American Optical Corporation

Henry Ferdinand Rugge

William T Link

William D Jansen

A conventional pressure cuff is attached to a living test subject. First means are provided for changing pressure in the cuff and thereby applying pressure to the subject. Second means communicating with the cuff are provided for measuring a quantity proportional to a time-dependent fluctuating component representative of pulsatile pressure within a blood vessel of the subject, the second means having a frequency response adequate to accurately follow the subject's blood pressure waveform, for instance at least about five times the subject's pulse rate, whereby the fluctuating quantity is proportional to amplitude of pulsatile pressure. The maximum value of the fluctuating quantity is determined as applied cuff pressure is changed. Third means are provided for determining when the fluctuating quantity is about a particular fraction of its maximum value for applied cuff pressure greater than the pressure applied when the maximum value occurred or resulted, the particular fraction corresponding with that fraction of the total length of the blood vessel within the cuff which extends from its upstream (proximal) end to the point at which the cuff applies maximum pressure to the blood vessel wall between diastolic and systolic pressure and typically being about one-half. Systolic pressure, which is equal to applied cuff pressure when the fluctuating quantity is about equal to the particular fraction of the maximum value of the fluctuating quantity, is then read out on suitable instrumentation.

Apparatus and process for determining systolic pressure

A conventional pressure cuff is attached to a living test subject. First means are provided for changing pressure in the cuff and thereby applying pressure to the subject. Second means communicating with the cuff are provided for measuring a quantity proportional to a time-dependent fluctuating component representative of pulsatile pressure within a blood vessel of the subject, the second means having a frequency response of at least about five times the subject's pulse rate, whereby the fluctuating quantity is proportional to amplitude of pulsatile pressure. The maximum value of the fluctuating quantity is determined as applied cuff pressure is changed. Third means are provided for determining when the fluctuating quantity is about one-half its maximum value for applied cuff pressure greater than the pressure applied when the maximum value occurred or resulted. Systolic pressure, which is equal to applied cuff pressure when the fluctuating quantity is about equal to one-half the maximum value of the fluctuating quantity, is then read out on suitable instrumentation.

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Berkeley, CA, United States of America

Henry Ferdinand Rugge