Respiration function examination simulator

Abstract

To provide a device or the like that enables the acquisition of a technique of precise examination at low costs.SOLUTION: In a flow sensor type spirometer not having a gas supply function and a gas concentration detection function, when a subject is being subjected to resting ventilation, a simulation of repeating calculation of He concentration according to actual exhalation and inhalation is executed, and thereby, the He concentration displayed in a display together with a spirogram gradually decreases and finally a stable equilibrium state is achieved.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a respiratory function test simulator that simulates a respiratory function test. [Background technology]

[0002] Conventionally, there are spirometers capable of measuring vital capacity (VC) and forced vital capacity (FVC) (see, for example, Patent Document 1, Patent Document 2, and Non-Patent Document 1). Among them, there are precision examination devices capable of supplying a test gas (e.g., helium (He)) to a subject and performing precision examinations such as functional residual capacity (FRC) (see, for example, Patent Document 2 and Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-153886 A [Patent Document 2] JP 2017-086704 A [Non-patent literature]

[0004] [Non-Patent Document 1] Respiratory Function Test Handbook (Japanese Respiratory Society, Pulmonary Physiology Specialist Committee) Medical Review Co., Ltd. Summary of the Invention [Problem to be solved by the invention]

[0005] Here, a spirometer test can only provide reliable test results if the subject inhales and exhales at the right timing and with the right intensity according to a specific test procedure. Therefore, it is extremely important that the test procedure and the subject's breathing are appropriate in clinical practice, and these are also included in the scope of questions in the National Medical Technologist Examination. For each test item, the examiner must learn the test procedure required and how to instruct the subject to breathe according to the test procedure. In light of this situation, it is considered preferable for the examiner to acquire skills not only through classroom learning, but also by using the spirometer that is actually used on the subject.

[0006] However, precision testing devices are expensive compared to airflow-type spirometers using pressure sensors (see, for example, Patent Document 1 and Non-Patent Document 1), and since the number of devices introduced to medical institutions is relatively small, it is difficult to learn the skills using the actual device. Furthermore, it is extremely difficult to introduce precision testing devices to educational institutions, and opportunities for students to experience precision testing are extremely limited. Even if precision testing devices were available, there would be a cost problem due to the use of testing gas to learn the skills of precision testing.

[0007] The present invention has been made in consideration of the above problems, and has an object to make it possible to acquire precision inspection techniques at low cost. [Means for solving the problem]

[0008] The above problems are solved by the following means. Note that, although the reference characters and the like used in the description and drawings of the embodiments of the invention described below are added in parentheses for reference, the components of the present invention are not limited to those added. Various changes and modifications can be made without departing from the technical scope of the present invention.

[0009] The first means is a respiratory function test simulator (1) that performs a simulation of a detailed examination related to gas concentration (FRC test, CV test, DLCO test), and is characterized by comprising a measurement unit (flow sensor 10, CPU 53) that measures respiratory flow or respiratory volume (spirogram and spirometry based on the spirogram, etc.), an output unit (display 56, speaker 58) that outputs guidance information corresponding to the detailed examination (type of gas used in the detailed examination, breathing method that the subject should perform), and a generation unit (CPU 53) that generates simulation data related to the detailed examination based on the data measured by the measurement unit.

[0010] The second means is the first means, wherein the guidance information is information on the gas used in the precision inspection (He in the case of the FRC inspection, O in the case of the CV inspection). 2 , and in the case of DLCO testing, four-type mixed gas) and breathing information to be instructed to the subject during the detailed examination (restful ventilation in the case of FRC testing, exhalation up to the maximum expiratory position and maintaining the expiratory flow rate within a specified range in the case of CV testing, inhalation up to the maximum inhalation position and breath holding at the maximum inhalation position and exhalation in one go in the case of DLCO testing).

[0011] The third means is characterized in that, in the first means, the generation unit generates a gas concentration curve based on data measured by the measurement unit (actual measurement data) and a predetermined value corresponding to a detailed examination (a reference value calculated by a reference value prediction formula based on the subject's data).

[0012] The fourth means is characterized in that, in the third means, the generation unit is capable of generating a first gas concentration curve based on data (actual measurement data) measured by the measurement unit and a first predetermined value calculated based on a prediction formula corresponding to a detailed examination (a reference value calculated by a reference value prediction formula based on the subject's data), and generates a second gas concentration curve having a degree of suitability different from the first gas concentration curve based on the data (actual measurement data) measured by the measurement unit and a second predetermined value corresponding to the detailed examination and different from the first predetermined value (for example, a set value obtained by multiplying the reference value by a predetermined coefficient).

[0013] The fifth means is any one of the first to fourth means, characterized in that the detailed examination is a functional residual capacity test (FRC), the guidance information includes information notifying the use of He and information instructing to perform quiet ventilation, and the generation unit generates a gas concentration curve indicating the He concentration.

[0014] The sixth means is any one of the first means to the fourth means, wherein the detailed examination is a closing volume examination (CV), and the guidance information is 2 The information includes information informing the user of the use of N, information instructing the user to exhale up to the maximum expiratory level, and information instructing the user to maintain the expiratory flow rate within a predetermined range. 2 A gas concentration curve is generated to indicate the concentration.

[0015] The seventh means is any one of the first means to the fourth means, wherein the detailed examination is a pulmonary diffusion test (DLCO), and the guidance information is CO, He, O 2、 N 2 The information includes information informing the user of the use of a four-type mixed gas including the above-mentioned, information instructing the user to inhale up to the maximum inhalation position, information instructing the user to hold the breath for a predetermined period at the maximum inhalation position, and information instructing the user to exhale in one gulp, and the generating unit generates a gas concentration curve indicating the CO concentration.

[0016] The eighth means is a program executed by a respiratory function test simulator (1) that executes a simulation of a detailed examination related to gas concentration (FRC test, CV test, DLCO test), and is characterized in that the program executes the following: measuring respiratory flow or respiratory volume (spirogram and spirometry based on the spirogram, etc.) by a measurement unit (flow sensor 10, CPU 53); outputting guidance information corresponding to the detailed examination (type of gas used in the detailed examination, breathing method that the subject should perform) by an output unit (display 56, speaker 58); and generating simulation data related to the detailed examination by a generation unit (CPU 53) based on the data measured by the measurement unit. Effect of the Invention

[0017] According to the present invention, it is possible to acquire precision testing techniques at low cost. [Brief description of the drawings]

[0018] [Figure 1] FIG. 2 is a diagram showing an example of a respiratory function test simulator according to the present embodiment. [Diagram 2] FIG. 1 is a diagram showing a comparison example between spirometry and detailed examination items. [Diagram 3] FIG. 13 is a diagram showing an example of a He concentration curve in an FRC inspection. [Figure 4] 1 is a flowchart showing an example of a simulation procedure for an FRC inspection. [Diagram 5] FIG. 13 is a diagram showing an example of calculating a He concentration. [Figure 6] FIG. 13 is a diagram showing an example of a simulation result of an FRC inspection. [Figure 7] FIG. 13 is a diagram showing an example of an N2 concentration curve in a CV test. [Figure 8] 1 is a flowchart showing an example of a simulation procedure for a CV inspection. [Figure 9] FIG. 13 is a diagram showing an example of a waveform of dummy data. [Figure 10] FIG. 13 is a diagram showing an example of a volume curve in a DLCO test. [Figure 11] 1 is a flowchart illustrating an example of a simulation procedure for a DLCO inspection. [Figure 12] FIG. 1 shows an example of a CO concentration curve in a DLCO test. [Figure 13] FIG. 13 is a diagram showing an example of a questionnaire result regarding detailed examination. [Figure 14] FIG. 13 is a diagram showing an example of a method for generating an N2 concentration curve. [Figure 15] FIG. 13 is a diagram showing an example of a method for generating an N2 concentration curve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

[0020] [Measurement function of the respiratory function test simulator] FIG. 1 is an explanatory diagram showing a respiratory function test simulator 1 according to this embodiment. In this embodiment, a flow sensor type spirometer is used as the respiratory function test simulator 1. Therefore, although it does not have the function of supplying test gas to the subject (and a sensor for measuring gas concentration), it is at least capable of measuring a spirogram (time-airflow curve) and can measure VC, FVC, and forced expiratory volume in 1 second (FEV 1 ), 1 second rate (FEV 1 / FVC) is obtained.

[0021] The respiratory function test simulator 1 is equipped with a respiratory function test flow sensor (hereinafter referred to as "flow sensor") 10. The flow sensor 10 is a flow detection unit that is attached to the mouth of a subject to measure the inhalation flow rate and exhalation flow rate of the subject. Information (signal) detected by the flow sensor 10 is a pressure difference signal (differential pressure signal before and after resistor 14) that has a one-to-one relationship (linear relationship) with the flow rate. This differential pressure signal is taken into the main body 50 and converted into a corresponding flow rate signal based on this differential pressure signal.

[0022] The flow sensor 10 is configured to include a resistor 14 that generates a pressure drop for inhalation and exhalation, a first pressure detection port 5a that detects the pressure (static pressure) on the subject side of the resistor 14, and a second pressure detection port 5b that detects the pressure (static pressure) on the opposite side of the resistor 14 from the subject. The resistor 14 generates a pressure difference (differential pressure) between the front and rear of the resistor 14 when the exhalation and inhalation pass through the resistor 14.

[0023] The main body 50 is equipped with a first pressure transmission tube 51a that transmits the pressure detected at the first pressure detection port 5a to the differential pressure sensor 51, a second pressure transmission tube 51b that transmits the pressure detected at the second pressure detection port 5b to the differential pressure sensor 51, the differential pressure sensor 51 that converts the differential pressure before and after the resistor 14 into a corresponding electrical signal, an A / D converter 52 that converts the electrical signal (analog signal) output by the differential pressure sensor 51 into a predetermined digital signal, a CPU 53 that executes a measurement program and calculates the flow rate of exhaled and inhaled air based on the converted digital signal, a RAM 54 that temporarily stores a digital signal related to the output signal of the differential pressure sensor 51 output by the A / D converter 52, a ROM 55 that stores the measurement program and measurement data including a calibration formula (relationship formula) between the flow rate and the output voltage of the differential pressure sensor 51, a display 56 that displays operation icons, measurement data, etc., a D / A converter 57 that generates an analog voltage corresponding to the digital signal from the CPU 53, and a speaker 58 that outputs operation guidance, etc. by voice.

[0024] The measurement data such as the flow rate and volume stored in the ROM 55 is transmitted to a controller 56a of the display 56. The controller 56a drives an LCD driver 56b based on a control signal from the CPU 53 to display the measurement data such as a spirogram on the display 56. The display 56 is equipped with a plurality of touch sensors (not shown), and the examiner operates the touch sensors to start and end a measurement program, input (including selection) measurement parameters, and the like.

[0025] [Simulation function of the respiratory function test simulator] The respiratory function test simulator 1 of this embodiment is capable of measuring a spirogram as described above, and is also capable of simulating a test that is usually performed by a precision testing device (Patent Document 2, Non-Patent Document 1). A simulation program for the precision test is stored in the ROM 55, and is executed by the CPU 53 based on the operation of the examiner.

[0026] FIG. 2 is a diagram explaining the difference between spirometry, which is a test item that can be obtained from a spirogram, and a test item of a detailed examination performed by supplying gas to a subject. Spirometry can be measured, for example, by a flow sensor type spirometer (see Patent Document 1), and is intended for screening of obstructive respiratory disorders and restrictive respiratory disorders. Spirometry includes VC, FVC, forced expiratory volume in 1 second, and rate in 1 second, as well as a flow volume curve. Since the gas inhaled by the subject is room air, the device can be made small and lightweight, and each test item is measured based on the airflow detected by a flow sensor.

[0027] On the other hand, detailed examination items can be measured by a volumetric spirometer (also called a rolling seal spirometer) that can make the subject inhale the test gas supplied into the cylinder by moving a bell in the cylinder in response to the subject's breathing, as shown in Patent Document 2 and Non-Patent Document 1, for example, and are intended to evaluate lung volume fraction, ventilation maldistribution, and gas exchange disorders. Spirometry can also be measured by a volumetric spirometer. Detailed examination items include functional residual capacity (FRC), closing volume (CV), and pulmonary diffusion capacity (DLCO), etc. FRC is performed by having the subject inhale a He mixed gas, and the He concentration is measured by a He sensor. CV is measured using 100% O 2 The test subject inhales N 2 The concentration is N 2 DLCO is measured by a four-gas mixture (He, CO, O 2 ,N 2 ) is inhaled by the subject, and the He concentration is measured by a He sensor, and the CO concentration is measured by a CO sensor.

[0028] As shown in Figure 2, the precision test items are items that cannot be measured with a flow sensor type spirometer. Therefore, normally, the skill must be acquired using an air volume type spirometer, but in this embodiment, as described below, the flow sensor type spirometer is provided with a precision test simulation function, making it possible to acquire precision test skills without using an air volume type spirometer.

[0029] In this embodiment, in regard to the simulation of a detailed examination, instead of simply displaying preset pseudo data, it is possible to present simulation data that is close to the behavior of actual data of a subject in a clinical setting by generating simulation data based on an actual spirogram obtained from the subject, thereby enabling the user to efficiently learn examination techniques.

[0030] The following formula shows an example of a method for calculating the gas concentration in this embodiment. Y = aX + b ... (Equation 1)

[0031] Y is the measured value, X is the gas concentration, a is the coefficient, and b is the intercept. In this way, when the relational equation between the measured value and the gas concentration is determined, the gas concentration can be calculated back by using a predicted value (which may be called a reference value) obtained by the reference value prediction equation based on the subject's actual data (age, sex, height, etc.) as the measured value, and a change curve of the gas concentration can be generated and displayed based on the back-calculated gas concentration and the actually measured spirogram. In the example of (Equation 1), the relationship between the measured value and the gas concentration is determined as a linear function, but it is not limited to this and may be determined as another function such as a quadratic function or a logarithmic function.

[0032] (FRC inspection simulation) The principle of the FRC test is that the lungs are connected to a circuit of known volume containing a known concentration of an indicator gas, and the patient is asked to breathe repeatedly. If the gas in both spaces is mixed sufficiently, the FRC can be calculated from the change in concentration of the indicator gas. Helium (He), which is not absorbed by the lungs, is often used as the indicator gas. As the subject rebreathes at the resting expiratory position until the He concentration reaches equilibrium, as shown in Figure 3, the He concentration curve gradually decreases from the peak with each quiet ventilation, and converges to the equilibrium concentration. In the simulation of the FRC test, this He concentration curve is reproduced.

[0033] FIG. 4 is a flow chart corresponding to the simulation of the FRC inspection. When the inspector selects an object for executing the FRC inspection simulation displayed on the display 56, the CPU 53 executes the simulation program, and the FRC inspection simulation is executed. The display 56 displays the O 2 gas, which is the inspection gas for the FRC. 2 A message prompting the user to prepare a He mixed gas is displayed (S110). In addition, a "Start Preparation" button is displayed to fill the cylinder with the test gas and prepare for the FRC measurement (S120). This information allows the tester to understand the type of test gas to be used in the FRC measurement.

[0034] When the examiner operates the "Preparation Start" button, the messages "Breathing Circuit Ventilation in Progress" and "Gas Injection in Progress" are displayed on the display 56 (S130). As described above, the respiratory function test simulator 1 is a flow sensor type spirometer and does not have a gas supply function, and these displays are pseudo, but the examiner can understand the process of the test gas being filled into the cylinder prior to the start of measurement. Note that a simulated sound of the test gas being filled into the cylinder may be output from the speaker 58 to make the environment closer to the actual test.

[0035] When the examiner operates the "Start measurement" button displayed on the display 56 after the messages "Respiratory circuit ventilation in progress" and "Gas injection in progress" have finished being displayed (after gas injection has been completed) (S140), the flow sensor 10 of the respiratory function test simulator 1 measures the subject's actual spirogram and displays it on the display 56 (S150). In addition, the display 56 displays the message "Please perform quiet ventilation" (S160). This allows the examiner to understand the process of having the subject inhale the test gas through quiet ventilation in the FRC test.

[0036] Next, the CPU 53 calculates the FRC predicted value (which may be called the FRC reference value) by a reference value prediction formula based on the actual data of the subject (age, sex, height, weight, etc.) as described above. The formula disclosed in Non-Patent Document 1 can be used as this reference value prediction formula. Note that the reference value prediction formula (reference value prediction formulas for FRC, and CV and DLCO described later) is not limited to that disclosed in Non-Patent Document 1, and other prediction formulas may be used. Furthermore, the actual data of the subject required for the reference value prediction formula may include not only age, sex, height, and weight, but also other data such as body surface area (BSA).

[0037] The following equation shows the relationship between the He concentration, the circuit capacitance, and the FRC. C1 (He concentration in the circuit before measurement begins) x (circuit capacity) = C2 (He concentration after equilibrium) × (circuit capacity + FRC) ... (Equation 2)

[0038] In this embodiment, the He concentration in the circuit before the start of measurement is set to 11%, and the calculated FRC prediction value is set to the FRC of (Equation 2), and the He concentration is calculated. In the example of FIG. 5(a), the capacity of the circuit before the start of measurement (before He inhalation) is shown as the FRC dead space volume, and the FRC dead space volume is 10.50L. The He amount in the circuit before the start of measurement is 11%×10.50L=1.155L. On the other hand, the FRC of the subject calculated based on the prediction formula is 3.38L, and since the subject has not inhaled He before the start of measurement, the He concentration in the lungs is 0%, and the He amount in the lungs is 0.0L. At this time, the sum of the He amount in the circuit and the He amount in the lungs is 1.155L.

[0039] As shown in Figure 5(b), when the subject inhales, the TV (TVI, which is equivalent to the inhaled volume of the tidal volume in this case) is subtracted from the FRC dead space volume, and the TV (TVI, in this case) is added to the FRC. In this example, 0.50L is inhaled, so 0.50L x 0.11% = 0.055L is taken into the lungs, the He concentration changes from 0% to 1.42%, and the amount of He in the circuit is 10.00L x 11% = 1.10L.

[0040] Next, as shown in Figure 5(c), when the subject exhales, the equivalent of TV (in this case, TVE, which is equivalent to the exhaled volume of the tidal volume) is subtracted from FRC+TV, and the equivalent of TV (in this case, TVE) is added to the FRC dead space volume after the subtraction. In this example, 0.50L is exhaled, so 0.50L x 1.42% = 0.0071L is returned to the circuit as the amount of He, and the amount of He in the circuit becomes 1.1071L, which is 10.54%.

[0041] As shown in Fig. 6, the gas concentration calculations in Fig. 5(b) and Fig. 5(c) are repeated in accordance with the subject's actual inhalation and exhalation, so that the He concentration displayed on the display 56 gradually decreases and finally reaches a stable equilibrium state (the rate of decrease in the He concentration falls within a predetermined range). In this example, as shown in Fig. 5(d), the He concentration is stable when the He concentration in the circuit and lungs reaches 8.33%, and the total amount of He in the circuit and the amount of He in the lungs remains at 1.155 L at this time. In this way, the examiner can understand how the He concentration changes due to the repeated quiet ventilation of the subject in the simulation of the FRC test (see Fig. 6).

[0042] 4, when the He concentration recalculated in accordance with the subject's quiet ventilation is stable (YES in S190), the CPU 53 notifies the user that the FRC test is ending by displaying "He concentration is stable" on the display 56 (S191). Then, the CPU 53 displays the test results (for example, the calculated FRC predicted value and other test results that can be obtained in the FRC test) on the display 56 (S200), and ends the simulation of the FRC test.

[0043] On the other hand, if the He concentration does not stabilize even after waiting for a predetermined period of time (NO in S190) due to an FRC value being set (not good) different from the predicted value (reference value) according to the reference value prediction formula, as described below, the CPU 53 displays an "End Measurement" button on the display 56 to end the FRC inspection (S192). Based on the examiner's operation of the "End Measurement" button, the inspection result (which may be the set FRC value or may be a result that the FRC could not be measured appropriately) is displayed on the display 56 (S200), and the simulation of the FRC inspection is ended.

[0044] If a precision test item cannot be measured properly, such as when the measurement ends before the He concentration stabilizes in the simulation of an FRC test, guidance that the item could not be measured properly may be given via the display 56 or speaker 58, and guidance may be given to write this fact as a comment in the electronic medical record, etc. (rather than leaving it unrecorded). This allows the examiner to understand how to deal with the case where the measurement ends with an irregular result.

[0045] In the example of Fig. 6, the He concentration smoothly decreases and reaches an equilibrium state, and the TV shown by the spirogram is stable at a constant amplitude. In this embodiment, by using a predicted value as the FRC, it is possible to reproduce a state in which the He concentration smoothly decreases and stabilizes by repeating quiet ventilation.

[0046] On the other hand, when the blockage is strong, the He concentration decreases to a certain extent, but it may take a long time to stabilize from there. In this embodiment, as described above, the predicted FRC value is used, but by setting an FRC value different from the predicted FRC value (for example, an FRC setting value obtained by multiplying the predicted FRC value by 1.2 as a coefficient), the He concentration when the blockage is strong can be reproduced. In this way, the examiner can experience both good and bad cases in the FRC inspection.

[0047] (CV inspection simulation) The CV test is a respiratory function test that detects uneven distribution of inspired air by flushing an indicator gas from the lungs. The indicator gas usually used is nitrogen (N 2 ) Figure 7 shows the N 2 FIG. 1 is an explanatory diagram showing the details of a concentration curve. 2 The concentration curve is a single exhalation curve, and is divided into four phases. The first phase is 100% O 2Phase 1 is dead space air only, phase 2 is a mixture of dead space air and alveolar air, phase 3 is alveolar air, and phase 4 is CV. Phase 3 shows a flat curve and is called the alveolar plateau. In this phase, pulsatile waves that correspond to the cardiac beat are observed. When alveolar air from various sites contributes to expiration at a constant rate, the alveolar plateau is formed. In phase 4, N increases toward the maximum expiratory level. 2 The concentration increases rapidly. The lung volume (expired volume) during the fourth phase is the CV.

[0048] FIG. 8 is a flow chart corresponding to the simulation of the CV inspection. When the inspector selects an object for executing the CV inspection simulation displayed on the display 56, the CPU 53 executes a simulation program, and the CV inspection simulation is executed. The display 56 displays the O 2 gas, which is an inhalation gas, 2 A message is displayed prompting the user to prepare the gas to be inhaled (S210). In addition, a "Start preparation" button is displayed to fill the cylinder with the gas to be inhaled and prepare for the CV measurement (S220). From this information, the examiner can understand the type of gas to be used in the CV measurement.

[0049] When the examiner operates the "Preparation Start" button, the messages "Respiratory circuit ventilation in progress" and "Gas injection in progress" are displayed on the display 56 (S230). After the display of the messages "Respiratory circuit ventilation in progress" and "Gas injection in progress" has ended (after gas injection has been completed), the examiner operates the "Measurement Start" button displayed on the display 56 (S240), and the actual spirogram of the subject is measured by the flow sensor 10 provided in the respiratory function test simulator 1 and displayed on the display 56 (S250). In addition, the message "Please perform quiet ventilation" is displayed on the display 56 (S260).

[0050] Next, the CPU 53 calculates a CV predicted value (which may be called a CV reference value) using a reference value prediction formula based on the actual data of the subject (age, sex, etc.) as described above. The formula disclosed in Non-Patent Document 1 can be used as this reference value prediction formula. ... previously prepared N 2 A calculation is performed to expand and contract the dummy data of the concentration curve in the direction of the expiratory volume, corresponding to the actual VC value (e.g., the value of a VC test performed prior to the CV test simulation) or the predicted VC value calculated using a reference value prediction formula based on the subject's data.

[0051] Here, for the fourth phase, a calculation is performed to expand and contract in the direction of the expiratory volume according to the predicted CV value, and the expansion amount is absorbed by the expansion and contraction of the third phase. If the expiratory volume assumed in the dummy data matches the measured VC or predicted VC value, there is no need to expand or contract the dummy data. Also, if the CV assumed in the dummy data matches the predicted CV value, there is no need to expand or contract the fourth phase.

[0052] In addition, standard dummy data may be prepared (stored in the ROM 55) for each data of the subject (age, sex, height, etc.), and the dummy data corresponding to the actual data of the subject (age, sex, height, etc.) may be selected and expanded or contracted. In this way, the dummy data expanded or contracted as necessary may be used as N 2 A concentration curve is provisionally set (S270). In addition, a plurality of dummy data corresponding to VC (for example, four dummy data of VC=2.5L, 3.5L, 4.5L, 5.5L) may be prepared, and the dummy data close to the VC of the actual subject may be selected and expanded or contracted.

[0053] Alternatively, one may be selected from a plurality of base waveforms (e.g., five, CV1, CV2, CV3, CV4, and CV5), and the selected base waveform may be expanded or contracted in the direction of the exhalation volume according to the actually measured exhalation volume. For example, one may be selected from a plurality of base waveforms in a predetermined order (e.g., the order CV1→CV2→CV3→CV4→CV5) for each measurement, or one may be selected based on a random number.

[0054] Then, a message urging the subject to exhale to the maximum expiratory level, "Please exhale slowly until you can no longer exhale," is displayed on the display 56 (S280). Next, a message urging the subject to inhale to the maximum inhalation level, "Please inhale slowly until you can no longer exhale," is displayed on the display 56 (S290). This message is to encourage the subject to inhale oxygen.

[0055] Next, the CPU 53 causes the display 56 to display a message encouraging the user to exhale to the maximum expiratory level, saying, "Exhale slowly until you can no longer exhale" (S300). The CPU 53 also causes the display 56 to display the flow actually measured by the flow sensor, and causes the display 56 to display a message instructing the user to maintain the expiratory rate within a predetermined range, saying, "Maintain the expiratory rate within the range of 0.3 to 0.5 L / s" (S310).

[0056] In addition, the CPU 53 controls the N 2 A concentration curve is generated (S320). 2 The generation of the concentration curve is performed using the provisionally set hidden N 2 The concentration curve is traced according to the breath volume being measured (N at the point corresponding to the breath volume). 2 This is done by displaying the concentration. 2The concentration appears to change in real time. For example, with regard to the third phase, when the expiratory flow (flow measured by the flow sensor) during measurement becomes less than a predetermined value (for example, less than 0.2 L / s), the third phase may be ended (the third phase portion of the provisionally set dummy data may be expanded or contracted) and the fourth phase may be started (the fourth phase portion of the provisionally set dummy data may be expanded or contracted and its tracing may be started).

[0057] Then, based on the detection of the inhalation after the expiration up to the maximum expiratory level is completed (S330), the CPU 53 2 Once the generation of the concentration curve is complete, the test results (eg, the calculated CV prediction value and other test results obtainable in the CV test) are displayed on the display 56 (S340), and the simulation of the CV test is completed.

[0058] In this embodiment, as described above, N 2 The predicted CV value is used to provisionally set the concentration curve, but by setting a CV value different from the predicted CV value (for example, a CV setting value obtained by multiplying the predicted CV value by 1.2 as a coefficient), the CV of the fourth phase can be increased, and the N 2 In this way, the examiner can experience both good and bad cases in the CV test.

[0059] (Simulation of DLCO inspection) FIG. 10 is an explanatory diagram showing the details of the volume curve in the DLCO test. In the DLCO test, CO, He, and O 2、 N 2 A four-type mixed gas containing 0.3%, 10%, 21%, or 68.7% of the original gas (for example, 0.3%, 10%, 21%, or 68.7%) is inhaled at maximum expiration (RV level) in one go, and after 10 seconds of breath holding, the first 750 mL, which is affected by the dead space, is discarded and 0.5 to 1 L of alveolar air is collected and analyzed. The CO concentration in the exhaled alveolar air (FACO) relative to the CO concentration in the inhaled air (FICO), and the He concentration in the exhaled alveolar air (FAHe) relative to the He concentration in the inhaled air (FIHe) are measured and compared.

[0060] In this embodiment, the He concentration curve and the CO concentration curve are generated by the following methods, the outline of which is shown in (1) to (9). (1) DLCO is a predicted value (reference value). (2) VI (inspiratory vital volume during DLCO measurement) uses actual measurement data obtained during measurement. VI in DLCO testing can be said to be the inhaled volume when a four-type mixed gas is inhaled all at once from the maximum expiratory position (RV level). (3) VA (alveolar volume under standard conditions (STPD)) is calculated from VI and RV (residual volume). (4) RV (residual volume) is a predicted value (reference value). (5) FIHe (He concentration in inhaled gas) is the initial He concentration setting. (6) FICO (CO concentration in inhaled gas) is the initial CO concentration setting. (7) FAHe (He concentration in exhaled alveolar gas) is calculated backwards from VA using the VA' calculation formula. (8) FACO (CO concentration in exhaled alveolar gas) is calculated backwards using the DLCO calculation formula. Then, (9) the gas distribution concentration is changed based on the following (Equation 3-1) and (Equation 3-2) so as to converge to the FAHe and FACO obtained by back calculation, and then displayed. The concentration curve is obtained by multiplying the difference concentration between FI and FA by (1-EXP (-elapsed time÷time constant)) and subtracting it from FI. That is, Current He gas concentration = FIHe - (FIHe - FAHe) x (1 - EXP (- elapsed time ÷ He time constant)) ... (Equation 3-1) Current CO gas concentration = FICO - (FICO - FACO) x (1 - EXP (- elapsed time ÷ CO time constant)) ... (Equation 3-2) This is expressed as:

[0061] The DLCO calculation formula is shown below. DLCO=[VA×1000×60 / ((PB-47)×BHT)]×ln(FACO(0) / FACO) …(Formula 4) Here, BHT is the breath-hold time, which is a fixed value (10.0 seconds). Note that BHT is not limited to 10.0 seconds and may be another time. Also, PB is the atmospheric pressure (a fixed value (760 Torr) or a manually set value). Also, 47 to be subtracted is the saturated water vapor partial pressure at 37°C. FACO(0) is the alveolar CO concentration immediately after CO inhalation. Where: FACO(0)=(FAHe / FIHe)×FICO…(Formula 4-1) VA(BTPS)=(VI+RV)…(Formula 4-2) VA'(BTPS)=(VI×(FIHe / FAHe)-VD)…(Formula 4-3) is established.

[0062] Using known parameters from the DLCO calculation formula (Equation 4), the FAHe concentration and FACO concentration are back-calculated. VA (alveolar volume at standard pressure (STPD)) is calculated from the VI obtained during measurement and the predicted RV (residual volume) value as follows: VA = (VI + RV) ... (Equation 4-4) Furthermore, FAHe is calculated backwards from the VA' formula, assuming VA=VA'. FAHe=FIHe×(VA' / VI)...(Formula 4-5) Use the FAHe obtained to calculate FACO(0). FACO(0)=(FAHe / FIHe)×FICO…(Formula 4-6)

[0063] FACO is back-calculated using DLCO prediction and BHT. D1=(VA×1000×60) / ((PB-47)×BHT) …(Formula 4-7) D2=exp(DLCO / D1) …(Formula 4-8) FACO = FACO (0) / D2 ... (Equation 4-9)

[0064] 11 is a flowchart corresponding to a DLCO test simulation. For example, when the examiner selects an object for executing a DLCO test simulation displayed on the display 56, the CPU 53 executes a simulation program and the DLCO test simulation is performed. A message prompting the examiner to prepare a four-type mixed gas is displayed on the display 56 (S410). In addition, a "Start preparation" button is displayed for filling the cylinder with gas for inhalation and preparing for CV measurement (S420). From this information, the examiner can understand the type of gas used in DLCO measurement.

[0065] When the examiner operates the "Preparation Start" button, the messages "Respiratory circuit ventilation in progress" and "Gas injection in progress" are displayed on the display 56 (S430). After the display of the messages "Respiratory circuit ventilation in progress" and "Gas injection in progress" has ended (after gas injection has been completed), the examiner operates the "Measurement Start" button displayed on the display 56 (S440), and the actual spirogram of the subject is measured by the flow sensor 10 provided in the respiratory function test simulator 1 and displayed on the display 56 (S450). In addition, the message "Please perform quiet ventilation" is displayed on the display 56 (S460).

[0066] Next, CPU 53 causes display 56 to display a message encouraging exhalation up to the maximum expiratory position, saying "Exhale slowly until you can no longer exhale" (S490). Next, CPU 53 causes display 56 to display a message encouraging inhalation up to the maximum inhalation position, saying "Inhale all at once" (S500). This message encourages the subject to inhale the four-type mixed gas. Next, CPU 53 causes display 56 to display a message instructing the subject to hold their breath for the set breath holding time, saying "If you can no longer inhale, hold your breath for 10 seconds" (S510).

[0067] Next, the CPU 53 calculates the predicted value of DLCO corresponding to the subject's data based on the prediction formula, as described above. The predicted value may be called a reference value. For the prediction formula, for example, a formula defined by the Japan Respiratory Society is used. Then, based on the calculated DLCO predicted value and the actual VI value, the He concentration curve and the CO concentration curve are calculated and generated by the above formula (S520). Here, as shown in FIG. 12, the values ​​of FIHe (cylinder gas concentration set value) and FICO (cylinder gas concentration set value) are used as the He concentration curve and the CO concentration curve corresponding to the breath holding time during which the inhalation flow measured by the flow sensor does not change, and the values ​​of FAHe and FACO calculated as described above are used as the He concentration curve and the CO concentration curve corresponding to the exhalation period after breath holding. In the example of FIG. 12, the respective concentrations are normalized so that the relative changes in the He concentration and the CO concentration can be understood. During the period during which the subject holds his breath, FIHe is displayed as the He concentration, and FICO is displayed as the CO concentration.

[0068] Next, the CPU 53 causes the display 56 to display a message instructing the user to exhale in one gulp, saying "Please exhale in one gulp" (S530). Accordingly, FAHe is displayed as the He concentration, and FACO is displayed as the CO concentration. Then, based on the fact that the expiratory flow has fallen below a predetermined value (S540), the CPU 53 causes the display 56 to display the test results (for example, the calculated DLCO predicted value and other test results that can be obtained in the DLCO test) (S550), and ends the simulation of the DLCO test.

[0069] In the above embodiment, FIHe is displayed as the He concentration curve and FICO is displayed as the CO concentration curve during the breath-holding time, and then FAHe is displayed as the He concentration curve and FACO is displayed as the CO concentration curve after exhalation (as if the curves were drawn in real time in response to the flow). However, the present invention is not limited to this form. The He concentration curve and the CO concentration curve may not be displayed during the breath-holding time, and the He concentration curve including FIHe and FAHe and the CO concentration curve including FICO and FACO may be displayed after a predetermined time has passed after exhalation (for example, after 1 to several seconds). This corresponds to the fact that, when DLCO is actually measured, the sample gas from the exhalation is sent to the analysis circuit (He concentration sensor, CO concentration sensor), and the first 750 mL is discarded and the analysis is completed before the gas concentration curve is displayed.

[0070] In this embodiment, as described above, the predicted DLCO value is used to generate the CO concentration curve, but by setting a DLCO value different from the predicted DLCO value (for example, a DLCO set value obtained by multiplying the predicted DLCO value by 0.8 as a coefficient), it is possible to reproduce the CO concentration when the gas exchange function is deteriorated. In this way, the examiner can experience both good and bad cases in the DLCO test.

[0071] As described above, according to this embodiment, in order to allow a subject to acquire testing techniques for precision testing that requires the functions of supplying a test gas to the subject and detecting a gas concentration, it is not necessary to actually use a test gas, and it is possible to acquire the testing techniques at low cost.

[0072] The simulation function of this embodiment has a function of guiding the examination procedure of the examination items (e.g., FRC, CV, DLCO) of the detailed examination, so that the user can learn the procedure for each examination item. Also, by guiding the type of gas used in the examination and the breathing method that the examinee should take according to the examination procedure, the user can learn what gas should be prepared and how the examinee should breathe for each examination item.

[0073] In addition, the simulation function of this embodiment performs a simulation of a gas concentration curve in a detailed examination based on the actually measured respiratory flow rate or respiratory volume (spirogram), so that it is possible to present data close to the actual examination environment to the examiner, and it is possible to improve the learning effect by providing a sense of reality compared to the case where a prescribed pseudo data is simply presented. For example, if the examinee is made to breathe inappropriately just for training purposes, an appropriate gas concentration curve will not be obtained, so the examiner can recognize the importance of having the examinee breathe correctly.

[0074] Furthermore, in this embodiment, it is possible to perform simulations of good and bad test results, so that the patient can become familiar with the various test results that occur in clinical settings.

[0075] Figure 13 shows how the awareness of examiners changed after undergoing the test simulations (training) of FRC, CV, and DLCO. For each detailed examination item, many examiners felt that the detailed examination was not easy before the test simulation was performed. However, after the test simulation was performed, an increasing number of examiners felt that the detailed examination was easier than expected, due to having experienced the test procedure and the breathing method that should be instructed to the examinee, and by being presented with a gas concentration curve based on actual measurement data. In this way, by eliminating the awareness that the detailed examination is difficult, the detailed examination can be performed accurately using the detailed examination equipment without confusion in the clinical setting.

[0076] As an example, as seen in the strained medical system during the COVID-19 pandemic, even if a significant number of advanced medical devices are introduced, if there is a shortage of examiners who can operate them properly, the strained situation will not improve at all. From this perspective, it is desirable to progress to some extent in acquiring the skills for precision testing even at the stage when precision testing devices have not yet been introduced. The respiratory function testing simulator of this embodiment also contributes to solving such problems.

[0077] (Other forms) In the above embodiment, an example has been described in which the respiratory function test simulator is a flow sensor type spirometer, but the respiratory function test simulator is not limited to this, and may be a precision testing device (air volume type spirometer (rolling seal type spirometer)) having a test gas supply function and a gas concentration detection function. For example, the precision testing device may be controlled to either (1) an actual measurement mode in which gas is actually supplied to the subject by the test gas supply function and the gas concentration is detected by the gas concentration detection function, or (2) a simulation mode in which no gas is supplied to the subject and no gas concentration is detected, and the simulation program of the above embodiment may be executed in (2) the simulation mode. Even in such a form, since no actual test gas is used, it is possible to acquire precision testing techniques at low cost.

[0078] In the above embodiment, the respiratory function test simulator is configured to measure the He concentration, N 2 The respiratory function test simulator may simulate NO (nitric oxide) in the exhaled breath. For example, the NO concentration curve in the exhaled breath may be simulated based on a relational expression that the lower the values ​​of spirometry items such as VC, FVC, forced expiratory volume in 1 second, and forced expiratory volume in 1 second, the higher the NO concentration in the exhaled breath.

[0079] In the above embodiment, an example has been described in which the parameters that can be actually measured by the respiratory function test simulator are the respiratory flow rate or respiratory volume that can be obtained by a flow sensor, and the parameters to be simulated are gas concentrations. However, the present invention is not limited to this form, and the parameters that can be actually measured by the respiratory function test simulator may be parameters other than the respiratory flow rate or respiratory volume, and the parameters to be simulated may be parameters other than the gas concentrations. For example, the chest and abdomen of a sleeping subject are imaged by a video camera, and feature amounts based on the actual images of the chest and abdomen that have been imaged, and respiratory rate and arterial oxygen saturation (SpO 2 ) in a sleep apnea test (PSG) are calculated. 2 ) and other parameters, the respiratory rate and arterial blood oxygen saturation (SpO2 This makes it possible to simulate a PSG examination performed remotely without installing an actual PSG device on the subject's side.

[0080] In the above embodiment, an example of simulating the He concentration in functional residual capacity using the gas dilution method has been described, but the present invention is not limited to this embodiment. It is also possible to simulate intraoral pressure in a functional residual capacity test (body plethysmograph method) using a body plethysmograph (also called a body box). It is also possible to simulate airway resistance using a body plethysmograph. This makes it possible to learn test techniques for test items that use a body plethysmograph, without actually introducing an expensive and large body plethysmograph.

[0081] In the above embodiment, N 2 The generation of the concentration curve is performed using the provisionally set hidden N 2 A method for tracing the concentration curve according to the exhaled volume during measurement has been shown. As shown in Figures 14 and 15, the predicted value of TLC (total lung capacity) and the average exhaled N calculated from the TLC formula are 2 Based on the concentration, the above tentatively set N 2 A concentration curve may be constructed.

[0082] The TLC calculation formula is shown below. TLC = [(VI × FAN 2 )-(Vd×FA'N 2 )]÷(FAN 2 -FEN 2 )...(Formula 5) Where: VI: Intake volume Vd: Dead space volume (anatomical dead space volume + mechanical dead space volume) FAN 2 : Alveolar air N 2 Concentration (80%) FA'N 2 : Exhalation N 2 Concentration (corrected for dilution due to dead space) F.E.N. 2 :Average expiratory N 2 concentration Let us assume that.

[0083] From equation (5), (Vd×FA'N 2 ) is N 2 In a simulation that displays a concentration curve in real time, this can be omitted because it does not have a significant visual impact. (FAN 2 -FEN 2 )=(VI×FAN 2 )÷TLC …(Formula 5-1) F.E.N. 2 =FAN 2 -((VI×FAN 2 )÷TLC) …(Formula 5-2) holds true.

[0084] Then, as shown in FIG. 14(a), the average expiratory N 2 Based on concentration, N 2 Construct a concentration curve. N 2 The concentration curve is based on the calculated mean exhaled N 2 Next, as shown in FIG. 14(b), ΔN 2 The slope of the third phase is calculated based on the predicted value, and the third phase portion according to the calculated slope is added to the constant value portion in Fig. 14(a), so that the N after the third phase is calculated. 2 The concentration increases as the third and subsequent phases are added. 2 N so that the concentration remains at the calculated value without increasing above it. 2 The entire concentration curve is N 2 Adjust in the direction of concentration (e.g., N 2 In addition, as shown in Fig. 14(c), the fourth phase is added to the third phase, and the N 2 The concentration rises sharply at the end of the exhalation. The appearance (starting point) of the fourth phase may be set based on the CV / VC predicted value and the CV predicted value. The waveform of the added fourth phase is N 2 The waveform may be one in which the concentration increases at a constant rate.

[0085] Next, as shown in FIG. 15(d), the first and second phase portions are added to the third and subsequent phase portions. The added first and second phase waveforms are, for example, a standard waveform pattern prepared in advance that has been expanded or contracted. As a result, the provisionally set N 2 The concentration curve is completed.

[0086] As mentioned earlier, N 2 The generation of the concentration curve is performed using the provisionally set hidden N 2 The concentration curve is traced according to the breath volume being measured (N at the point corresponding to the breath volume). 2 The measurement is performed by displaying the cardiac oscillation concentration. Here, as shown in FIG. 15(e), during the CV simulation period (the period during which the subject is actually exhaling), a waveform simulating cardiac oscillation may be displayed with a period of 60 to 90 bpm (1.0 to 1.5 Hz) during the third phase display. For example, the period and amplitude of each waveform corresponding to cardiac oscillation may be determined based on a random number extracted from a random number generated within a predetermined range. The examiner can experience the appearance of cardiac oscillation in the CV measurement. [Explanation of symbols]

[0087] 1. Respiratory function test simulator 10 Flow Sensor 14 Resistor 5a First pressure detection port (pressure detection part) 5b Second pressure detection port (pressure detection part) 50 Body 51 Differential pressure sensor 52 A / D converter 53 CPU 54 RAM 55 ROM 56 Touch panel display 57 D / A Converter 58 Speaker

Claims

1. A respiratory function test simulator for performing a simulation of a detailed test regarding a gas concentration, comprising: A measurement unit for measuring respiratory flow or respiratory volume; an output unit that outputs guidance information corresponding to the detailed examination; a generating unit that generates simulation data related to the detailed examination based on the data measured by the measuring unit; A respiratory function test simulator comprising:

2. 2. The respiratory function test simulator according to claim 1, The guidance information includes information on a gas used in the detailed examination and information on breathing to be instructed to the subject in the detailed examination. Respiratory function test simulator.

3. 2. The respiratory function test simulator according to claim 1, The generating unit generates a gas concentration curve based on the data measured by the measuring unit and a predetermined value corresponding to the detailed examination. Respiratory function test simulator.

4. 4. The respiratory function test simulator according to claim 3, The generation unit is A first gas concentration curve is generated based on the data measured by the measurement unit and a first predetermined value calculated based on a prediction formula corresponding to the detailed examination, generating a second gas concentration curve having a degree of suitability different from that of the first gas concentration curve, based on the data measured by the measurement unit and a second predetermined value corresponding to the detailed inspection and different from the first predetermined value; Respiratory function test simulator.

5. A respiratory function test simulator according to any one of claims 1 to 4, The detailed examination is a functional residual capacity test (FRC), The guidance information includes information informing the use of He and information instructing the patient to perform quiet ventilation; The generating unit generates a gas concentration curve indicating a He concentration. Respiratory function test simulator.

6. A respiratory function test simulator according to any one of claims 1 to 4, The detailed examination is a closing volume examination (CV), The guidance information is ２ information instructing the user to exhale to the maximum expiratory level, and information instructing the user to maintain the expiratory flow rate within a predetermined range, The generating unit is N ２ Generate a gas concentration curve showing the concentration, Respiratory function test simulator.

7. A respiratory function test simulator according to any one of claims 1 to 4, The detailed examination is a pulmonary function diffusion examination (DLCO), The guidance information is CO, He, O ２、 N ２ information instructing the use of a four-kind mixed gas including The generating unit generates a gas concentration curve indicating a CO concentration. Respiratory function test simulator.

8. A program executed by a respiratory function test simulator that executes a simulation of a detailed test regarding gas concentration, Measuring a respiratory flow rate or a respiratory volume by a measuring unit; outputting guidance information corresponding to the detailed examination by an output unit; and generating, by a generating unit, simulation data relating to the precision inspection based on the data measured by the measuring unit.

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