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US3769964A Expired / Lapsed US ⏱️ 0.0 years remaining

System and method for accurately measuring arterial blood pressure

Assignee: Rieke LLC
•
Filing: 1970-08-28
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Granted: 1973-11-06
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Expires: 1990-08-28
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Abstract

Abstract The system includes a sensor with a liquid filled bladder inside of a human body finger clamping device. A transducer connected to the clamping device translates the liquid pressure into an electrical signal. The pressure is adjustable externally and the resulting electrical signal is displayed on an oscilloscope to give an indication of the pressure applied by the liquid to a finger clamped in the finger clamping device. Blood pressure pulses sensed by the sensor produce an alternating current portion of the electrical signal and this is displayed on a chart recorder to give an indication of the pulse pressures. To determine blood pressure, a finger is inserted into the clamp and external pressure is applied to the finger. The external pressure is adjusted to the lowest pressure at which the pulse pressure indications are at a maximum value. The electrical signal will then have a maximum (peak) voltage and a minimum voltage displayed on the oscilloscope. True systolic pressure is represented by the maximum peak voltage and true diastolic pressure is represented by the minimum peak voltage. The device is built to have a minimum of compliance, so that the natural expansion and contraction of the finger arteries is at a minimum. This prevents any stiffness of the artery walls from affecting the blood pressure reading. The difference between the true systolic pressure and a systolic pressure reading taken conventionally by collapsing an artery, is a measure of the stiffness of the artery.

Inventors

  • 👤 R Smith

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 04:46
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/021; A61B5/022; A61B5/02233; A61B5/02241

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 144 words
A method for obtaining two values of pressures which values can be added to give a resultant value very near the true systolic blood pressure comprising a mounting to a portion of an animal body a device which can apply with low compliance an adjustable external pressure to the portion of the animal body and which will indicate both an external pressure applied and a peak positive pulse pressure of the body against the device and b adjusting the external pressure applied to the portion of the body until the peak positive pulse pressure is at a maximum and the external pressure applied is at the lowest value at which the maximum pulse pressure is obtained, at which point the value of the peak positive pulse pressure added to the external pressure will give the resultant value very near the true systolic blood pressure.
Claim 2
Independent Claim 144 words
A method for obtaining two values of pressures which values can be added to give a resultant value very near the true systolic blood pressure comprising a mounting to a portion of an animal body a device which can apply with low compliance an adjustable external pressure to the portion of the animal body and which will indicate both an external pressure applied and a peak positive pulse pressure of the body against the device and b adjusting the external pressure applied to the portion of the body until the peak positive pulse pressure is at a maximum and the external pressure applied is at the lowest value at which the maximum pulse pressure is obtained, at which point the value of the peak positive pulse pressure added to the external pressure will give the resultant value very near the true systolic blood pressure.
Claim 3
Independent Claim 147 words
A method for obtaining two values of pressures which values can be added to give a value very near the true systolic blood pressure comprising: a mounting to a portion of an animal body a device which can apply with low compliance an adjustable external pressure to the portion of the animal body and which will indicate both an external pressure applied and a peak positive pulse pressure of the body against the device and b adjusting the external pressure applied to the portion of the body to the highest pressure below the lowest external pressure at which the pulse pressure is a maximum and which highest pressure has a pulse pressure less than at a slightly lower pressure, at which point the value of the peak positive pulse pressure added to the external pressure will give a resultant value very near the true systolic blood pressure.
Claim 4
Independent Claim 147 words
A method for obtaining two values of pressures which values can be added to give a value very near the true systolic blood pressure comprising: a mounting to a portion of an animal body a device which can apply with low compliance an adjustable external pressure to the portion of the animal body and which will indicate both an external pressure applied and a peak positive pulse pressure of the body against the device and b adjusting the external pressure applied to the portion of the body to the highest pressure below the lowest external pressure at which the pulse pressure is a maximum and which highest pressure has a pulse pressure less than at a slightly lower pressure, at which point the value of the peak positive pulse pressure added to the external pressure will give a resultant value very near the true systolic blood pressure.
Claim 5
Independent Claim 109 words
An apparatus for measuring actual blood pressure comprising: (a) a display means (b) a transducer for producing electrical signals representative of pressure variations, (c) means for transmitting signals from said transducer to said display means, (d) a liquid-filled sensor adapted for association with an animal body part, (e) a pump (f) means operatively connecting said transducer and said liquid-filled sensor, (g) a reservoir having a chamber containing liquid and a barrier, (h) a first conduit means for connecting said chamber above said barrier with said pumP, and (i) a second conduit means for connecting said sensor with said chamber below said barrier and which has continuously adjustable valve means.
Claim 6
Independent Claim 109 words
An apparatus for measuring actual blood pressure comprising: (a) a display means (b) a transducer for producing electrical signals representative of pressure variations, (c) means for transmitting signals from said transducer to said display means, (d) a liquid-filled sensor adapted for association with an animal body part, (e) a pump (f) means operatively connecting said transducer and said liquid-filled sensor, (g) a reservoir having a chamber containing liquid and a barrier, (h) a first conduit means for connecting said chamber above said barrier with said pumP, and (i) a second conduit means for connecting said sensor with said chamber below said barrier and which has continuously adjustable valve means.

References Cited (Backward Citations)

US2989051A Cited
FR726777A Cited
US2845060A Cited
US3056401A Cited
US3486499A Cited
US3535067A Cited
US3517661A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-11-05 1977-05-07 1977-11-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-11-05 1981-05-07 1981-11-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-11-05 1985-05-07 1985-11-06 $7700.00 Window Closed / Lapsed

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