Continuous non-invasive blood pressure monitoring method and apparatus
First Claim
Patent Images
1. A method for monitoring blood pressure, the method comprising:
- a) detecting a first pulse signal at a first location on a subject and detecting a second pulse signal at a second location on the subject;
b) measuring a reference blood pressure P0 and a corresponding time difference T0 between the first and second pulse signals;
c) from the reference blood pressure and corresponding time difference, determining a first plurality of constant parameters in a multi-parameter equation relating blood pressure and the time-difference;
d) monitoring the subject'"'"'s blood pressure by periodically measuring a time difference T between the first and second pulse signals; and
, e) computing an estimated blood pressure, P, from the time difference, T, using the multi-parameter equation and the first plurality of constant parameters.
5 Assignments
0 Petitions
Accused Products
Abstract
A non-invasive apparatus and method for monitoring the blood pressure of a subject detects a pulse signal at both a first and second location on the subject'"'"'s body The elapsed time between the arrival of corresponding points of the pulse signal at the first and second locations is determined. Blood pressure is related to the elapsed time by relationships such as:
P=a+b ln(T),
where a and b are constants dependent upon the nature of the subject and the signal detecting devices. The system can be calibrated by measuring a single pair of reference blood pressure and corresponding elapsed time
80 Citations
50 Claims
-
1. A method for monitoring blood pressure, the method comprising:
-
a) detecting a first pulse signal at a first location on a subject and detecting a second pulse signal at a second location on the subject;
b) measuring a reference blood pressure P0 and a corresponding time difference T0 between the first and second pulse signals;
c) from the reference blood pressure and corresponding time difference, determining a first plurality of constant parameters in a multi-parameter equation relating blood pressure and the time-difference;
d) monitoring the subject'"'"'s blood pressure by periodically measuring a time difference T between the first and second pulse signals; and
,e) computing an estimated blood pressure, P, from the time difference, T, using the multi-parameter equation and the first plurality of constant parameters. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 50)
-
-
16. A method for estimating a blood pressure of a subject, the method comprising:
-
a) detecting a first pulse signal at a first location;
b) detecting a second pulse signal at a second location;
c) determining an elapsed time, T, between the arrival of corresponding points of the first and second pulse signals; and
,d) computing an estimated blood pressure, P, from the elapsed time by performing the calculation;
P=a+b ln(T) where a and b are constants. - View Dependent Claims (17, 18, 19, 20, 21)
-
-
22. A method for estimating the blood pressure, P, of a subject, the method comprising:
-
a) detecting a first pulse signal at a first location on the subject;
b) detecting a second pulse signal at a second location on the subject;
c) performing a calibration by measuring the subject'"'"'s blood pressure P0 and measuring a corresponding elapsed time, T0, between the arrival of corresponding points of the first and second pulse signals;
d) subsequently monitoring the subject'"'"'s blood pressure by determining an elapsed time, T, between the arrival of corresponding points of the first and second pulse signals; and
,e) calculating an estimated blood pressure, P, based on the value;
where c1 and c2 are constants. - View Dependent Claims (23, 24, 25, 26, 27, 28)
-
-
29. A method for estimating the blood pressure, P, of a subject, the method comprising:
-
a) detecting a first pulse signal at a first location on the subject;
b) detecting a second pulse signal at a second location on the subject;
c) performing a calibration by measuring the subject'"'"'s blood pressure P0 and measuring a corresponding elapsed time, T0, between the arrival of corresponding points of the first and second pulse signals;
d) subsequently monitoring the subject'"'"'s blood pressure by determining an elapsed time, T, between the arrival of corresponding points of the first and second pulse signals; and
,f) calculating and estimated blood pressure, P, substantially according to the equation;
P=P0+(c3T0+c4)ln(T/T0) where c3 and c4 are constants. - View Dependent Claims (30, 31, 32, 33, 34)
-
-
35. A method for estimating the blood pressure, P, of a subject, the method comprising:
-
a) detecting a first pulse signal at a first location on the subject;
b) detecting a first pulse signal at a second location on the subject;
c) measuring a reference blood pressure P0 and measuring a corresponding time difference, T, between corresponding points of the first an second pulse signals;
d) from the reference blood pressure and corresponding time difference, determining a plurality of constant parameters in a multi-parameter equation relating blood pressure arid the time-difference by;
i) determining a first parameter of the plurality of parameters as a predetermined function of the corresponding time difference; and
,ii) determining a second parameter of the plurality of parameters as a predetermined function of the reference blood pressure and the time difference; and
,d) subsequently monitoring the subject'"'"'s blood pressure by determining a time difference, T, between corresponding points of the first and second pulse signals and computing an estimated blood pressure from the time difference T using the multi-parameter equation and the first and second parameters.
-
-
36. Apparatus for estimating a blood pressure of a subject, the apparatus comprising;
-
a) a computer processor;
b) an input for receiving a first signal corresponding to a pulse signal detected at first location;
c) an input for receiving a second signal corresponding to the pulse signal detected at a second location;
d) a program store containing computer software comprising instructions which, when run on the processor cause the processor to measure an elapsed time, T, between corresponding points on the first and second signals and compute an estimated blood pressure, P, from the elapsed time by performing the calculation;
P=a+b ln(T) where a and b are constants. - View Dependent Claims (37, 38, 39, 40)
-
-
41. Apparatus for estimating a blood pressure of a subject, the apparatus comprising;
-
a) signal detection means for detecting first and second pulse signals;
b) correlation means for determining an elapsed time, T, between the first and second pulse signals;
c) computation means for computing an estimated blood pressure, P, from the elapsed time according to a non-linear function which is generally decreasing and concave upward in a manner specified by two or more settable parameters; and
,d) calibration means for receiving a reference blood pressure and associating the reference blood pressure with an elapsed time determined by the correlation means; and
,e) means responsive to the calibration means for establishing values for the two or more settable parameters from the reference blood pressure and elapsed time. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49)
-
Specification