Apparatus and process for determining systolic pressure
First Claim
1. An apparatus for determining systolic pressure, comprising:
- a pressure cuff attachable to a living test subject adjacent a blood vessel;
means for changing pressure in the cuff and thereby applying pressure to the subject;
means communicating with said cuff for measuring a quantity proportional to a time-dependent fluctuating component representative of the pulsatile pressure within the blood vessel, said means having a frequency response of at least about five times the pulse rate of the subject whereby said quantity is proportional to the amplitude of said pulsatile pressure;
means for determining the maximum value attained by said quantity as the applied pressure is changed;
means for storing a representation of said maximum value;
means for determining when said quantity is substantially equal to about one-half of said maximum value for an applied pressure greater than the pressure applied when said maximum value results; and
means for reading out applied pressure corresponding to said quantity being substantially equal to about one-half of said maximum value, said read-out pressure corresponding to the systolic pressure of said subject.
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Accused Products
Abstract
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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Citations
15 Claims
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1. An apparatus for determining systolic pressure, comprising:
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a pressure cuff attachable to a living test subject adjacent a blood vessel; means for changing pressure in the cuff and thereby applying pressure to the subject; means communicating with said cuff for measuring a quantity proportional to a time-dependent fluctuating component representative of the pulsatile pressure within the blood vessel, said means having a frequency response of at least about five times the pulse rate of the subject whereby said quantity is proportional to the amplitude of said pulsatile pressure; means for determining the maximum value attained by said quantity as the applied pressure is changed; means for storing a representation of said maximum value; means for determining when said quantity is substantially equal to about one-half of said maximum value for an applied pressure greater than the pressure applied when said maximum value results; and means for reading out applied pressure corresponding to said quantity being substantially equal to about one-half of said maximum value, said read-out pressure corresponding to the systolic pressure of said subject. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A process for determining systolic pressure, comprising:
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changing the pressure in a pressure cuff attached to a living test subject adjacent a blood vessel so as to apply different pressure to the subject; measuring at said cuff with a measuring device having a frequency response of at least about five times the pulse rate of the subject at said cuff, a quantity proportional to a time-dependent fluctuating component representative of the pulsatile pressure within the blood vessel, said quantity being proportional to the amplitude of said pulsatile pressure; determining the maximum value attained by said quantity as the applied pressure is changed; storing a representation of said maximum value; determining when said quantity is substantially equal to about one-half of said maximum value for an applied pressure greater than the pressure applied when said maximum value results; and reading out the applied pressure corresponding to said quantity being substantially equal to about one-half of said maximum value, said read-out pressure corresponding to the systolic pressure of said subject. - View Dependent Claims (10, 11, 12, 13)
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14. An automatic blood pressure monitoring system for measuring and monitoring systolic blood pressure of a person comprising:
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transducer means in pressure-communication with said person for converting said person'"'"'s blood pressure to a varying electrical analog signal; pump means for applying a controllably variable pressure to said transducer means; said transducer means including cuff means for applying said controllably variable pressure to a blood vessel of said subject; converter means for receiving said electrical analog signal and converting said electrical analog signal to a digital signal; digital processing means adapted to receive said digital signal for determining (1) maximum blood pressure of said person and a first value of said controllably variable pressure corresponding thereto, (2) one-half said maximum blood pressure when occurring at a second value of said controllably variable pressure higher than said first value, and (3) the magnitude of said second value; and means for providing read-out of said second value as systolic blood pressure.
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15. A method for automatically measuring and monitoring systolic blood pressure of a person including the steps of:
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A. converting said person'"'"'s blood pressure to a varying electrical analog signal; B. applying a controllably variable pressure to said person in a manner which affects said electrical analog signal; C. converting said affected electrical analog signal to a digital signal; D. digitally processing said signal to provide (1) maximum blood pressure of said person and a first value of said controllably variable pressure corresponding thereto;
(2) one-half said maximum blood pressure when occurring at a second value of said controllably variable pressure higher than said first value; and
(3) the magnitude of said second value; andE. providing read-out of said second value.
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Specification