JP2019062990A - Circulatory system indicator calculation program, circulatory system indicator calculation device, circulatory system indicator calculation system and circulatory system indicator calculation method - Google Patents

Abstract

To provide a circulatory system indicator calculation program, a circulatory system indicator calculation device, a circulatory system indicator calculation system and a circulatory system indicator calculation method in which a value becoming an indicator of a pre-load is calculated every one heartbeat from a waveform of time change of a measured vascular internal pressure.SOLUTION: A circulatory system indicator calculation device 1 has: circulatory system indicator calculating means 102 for finding a regression curve to the diastolic waveform of a cardiac cycle every one heartbeat among time change of intravascular pressure of a patient 4, and calculating an indicator of a circulatory system of the patient 4 from a focusing value of the regression curve; and display processing means 103 for displaying and processing the time change of the indicator of the calculated circulatory system.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a circulatory index calculation program, a circulatory index calculation device, a circulatory index calculation system, and a circulatory index calculation method.

  In the field of medicine, in order to understand the state of the circulatory system including the heart, arteries, veins and peripheral blood vessels, it is necessary to know the values which are indicators of the circulatory system such as venous pressure, arterial pressure, cardiac output, blood volume etc. , It is very important to manage the condition of the patient during surgery.

  As a prior art, a circulatory system index calculation device has been proposed which measures cardiac output as one of the indexes for grasping the state of the circulatory system (see, for example, Patent Document 1).

  The circulatory system index calculation device disclosed in Patent Document 1 is used when obtaining a cardiac output using a thermodilution method, and acquires blood temperature information of a patient and an electrocardiogram, and the patient's heart is obtained. The thermodilution curve and cardiac output are calculated based on blood temperature information when cold water is injected into the inside, and the electrocardiogram and thermodilution curve measured simultaneously with the patient's blood temperature information are synchronized in the same screen. Among the electrocardiograms, the first electrocardiogram including the extrasystole and the second electrocardiogram not including the extrasystole are displayed on the screen in different display modes. The doctor confirms the displayed screen, determines the presence or absence of extrasystoles during measurement, and considers the effect of extrasystoles in the measurement result.

  The above-described circulatory system index calculation device of Patent Document 1 displays information for determining the presence or absence of extrasystole during measurement, and therefore, compared to the case where the information for determining the presence or absence of the extrasystole is not present. While reducing the number of re-measurements and reducing the burden on the patient, thermodilution requires the injection of cold water into the patient's heart and is associated with a relatively large invasion.

  Therefore, a circulatory index calculation device has been proposed that calculates the cardiac output from the measured arterial pressure waveform as suppressing the degree of invasion compared to the thermal dilution method (see, for example, Non-Patent Document 1). .

  The circulatory system index calculation device disclosed in Non-Patent Document 1 converts an arterial pressure waveform measured in consideration of blood vessel compliance into an arterial blood vessel volume waveform, and evaluates data on the converted arterial blood volume waveform. Perform correlation processing to calculate cardiac output before correction, determine calibration coefficient using nomogram, calculate cardiac output after correction from cardiac output before correction, and display on display unit . The conversion from the arterial pressure waveform to the arterial blood vessel volume waveform is performed by a predetermined equation using coefficients determined by specific information such as the patient's height, weight, and age. Further, in the autocorrelation processing, the heart rate is calculated by obtaining a waveform for each cardiac cycle, and the stroke volume before correction is calculated from the autocorrelation result, and the heart rate and the stroke volume The cardiac output before correction is obtained from the product. Although the method of calculating the nomogram is not disclosed, it is calculated using factors related to specific information such as the patient's height, weight and age as variables.

JP, 2016-187538, A

Satoshi Sato et al., "Introduction to equipment: Minimally invasive continuous cardiac output monitor system" LiDCOrapid ", Circulation control, Japan, Vol. 35, No. 2, 2014, pp. 166-176.

  The above-mentioned circulatory system index calculation device of nonpatent literature 1 calculates cardiac output from the measured arterial pressure waveform, but cardiac output is affected by preload and afterload. , Do not measure the index caused by only one or the other.

  Therefore, an object of the present invention is to provide a circulatory index calculation program, a circulatory index calculation device, and a circulatory index calculation system for calculating a value serving as an index of preload in each heartbeat from the waveform of time variation of measured intravascular pressure And providing a circulatory index calculation method.

  One aspect of the present invention provides the following circulatory system index calculation program, circulatory system index calculation apparatus, circulatory system index calculation system, and circulatory system index calculation method in order to achieve the above object.

[1] computer,
As a calculation means for obtaining a regression curve for the diastolic waveform of the cardiac cycle among the temporal changes in the intravascular pressure of the patient for each heartbeat, and calculating an indicator of the circulatory system of the patient in the heartbeat from the convergence value of the regression curve Circulatory index calculation program to make it function.
[2] The calculation means obtains a regression curve for the temporal change of arterial pressure as the intravascular pressure, and a decay function representing a pressure response of one heartbeat for blood vessel resistance and blood vessel compliance as a circulatory system. The circulatory system index calculation program according to the above [1].
[3] The circulatory system index calculation program according to [1] or [2], wherein the calculation means calculates the index of the circulatory system from an average of the convergence values of a plurality of heartbeats.
[4] The circulatory system index calculation program according to any one of the above [1] to [3], wherein the calculation means calculates an average circulation filling pressure as an index of the circulatory system.
[5] The circulatory system index calculation program according to [2], wherein the calculation means calculates the convergence value of the attenuation function and further calculates a time constant of the attenuation function [6],
The circulatory system index calculation program according to any one of the above [1] to [5], which further functions as display processing means for performing display processing of the time change of the index of the circulatory system calculated by the calculation means.
[7] The circulatory system index calculation program according to [6], wherein the display processing means synchronously displays the time change of the index of the circulatory system and the time change of the biological information of the patient.
[8] Of the temporal changes in the intravascular pressure of the patient, a regression curve for the diastolic waveform of the cardiac cycle is determined for each heartbeat, and the indicator of the patient's circulatory system in the heartbeat is calculated from the convergence value of the regression curve. Circulatory index calculation device having calculation means.
[9] A measuring instrument for measuring the intravascular pressure of a patient,
The regression curve for the diastolic waveform of the cardiac cycle among the temporal changes of the intravascular pressure of the patient measured by the measuring device is determined for each heartbeat, and the circulatory system of the patient in the heartbeat from the convergence value of the regression curve. A circulatory system index calculation device having calculation means for calculating an index of
A circulatory system index calculation system comprising: a display device that displays and processes temporal changes of the circulatory system index calculated by the circulatory system index calculation device.
[10] Of the temporal change of the intravascular pressure of the patient, the step of defining the diastole of the cardiac cycle,
Determining a regression curve for the waveform in the diastolic range of the cardiac cycle every heartbeat;
Calculating an indicator of the circulatory system of the patient at the heartbeat from the convergence value of the regression curve.

According to the invention of claims 1, 8 to 10, it is possible to calculate a value serving as an index of preload every heartbeat, from the waveform of time change of the measured intravascular pressure.
According to the invention as set forth in claim 2, a regression curve for the temporal change of arterial pressure among the intravascular pressure is determined, and a decay function representing a pressure response of one heartbeat for the vascular flow path resistance and vascular compliance as a circulatory system is regressed. It can be used as a curve.
According to the third aspect of the present invention, it is possible to calculate an index of the circulatory system from the average of convergence values of a plurality of heartbeats.
According to the invention which concerns on Claim 4, an average circulation filling pressure can be calculated as a parameter | index of a circulatory system.
According to the fifth aspect of the present invention, it is possible to calculate the convergence value of the attenuation function and to further calculate the time constant of the attenuation function.
According to the sixth aspect of the present invention, it is possible to display and process the time-based change of the index of the circulatory system calculated by the calculation means.
According to the seventh aspect of the present invention, it is possible to synchronously display the temporal change of the circulatory index and the temporal change of the patient's biological information.

FIG. 1 is a schematic view showing an example of the configuration of a circulatory system index calculation system according to the embodiment. FIG. 2 is a block diagram showing a configuration example of a circulatory system index calculation device according to the embodiment. FIG. 3 is a schematic diagram showing an example of the configuration of arterial pressure information. FIG. 4 is a schematic view showing an example of the configuration of biological information. FIG. 5 is a schematic view showing an example of the configuration of circulatory system index information. FIG. 6 is a graph showing an arterial pressure waveform and its differential value for explaining the operation of the circulatory system index calculation means. FIG. 7 is a graph showing an arterial pressure waveform of one heartbeat for explaining the operation of the circulatory system index calculation means. FIG. 8 is a graph for explaining the fitting operation of the circulatory system index calculation means. FIG. 9 is a schematic diagram for explaining an example of the display operation of the display processing means. FIG. 10 is a flowchart for explaining the operation of the circulatory system index calculation system. FIG. 11 is a graph showing the relationship between the cardiac output and the amount of venous return and the mean right atrial pressure. FIG. 12 is a circuit diagram as a model representing attenuation of arterial pressure.

Embodiment
(Configuration of circulatory system index calculation system)
FIG. 1 is a schematic view showing an example of the configuration of a circulatory system index calculation system according to the embodiment.

  The circulatory index calculation system 6 calculates a value to be an index of the circulatory system from the measured intravascular pressure of the patient 4 when operating the patient 4 or the like, and notifies the doctor 5 of the condition of the patient 4 This is for displaying a value that is an indicator of the circulatory system, or for displaying a value that is an indicator of the circulatory system in synchronization with biological information. Here, the circulatory system index calculation system 6 measures arterial pressure as an example of an intravascular pressure, and calculates an average circulating filling pressure as a value serving as an index of the circulatory system, and the average circulating filling pressure is calculated every heartbeat. It shall be calculated.

  The circulatory index calculation system 6 is a device designed exclusively for the display unit 12 and the operation unit 13 or an information processing apparatus such as a PC (Personal Computer) or a tablet terminal, and calculates the circulatory index for processing information. Apparatus 1, arterial pressure sensor 2 for measuring arterial pressure of patient 4 by, for example, A line, biometric sensor 3 for measuring biological information such as electrocardiogram, blood pressure, pulse, brain wave, respiration etc. of patient 4, arterial pressure sensor 2 And a biological information monitor 3A for displaying the information measured by the biological sensor 3 and the information calculated by the circulatory index calculation device 1. The circulatory system index calculation device 1, the arterial pressure sensor 2, the living body sensor 3, and the living body information monitor 3A are operated by the doctor 5.

  The circulatory system index calculation device 1 calculates an average circulation filling pressure as an index indicating the state of the patient 4 based on the information obtained from the arterial pressure sensor 2 and the living body sensor 3 and temporally displays the display unit 12 together with the biological information. And / or an electronic component such as a central processing unit (CPU), a hard disk drive (HDD), or a flash memory having a function for processing information in the main body.

  The circulatory system index calculation device 1 may be configured as a server device that does not have the display unit 12 and the operation unit 13. In that case, it operates according to the request of the terminal device, and when configured as a server device, it is remote. It may be placed on the ground. In addition, the circulatory system index calculation device 1 may be disposed in an operating room where a patient 4 is operated, or may be disposed in a room monitoring a plurality of operating rooms and connected to a plurality of biological information monitors 3A It may be Further, the circulatory system index calculation device 1 may control an injection device (not shown) so as to transfuse and transfuse the patient 4, for example, based on the calculated index.

  The arterial pressure sensor 2 includes a needle inserted into the artery of the patient 4, an arterial line connected to the needle and one end, and a pressure transducer provided at the other end of the arterial line and outputting a voltage proportional to the arterial pressure. Have. The output signal of the pressure transducer is input to the circulatory system index calculation device 1 through the biological information monitor 3A.

  The respective devices are communicably connected to each other by a dedicated line, but may be connected by a wired or wireless communication network, or connected using a communication network such as an intranet or LAN (Local Area Network). It may be

  In the above configuration, the circulatory index calculation device 1 receives the information output from the arterial pressure sensor 2 and the biological sensor 3 via the biological information monitor 3A, and calculates the average circulation filling pressure based on the received information on the arterial pressure. While calculating, the information on the living body obtained from the living body sensor 3 is appropriately combined and displayed on the display unit 12. The doctor 5 confirms the information displayed on the display unit 12 or the biological information monitor 3A, determines the state of the patient 4, and performs treatment such as infusion and blood transfusion.

  Note that all or a part of the functions of the circulatory index calculation device 1, the arterial pressure sensor 2, the biological sensor 3 and the biological information monitor 3A may be integrated, or a part or all of the functions of each device May be included in the In particular, the function of the circulatory system index calculation device 1 may be built in the biological information monitor 3A. Further, all or a part of the functions of the circulatory system index calculation device 1, the arterial pressure sensor 2, and the living body sensor 3 may be configured to be operated by a device disposed at a remote place. Further, the plurality of biological information monitors 3A may be associated with the circulatory index calculation device 1, and the circulatory index calculation device 1 may simultaneously calculate the indicators of the circulatory system of a plurality of patients. In addition, the circulatory system index calculation device 1 may receive arterial pressure information and biological information directly from the arterial pressure sensor 2 and the biological sensor 3, or via the biological information monitor 3A as illustrated in FIG. May be received.

(Configuration of circulatory system index calculation device)
FIG. 2 is a block diagram showing a configuration example of the circulatory system index calculation device 1 according to the embodiment.

  The circulatory system index calculation device 1 comprises a CPU and the like, controls the respective units, and executes various programs, and a storage unit 11 composed of a storage medium such as an HDD and a flash memory and storing information. The display unit 12 displays information by an image and characters, the operation unit 13 outputs an operation signal to the control unit 10 according to the operation content, and the communication unit 14 communicates with an external device.

  The control unit 10 executes a circulatory index calculation program 110 to be described later to obtain an arterial pressure information acquisition unit 100, a biological information acquisition unit 101, a circulatory index calculation unit 102, a display processing unit 103, an information output unit 104, and the like. Function.

  The arterial pressure information acquisition unit 100 acquires a signal proportional to the arterial pressure from the arterial pressure sensor 2 through the communication unit 14 and the biological information monitor 3A, converts it into a numerical value of the arterial pressure, and combines it with the time information as arterial pressure information 111. The data is recorded in the storage unit 11.

  The biological information acquisition unit 101 acquires information such as an electrocardiogram, a sphygmomanometer, and a pulse oximeter from the biological sensor 3 via the communication unit 14 and the biological information monitor 3A, and records the information as biological information 112 in the storage unit 11 together with time information. .

  The circulatory index calculation means 102 calculates an average circulating filling pressure as a value to be an index of circulatory system from the arterial pressure information 111, and records it in the storage unit 11 as circulatory index information 113 together with time information.

  The circulatory index calculation means 102 obtains, for each heartbeat, a regression curve for the diastolic waveform of the cardiac cycle, with respect to the waveform in which arterial pressure information 111 is drawn with time on the horizontal axis and arterial pressure on the vertical axis. Determine the average circulation filling pressure from the convergence value of the curve. The regression curve is a model that takes into consideration the flow resistance of all blood vessels between arteries and veins including capillaries and the change in intraluminal volume associated with the dilation and contraction of the blood vessels themselves, and employs exponential decay. The convergence value and the time constant are calculated from the parameters that define the regression curve. Details will be described later.

  The display processing means 103 displays on the display unit 12 all or part of the arterial pressure information 111, the biological information 112 and the circulatory index information 113 selected appropriately. As the display method, real-time display, history display, average value display of a plurality of pulsations, and display of a predicted value can be appropriately selected, and when displaying a plurality of information, each information is displayed synchronously in time I assume. The display method is not limited to numerical methods, graphs, colors, etc.

  The information output means 104 outputs the biological information monitor 3A to display all or part of the arterial pressure information 111 and the circulatory index information 113 appropriately selected together with the biological information 112 displayed on the biological information monitor 3A. It is In particular, the information output unit 104 preferably outputs information so that the arterial pressure information 111, the biological information 112, and the circulatory system index information 113 are displayed synchronously on the biological information monitor 3A.

  The storage unit 11 stores a circulatory index calculation program 110 that causes the control unit 10 to operate as the respective units 100 to 104, arterial pressure information 111, biological information 112, circulatory index information 113, and the like.

  FIG. 3 is a schematic view showing an example of the configuration of the arterial pressure information 111. As shown in FIG.

  The arterial pressure information 111 is information acquired by the arterial pressure information acquisition unit 100 from the arterial pressure sensor 2 and has a time t at which a value is acquired and an arterial pressure p.

  FIG. 4 is a schematic view showing an example of the configuration of the biological information 112. As shown in FIG.

The living body information 112 is information obtained from the living body sensor 3 by the living body information acquiring means 101, and the living body information such as time t when the value is acquired, electrocardiogram V _h , heart rate H _r , blood pressure P _b , body temperature T _b . And information. The biological information shown in the figure is an example and is not limited thereto.

  FIG. 5 is a schematic view showing an example of the configuration of circulatory system index information 113. As shown in FIG.

The circulatory system index information 113 is information calculated by the circulatory system index calculation means 102 as a value serving as a circulatory system index from the arterial pressure information 111, and the time t at which the value is calculated and the average circulation which is the circulatory system index And has a charge pressure P _sf .

(Operation of circulatory system index calculation system)
Next, on the premise that the operation of the present embodiment is described above, (1) basic operation, (2) average circulation filling pressure calculation operation, and (3) while referring to FIG. 1 to FIG. 10 and FIG. The display processing operation will be described separately.

(1) Basic Operation FIG. 10 is a flowchart for explaining the operation of the circulatory system index calculation system 6.

  First, after the patient 4 enters the operating room, the doctor 5 inserts a needle as a part of the arterial pressure sensor 2 into the artery for the patient 4, an electrocardiogram as the biological sensor 3, a noninvasive blood pressure monitor, Wear a pulse oximeter, an electroencephalograph, etc. A needle as a part of the arterial pressure sensor 2 is connected to a pressure transducer via an arterial line to measure arterial pressure.

  Next, if necessary, a vein indwelling needle is inserted into the vein of the patient 4 to perform anesthesia, and a sedation pump for anesthesia and an analgesic pump are connected respectively. Also, a ventilator is attached to the patient 4.

  Thereafter, the arterial pressure information acquisition means 100 of the circulatory system index calculation device 1 acquires a signal proportional to the arterial pressure from the arterial pressure sensor 2 via the communication unit 14 and the biological information monitor 3A (S1) numerical value of arterial pressure , And as shown in FIG. 3, it is recorded in the storage unit 11 as arterial pressure information 111 together with time information.

  Further, the biological information acquisition means 101 of the circulatory system index calculation device 1 acquires information such as an electrocardiogram, a sphygmomanometer and a pulse oximeter from the biological sensor 3 via the communication unit 14 and the biological information monitor 3A (S2). As shown in FIG. 4, the information is recorded in the storage unit 11 as the biological information 112 together with the time information.

  Next, the circulatory system index calculating means 102 calculates an average circulating filling pressure as a value to be an index of the circulatory system from the arterial pressure information 111. The specific procedure of the calculation method will be described below (S3 to S7).

(2) Average Circulation Fill Pressure Calculation Operation FIG. 6 is a graph showing an arterial pressure waveform and its differential value for explaining the operation of the circulatory system index calculation means 102.

  First, as shown in the upper part of FIG. 6, the circulatory index calculation means 102 takes the horizontal axis as time, and the vertical axis as arterial pressure, as shown in the lower part of FIG. The arterial pressure waveform is differentiated by time (S3).

Of the arterial pressure waveform, a positive peak is obtained from the derivative of the ascending leg with respect to time (t = t _p1 , t _p2 ...), And the circulatory system index calculating means 102 detects the start of the rising of the peak (t = t _B0 , T _B1 ...) as the beginning of one heartbeat. That is, the circulatory system index calculation means 102 specifies each of the range (t _{B0 to} t _B1 ), the range (t _{B1 to} t _B2 ),... As the range of one heartbeat (S4).

  Next, the circulatory index calculation means 102 specifies the start point of diastole within the range of one heartbeat (S5). The specific procedure of the identification method is described below.

  FIG. 7 is a graph showing an arterial pressure waveform of one heartbeat for explaining the operation of the circulatory system index calculation means 102.

The arterial pressure waveform of one heart beat generally has a shape as shown in FIG. 7, and the systole (t _{Bi-1 to} t) is bounded by a valley P _n in the left of the figure of the notch which is a double notch. _ai ) and diastole (t _{ai to} t _Bi ). Circulation index calculation means 102, a tangent is drawn l _t in contact with both of the vicinity of the peak P _d is the peak P _p and dicrotic wave are shock waves to identify valleys P _n on the left of the notch, the tangent line l _t And a point at which the distance d _max is maximum is calculated, and this point is set as a valley P _n (t = t _ai ) on the left side of the notch.

Next, the circulatory system index calculation means 102 is a starting point for obtaining a regression curve at time (t = t _Ai ) after a predetermined time period t _nf (for example, t _nf = 100 msec) from time (t = t _ai ) I assume. In other words, the circulatory system index calculation unit 102 obtains a regression curve for the waveform of the descending limb of the range _(t Ai _{~t Bi).} In addition, the method of calculating | requiring the range of the descending leg mentioned above is an example, and if a starting point and an end point are defined, a method will not be limited. Note that t _nf may be a constant, may be short when the heart rate is high, and may be long according to the pulse rate if the heart rate is low.

Circulation index calculation means 102, the attenuation waveform of the diastolic, as an example, using the following equation by fitting (S6), a regression curve for the waveform in the range _{(t Ai ~t Bi).}

_{Here, P es} is the arterial pressure at _{t =} t _{Ai, P 0} represents the convergence value. The least squares method is used as a specific example of the method of obtaining a regression curve, and the fitting can be performed using the Levenberg-Markert method as an example of a least squares algorithm.

In the above equation (Equation 1), the arterial pressure is attenuated when blood circulation is temporarily stopped in consideration of the flow path resistance of the blood vessel and the compliance of the blood vessel, and when blood is uniformly distributed in the blood vessel It is derived from a model in which the intravascular pressure converges to P ₀ . That is, P ₀ is a value corresponding to the average circulation filling pressure P _sf which is a steady-state value of the intravascular pressure when blood circulation is temporarily stopped.

  The above equation (Equation 1) can be analogically derived from a model using the following electric circuit, as an example.

  FIG. 12 is a circuit diagram as a model representing attenuation of arterial pressure.

The pressure due to the cardiac output is the voltage V, the flow rate is the current I, the compliance of the blood vessel is the capacitance C of the capacitor, the flow path resistance of the blood vessel is the resistance R of the resistance, and the average circulation filling pressure is a constant voltage replacing the power supply of V _0, as shown in FIG. 12, to connect the capacitor and resistor in parallel, the circuit connected to these with cells in series, assuming as a pseudo models, the voltage V of the damping circuit after pulse response Attenuating exponentially, the value converges to V ₀ . In addition, the correlation with the result described in the paper described below can be cited as a basis for showing that the function is appropriate as indicating the characteristics of the pressure of the circulatory system.

That is, the inventors confirmed that the convergence value P ₀ obtained by fitting the above-described equation (Equation 1) for each heartbeat is well correlated with the value of the average circulation filling pressure in the document shown below ( Jacinta J. Maas, et al., “Bedside Assessment of Total Systemic Vascular Compliance, Stressed Volume, and Cardiac Function Curves in Intensive Care Unit Patients”, Anesthesia & Analgesia, October 2012, Volume 115, Issue 4, p 880- See 887). According to the literature, when the brachial artery is avascularized and the radial artery pressure and the central venous pressure are measured, the radial artery pressure is attenuated and the central venous pressure is increased. As a result of the reduction of the radial artery pressure, and as a result of the increase of the central venous pressure, both converge to the same value, and the value converged to the same value is the average circulation filling pressure P _sf . The average circulating filling pressure P _sf and the convergence value P ₀ obtained by fitting for each heartbeat correlate well.

  Note that the above-described approximate and derived mathematical expressions are exemplifications, and are not limited to the above mathematical expressions (equation 1) as long as they are mathematical expressions derived from a model in which the flow path resistance of blood vessels and compliance of blood vessels are considered. As long as at least a convergence value is obtained, a constant may be appropriately multiplied, or different mathematical expressions may be used.

  FIG. 8 is a graph for explaining the fitting operation of the circulatory system index calculation means 102.

In FIG. 8, the broken line indicates the arterial pressure waveform of continuous pulsation, and the solid line is the one obtained by fitting the above equation to the range (t _{Ai to} t _Bi ). The solid line extends to the steady state value P ₀ of the intravascular pressure, and the steady state value P ₀ corresponds to the average circulating filling pressure P _sf when the blood circulation is suspended.

The circulatory index calculation means 102 determines the parameters (P _es , P ₀ , τ) by fitting the above equation to the arterial pressure waveform of the broken line, calculates the average circulatory filling pressure P _sf from P _0, and Calculate τ (S7). As shown in FIG. 5, the circulatory index calculation means 102 stores the calculated average circulation filling pressure P _sf in the storage unit 11 as circulatory index information 113 together with the time of the corresponding arterial pressure waveform. The corresponding time may be selected from the start point, the end point of the arterial pressure waveform of one heartbeat, or any time between the start point and the end point.

Next, the circulatory system index calculation means 102 associates the average circulation filling pressure P _sf obtained for each heartbeat and the time constant τ with the biological information 112 of the time corresponding to the heartbeat (S8). That is, the biological information 112 at the same time and the circulatory system index information 113 shown in FIG. 4 and FIG. 5 are associated with each other.

(3) Display Processing Operation Next, the display processing means 103 or the information output means 104 displays the average circulation full pressure P _sf and the biological information 112 associated with this on the display unit 12 (S 9).

  FIG. 9 is a schematic diagram for explaining an example of the display operation of the display processing means 103 or the information output means 104.

  The display screen 103A is a display content displayed on the display unit 12 by the display processing unit 103 or a display content displayed on the biological information monitor 3A by the information output unit 104, and is a header display displaying menu, patient information, and time information An area 1030, a biological information display area 1031 graphically displaying temporally the biological information 112 and the biological information 112, and a circulatory index information display area 1032 temporally displaying the circulatory index information 113 and the circulatory index information 113 The graph display of the biological information display area 1031 and the graph display of the circulatory system index information display area 1032 are displayed in synchronization with each other.

  The doctor 5 confirms the display content of the display screen 103A displayed on the display unit 12 or the biological information monitor 3A, determines the state of the circulatory system of the patient 4, and appropriately performs treatment such as infusion and blood transfusion.

(Effect of the embodiment)
According to the embodiment described above, among the temporal changes in arterial pressure of the patient 4, a regression curve for the diastolic waveform of the cardiac cycle is determined for each heartbeat, and the average circulation filling pressure P _{sf is} determined from the convergence value of the regression curve. Is calculated, it is possible to calculate a value serving as an index of preload for each heartbeat from the waveform of the time change of the measured intravascular pressure. Further, since the average circulatory filling pressure P _sf is an index determined from blood vessel volume and blood volume, the patient's blood vessel volume and blood volume, and comparison between the preoperative value and the intraoperative or postoperative value, and The patient's vascular volume and blood volume progress can be monitored.

  In addition, although the conventional method for measuring the mean circulating filling pressure requires anemia and requires at least several tens of seconds to obtain a value, it is accompanied by a large invasiveness, but the present invention requires at least anemia. The above-mentioned invasion can be reduced because Further, the conventional average circulation pressure is considered to be an average value for a plurality of heartbeats since it takes several tens of seconds to be measured, but the present invention can be determined for each heartbeat. In addition, accuracy can be improved by averaging the average circulation filling pressure of a plurality of heartbeats obtained by the present invention.

Also, conventionally, stroke volume variation (SVV) and pulse pressure variation (PPV) have been measured in order to evaluate the responsiveness of an infusion solution. The SVV calculates the cardiac output based on the pressure waveform obtained from the arterial pressure line, and represents the respirability fluctuation of the single cardiac output by the change rate. The PPV is to calculate the rate of change of the respiratory fluctuation of pulse pressure obtained from the arterial pressure line. These values are for evaluating how much infusion solution should be given, and both PPV and SVV are numerical values that are responsive to infusion solutions, but they fluctuate with exhalation and inhalation, and each heartbeat Although it could not be used to monitor the patient's blood vessel volume and blood volume, and the patient's blood vessel volume and blood volume progress, because the numerical values of the Since P ₀ corresponding to the pressure P _sf can be determined for each heartbeat, the patient's appropriate blood volume can be managed by comparing the preoperative value with the intraoperative or postoperative value, The patient's vascular volume and blood volume progress can be monitored.

Further, as described below, it is possible to further analyze the venous return resistance from the average circulation filling pressure _Psf .

  FIG. 11 is a graph showing the relationship between the cardiac output and the amount of venous return and the mean right atrial pressure.

The cardiac output curve and the cardiac arrest and return flow curve are generally shaped as shown in FIG. 11, although there are intra- and inter-individual variations. The intersection of the venous return curve with the horizontal axis is the mean circulation filling pressure P _sf , the intersection of the cardiac output curve and the pacing return curve is the circulation equilibrium point P _ce , and the central venous pressure C _vp is its pressure It is said that. The central venous pressure _Cvp is a right atrial pressure and is measured from a central venous line or the like.

In FIG. 11, the inverse number of the slope of the curve falling downward to the right indicates venous return resistance, and therefore, if two points P _sf and P _ce are determined, the venous return resistance can be obtained. Conventionally, since the average circulatory filling pressure P _sf could not be measured in real time, venous regurgitation resistance could not be determined in the clinic, but since P _sf can be calculated according to the present invention, venous regurgitation resistance can be calculated clinically. . In addition, by sequentially calculating the venous return resistance, it is possible to measure the time change of the venous return resistance.

Other Embodiments
The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the present invention.

  For example, although the arterial pressure of the aorta, ie, the arterial pressure corresponding to the intravascular pressure of the systemic circulation was measured in the above embodiment, the arterial pressure corresponding to the intravascular pressure of the pulmonary circulation, ie, the pulmonary artery pressure may be measured. Although the absolute value of the numerical value is smaller than the arterial pressure, the average circulatory filling pressure can also be determined from the pulmonary artery pressure. In addition, the aortic pressure and the pulmonary artery pressure may be collectively measured as the intravascular pressure of the whole circulation, and the mean circulatory filling pressure may be determined from the aortic pressure and the pulmonary artery pressure.

  In the above embodiment, the regression curve is determined for the descending leg of the arterial pressure, but the regression curve may be determined for the increase curve of the venous pressure to determine the average circulation filling pressure. Although it is necessary to take measures against noise and the like because the fluctuation range of the vein pressure is small, theoretically, the average circulation filling pressure is calculated also from the vein pressure.

  Although the range of one heartbeat is defined from the differential value of the arterial pressure waveform in the above embodiment, the range of one heartbeat may be defined from other information including biological information such as a waveform of an electrocardiogram.

  Further, it is needless to say that the real time display of the time constant τ, the history display, the average value display of a plurality of pulsations, and the display of the predicted value may be further displayed on the display unit 12 and / or the biological information monitor 3A. The real-time display of other biological information calculated from the above, the history display, the average value display of a plurality of pulsations, and the display of the predicted value may be further displayed on the display unit 12 and / or the biological information monitor 3A.

  Moreover, the display unit 12, the operation unit 13, and the communication unit 14 are, of course, not essential components of the circulatory system index calculation device 1, and may be omitted or may be separate devices. Similarly, the biometric sensor 3 is not an essential component of the circulatory system index calculation system 6, and may be omitted or may be prepared as a separate system.

  Although the functions of the respective units 100 to 104 of the control unit 10 are realized by a program in the above embodiment, all or a part of the respective units may be realized by hardware such as an ASIC. Further, the program used in the above embodiment may be provided by being stored in a recording medium such as a CD-ROM or the like, or may be provided by distributing via the Internet. Moreover, the program which operate | moves on a cloud may be sufficient. In addition, changing, deleting, adding, and the like of the order of the operations described in the above embodiment can be made within the scope of the present invention.

1: circulatory system index calculation device 2: arterial pressure sensor 3: living body sensor 3A: living body information monitor 4: patient 5: doctor 6: circulatory system index calculation system 10: control unit 11: storage unit 12: display unit 13: operation unit 14: Communication unit 100: Arterial pressure information acquisition means 101: Biological information acquisition means 102: Circulation index calculation means 103: Display processing means 103A: Display screen 104: Information output means 110: Circulation index calculation program 111: Arterial pressure information 112: biometric information 113: circulatory index information 1030: header display area 1031: biometric information display area 1032: circulatory index information display area

Claims (10)

Computer,
As a calculation means for obtaining a regression curve for the diastolic waveform of the cardiac cycle among the temporal changes in the intravascular pressure of the patient for each heartbeat, and calculating an indicator of the circulatory system of the patient in the heartbeat from the convergence value of the regression curve Circulatory index calculation program to make it function.   The calculation means obtains a regression curve for the temporal change of arterial pressure as the intravascular pressure, and uses a decay function representing a pressure response of one heartbeat for blood vessel resistance as circulatory system and blood vessel compliance as the regression curve. The circulatory system index calculation program according to Item 1.   The circulatory system index calculation program according to claim 1 or 2, wherein the calculation means calculates the index of the circulatory system from an average of the convergence values of a plurality of heartbeats.   The circulatory system index calculation program according to any one of claims 1 to 3, wherein the calculation means calculates an average circulation filling pressure as an index of the circulatory system.   The circulatory system index calculation program according to claim 2, wherein the calculation means calculates the convergence value of the attenuation function and further calculates a time constant of the attenuation function. The computer,
The circulatory system index calculation program according to any one of claims 1 to 5, further functioning as display processing means for performing display processing of the temporal change of the index of the circulatory system calculated by the calculation means.   The circulatory system index calculation program according to claim 6, wherein the display processing means synchronously displays the time change of the circulatory system index and the time change of the patient's biological information.   A calculation means for obtaining a regression curve for the diastolic waveform of the cardiac cycle among temporal changes in the intravascular pressure of the patient for each heartbeat and calculating an indicator of the circulatory system of the patient in the heartbeat from the convergence value of the regression curve Circulatory index calculation device having. A measuring device for measuring the intravascular pressure of the patient;
The regression curve for the diastolic waveform of the cardiac cycle among the temporal changes of the intravascular pressure of the patient measured by the measuring device is determined for each heartbeat, and the circulatory system of the patient in the heartbeat from the convergence value of the regression curve. A circulatory system index calculation device having calculation means for calculating an index of
A circulatory system index calculation system comprising: a display device that displays and processes temporal changes of the circulatory system index calculated by the circulatory system index calculation device. Defining a range of diastole of cardiac cycle among temporal changes of intravascular pressure of the patient;
Determining a regression curve for the waveform in the diastolic range of the cardiac cycle every heartbeat;
Calculating an indicator of the circulatory system of the patient at the heartbeat from the convergence value of the regression curve.

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