KR102045434B1 - Method and apparatus for predicting prognosis in patients with traumatic brain injury using pressure variability index - Google Patents

Abstract

Disclosed is a method for determining prognosis of brain injury patients using variability index. Prognosis method of the brain injury patient using the variability indicator according to an embodiment of the present invention comprises the steps of obtaining an intracranial pressure (ICP) signal and arterial blood pressure (ABP) signal of the brain injury patient; Calculating a pressure variability index (PVx) indicating a correlation of variability between the ICP signal and the ABP signal during a predetermined time window; And determining the prognosis of the brain injury patient based on the calculated volatility index.

Description

METHOD AND APPARATUS FOR PREDICTING PROGNOSIS IN PATIENTS WITH TRAUMATIC BRAIN INJURY USING PRESSURE VARIABILITY INDEX}

The present invention relates to a method and apparatus for determining the prognosis of a brain injury patient using variability indicators based on intracranial pressure (ICP) signals and arterial blood pressure (ABP) signals.

ICP signal is an important indicator that reflects the condition of patients with traumatic brain injury and is one of the biosignal indicators that are frequently measured and analyzed around the world. In previous studies, ICP> 20 mmHg has been considered a threshold that requires clinical intervention, but fixed ICP thresholds do not reflect the normal range of ICPs that may vary from patient to patient to predict prognosis. There is a definite limitation.

The most widely validated variable proposed to address this problem is the pressure reactivity index (PRx). Conceptually, PRx reflects the degree of change in ABP and ICP due to changes in the cerebrovascular system. However, the major weakness of PRx is that it is difficult to predict the prognosis of brain injury patients, mainly when high intracranial compliance (ie, when ICP <20 mmHg).

Therefore, by developing the volatility indicator using ABP and ICP signals, the volume of pressure delivery is closely related to the pressure fluctuation, so that the prognosis of brain injury patients can be judged regardless of the state of compliance in the brain. There is a need for a method and apparatus.

Related prior arts include Korean Patent No. 10-1746159 (name of the invention: Apparatus and method for detecting peaks of intracranial pressure waveform using characteristic points of arterial blood pressure waveform, publication date: October 31, 2016).

The present invention is to provide a method and apparatus for determining the prognosis of brain injury patients using variability indicators based on intracranial pressure (ICP) signal and arterial blood pressure (ABP) signal.

The problem to be solved by the present invention is not limited to the problem (s) mentioned above, and other object (s) not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the method for determining the prognosis of the brain injury patient using the variability indicator provided by the present invention obtains the intracranial pressure (ICP) signal and arterial blood pressure (ABP) signal of the brain injury patient Doing; Calculating a pressure variability index (PVx) indicating a correlation of variability between the ICP signal and the ABP signal during a predetermined time window; And determining the prognosis of the brain injury patient based on the calculated volatility index.

Preferably, the method further includes deriving a trend line of each of the ICP signal and the ABP signal using a predetermined first time period average value of the ICP signal and the ABP signal. The calculating of the volatility index may include calculating the volatility index using trend lines of the ICP signal and the ABP signal, respectively.

Preferably, the calculating of the volatility index comprises: calculating a standard deviation (SD) of each of the ICP signal and the ABP signal according to a second predetermined time period during the time interval; And calculating a volatility index indicating a correlation between the standard deviation of each of the ICP signal and the ABP signal.

Preferably, the calculating of the standard deviation may be calculated for each of the ICP signal and the ABP signal from a time before the time interval from the time of calculating the standard deviation according to the second time period.

Preferably, the variability index may be based on a Pearson correlation coefficient of variability between the ICP signal and the ABP signal.

Preferably, the prognosis of the brain injury patient may be further determined based on whether the brain injury patient is within a predetermined time after the brain injury occurs.

In addition, in order to achieve the above object, the apparatus for determining the prognosis of the brain injury patient using the variability indicator provided by the present invention includes a data collector for acquiring intracranial pressure (ICP) signal and arterial blood pressure (ABP) signal of the brain injury patient; A calculator for calculating a volatility index indicating a correlation between the volatility between the ICP signal and the ABP signal during a predetermined time interval; And based on the calculated volatility indicator, the determination unit for determining the prognosis of the brain injury patient.

Preferably, the calculator further derives a trend line of each of the ICP signal and the ABP signal by using a predetermined first time period average value for the ICP signal and the ABP signal, and calculates the trend line of each of the ICP signal and the ABP signal. The volatility index may be calculated using trend lines of each signal.

Preferably, the calculator calculates a standard deviation of each of the ICP signal and the ABP signal according to a second predetermined time period during the time interval, and calculates a correlation between the standard deviation of each of the ICP signal and the ABP signal. The volatility indicators indicated can be calculated.

Preferably, when the calculation unit calculates the standard deviation, it may be calculated for each of the ICP signal and the ABP signal from a time before the time interval from the time of calculating the standard deviation according to the second time period.

Preferably, the variability index may be based on a Pearson correlation coefficient of variability between the ICP signal and the ABP signal.

Preferably, the determination unit may further determine based on whether or not within a predetermined time after the brain injury of the brain injury patient.

The present invention utilizes variability indicators based on intracranial pressure (ICP) and arterial blood pressure (ABP) signals to more accurately determine the prognosis of patients with brain injury even when high intracranial compliance (ie, when ICP <20 mmHg). There is an effect that can be done.

In addition, the present invention has the effect of evaluating the condition of the patient in real time for a brain injury patient having a large state variability and frequent secondary damage, and may provide a means for selecting and evaluating a therapy.

1 is a flowchart illustrating a prognosis determination method of a brain injury patient using the volatility indicator (PVx) according to an embodiment of the present invention.
2 is a flowchart illustrating a prognosis determination method of a brain injury patient using a volatility index (PVx) according to another embodiment of the present invention.
3 is a view illustrating a prognosis determination apparatus of a brain injury patient using the volatility indicator (PVx) according to an embodiment of the present invention.
4 is a diagram illustrating a calculation process of a volatility index PVx according to an embodiment of the present invention.
FIG. 5 is a pseudo code illustrating a process of calculating a correlation of variability of an ICP signal and an ABP signal according to an embodiment of the present invention.
6 is a diagram illustrating a trend line according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating a result of calculating the variability index PVx according to an embodiment of the present invention divided into a case for a surviving patient (a) and a case for a deceased patient (b).
8 and 9 are diagrams for comparing the variability index (PVx) and the pressure-reactivity index (PRx) of the prior art according to an embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart illustrating a prognosis determination method of a brain injury patient using the volatility indicator (PVx) according to an embodiment of the present invention.

In step S110, the prognostic determination device acquires an intracranial pressure (ICP) signal and an arterial blood pressure (ABP) signal of a brain injury patient.

Here, intracranial pressure (ICP) refers to the pressure of the cerebrospinal fluid that fills the lumen of the skull, it can be measured by inserting a probe to measure the pressure in the skull. In addition, arterial blood pressure (ABP) refers to blood pressure measured in an artery, and can be measured by intubating the artery and connecting it to a pressure gauge.

In this case, the prognosis determination apparatus may receive and acquire the ICP signal and the ABP signal measured in this way by wire or wirelessly. More specifically, the prognostic determination device includes a separate configuration capable of receiving wired or wireless ICP signal and ABP signal from each of the separate ICP signal monitoring device and the ABP signal monitoring device, or measuring the ICP signal and the ABP signal. Thus, the ICP signal and the ABP signal can be obtained from the configuration.

In step S120, the prognostic determination device calculates a pressure variability index (PVx) indicating a correlation of variability between the ICP signal and the ABP signal during a predetermined time window.

In this case, the prognostic determination device may calculate a correlation between the variability of the ICP signal and the variability of the ABP signal at the same time point for a certain time interval. In addition, the volatility index PVx can be calculated based on the result value indicating the correlation. On the other hand, the correlation may be calculated by a certain value may mean a relationship in which the two objects are assumed to be related to each other.

For example, the prognostic determination device calculates the variability such as standard deviation, variance, etc. on a predetermined basis with respect to the ICP signal and the ABP signal every 5 seconds for a 300 second time interval, calculates a correlation between the calculated variability, and then correlates the correlation. The relationship can be used to calculate the volatility index (PVx).

In another embodiment, the variability index PVx may be calculated based on the Pearson correlation coefficient of the variability between the ICP signal and the ABP signal.

Here, Pearson's correlation coefficient r is a coefficient used to analyze the relationship between two variables. That is, the degree of change of two variables X (variability of ICP signal) and Y (variability of ABP signal) can be calculated by dividing the degree of change of X and Y separately. At this time, if the value of X and Y are completely the same, it is 1, if it is completely different, it is 0, and if it is completely the same in the opposite direction, it has a value of -1. Pearson's correlation coefficient r may be calculated using Equation 1 below.

[Equation 1]

Where r is the Pearson correlation coefficient, n is the number of two variables x and y, and x _i and y _i are variables having an index of i.

On the other hand, referring to Figure 5, the prognostic determination device for the process of calculating the Pearson correlation coefficient (PVx) between the variability of the two signals, using the variability of the ICP signal (ICPv) and the ABP signal (BPv) The pseudo code is shown.

Finally, in step S130, the prognostic determination device determines the prognosis of the brain injury patient based on the calculated volatility index PVx.

In this case, referring to FIG. 7, a case (a) for a patient surviving after a brain injury and a case (b) for a patient who has died are shown.

In surviving patients (a), both ABP and ICP signals were stable. However, the pressure-responsiveness index (PRx) is positive, indicating that cerebral autoregulation has deteriorated. It can be seen that the minute variation of the variability of the ICP signal SD and the ABP signal is reflected in the PVx but not in the PRx.

On the other hand, in the case of the deceased patient (b), in most cases, the ICP signal was kept below 20 mmHg. However, the ICP signal suddenly increased up to 40 mmHg during recording. At this time, the volatility of ICP signal and ABP signal increased, and the increase was reflected in PVx. However, it can be seen that PRx remained negative despite sudden changes in the ABP and ICP signals.

8 and 9 show the results of comparing the volatility index PVx of the present invention with the pressure-reactivity index PRx of the prior art.

Specifically, referring to FIG. 8, the difference in distribution of PVx and PRx between the survival patient group (light gray) and the death patient group (dark gray) is shown by a box plot. Regardless of the average ICP signal, overall (A) PVx was higher in the deceased patient group, which was the same in PRx. When the average ICP signal was 20 mmHg or more (B), the difference in the value distribution of PRx was more obvious. However, the difference was reduced when the ICP was less than 20 mmHg (C). That is, it can be seen that the difference in the value distribution of PVx is maintained regardless of the average ICP signal. For reference, asterisk (*) and double asterisk (**) indicate P = 0.05 and P <0.001 when the PVx of the surviving and deceased patient groups was analyzed by Mann-Whitney U-test, respectively.

In addition, referring to Figure 9, the ROC curve of the correlation index and the mean pressure value is shown (A) PVx showed better performance than PRx in predicting death (AUC = .74 and .66). (B) In particular, PVx was more effective than when the average ICP was less than 20 mmHg (AUC = .74), but PRx was significantly lowered under the same conditions (AUC = .58). (C) However, PRx predicted mortality with significant accuracy (AUC = .74) when the ICP was above 20 mmHg. In addition, the average pressure value (ICP signal, ABP signal) did not have good predictive performance (AUC≤.65) for mortality compared to the moving correlation indexes (PVx, PRx). This means that (D) for all subjects (AUC of ICP = .60, MAP = .56, CPP (cerebral perfusion pressure) =. 49), (E) MAP with an ICP of less than 20 mmHg = .56, CPP (cerebral) perfusion pressure) = .49), and (F) ICP above 20 mmHg (AUC of ICP = .64, MAP = .53, CPP = .65).

In another embodiment, the prognosis determination device may further determine the prognosis of the brain injury patient based on whether the prognosis apparatus is within a predetermined time after the brain injury occurs.

For example, if the prognosis determination device is within 24 hours after admission of the brain injury patient, the prognosis of the brain injury patient may be determined using the variability index PVx. However, if 24 hours have passed since hospitalization, other factors may affect the patient, so there may be limitations in determining the prognosis using only the volatility index (PVx).

As described above, the method for determining the prognosis of the brain injury patient using the volatility index (PVx) according to an embodiment of the present invention is particularly compared to the method using the pressure-responsiveness index (PRx), particularly in an environment where the ICP signal is less than 20 mmHg. In, there is an effect that can more accurately determine the prognosis of the brain injury patient.

2 is a flowchart illustrating a prognosis determination method of a brain injury patient using a volatility index (PVx) according to another embodiment of the present invention.

In step S210, the prognostic determination device acquires the intracranial pressure (ICP) signal and the arterial blood pressure (ABP) signal of the brain injury patient.

In step S220, the prognostic determination device derives a trend line of each of the ICP signal and the ABP signal using a predetermined first time period average value for the ICP signal and the ABP signal.

That is, the prognostic determination device may calculate an average value for the ICP signal and the ABP signal at every first time period, and connect the average values to derive the trend line.

For example, referring to FIG. 6, the prognostic determination device may calculate and display an average value of the ICP signal and the ABP signal every 1 second, and derive a trend line by connecting the average values.

In step S230, the prognostic determination device calculates a volatility index PVx indicating a correlation of the volatility between the ICP signal and the ABP signal during the predetermined time interval.

In this case, the prognostic determination apparatus may analyze the variability of each of the ICP signal and the ABP signal using the trend lines of the ICP signal and the ABP signal, respectively, and calculate the variability index PVx indicating the correlation.

In another embodiment, a standard deviation (SD) may be used as the variability of the ICP signal and the ABP signal. In addition, the variability index PVx may be calculated using the standard deviation through the processes of steps S233 and S236.

In step S233, the prognostic determination device calculates the standard deviation of each of the ICP signal and the ABP signal according to the second predetermined time period during the time period.

For example, the prognostic determination device may calculate the standard deviation of each of the ICP signal and the ABP signal repeatedly every 5 seconds during the 300 second time interval. At this time, the standard deviation is a value indicating how the data are collected (scatter plot) based on the average value.

In step S236, the prognostic determination device calculates a volatility index PVx indicating a correlation between the standard deviation of each of the ICP signal and the ABP signal.

For example, the prognostic determination device may calculate the standard deviation of each of the ICP signal and the ABP signal as ICPv and ABPv for 300 seconds. In addition, a volatility index PVx may be calculated by calculating a correlation between ICPv and ABPv.

Meanwhile, referring to FIG. 4, after (a) calculating ICPv and ABPv for a predetermined time interval (300 seconds), (b) deriving correlation between ICPv and ABPv, and (c) volatility index PVx ) Is shown.

In another embodiment, the prognostic determination device may calculate for each of the ICP signal and the ABP signal from a time point before the time interval is calculated from the time point at which the standard deviation is calculated according to the second time period.

For example, if the prognostic determination device calculates the ICPv and the ABPv in real time every 5 seconds, the standard deviation may be calculated by analyzing the ICP signal and the ABP signal from 300 seconds before each calculation time.

Finally, in step S240, the prognosis determination device determines the prognosis of the brain injury patient based on the calculated volatility index PVx.

As described above, the prognosis determination method of the brain injury patient using the volatility indicator (PVx) according to another embodiment of the present invention, by using the trend line configured by calculating the average value for the ICP signal and ABP signal every first time period, (pulse wave) and the respiratory wave (respiratory wave) to minimize the effects of the slow wave (slow wave) to reflect the variability of the effect has the effect of calculating the more accurate variability index (VRx).

FIG. 3 is a diagram illustrating a prognosis determination apparatus of a brain injury patient using a volatility indicator (PVx) according to an embodiment of the present invention.

Referring to FIG. 3, the apparatus 300 for determining the prognosis of the brain injury patient using the volatility indicator PVx according to an embodiment of the present invention includes a data collector 310, a calculator 320, and a determiner 330. Include. Optionally, the prognostic determination device 300 may further include a measuring unit (not shown) capable of measuring the ICP signal and the ABP signal of the brain injury patient.

Meanwhile, the prognostic determination device 300 may be mounted on a computer, a smartphone, a tablet PC, a notebook, and the like including a CPU and a memory.

The data collector 310 acquires an intracranial pressure (ICP) signal and an arterial blood pressure (ABP) signal of a brain injury patient.

In this case, the ICP signal and the ABP signal may be obtained from a measuring unit (not shown) or may be received from an external ICP signal monitoring device and an ABP signal monitoring device.

The calculating unit 320 calculates a volatility index PVx indicating a correlation between the variability between the ICP signal and the ABP signal during a predetermined time interval.

In another embodiment, the calculation unit 320 further derives a trend line of each of the ICP signal and the ABP signal by using a predetermined first time period average value for the ICP signal and the ABP signal, and uses the trend line. The volatility index PVx can be calculated.

In another embodiment, the calculation unit 320 calculates the standard deviation of each of the ICP signal and the ABP signal according to the second predetermined time period during the time interval, and the correlation between the standard deviation of the ICP signal and the ABP signal, respectively. The volatility index PVx indicating the relationship can be calculated.

In another exemplary embodiment, when the calculation unit 320 calculates the standard deviation, the calculation unit 320 may calculate the ICP signal and the ABP signal from the time when the standard deviation is calculated according to the second time period, and before the time interval. have.

In another embodiment, the volatility index PVx may be based on the Pearson correlation coefficient of the volatility between the ICP signal and the ABP signal.

The determination unit 330 determines the prognosis of the brain injury patient based on the calculated volatility index PVx.

In another embodiment, the determination unit 330 may further determine based on whether or not within a predetermined time after the brain injury of the brain injury patient.

Meanwhile, the above-described embodiments of the present invention can be written as a program that can be executed in a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable recording medium.

The computer-readable recording medium may include a magnetic storage medium (for example, a ROM, a floppy disk, a hard disk, etc.) and an optical reading medium (for example, a CD-ROM, DVD, etc.).

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

Claims (12)

In the method performed in the apparatus for determining the prognosis of the brain injury patient using the variability indicator,
Obtaining an intracranial pressure (ICP) signal and an arterial blood pressure (ABP) signal of a brain injury patient;
Calculating a pressure variability index (PVx) indicating a correlation of variability between the ICP signal and the ABP signal during a predetermined time window; And
Determining the prognosis of the brain injury patient based on the calculated volatility index,
Deriving a trend line of each of the ICP signal and the ABP signal by using a predetermined first time period average value of the ICP signal and the ABP signal,
Computing the volatility index
The volatility index is calculated using trend lines of the ICP signal and the ABP signal, respectively.
Computing the volatility index
Calculating a standard deviation (SD) of each of the ICP signal and the ABP signal according to a second predetermined time period during the time period; And
Calculating a volatility index indicating a correlation between the standard deviation of each of the ICP signal and the ABP signal
Prognosis determination method of a brain injury patient using a variability indicator comprising a. delete delete The method of claim 1,
The step of calculating the standard deviation
And a method for determining the prognosis of the brain injury patient using the variability indicator, wherein the ICP signal and the ABP signal are calculated for each of the ICP signals from a time point before the time interval from the time point for calculating the standard deviation according to the second time period. The method of claim 1,
The volatility index is
The prognosis determination method of the brain injury patient using the variability index, characterized in that based on the Pearson correlation coefficient of the variability between the ICP signal and the ABP signal. The method of claim 1,
Determining the prognosis of the brain injury patient
The prognosis determination method of the brain injury patient using the variability indicator, characterized in that further determining based on whether or not within a predetermined time after the brain injury of the brain injury patient. A data collector for acquiring intracranial pressure (ICP) and arterial blood pressure (ABP) signals of a brain injury patient;
A calculator for calculating a volatility index indicating a correlation between the volatility between the ICP signal and the ABP signal during a predetermined time interval; And
On the basis of the calculated volatility indicator, comprising a determination unit for determining the prognosis of the brain injury patient,
The calculation unit
Deriving a trend line of each of the ICP signal and the ABP signal by using a predetermined first time period average value for the ICP signal and the ABP signal,
The volatility index is calculated using trend lines of the ICP signal and the ABP signal, respectively.
The calculation unit
During the time period, a standard deviation of each of the ICP signal and the ABP signal is calculated according to a predetermined second time period,
The apparatus for determining the prognosis of the brain injury patient using the volatility index, characterized in that it calculates a volatility index indicating a correlation between the standard deviation of each of the ICP signal and the ABP signal. delete delete The method of claim 7, wherein
When the calculation unit calculates the standard deviation,
The apparatus for determining the prognosis of the brain injury patient using the variability index, characterized in that for each of the ICP signal and the ABP signal from the time point before the time interval from the time of calculating the standard deviation according to the second time period. The method of claim 7, wherein
The volatility index is
And a Pearson correlation coefficient of the variability between the ICP signal and the ABP signal. The method of claim 7, wherein
The determination unit
The apparatus for determining the prognosis of the brain injury patient using the variability indicator, characterized in that further determining based on whether or not within a predetermined time after the brain injury of the brain injury patient.

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