Biometric information display device and method for displaying biological information

Abstract

To provide a biological information display device and a biological information display method capable of more accurately monitoring the state of a subject.SOLUTION: A biological information display device M includes: a heart rate acquisition part 12 for acquiring a heart rate of a subject; a respiration rate acquisition part 41 for acquiring a respiration rate of the subject; a hemodynamics calculation part 17 for calculating a hemodynamics parameter of the subject, and calculating a respiratory variation of the hemodynamics parameter on the basis of a plurality of hemodynamics parameters calculated in a predetermined period; and a display control part 72 for executing control to output the respiratory variation to a display part 71. The hemodynamics calculation part 17 calculates a one respiratory cycle heart rate, which is a heart rate included in one respiratory cycle, using the heart rate and the respiration rate. The display control part 72 executes control to output, to the display part 71, a setting screen of a length of a predetermined period, the setting screen including the one respiratory cycle heart rate. The hemodynamics calculation part 17 sets the length of the predetermined period on the basis of setting contents in the setting screen, and calculates a respiratory variation in the predetermined period after the setting.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a biological information display device and a biological information display method.

[0002] Conventionally, when performing a treatment such as administering an infusion to a subject, as useful parameters for confirming the state of the subject, the respiratory variation of the subject's stroke volume (hereinafter, also referred to as "SVV (Stroke Volume Variation)"), or a parameter related to hemodynamics such as the respiratory variation of pulse pressure (hereinafter, also referred to as "PPV (Pulse Pressure Variation)") (hereinafter, referred to as "hemodynamic parameter") is used.

[0003] Specifically, when the pressure in the thoracic cavity fluctuates due to breathing, blood is pushed out and the stroke volume and pulse pressure fluctuate. In a state where the circulating blood volume is low, the fluctuations of SVV and PPV become large. Therefore, a large value of SVV or PPV indicates that the circulating blood volume is insufficient. In addition, Patent Document 1 discloses an artifact removal method in an apparatus for analyzing SVV.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] The device described in Patent Document 1 above calculates the SVV for one respiratory cycle. However, there are cases where the number of beats in one respiratory cycle is small, and in such cases, the amount of stroke volume data used to calculate SVV is insufficient, so a technology that can more accurately monitor the subject's condition is desired.

[0007] This disclosure provides a biometric information display device and a biometric information display method that can more accurately monitor the condition of a subject. [Means for solving the problem]

[0008] A biometric information display device relating to one aspect of this disclosure is A heart rate acquisition unit that acquires the heart rate of the subject, A respiratory rate acquisition unit that acquires the respiratory rate of the subject, A hemodynamic calculation unit calculates the hemodynamic parameters of the subject and calculates the respiratory variation of the hemodynamic parameters based on a plurality of hemodynamic parameters calculated over a predetermined period. The system includes a display control unit that controls the output of the respiratory fluctuations to the display unit, The hemodynamic calculation unit further calculates the number of beats per breath, which is the number of beats included in one respiratory cycle, using the heart rate and the respiratory rate. The display control unit further controls the output of a setting screen for setting the length of the predetermined period, which includes the number of beats per breath, to the display unit. The circulatory dynamics calculation unit acquires setting information indicating the content set on the setting screen, sets the length of the predetermined period based on the acquired setting information, and calculates the respiratory fluctuations during the predetermined period after setting. [Effects of the Invention]

[0009] According to this disclosure, the subject's condition can be monitored more accurately. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 shows the configuration of a biometric information processing device according to one aspect of the present disclosure. [Figure 2] Figure 2 shows an example of a measurement configuration using a monitoring device, which is an example of a biological information processing device shown in Figure 1. [Figure 3] Figure 3 shows the configuration of the circulatory dynamics calculation unit shown in Figure 1. [Figure 4] Figure 4 shows an example of the screen displayed on the display unit shown in Figure 1. [Figure 5] Figure 5 illustrates how the number of data points used to calculate respiratory variability changes depending on the number of cycles set in the settings screen shown in Figure 4. [Figure 6] Figure 6 is a diagram illustrating the state in which the length of a predetermined period is changed manually by an operator using the period setting unit shown in Figure 3. [Figure 7] Figure 7 is a diagram illustrating the state in which the length of a predetermined period is automatically changed by the period setting unit shown in Figure 3. [Figure 8] Figure 8 is a diagram illustrating the state in which the length of a predetermined period is automatically changed by the period setting unit shown in Figure 3. [Figure 9] Figure 9 is a diagram illustrating the state in which the length of a predetermined period is automatically changed by the period setting unit shown in Figure 3. [Figure 10] Figure 10 is a flowchart for explaining an outline of an operation flow when calculating and displaying a respiratory variation of a circulatory parameter by a biological information processing apparatus according to an embodiment of the present disclosure. [Figure 11] Figure 11 is a flowchart for explaining an operation flow when the circulatory parameter calculation unit shown in FIG. 1 operates in a manual mode. [Figure 12] Figure 12 is a flowchart for explaining an operation flow when the circulatory parameter calculation unit shown in FIG. 1 operates in an automatic mode.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, an example of an embodiment of a biological information display device and a biological information display method according to the present invention will be described based on the accompanying drawings.

[0012] [Configuration of Biological Information Processing Apparatus] FIG. 1 is a diagram showing a configuration of a biological information processing apparatus (biological information display device) M according to an aspect of the present disclosure. FIG. 2 is a diagram showing an example of a measurement form using a monitor device M1 which is an example of the biological information processing apparatus M shown in FIG. 1.

[0013] The biological information processing apparatus M includes a display device 1 that calculates and controls display of circulatory parameters related to the circulatory dynamics of a subject, a blood pressure measurement device 2 that measures blood pressure during the systolic and diastolic phases of the heart, a respiration measurement device 4, a reception unit 6, an electrocardiogram electrode 31, a photoelectric pulse wave detection sensor 32, a measurement data transmitter 65, and a display unit 71.

[0014] The blood pressure measurement device 2 is a device that measures the blood pressure of a subject by a non-invasive blood pressure (NIBP) measurement method, and includes a cuff 21, an exhaust valve 22, a pressure pump 23, a pressure sensor 24, a cuff pressure detection unit 25, and an A / D converter 26. Specifically, as shown in FIG. 2, the blood pressure measurement device 2 measures blood pressure by attaching the cuff 21 to the upper arm of the subject.

[0015] The cuff 21 is opened or closed to the atmosphere by the opening and closing of the exhaust valve 22. The exhaust valve 22 is opened and closed based on a control signal output from the display device 1. Air is also supplied to the cuff 21 from the pressurizing pump 23. The supply of air is controlled based on a control signal output from the display device 1.

[0016] Furthermore, a pressure sensor 24 is connected to the cuff 21, and the sensor output of the pressure sensor 24 is detected by the cuff pressure detection unit 25. The sensor output from the cuff pressure detection unit 25 is converted into a digital signal by the A / D converter 26 and then input to the pulse pressure acquisition unit 11 of the display device 1.

[0017] As shown in Figure 2, the electrocardiogram electrode 31 is attached to the subject's chest and measures the time interval using the R wave generation point of the electrocardiogram as the reference point. The electrocardiogram electrode 31 is also electrically connected to the measurement data transmitter 65. The measurement data from the electrocardiogram electrode 31 is input to the measurement data transmitter 65 and wirelessly transmitted from the measurement data transmitter 65 to the time interval detection unit 36 ​​of the display device 1 shown in Figure 1.

[0018] As shown in Figure 2, the photoelectric pulse wave detection sensor 32 is attached to the peripheral part of the subject, such as a finger, to measure, for example, a pulse wave. The pulse wave transit time (PWTT) is obtained from the measurement data obtained from the electrocardiogram electrodes 31 and the pulse wave obtained from the photoelectric pulse wave detection sensor 32. The photoelectric pulse wave detection sensor 32 is electrically connected to the measurement data transmitter 65. The measurement data from the photoelectric pulse wave detection sensor 32 is input to the measurement data transmitter 65 and wirelessly transmitted from the measurement data transmitter 65 to the pulse wave detection unit 33 in the display device 1 shown in Figure 1.

[0019] The respiratory measurement device 4 continuously measures the subject's respiration. The measurement data obtained by the respiratory measurement device 4 is input to the respiratory rate acquisition unit 41 of the display device 1.

[0020] The reception unit 6 receives input operations from the operator and generates instruction signals corresponding to those input operations. The reception unit 6 is, for example, a touch panel placed on top of the display unit 71 (described later), operation buttons provided on the housing of the display device 1, or a mouse or keyboard connected to an input / output interface (not shown) (for example, a USB interface). The instruction signals generated by the reception unit 6 are input to the display device 1.

[0021] [Display device configuration] The display device 1 comprises a pulse wave detection unit 33, an A / D converter 34, a time interval detection unit 36, a calculation unit 70, a display control unit 72, and a receiving unit 74. The calculation unit 70 includes a pulse pressure acquisition unit 11, a heart rate acquisition unit 12, a pulse wave propagation time acquisition unit 13, a pulse wave propagation time respiratory variation acquisition unit 14, a pulse wave amplitude acquisition unit 15, a pulse wave amplitude respiratory variation acquisition unit 16, a hemodynamic calculation unit 17, an intrinsic coefficient calculation unit 18, a storage unit 19, and a respiratory rate acquisition unit 41.

[0022] The time interval detection unit 36 ​​acquires an electrocardiogram waveform based on the measurement data received from the electrocardiogram electrodes 31 via the measurement data transmitter 65. The time interval detection unit 36 ​​also converts the measurement data into a digital signal and outputs it to the heart rate acquisition unit 12 and pulse wave propagation time acquisition unit 13 of the calculation unit 70.

[0023] The pulse wave detection unit 33 acquires the waveform of the peripheral portion of the photoelectric pulse wave based on the measurement data received from the photoelectric pulse wave detection sensor 32 via the measurement data transmitter 65. The pulse wave detection unit 33 then outputs the measurement data to the A / D converter 34. The A / D converter 34 converts the measurement data into a digital signal and outputs it to the pulse wave propagation time acquisition unit 13 and the pulse wave amplitude acquisition unit 15 of the calculation unit 70.

[0024] The pulse pressure acquisition unit 11 measures the subject's pulse pressure (PP) based on blood pressure data measured by the blood pressure measuring device 2. Pulse pressure PP is calculated, for example, from the difference between the systolic (maximum) blood pressure value and the diastolic (minimum) blood pressure value. The measured pulse pressure PP is input to the intrinsic coefficient calculation unit 18. The pulse pressure acquisition unit 11 also stores the pulse pressure PP and the current time in the storage unit 19, for example.

[0025] The heart rate acquisition unit 12 calculates the number of beats per minute (heart rate, HR) based on a reference point (R wave generation time) measured by the time interval detection unit 36. The calculated heart rate (HR) is input to the hemodynamic calculation unit 17.

[0026] The pulse wave propagation time acquisition unit 13 calculates the pulse wave propagation time (PWTT), which is the time it takes for the R wave of the electrocardiogram to reach the peripheral SpO2 pulse wave, based on the reference point (R wave generation time) measured by the time interval detection unit 36 ​​and the peripheral waveform detected by the photoelectric pulse wave detection sensor 32. The pulse wave propagation time acquisition unit 13 then outputs the calculated pulse wave propagation time (PWTT) to the hemodynamic calculation unit 17 and the pulse wave propagation time respiratory variation acquisition unit 14.

[0027] The respiratory rate acquisition unit 41 detects the subject's respiratory cycle based on the respiratory data measured by the respiratory measurement device 4. For example, the respiratory measurement device 4 is a detector that detects the concentration of carbon dioxide in exhaled breath. Based on the detection results from the respiratory measurement device 4, the respiratory rate acquisition unit 41 identifies at least one of the subject's breathing start timing and end timing. Then, based on these identified timings, the respiratory rate acquisition unit 41 detects the subject's respiratory cycle.

[0028] Furthermore, the respiratory rate acquisition unit 41 detects the subject's respiratory rate (RR) per minute based on the respiratory data. The respiratory rate acquisition unit 41 then inputs the detected respiratory cycle and respiratory rate RR to the pulse wave propagation time respiratory variation acquisition unit 14, the pulse wave amplitude respiratory variation acquisition unit 16, and the hemodynamic calculation unit 17. For example, as a respiratory cycle notification, the respiratory rate acquisition unit 41 notifies at least one of the start and end timings of the respiratory cycle.

[0029] Furthermore, the respiratory measurement device 4 is not limited to a device that detects the concentration of carbon dioxide in exhaled breath; it may also be a device that measures the subject's respiration using impedance changes, or a device that measures anesthetic gases output from an anesthesia machine, etc.

[0030] Furthermore, the biological information processing device M may not be configured to include the respiratory measurement device 4. In this case, the biological information processing device M determines at least one of the start and end timings of the respiratory cycle, for example, by setting the length of one respiratory cycle to a fixed value such as 20 seconds.

[0031] The pulse wave propagation time respiratory variation acquisition unit 14 measures the respiratory variation of the pulse wave propagation time PWTT based on the pulse wave propagation time PWTT calculated by the pulse wave propagation time acquisition unit 13 and the respiratory cycle detected by the respiratory rate acquisition unit 41. The measurement data showing the respiratory variation of the measured pulse wave propagation time PWTT is input to the intrinsic coefficient calculation unit 18.

[0032] The pulse wave amplitude acquisition unit 15 measures the amplitude of the pulse wave from the peripheral waveform acquired by the pulse wave detection unit 33. The measured pulse wave amplitude is input to the pulse wave amplitude respiratory variation acquisition unit 16.

[0033] The pulse wave amplitude respiratory variation acquisition unit 16 measures the respiratory variation (PAV) of the pulse wave amplitude based on the pulse wave amplitude measured by the pulse wave amplitude acquisition unit 15 and the respiratory cycle detected by the respiratory rate acquisition unit 41. The measured respiratory variation PAV of the pulse wave amplitude is input to the intrinsic coefficient calculation unit 18.

[0034] The unique coefficient calculation unit 18 calculates subject-specific coefficients based on the pulse pressure PP measured by the pulse pressure acquisition unit 11, the respiratory variation of the pulse wave propagation time PWTT measured by the pulse wave propagation time respiratory variation acquisition unit 14, and the respiratory variation of the pulse wave amplitude PAV measured by the pulse wave amplitude respiratory variation acquisition unit 16. The calculated coefficients are, for example, the coefficients K, α, and β described later, and are input to the hemodynamic calculation unit 17.

[0035] [Configuration of the circulatory dynamics calculation unit] (Calculation of respiratory variability in hemodynamic parameters) Figure 3 shows the configuration of the circulatory dynamics calculation unit 17 shown in Figure 1. As shown in Figure 3, the circulatory dynamics calculation unit 17 includes a parameter calculation unit 81, an HR / RR calculation unit 82, a period setting unit 83, and a variability rate calculation unit 84.

[0036] The parameter calculation unit 81 calculates the subject's hemodynamic parameters based on the heart rate (HR) calculated by the heart rate acquisition unit 12, the pulse wave time (PWTT) measured by the pulse wave time acquisition unit 13, and the coefficients K, α, and β calculated by the intrinsic coefficient calculation unit 18. As a hemodynamic parameter, the parameter calculation unit 81 calculates, for example, the flow rate of blood flowing into the aorta during cardiac systole (stroke volume, SV).

[0037] There is a correlation between stroke volume (SV) and pulse wave propagation time (PWTT), as shown in Equation 1. In Equation 1, K, α, and β are subject-specific coefficients. SV = K * (α * PWTT + β) ... (Equation 1)

[0038] The parameter calculation unit 81 substitutes the coefficients K, α, and β calculated by the intrinsic coefficient calculation unit 18 into Equation 1. The parameter calculation unit 81 also substitutes, for example, the pulse wave propagation time PWTT received from the pulse wave propagation time acquisition unit 13 into PWTT in Equation 1. This allows the parameter calculation unit 81 to calculate the stroke volume SV. The stroke volume SV calculated by the parameter calculation unit 81 will hereinafter be referred to as "stroke volume esSV".

[0039] The parameter calculation unit 81 periodically calculates the stroke volume esSV, associates the calculated stroke volume esSV with the calculation timing, and stores it in the storage unit 19 shown in Figure 1.

[0040] The variability calculation unit 84, for example, upon receiving input of a newly detected respiratory cycle by the respiratory rate acquisition unit 41, calculates the respiratory variation of the hemodynamic parameters over a predetermined period based on that respiratory cycle. The predetermined period is the length of the most recent one or more respiratory cycles.

[0041] Here, the predetermined period is defined as the most recent respiratory cycle detected by the respiratory rate acquisition unit 41. In this case, the variability calculation unit 84 reads out the multiple stroke volumes esSV stored in the memory unit 19 that were calculated for the most recent respiratory cycle.

[0042] The variability calculation unit 84 then identifies the maximum value esSVmax and the minimum value esSVmin from the read stroke volume esSV. Using the maximum value esSVmax and the minimum value esSVmin, the variability calculation unit 84 can calculate the respiratory variability (Stroke Volume Variation, SVV) of the stroke volume esSV as shown in Equation 2 below. The variability calculation unit 84 stores the calculated respiratory variability SVV in the storage unit 19. SVV=2*(esSVmax-esSVmin) / (esSVmax+esSVmin)...(Formula 2)

[0043] The variability calculation unit 84 may calculate the respiratory variability (PPV) of pulse pressure PP measured by the pulse pressure acquisition unit 11 shown in Figure 1 as the respiratory variability (SVV) of stroke volume esSV, instead of the respiratory variability (SVV) of stroke volume esSV, as the respiratory variability of hemodynamic parameters over a predetermined period.

[0044] For example, when the variability calculation unit 84 receives input of a newly detected respiratory cycle from the respiratory rate acquisition unit 41, it reads out multiple pulse pressure PPs from the multiple pulse pressure PPs stored in the memory unit 19 that were measured during the most recent respiratory cycle.

[0045] The variability calculation unit 84 then identifies the maximum value PPmax and the minimum value PPmin of the read pulse pressure PP. Using the maximum value PPmax and the minimum value PPmin, the variability calculation unit 84 can calculate the respiratory variability PPV of pulse pressure PP as shown in Equation 3 below. The variability calculation unit 84 stores the calculated respiratory variability PPV in the storage unit 19. PPV=2*(PPmax-PPmin) / (PPmax+PPmin)...(Formula 3)

[0046] (Display of respiratory fluctuations) The display control unit 72 controls the output of the circulatory dynamics parameters and the respiratory fluctuations of the circulatory dynamics parameters, calculated by the fluctuation rate calculation unit 84, to the display unit 71, which is a monitor or similar device. As a result, the display unit 71 displays a screen including the circulatory dynamics parameters and the respiratory fluctuations of the circulatory dynamics parameters.

[0047] Figure 4 shows an example of the screen displayed on the display unit 71 shown in Figure 1. As shown in Figure 4, the screen displayed on the display unit 71 shows the subject's latest heart rate (HR), blood pressure, non-invasive continuous estimated cardiac output (esCCO), and stroke volume (esSV). The screen also includes a region R for setting hemodynamic parameters, as will be described later. Region R is displayed, for example, when a menu button (not shown) displayed on the screen is selected by the operator.

[0048] The display control unit 72 periodically refers to the storage unit 19, for example, and controls the system so that the latest hemodynamic parameters are displayed on the screen. In the example shown in Figure 4, the non-invasive continuous estimated cardiac output (esCCO) value of "3.73" and the stroke volume (esSV) value of "47" are displayed as examples of the latest hemodynamic parameters.

[0049] Furthermore, the display control unit 72 periodically refers to the memory unit 19, for example, and controls the display so that the latest respiratory fluctuations of the hemodynamic parameters are shown on the screen. In the example shown in Figure 4, as indicated by arrow A, the respiratory fluctuation SVV value "3.1" is displayed as an example of the latest respiratory fluctuations of the hemodynamic parameters.

[0050] (Setting a predetermined period) Here, if the predetermined period is the most recent respiratory cycle, the number of beats included in that predetermined period may be small, and in such cases, there is a problem that the number of hemodynamic parameter data used to calculate respiratory variability (hereinafter referred to as "number of data used") is insufficient.

[0051] Specifically, Non-Patent Literature 1 states that a condition for detecting respiratory variability in hemodynamic parameters is that the value obtained by dividing the heart rate (HR) by the respiratory rate (RR) (HR / RR) is greater than 3.6. The HR / RR value corresponds to the number of heartbeats included in one respiratory cycle. Hereafter, HR / RR will also be referred to as "beats per breath". Generally, in healthy adults, the heart rate (HR) is approximately 80, the respiratory rate (RR) is approximately 12, and the beats per breath (HR / RR) is approximately 6.7.

[0052] If the heart rate (HR) is low or the respiratory rate (RR) is high, resulting in a heart rate / respiratory rate (HR / RR) of 3.6 or less per breath, the number of hemodynamic parameter data points calculated for one respiratory cycle, i.e., the number of usable data points, is insufficient. For this reason, the hemodynamic calculation unit 17 shown in Figure 3 can change the length of a predetermined period used to calculate respiratory variability (SVV) and respiratory variability (PPV).

[0053] (a) Displaying the settings screen As shown in Figure 4, region R contains multiple tabs Tb. These multiple tabs Tb include, for example, tab Tb1 for selecting the display of circulatory dynamics parameters, and tab Tb2 for selecting the display of a setting screen for a predetermined period. Tab Tb1 is labeled with the text, for example, "esCCO". Tab Tb2 is labeled with the text, for example, "esSVV settings". Figure 4 shows the screen displayed when an operator selects tab Tb1 and then tab Tb2, as input operations performed on the reception unit 6 shown in Figure 1.

[0054] When the above-described input operation is performed, the reception unit 6 outputs an instruction signal indicating the content of the input operation to the receiving unit 74 of the display device 1. When the receiving unit 74 receives the instruction signal output from the reception unit 6, it outputs the instruction signal to the display control unit 72. When the display control unit 72 receives the instruction signal output from the receiving unit 74, it controls the display so that a setting screen as shown in Figure 4 is displayed in area R.

[0055] The settings screen includes a selection button B11 for manually changing the length of a predetermined period, a selection button B12 for automatically changing the length of a predetermined period, a window W1 that displays the number of respiratory cycles included in the predetermined period (hereinafter also simply referred to as "number of cycles"), a window W2 that displays the value of the heart rate / Rapid response (HR / RR) during one breath, a selection button B21 for increasing the number of cycles, and a selection button B22 for decreasing the number of cycles.

[0056] The HR / RR calculation unit 82 shown in Figure 3 uses the heart rate HR calculated by the heart rate acquisition unit 12 and the respiratory rate RR detected by the respiratory rate acquisition unit 41 to calculate the HR / RR per breath, for example, periodically. The HR / RR calculation unit 82 then stores the calculated HR / RR per breath in the storage unit 19. The display control unit 72 controls the display of the latest HR / RR per breath stored in the storage unit 19 in window W2.

[0057] The operator can select either selection button B11 or selection button B12. If the operator has not selected either selection button B11 or selection button B12, selection button B11 is automatically selected. In other words, in this state, the circulatory dynamics calculation unit 17 operates in manual mode, as described later, and does not change the length of the predetermined period when there is no operation from the operator.

[0058] Furthermore, the operator can select selection buttons B21 and B22. For example, suppose the operator selects selection button B21. In this case, the reception unit 6 shown in Figure 1 outputs an instruction signal (setting information) indicating the content of the operation to the receiving unit 74. When the receiving unit 74 receives the instruction signal output from the reception unit 6, it outputs the instruction signal to the display control unit 72 and the calculation unit 70. When the display control unit 72 receives the instruction signal output from the receiving unit 74, it increments the number displayed in window W1 by one.

[0059] Of the calculation unit 70, the period setting unit 83 shown in Figure 3 sets the length of a predetermined period based on the respiratory cycle detected by the respiratory rate acquisition unit 41 and the number of cycles set on the setting screen. More specifically, when the period setting unit 83 receives an instruction signal from the receiving unit 74 indicating that the selection button B21 has been selected, it increases the number of cycles by one based on the instruction signal and readjusts the length of the predetermined period so that the period of the increased number of cycles becomes the predetermined period. The period setting unit 83 then notifies the fluctuation rate calculation unit 84 of the readjusted predetermined period.

[0060] For example, suppose an operator performs an operation to select selection button B22 to the reception unit 6. In this case, the reception unit 6 outputs an instruction signal indicating the content of the operation to the receiving unit 74. When the receiving unit 74 receives the instruction signal output from the reception unit 6, it outputs the instruction signal to the display control unit 72 and the calculation unit 70. When the display control unit 72 receives the instruction signal output from the receiving unit 74, it decreases the number displayed in window W1 by one.

[0061] When the period setting unit 83 of the calculation unit 70 receives an instruction signal from the receiving unit 74 indicating that the selection button B22 has been selected, it decreases the number of cycles by one based on the instruction signal and readjusts the length of the predetermined period so that the period of the reduced number of cycles becomes the predetermined period. The period setting unit 83 then notifies the fluctuation rate calculation unit 84 of the readjusted predetermined period.

[0062] The variability calculation unit 84 calculates the respiratory variability (SVV) and PPV of the hemodynamic parameters using a plurality of hemodynamic parameters calculated during a predetermined period, based on a predetermined period notified by the period setting unit 83.

[0063] Figure 5 is a diagram illustrating how the number of data points used to calculate respiratory variability (SVV) and PPV changes depending on the number of cycles set in the settings screen shown in Figure 4. In Figure 5, graph G1 shows the respiratory waveform based on the measurement data measured by the respiratory measurement device 4 shown in Figure 1, and graph G2 shows the electrocardiogram waveform based on the measurement data from the electrocardiogram electrodes 31 shown in Figure 1.

[0064] When the respiratory waveform shown in graph G1 and the electrocardiogram waveform shown in graph G2 are obtained, if the number of cycles included in a predetermined period is "1", the number of beats included in that predetermined period will be "3". If the number of cycles included in a predetermined period is "2", the number of beats included in that predetermined period will be "5". Thus, as the number of cycles increases, the number of beats increases, and the number of data points used to calculate respiratory variability (SVV) and PPV increases.

[0065] (b) Manual mode Figure 6 illustrates the state in which the length of a predetermined period is changed manually by the operator using the period setting unit 83 shown in Figure 3. Here, we will explain the case in which the respiratory variation SVV of stroke volume esSV is calculated and displayed as a respiratory variation of hemodynamic parameters.

[0066] In Figure 6, the settings screen is displayed for region R, similar to Figure 4. Furthermore, it is assumed that the selection button B11 is selected on the settings screen. In this case, the circulatory dynamics calculation unit 17 operates in manual mode.

[0067] As shown in Figure 6, let's assume that "1" is displayed in window W1 and "1.8" is displayed in window W2. In the following explanation, we will assume that the threshold for heart rate / reciprocal rate (HR / RR) per breath is "3.6". In this case, a heart rate / reciprocal rate of "1.8" per breath is below the threshold.

[0068] The display control unit 72 controls the system so that the operator can easily recognize that the HR / RR during one breath is below a threshold, for example, by displaying the border of window W2 in red on the screen.

[0069] When the variability calculation unit 84 receives a new respiratory cycle notification from the respiratory rate acquisition unit 41, it reads out multiple stroke volumes esSV calculated for the most recent respiratory cycle. As described above, if the heart rate / Ratio during one breath is below the threshold, the number of data points read out by the variability calculation unit 84 will also be below the threshold. In such cases, the variability calculation unit 84 does not calculate respiratory variability SVV, and instead stores an error value indicating an error in the storage unit 19, for example.

[0070] The display control unit 72 reads out the error value as the respiratory variation of the latest hemodynamic parameters stored in the memory unit 19. The display control unit 72 then controls the screen to display "---" to indicate that the respiratory variation SVV of the hemodynamic parameters cannot be calculated, for example, as shown by arrow A in Figure 6.

[0071] In this state, suppose the operator selects the selection button B21. In this case, the number displayed in window W1 changes from "1" to "2". The period setting unit 83 increases the number of cycles from "1" to "2" and sets a predetermined period using the increased number of cycles "2". Then, the period setting unit 83 notifies the fluctuation rate calculation unit 84 of the set predetermined period.

[0072] When the variability calculation unit 84 receives notification of a predetermined period from the period setting unit 83, it reads out multiple stroke volume esSV calculated during that predetermined period. Then, if the number of stroke volume esSV data read out, i.e., the number of data used, is greater than or equal to a threshold, the variability calculation unit 84 calculates respiratory variability SVV using these multiple stroke volume esSV. As a result, respiratory variability SVV is displayed on the screen.

[0073] Furthermore, if the number of data points used remains below the threshold, the variability calculation unit 84 determines that it cannot calculate the respiratory variability (SVV) and, for example, saves an error value to the storage unit 19. In this case, the screen continues to display an indication that the respiratory variability (SVV) cannot be calculated.

[0074] (c) Automatic mode Figures 7 to 9 illustrate the state in which the length of a predetermined period is automatically changed by the period setting unit 83 shown in Figure 3. Figures 7 to 9 show the screen when the selection button B12 is selected by the operator on the setting screen.

[0075] As shown in Figure 1, when an input operation as described above is performed, the receiving unit 6 outputs an instruction signal indicating the content of the input operation to the receiving unit 74 of the display device 1. When the receiving unit 74 receives the instruction signal output from the receiving unit 6, it outputs the instruction signal to the calculation unit 70.

[0076] The circulatory dynamics calculation unit 17 in the calculation unit 70 operates in the manual mode described above until it receives an instruction signal indicating that the selection button B12 has been selected. On the other hand, once the circulatory dynamics calculation unit 17 receives the instruction signal, it operates in automatic mode.

[0077] More specifically, the period setting unit 83 increases the number of cycles so that the predetermined period becomes longer until the number of data used exceeds a threshold. Specifically, as shown in Figure 7, the heart rate per breath (HR / RR) displayed in window W2 is "1.8". In this case, the variability calculation unit 84 notifies the period setting unit 83 that the number of data used is below the threshold, similar to the case shown in Figure 6.

[0078] When the period setting unit 83 receives notification that the number of data used is below a threshold, it increases the number of cycles by one and resets the predetermined period, and notifies the fluctuation rate calculation unit 84 and the display control unit 72 of the reset predetermined period. The period setting unit 83 also notifies the display control unit 72 of the increased number of cycles.

[0079] When the display control unit 72 receives notification of the number of cycles from the period setting unit 83, it controls the system so that the notified number of cycles is displayed in window W1. Specifically, the display control unit 72 changes the "1" displayed in window W1 in Figure 7 to "2" as shown in Figure 8.

[0080] When the variability calculation unit 84 receives notification of a predetermined period from the period setting unit 83, it reads out multiple stroke volumes esSV calculated during the notified predetermined period and attempts to calculate respiratory variability SVV.

[0081] Here, we assume that the number of data points used in the two respiratory cycles read by the variability calculation unit 84 is still below the threshold. In this case, as shown by arrow A in Figure 8, the screen continues to display that respiratory variability (SVV) cannot be calculated. The variability calculation unit 84 also notifies the period setting unit 83 again that the number of data points used is below the threshold.

[0082] When the period setting unit 83 receives notification again that the number of data used is below the threshold, it increases the number of cycles by one and resets the predetermined period, and notifies the fluctuation rate calculation unit 84 and the display control unit 72 of the reset predetermined period. The period setting unit 83 also notifies the display control unit 72 of the increased number of cycles.

[0083] When the display control unit 72 receives notification of the number of cycles from the period setting unit 83, it performs control to change the "2" displayed in window W1 in Figure 8 to "3" as shown in Figure 9.

[0084] When the variability calculation unit 84 receives notification of a predetermined period from the period setting unit 83, it reads out multiple stroke volumes esSV calculated during the notified predetermined period and attempts to calculate respiratory variability SVV. Here, it is assumed that the number of usage data included in the three respiratory cycles read out by the variability calculation unit 84 is greater than or equal to a threshold, and respiratory variability SVV is calculated. In this case, as shown by arrow A in Figure 9, the value of respiratory variability SVV, for example "3.1", is displayed on the screen. Also, in this case, for example, the red color on the edge of window W2 disappears.

[0085] [Operation Flow] (Overview of the overall operation) Figure 10 is a flowchart illustrating the general flow of operations when the biological information processing device M according to the embodiment of this disclosure calculates and displays respiratory fluctuations of hemodynamic parameters. Here, we will explain the case in which the respiratory fluctuation SVV of stroke volume esSV is calculated and displayed as a respiratory fluctuation of hemodynamic parameters.

[0086] Referring to Figure 10, first, when the operator starts the biometric information processing device M, each acquisition unit in the calculation unit 70 performs measurements, etc. Specifically, the heart rate acquisition unit 12 calculates the heart rate HR (step S11), and the respiratory rate acquisition unit 41 detects the respiratory cycle and respiratory rate RR (step S12).

[0087] Next, the HR / RR calculation unit 82 in the hemodynamic calculation unit 17 calculates the number of beats per breath (HR / RR) using the heart rate (HR) calculated in step S11 and the respiratory rate (RR) detected in step S12. The HR / RR calculation unit 82 then stores the calculated number of beats per breath (HR / RR) in the storage unit 19 (step S13).

[0088] Next, the parameter calculation unit 81 in the hemodynamic calculation unit 17 calculates the stroke volume esSV based on the heart rate HR and other values ​​calculated in step S11, and stores the calculated stroke volume esSV in the storage unit 19 (step S14).

[0089] Next, suppose the operator selects, for example, a menu button on the screen, which displays area R, and then, within area R, selects tab Tb2 for selecting the display of the settings screen. In this case, the display control unit 72 controls the display unit 71 so that the settings screen shown in Figure 4 is displayed (step S15).

[0090] Next, the circulatory dynamics calculation unit 17 checks whether it has received an instruction signal indicating that the operator has selected selection button B12 (step S16). If the circulatory dynamics calculation unit 17 has not received an instruction signal indicating the content of the operation (NO in step S16), it operates in manual mode (step S17).

[0091] On the other hand, the circulation dynamics calculation unit 17 operates in automatic mode (step S18) when it receives an instruction signal indicating that the operator has selected the selection button B12 (YES in step S16).

[0092] (Operation flow in manual mode) Figure 11 is a flowchart illustrating the operation flow when the circulatory dynamics calculation unit 17 shown in Figure 1 is operating in manual mode.

[0093] Referring to Figure 11, first, when the variability calculation unit 84 receives a notification of a new respiratory cycle detected by the respiratory rate acquisition unit 41, it reads out multiple stroke volumes esSV calculated over a predetermined period based on the notified respiratory cycle. Here, the predetermined period corresponds to the most recent respiratory cycle (step S21).

[0094] Next, the variability calculation unit 84 determines whether or not respiratory variability (SVV) can be calculated by checking whether the number of stroke volumes (esSV) read out, i.e., the number of data used, is above a threshold (step S22).

[0095] The variability calculation unit 84 then determines that it can calculate respiratory variability (SVV) if the number of data points used is equal to or greater than a threshold (YES in step S22), and calculates the respiratory variability (SVV). The display control unit 72 then controls the display of the respiratory variability (SVV) calculated by the variability calculation unit 84 on the screen (step S23).

[0096] On the other hand, the variability calculation unit 84 determines that the respiratory variability (SVV) cannot be calculated if the number of data points used is less than a threshold (displaying "NO" in step S22), and outputs an error value as the respiratory variability (SVV). The display control unit 72 then controls the system to display, for example, "---" on the screen to indicate that the respiratory variability of the hemodynamic parameters cannot be calculated (step S24).

[0097] Next, the period setting unit 83 checks whether it has received an instruction signal indicating that the operator has performed an operation to select either selection button B21 or selection button B22 (step S25). If the period setting unit 83 has not received an instruction signal indicating the content of the operation (NO in step S25), it does not change the predetermined period and the operations from step S21 onwards are repeated.

[0098] On the other hand, when the period setting unit 83 receives an instruction signal indicating that the operator has selected either selection button B21 or selection button B22 (YES in step S25), it changes the number of cycles, which is the number of respiratory cycles included in the predetermined period, based on the instruction signal and resets the predetermined period (step S26). Then, the stroke volume esSV calculated for the reset predetermined period is read out (step S21), and the operations from step S22 onward are performed again.

[0099] (Operation flow in automatic mode) Figure 12 is a flowchart illustrating the operation flow when the circulatory dynamics calculation unit 17 shown in Figure 1 operates in automatic mode.

[0100] The operations from step S31 to step S33 shown in Figure 12 are the same as those from step S21 to step S23 shown in Figure 11, so a detailed explanation will not be repeated here. Once the respiratory variation SVV is calculated and displayed (step S33), the operations from step S31 onwards are performed again.

[0101] In step S32, the variability calculation unit 84 determines that it is not possible to calculate respiratory variability (SVV) if the number of data used is less than the threshold (NO in step S32). In this case, the variability calculation unit 84 notifies the period setting unit 83 that the number of data used is less than the threshold (step S34).

[0102] Next, when the period setting unit 83 receives notification of the above content from the fluctuation rate calculation unit 84, it increases the number of cycles by one and resets the predetermined period (step S35). Then, the stroke volume esSV calculated for the reset predetermined period is read out (step S31), and the operations from step S32 onwards are performed again.

[0103] Furthermore, regardless of whether it is operating in manual or automatic mode, the circulatory dynamics calculation unit 17 resets the cycle count to "1" after a predetermined time has elapsed since, for example, the number of breaths was increased. This prevents the cycle count from continuing to increase. The upper limit of the cycle count is, for example, "8".

[0104] As described above, in the biomedical information processing device M according to one aspect of this disclosure, the heart rate acquisition unit 12 acquires the subject's heart rate HR. The respiratory rate acquisition unit 41 acquires the subject's respiratory rate RR. The hemodynamic calculation unit 17 calculates the subject's hemodynamic parameters and calculates the respiratory variability SVV and PPV of the hemodynamic parameters based on a plurality of hemodynamic parameters calculated over a predetermined period. The display control unit 72 controls the output of the calculated respiratory variability SVV and PPV to the display unit 71. The hemodynamic calculation unit 17 further calculates the number of beats per breath HR / RR, which is the number of beats included in one respiratory cycle, using the heart rate HR and respiratory rate RR. The display control unit 72 further controls the output of a setting screen to the display unit 71, which is a setting screen for setting the length of a predetermined period and includes the number of beats per breath HR / RR. The hemodynamic calculation unit 17 then acquires setting information indicating the content set on the setting screen, sets the length of the predetermined period based on the acquired setting information, and calculates the respiratory variability SVV and PPV for the predetermined period after setting.

[0105] With this configuration, for example, the operator can determine whether the number of hemodynamic parameter data points used to calculate respiratory variability (SVV) and PPV, i.e., the number of hemodynamic parameter data points calculated over a predetermined period, is sufficient by checking the heart rate (HR / RR) per breath displayed on the display unit 71. If the operator determines that the number of data points is insufficient, they can extend the predetermined period in the settings screen to increase the number of data points. This allows for the calculation of respiratory variability (SVV) and PPV of hemodynamic parameters using a sufficient number of data points, thereby enabling more accurate monitoring of the subject's condition.

[0106] Furthermore, in a bio-information processing device M according to another aspect of this disclosure, the length of the predetermined period is the length of one or more respiratory cycles. The display control unit 72 controls the setting screen to display the number of respiratory cycles included in the predetermined period in a configurable manner. The hemodynamic calculation unit 17 then sets the length of the predetermined period based on the respiratory cycles detected based on at least one of the start timing and end timing of the subject's breathing, and the number of respiratory cycles set on the setting screen. In this way, the configuration that allows the number of respiratory cycles to be set on the setting screen allows the operator to easily change the length of the predetermined period.

[0107] Furthermore, in a bio-information processing device M according to another aspect of this disclosure, the respiratory rate acquisition unit 41 further determines at least one of the start timing and end timing of the subject's breathing based on the detection result from the respiratory measurement device 4 which detects the concentration of carbon dioxide in the subject's exhaled breath.

[0108] Generally, most cardiac output monitors have the function to measure the respiratory variation (SVV) of stroke volume (SV). However, since most of these devices are specialized in measuring cardiac output and its related parameters, they do not have a function to measure the respiratory cycle, and the respiratory cycle is treated as a fixed value. In contrast, the bio-information processing device M according to the present invention can more accurately determine the respiratory cycle through the above-described configuration, and therefore can more accurately calculate the respiratory variations (SVV, PPV) of hemodynamic parameters.

[0109] Furthermore, in a biomedical information processing device M according to another aspect of this disclosure, the display control unit 72 further controls the setting screen to display that it is possible to set an automatic change in the length of a predetermined period. The circulatory dynamics calculation unit 17 sets the predetermined period to a longer length if an automatic change in the length of a predetermined period is set on the setting screen and the number of usage data for circulatory dynamics parameters calculated during the predetermined period is less than a threshold. In this way, the length of the predetermined period is automatically changed according to the number of usage data for circulatory dynamics parameters calculated during the predetermined period, thereby reducing the workload for the operator.

[0110] Furthermore, in a biomedical information processing device M according to another aspect of this disclosure, when the hemodynamic calculation unit 17 automatically changes the length of a predetermined period, it increases the number of respiratory cycles included in the predetermined period until the number of data used exceeds a threshold, and sets the length of the predetermined period based on the respiratory cycle detected based on at least one of the start timing and end timing of the subject's breathing, as well as the number of respiratory cycles included in the predetermined period.

[0111] In this way, if the number of hemodynamic parameter data calculated during a predetermined period is less than a threshold, the number of respiratory cycles included in the predetermined period is increased, and if the number of data exceeds the threshold, the increase in the number of respiratory cycles included in the predetermined period is terminated. This configuration makes it possible to set the number of data used to calculate the respiratory variability (SVV) and PPV of hemodynamic parameters to an appropriate number.

[0112] Furthermore, in a biological information processing device M according to another aspect of this disclosure, the hemodynamic calculation unit 17 does not calculate respiratory variability (SVV) and PPV if the number of hemodynamic parameter data calculated during a predetermined period is less than a threshold. This configuration avoids the calculation and display of inaccurate respiratory variability (SVV) and PPV, allowing operators to more accurately monitor the subject's biological information.

[0113] Although embodiments of this disclosure have been described above, the technical scope of this application should not be interpreted as being limited by the description of these embodiments. These embodiments are examples, and it will be understood by those skilled in the art that various modifications to the embodiments are possible within the scope of the invention described in the claims. The technical scope of this application should be determined based on the scope of the invention described in the claims and the scope of its equivalents. [Explanation of symbols]

[0114] M: Biometric information processing device (biometric information display device), 1: Display device, 2: Blood pressure measuring device, 4: Respiratory measuring device, 6: Reception unit, 11: Pulse pressure acquisition unit, 12: Heart rate acquisition unit, 13: Pulse wave propagation time acquisition unit, 14: Pulse wave propagation time respiratory variation acquisition unit, 15: Pulse wave amplitude acquisition unit, 16: Pulse wave amplitude respiratory variation acquisition unit, 17: Hemodynamic calculation unit, 18: Intrinsic coefficient calculation unit, 19: Memory unit, 41: Respiratory rate acquisition unit, 71: Display unit, 72: Display control unit, 74: Receiving unit, 81: Parameter calculation unit, 82: HR / RR calculation unit, 83: Period setting unit, 84: Variability calculation unit

Claims

1. A heart rate acquisition unit that acquires the heart rate of the subject, A respiratory rate acquisition unit that acquires the respiratory rate of the subject, A hemodynamic calculation unit calculates the hemodynamic parameters of the subject and calculates the respiratory variation of the hemodynamic parameters based on a plurality of hemodynamic parameters calculated over a predetermined period. The system includes a display control unit that controls the output of the respiratory fluctuations to the display unit, The hemodynamic calculation unit further calculates the number of beats per breath, which is the number of beats included in one respiratory cycle, using the heart rate and the respiratory rate. The display control unit further controls the output of a setting screen for setting the length of the predetermined period, which includes the number of beats per breath, to the display unit. The circulatory dynamics calculation unit acquires setting information indicating the content set on the setting screen, sets the length of the predetermined period based on the acquired setting information, and calculates the respiratory fluctuations during the predetermined period after setting. The display control unit further controls the setting screen to display the setting screen in a way that allows for automatic change of the length of the predetermined period. The circulatory dynamics calculation unit sets the predetermined period to a longer length when the automatic change of the predetermined period length is set on the setting screen and the number of circulatory dynamics parameter data calculated during the predetermined period is less than a threshold.

2. The length of the predetermined period is the length of one or more respiratory cycles. The display control unit performs control on the setting screen to display the number of respiratory cycles included in the predetermined period in a configurable manner. The bio-information display device according to claim 1, wherein the hemodynamic calculation unit sets the length of the predetermined period based on the respiratory cycle detected based on at least one of the start timing and end timing of the subject's breathing, and the number of respiratory cycles set on the setting screen.

3. The biometric information display device according to claim 2, wherein the respiratory rate acquisition unit further determines at least one of the start timing and end timing of the subject's breathing based on the detection result from a detector that detects the concentration of carbon dioxide in the subject's exhaled breath.

4. The length of the predetermined period is the length of one or more respiratory cycles. The bio-information display device according to claim 1 or 2, wherein the hemodynamic calculation unit, when performing an automatic change of the length of the predetermined period, increases the number of respiratory cycles included in the predetermined period until the number of data points exceeds the threshold, and sets the length of the predetermined period based on the respiratory cycle detected based on at least one of the start timing and end timing of the subject's breathing, and the number of respiratory cycles included in the predetermined period.

5. Steps to obtain the subject's heart rate, The steps include obtaining the respiratory rate of the subject, A step of calculating the number of beats per breath, which is the number of beats included in one respiratory cycle, using the heart rate and the respiratory rate. The steps include calculating the hemodynamic parameters of the subject, A setting screen for setting the length of a predetermined period, comprising the step of controlling the output of the setting screen, which includes the number of beats during one breath, to the display unit, The steps include setting the length of the predetermined period based on the settings screen, A step of calculating the respiratory variation of the hemodynamic parameters based on a plurality of hemodynamic parameters calculated during the set predetermined period, The step includes a step of performing control to output the respiratory fluctuations to the display unit, In the step of controlling the output of the setting screen to the display unit, further control is performed to display the setting screen in a way that allows automatic change of the length of the predetermined period to be set. A method for displaying biological information, wherein, in the step of calculating the respiratory variation of the hemodynamic parameters, if the automatic change of the length of the predetermined period is set on the setting screen, and the number of data points for the hemodynamic parameters calculated during the predetermined period is less than a threshold, the predetermined period is set to be longer.

6. A heart rate acquisition unit that acquires the heart rate of a subject, A respiratory rate acquisition unit that acquires the respiratory rate of the subject, A hemodynamic calculation unit calculates the hemodynamic parameters of the subject and calculates the respiratory variation of the hemodynamic parameters based on a plurality of hemodynamic parameters calculated over a predetermined period. The system includes a display control unit that controls the output of the respiratory fluctuations to the display unit, The hemodynamic calculation unit further calculates the number of beats per breath, which is the number of beats included in one respiratory cycle, using the heart rate and the respiratory rate. The display control unit further controls the output of a setting screen for setting the length of the predetermined period, which includes the number of beats per breath, to the display unit. The circulatory dynamics calculation unit acquires setting information indicating the content set on the setting screen, sets the length of the predetermined period based on the acquired setting information, and calculates the respiratory fluctuations during the predetermined period after setting. The circulatory dynamics calculation unit does not calculate the respiratory fluctuations if the number of circulatory dynamics parameter data calculated during the predetermined period is less than a threshold, in this biological information display device.

7. A step of obtaining the heart rate of a subject, The steps include obtaining the respiratory rate of the subject, A step of calculating the number of beats per breath, which is the number of beats included in one respiratory cycle, using the heart rate and the respiratory rate. The steps include calculating the hemodynamic parameters of the subject, A setting screen for setting the length of a predetermined period, comprising the step of controlling the output of the setting screen, which includes the number of beats during one breath, to the display unit, The steps include setting the length of the predetermined period based on the settings screen, A step of calculating the respiratory variation of the hemodynamic parameters based on a plurality of hemodynamic parameters calculated during the set predetermined period, The step includes a step of performing control to output the respiratory fluctuations to the display unit, A method for displaying biological information, wherein, in the step of calculating the respiratory variation of the hemodynamic parameters, if the number of data points for the hemodynamic parameters calculated during the predetermined period is less than a threshold, the calculation of the respiratory variation is not performed.

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