JPWO2019122406A5

JPWO2019122406A5 -

Info

Publication number: JPWO2019122406A5
Application number: JP2020534347A
Authority: JP
Publication date: 2022-05-23
Anticipated expiration: 2038-12-21

Claims

A device for continuously assessing the mean arterial pressure of a patient,
-Means to receive mean arterial pressure measurement data,
-Means that receive the plethysmography signal and continuously calculate the parameter Vp from the plethysmography signal,
-Calculation method to calculate the coefficient Calib from the following a and b for each actual measurement of mean arterial pressure,
Mean arterial pressure value measured at time t0, and
b. The value Vp0, associated with the parameter Vp, measured at time t0 in the patient.
-It is a calculation method that calculates the estimated value (MAPest) of the average arterial pressure of the patient at time t after t0 by the formula MAPest = Calib × Vpt, in which Vpt is obtained at time t. It is the value of the parameter measurement, and the parameter Vp is the overlapping wave height, the calculation means, and
-Means to present the calculated mean arterial pressure at each time t,
Including devices.

The device of claim 1, wherein the parameter value Vpt is obtained by photopretismography taken from a finger or earlobe.

The device according to claim 1 or 2, wherein the value of the perfusion index, the value of the reciprocal of the perfusion index, or the value of the logarithm of the reciprocal of the perfusion index + 1 is also calculated.

The device according to any one of claims 1 to 3, wherein the value Vpt used is a value averaged from a plurality of values measured over a predetermined time.

By measuring new arterial pressure values and measuring new values for the parameter Vp, the value Calib is sometimes recalculated, especially at regular intervals, and
After that, this new value Calib will be used.
The device according to any one of claims 1 to 4, wherein the device comprises.

It is a calculation method that calculates some values MAPest at time t after -t0 by the formula MAPest = Calib × Vpt. In the formula, Vpt is the value of the parameter measurement obtained at time t. , Parameter Vp is a plurality of parameters other than overlapping wave heights, calculation means, and
--Value MAPestfinal,
i. Different MAPest values calculated at time t
ii. One or more MAPestfinal values calculated before time t
Calculation means to calculate by statistical estimation taking into consideration
The device according to any one of claims 1 to 5, further comprising.

The device of claim 6, wherein the value MAPestfinal is calculated by Kalman filtering in a discrete context.

-Means to warn when calculated mean arterial pressure falls below a given value,
-Means to automatically activate the device to measure mean arterial pressure when the calculated mean arterial pressure falls below a given value, and
-Means to automatically administer a dose of vasopressor when the calculated or estimated mean arterial pressure falls below a given value
The device according to any one of claims 1 to 7, further comprising at least one of the above.

The device according to any one of claims 1 to 8, wherein the overlapping wave height is calculated by the following:
-Determining the foot of the pulse wave by calculating the second derivative of the plethysmography signal, the foot of the pulse wave corresponds to the maximum of this second derivative of the rising edge of the pulse wave. Determining the foot of the pulse wave,
-Next to the pulse wave foot, to determine the pulse wave peak,
-Splitting the signal into several time windows (especially windows from 20 ms to 100 ms, especially 50 ms), and
-Looking at the maximum value of each time window, corresponding to the maximum value V found in one time window, the maximum value of the next time window is smaller than this value V, the local maximum value is the pulse wave maximum To see the maximum value of each time window, corresponding to
To determine the peak of the pulse wave by
-Determining the height of overlapping waves
-Obtaining the second derivative of the signal after maximizing the pulse wave,
-After this pulse wave peak, split the signal into a given time window (between 50 ms and 300 ms, especially 150 ms),
-Finding the local maximum of the quadratic derivative of the signal in each time window to determine the area of interest in the time window where the local maximum of the quadratic derivative of this signal resides,
-Searching for the absolute minimum of the first derivative of the signal in this area of interest, where the points corresponding to the overlapping waves correspond to the points that reach the absolute minimum of the first derivative of interest. Determining the area,
-Measuring overlapping waves at this point
To determine the overlapping wave height by.

A computer-implemented method for continuously assessing a patient's mean arterial pressure based on a parameter value Vp that is continuously calculated from a plethysmography signal .
I. Calibrate Calib,
Mean arterial pressure value measured at time t0
b. The value Vp0 associated with the parameter, measured at time t0 in the patient.
Stage to calculate from,
II. At the stage of calculating the estimated value MAPest of the arterial pressure of the patient at time t after t0 by the formula MAPest = Calib × Vpt, in the formula, Vpt is the parameter measurement obtained at time t. The value and the parameter value Vpt is the overlapping wave height, including the steps, the method.

10. The method performed by a computer according to claim 10 , wherein the parameter value Vpt is obtained by photopretismography taken from a finger or earlobe.

The method performed by the computer according to claim 10 or 11 , wherein the value of the perfusion index, the value of the reciprocal of the perfusion index, or the value of the logarithm of the reciprocal of the perfusion index + 1 is also calculated.

The method performed by the computer according to any one of claims 10 to 12 , wherein the value Vpt used is a value averaged from a plurality of values measured over a predetermined time.

By measuring new arterial pressure values and measuring new values for the parameter Vp, the value Calib is sometimes recalculated, especially at regular intervals, and then this new value Calib is used. The method performed by the computer according to any one of claims 10 to 13 , characterized in that.

A computer -operated method of Exvivo for continuously assessing the patient's mean arterial pressure.
The method of any one of claims 10-14 is repeated for different parameters in order to obtain some value MAPest at time t.
b. The value MAPestfinal is
i. Different MAPest values calculated at time t
ii. A method characterized by being calculated by statistical inference taking into account one or more MAPestfinal values calculated before time t.

The computer-executed method of Exvivo according to claim 15 , wherein the value MAPestfinal is calculated by Kalman filtering in a discrete context.

The method of Exvivo performed by a computer according to any one of claims 10 to 16 , characterized in that it is performed during the patient's general anesthesia.

The implementation of the method according to any one of claims 10 to 17 , and the step of emitting a signal, particularly by emitting an image signal or an audible signal or a combination of these signals when the value MAPest falls below a predetermined threshold. Exvivo's method performed by a computer to warn the patient of hypotension.

Exvivo performed by the computer of any one of claims 10-18 , further comprising performing measures to automatically administer a dose of vasopressor when MAPest falls below a predetermined value. the method of.

The method of Exvivo performed by the computer according to any one of claims 10 to 19 , wherein the overlapping wave height is calculated by:
-Determining the foot of the pulse wave by calculating the second derivative of the plethysmography signal, the foot of the pulse wave corresponds to the maximum of this second derivative of the rising edge of the pulse wave. Determining the foot of the pulse wave,
-Next to the pulse wave foot, to determine the pulse wave peak,
-Splitting the signal into several time windows (especially windows from 20 ms to 100 ms, especially 50 ms), and
-Looking at the maximum value of each time window, corresponding to the maximum value V found in one time window, the maximum value of the next time window is smaller than this value V, the local maximum value is the pulse wave maximum To see the maximum value of each time window, corresponding to
To determine the peak of the pulse wave by
-Determining the height of overlapping waves
-Obtaining the second derivative of the signal after maximizing the pulse wave,
-After this pulse wave peak, split the signal into a given time window (between 50 ms and 300 ms, especially 150 ms),
-Finding the local maximum of the second derivative of a signal in each time window to determine the area of interest in the time window where the local maximum of the second derivative of this signal resides,
-Searching for the absolute minimum of the first derivative of the signal in this area of interest, where the points corresponding to the overlapping waves correspond to the points that reach the absolute minimum of the first derivative of interest. Determining the area,
-Measuring overlapping waves at this point
To determine the overlapping wave height by .

A computer product / program for containing program code instructions recorded on a computer-readable medium, when the program is executed on a computer, the steps of the method according to any one of claims 10 to 20 are performed. Computer products / programs.

A computer-readable recording medium on which a computer program containing program code instructions for carrying out the steps of the method according to any one of claims 10 to 20 is recorded.