output through amplifiers 4, 6 to a pulse generator 8 which controls the circuit 11. The cuff pressure rises gradually until a pulse is detected at the diastolic pressure, whereupon a valve 13 is closed to record this pressure on a gauge 28. The pressure then continues to rise to a point above systolic, where the pump is switched off and the pressure is allowed to leak off slowly through a valve 35. When the pulse is subsequently detected, at systolic pressure, a further value 14 is closed to record the pressure on a second gauge 29. Both gauges may be connected to remote reading instruments. If the pressure rises above a predetermined point without a diastolic pressure having been recorded, a pressure-sensitive valve 24 releases a contact 26 to open a rapid discharge valve 17, which exhausts the conduit 23 to atmosphere. During normal use, however, this is overridden by a parallel switch 15 which is closed when the valve 13 is closed. A similar pressureresponsive valve 25, operating in the reverse direction, opens its contact to release the rapid discharge valve 17 if the pressure, during the decreasing portion of the cycle, falls below a predetermined minimum without a pulse having being detected at the systolic pressure. Again, under normal working conditions, it is overridden by a parallel switch 16 when the systolic pressure is recorded. Specification 792,875 is referred to.