US4984577A
Expired / Lapsed
US
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Oscillometric non-invasive method for measuring blood pressure and apparatus for automated oscillometric blood pressure measuring
Assignee: Koninklijke Philips NV
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Filing: 1989-03-20
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Granted: 1991-01-15
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Expires: 2009-03-20
Abstract
Abstract A method and an apparatus for automatic oscillometric blood pressure measuring determines a sequence of peak amplitudes. Two points p e1 , p e2 are evaluated on an envelope (10) of said peak sequence, said points p e1 , p e2 are the base for determining blood pressure values such as mean, diastolic and systolic pressures.
Inventors
- 👤 Michael Frankenreiter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:40
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/02; A61B5/021; A61B5/022; A61B5/02108; A61B5/02116; A61B5/02225
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
213 words
An oscillometric non-invasive method for measuring blood pressure, comprising the steps of: (a) applying a blood pressure cuff about a subject's limb containing an artery; (b) inflating said cuff to a cuff pressure above the systolic blood pressure of said artery, therby occluding said artery; (c) reducing said cuff pressure step by step, thereby permitting an increasing flow through the progressively less occluded artery; (d) monitoring arterial counterpressure oscillations at each cuff pressure reducing step; (e) converting said counterpressure oscillations to voltage signals; (f) processing said voltage signals into a sequence of peak amplitudes enveloped by an envelope; (g) evaluating at least two points p e1 and p e2 on said envelope, the first point p e1 disposed within an area of a decreasing branch of said envelope, said area corresponding to situations wherein the contact between said cuff and said limb is sufficiently strong for obtaining correct peak amplitudes, the second point p e2 disposed on an increasing branch of said envelope; (h) determining at least two cuff pressure values, said pressure values including values p 1 and p 2 corresponding respectively to said points p e1 and p e2 ; and (i) determining mean, systolic, and diastolic pressures using said at least cuff pressure values p 1 and p 2 .
Claim 2
Dependent Claim
213 words
An oscillometric non-invasive method for measuring blood pressure, comprising the steps of: (a) applying a blood pressure cuff about a subject's limb containing an artery; (b) inflating said cuff to a cuff pressure above the systolic blood pressure of said artery, therby occluding said artery; (c) reducing said cuff pressure step by step, thereby permitting an increasing flow through the progressively less occluded artery; (d) monitoring arterial counterpressure oscillations at each cuff pressure reducing step; (e) converting said counterpressure oscillations to voltage signals; (f) processing said voltage signals into a sequence of peak amplitudes enveloped by an envelope; (g) evaluating at least two points p e1 and p e2 on said envelope, the first point p e1 disposed within an area of a decreasing branch of said envelope, said area corresponding to situations wherein the contact between said cuff and said limb is sufficiently strong for obtaining correct peak amplitudes, the second point p e2 disposed on an increasing branch of said envelope; (h) determining at least two cuff pressure values, said pressure values including values p 1 and p 2 corresponding respectively to said points p e1 and p e2 ; and (i) determining mean, systolic, and diastolic pressures using said at least cuff pressure values p 1 and p 2 .
Claim 3
Dependent Claim
28 words
A method as recited in claim 1 wherein step (g) further comprises evaluating said two points p e1 and p e2 at the same level of said envelope.
Claim 4
Dependent Claim
41 words
A method as recited in claim 2 wherein step (g) further comprises evaluating said two points p e1 and p e2 on said envelope (10) within the range of 0.65 to 0.85 of the maximum of said sequence of peak amplitudes.
Claim 5
Dependent Claim
35 words
A method as recited in claim 2 wherein step (g) further comprises evaluating said two points p e1 and p e2 on said envelope at 3/4 of the maximum of said sequence of peak amplitudes.
Claim 6
Dependent Claim
39 words
A method as recited in claim 2 wherein step (i) further comprises determining said mean pressure by approximating said envelope between p e1 and p e2 to a triangle according to equation 1, mean pressure=p.sub.1 +1/3(p.sub.2 -p.sub.1) Eq. 1
Claim 7
Dependent Claim
36 words
A method as recited in claim 1 wherein step (i) further comprises determining said diastolic and systolic pressures according to equations 2 and 3, systolic pressure=p.sub.2 +1/3(p.sub.2 -p.sub.1) Eq. 2 diastolic pressure=p.sub.1 -1/6(p.sub.2 -p.sub.1) Eq. 3
Claim 8
Independent Claim
205 words
An apparatus for automatic oscillometric blood pressure measuring, comprising: an inflatable and deflatable cuff; controlling means for controlling cuff pressures, so as to inflate said cuff to a maximum cuff pressure and deflate said cuff in predetermined cuff pressure reducing steps; monitoring means for monitoring arterial counterpressure oscillations at each of said cuff pressure reducing steps; pressure transducer means coupled to said cuff for converting said counterpressure oscillations to voltage signals; processing means for processing said voltage signals into a sequence of peak amplitudes, said sequence being enveloped by an envelope; evaluating means for evaluating at least two points p e1 and p e2 on said envelope, the first point p e1 disposed within an area of a decreasing branch of said envelope, said area corresponding to situations wherein the contact between said cuff and a limb of said subject is sufficiently strong for obtaining correct peak amplitudes, the second point p e2 disposed on an increasing branch of said envelope; and determining means for determining cuff pressure values p 1 and p 2 corresponding to said points p e1 and p e2 , said determining means further determining mean, systolic, and diastolic pressures using said cuff pressure values p 1 and p 2 .
Claim 9
Independent Claim
205 words
An apparatus for automatic oscillometric blood pressure measuring, comprising: an inflatable and deflatable cuff; controlling means for controlling cuff pressures, so as to inflate said cuff to a maximum cuff pressure and deflate said cuff in predetermined cuff pressure reducing steps; monitoring means for monitoring arterial counterpressure oscillations at each of said cuff pressure reducing steps; pressure transducer means coupled to said cuff for converting said counterpressure oscillations to voltage signals; processing means for processing said voltage signals into a sequence of peak amplitudes, said sequence being enveloped by an envelope; evaluating means for evaluating at least two points p e1 and p e2 on said envelope, the first point p e1 disposed within an area of a decreasing branch of said envelope, said area corresponding to situations wherein the contact between said cuff and a limb of said subject is sufficiently strong for obtaining correct peak amplitudes, the second point p e2 disposed on an increasing branch of said envelope; and determining means for determining cuff pressure values p 1 and p 2 corresponding to said points p e1 and p e2 , said determining means further determining mean, systolic, and diastolic pressures using said cuff pressure values p 1 and p 2 .
Claim 10
Dependent Claim
29 words
An apparatus as recited in claim 7 wherein said evaluating means evaluate said first and second points p e1 and p e2 at the same level of said envelope.
Claim 11
Dependent Claim
40 words
An apparatus as recited in claim 8 wherein said evaluating means evaluate said two points p e1 and p e2 on said envelope (10) within the range of 0.65 to 0.85 of the maximum of said sequence of peak amplitudes.
Claim 12
Dependent Claim
35 words
An apparatus as recited in claim 8 wherein said evaluating means evaluate said two points p e1 and p e2 on said envelope (10) at 3/4 of the maximum of said sequence of peak amplitudes.
Claim 13
Dependent Claim
25 words
An apparatus as recited in claim 8 wherein said determining means determine mean pressure value according to equation 1: mean pressure=p.sub.1 +1/3(p.sub.2 -p.sub.1) Eq. 1
Claim 14
Dependent Claim
34 words
An apparatus as recited in claim 8 wherein said determining means determine systolic and diastolic pressures according to equations 2 and 3: systolic pressure=p.sub.2 +1/3(p.sub.2 -p.sub.1) Eq. 2 diastolic pressure=p.sub.1 -1/6(p.sub.2 -p.sub.1) Eq. 3
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-01-14 | 1994-07-16 | 1995-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-14 | 1998-07-16 | 1999-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-14 | 2002-07-16 | 2003-01-15 | $7700.00 | Window Closed / Lapsed |