JP5451474B2 - Target heart rate arrival time prediction apparatus and target heart rate arrival time prediction method - Google Patents

Description

  The present invention relates to a target heart rate arrival time predicting apparatus and method in an examination involving exercise load.

  Exams with exercise load are performed as a diagnosis of heart disease, evaluation of cardiac function, endurance measurement and training index. These tests include, for example, exercise load tests and stress myocardial scintigraphy tests. In the exercise load test, an exercise load is applied to the subject, and an electrocardiogram, a heart rate, etc. are measured to determine the presence or absence of ischemic heart disease and to measure endurance. In the loaded myocardial scintigraphy, an exercise load is applied, thallium is intravenously administered during maximum exercise, and imaging is performed by a gamma camera to detect ischemia.

  All of the above examinations are performed until a gradually increasing exercise load is applied and the target heart rate necessary for the examination is reached. In consideration of the physical load on the subject, the test is generally completed in about 10 to 15 minutes. There is an individual difference in physical strength, and the time required to reach the target heart rate is different. Therefore, a method for adjusting the time required to reach the target heart rate is also known (see, for example, Patent Document 1).

JP-A-6-154355

  However, in the above invention, the subject or doctor does not know the time until the test is completed. Since the time to completion is not known, a doctor who is not skilled to a certain degree cannot adjust the load empirically to adjust the time to reach the target heart rate or determine the timing of thallium administration. In addition, since the exercise load at the time when the target heart rate is reached, the subject feels very large, and if he does not know the time until completion, he / she will feel mentally uneasy.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a target heart rate arrival time predicting apparatus and a target heart rate arrival time predicting method capable of displaying the time until the target heart rate is reached.

The target heart rate arrival time prediction apparatus includes a subject information input unit, a target heart rate determination unit, a load protocol storage unit, a heart rate measurement unit, a calculation unit, and a display unit. The subject information input unit receives input of subject information. The target heart rate determination unit determines the target heart rate based on the subject information. The load protocol storage unit stores a load protocol indicating a plan over time for a load applied to the subject. The heart rate measuring unit measures the heart rate of the subject. The calculation unit reaches the target heart rate based on the measured heart rate and the amount of exercise during the heart rate measurement obtained based on the load of the load protocol during the heart rate measurement. Calculate the predicted arrival time. The display unit displays the predicted arrival time.

  According to the target heart rate arrival time predicting apparatus, since the predicted arrival time until the target heart rate is reached is displayed on the display unit, the doctor does not need to empirically predict the end time. In the case of a loaded myocardial scintigraphy, the timing of thallium administration can be determined with reference to the time to reach the target heart rate. For the subject, the expected arrival time up to the target heart rate can be visually confirmed, so that the subject is free from anxiety about how long the test will continue.

It is a figure which shows schematic structure of the load test system which concerns on this embodiment. It is a flowchart which shows the flow of operation | movement of an exercise load electrocardiograph. It is a figure which shows an example of a load protocol. It is a flowchart which shows the flow of calculation of prediction arrival time. It is a figure which shows the relationship of heart rate -Mets. It is a figure which shows the time-Mets relationship along a load protocol. It is a figure which shows the example by which estimated arrival time is displayed on a display part.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

  FIG. 1 is a diagram showing a schematic configuration of a load test system according to the present embodiment.

  The load test system 10 includes a load device 20 and an exercise load electrocardiograph 30.

  The load device 20 is a treadmill or an ergometer. A treadmill is a device that allows a subject to walk and run on a belt. The exercise load can be changed by changing the speed and inclination of the belt. An ergometer is a bicycle-type instrument that is mechanically or electrically braked. The exercise load can be changed by changing the resistance of the pedal.

  The inspection using the load device 20 includes a step load test and a lamp load test. In the step load test, a different exercise load is set for each predetermined time as a multistage stage, and the load is increased each time the stage is advanced. In the lamp load test, the stage is not particularly set, and the load increases with time.

  The load device 20 is controlled by the exercise load electrocardiograph 30.

  The exercise load electrocardiograph 30 functions as a target heart rate arrival time predicting device that predicts the time for the subject's heart rate to reach the target heart rate.

  The exercise load electrocardiograph 30 includes an input unit 31, an electrode 32, a dielectric cord 33, an amplifier 34, a communication port 35, a memory 36, a storage unit 37, a display unit 38, and a CPU 39.

  The input unit 31 includes input means such as a keyboard, a touch panel, or dedicated keys, and accepts various inputs. For example, the input unit 31 functions as a subject information input unit that accepts input of subject information, input of the subject's age, weight, sex, and the like. The input unit 31 also receives an input of a load protocol when a load is applied to the subject by the load device 20.

  The load protocol is a load plan over time defined by the load amount of the load device and its duration (load increase rate). When the duration is set to the load amount, it is defined as a step load test in which the duration is one stage. When a gradually increasing rate is set for the load amount, it is set as a lamp load test in which the load is gradually increased linearly. The load amount of the load device is defined by speed and inclination in the case of a treadmill, weight of the pedal (Watt) in the case of using an ergometer, and the like. These are examples, and other load devices can be applied to the present embodiment.

  The electrode 32 is included in the heart rate measurement unit and is affixed to the subject's chest and back to detect an action potential generated by excitement of the subject's myocardium. From the detected action potential, the biological information of the subject, for example, heart rate and heart motion can be known.

  The dielectric cord 33 is connected to the electrode 32, and inputs a signal related to biological information from the electrode 32 to the amplifier 34. The amplifier 34 amplifies the biological information and inputs it to the CPU 39.

  The communication port 35 connects the load device 20 and the CPU 39. The load device 20 is controlled by the CPU 39 via the communication port 35 based on a load plan such as a load protocol.

  The memory 36 is a storage means such as a flash memory 36 for temporarily storing data to be processed. The storage unit 37 is a storage unit such as a hard disk or an external storage medium, and stores various data. Both the memory 36 and the storage unit 37 are connected to the CPU 39.

  The display unit 38 is a display such as a liquid crystal display device, and displays a measurement result by the electrode 32 and the like.

  The CPU 39 serves as a calculation unit and a target heart rate determination unit, and is in charge of overall control of the exercise load electrocardiograph 30. Hereinafter, the operation of the exercise load electrocardiograph 30 will be described in detail. The action of the exercise load electrocardiograph 30 is basically achieved by the CPU 39.

  FIG. 2 is a flowchart showing an operation flow of the exercise load electrocardiograph, and FIG. 3 is a diagram showing an example of a load protocol.

  First, the exercise electrocardiograph 30 receives input of subject information such as age and weight of the subject at the input unit 31 (step S1). Furthermore, the exercise load electrocardiograph 30 receives an input of a load protocol at the input unit 31 (step S2). Note that a load protocol and a load protocol may be created by setting a load amount and a duration (stage) through the input unit 31 in advance. In this case, the created load protocol is stored in the storage unit 37, and in step S <b> 2, load protocol candidates stored in the storage unit 37 are selected through the input unit 31. The input load protocol is stored in the storage unit 37 as a table as shown in FIG. 3, for example. The amount of exercise (Mets) may be calculated in advance or afterwards.

  The exercise load electrocardiograph 30 calculates a target heart rate to be reached by the subject in the load test based on the inputted subject information of the subject (step S3). The target heart rate is calculated by a generally known calculation method. For example, the maximum heart rate is estimated by subtracting the age of the subject from 220, and 70% of the maximum heart rate is set as the target heart rate, or the predicted maximum heart rate from the list by age, trainer / non-trainer The number is determined, and 70% of the number is set as the target heart rate.

  Next, the exercise electrocardiograph 30 measures the heart rate at rest before the start of the load test through the electrode 32, acquires heart rate data, and stores it in the storage unit 37 (step S4). The heart rate is displayed on the display unit 38 so that the user can see it.

  The exercise load electrocardiograph 30 determines whether to start a load test (step S5). The determination of the start of the load test is made based on whether or not the user has input the start of the load test from the input unit 31.

  When the load test is not started (step S5: NO), the exercise load electrocardiograph 30 determines whether or not to measure the resting heart rate again (step S6). This determination follows an input to the input unit 31 from a user such as a doctor. When the user determines that the heart rate of the subject measured in step S4 is not normal due to tension or the like, the user inputs heartbeat remeasurement through the input unit 31. If the heart rate is remeasured (step S6: YES), the process returns to step S4. When the heartbeat is not remeasured (step S6: NO), the process returns to step S5.

  When starting the load test (step S5: YES), the exercise load electrocardiograph 30 starts driving the load device 20 through the communication port 35 according to the load protocol selected in step S2 (step S7). The subject is given an amount of exercise (Mets) based on the load set by the load protocol over time. The relationship between the load amount and the exercise amount is generally known for each load device 20. For example, in a certain device, the amount of exercise (Mets) = (load amount × 12.24 + 300) / (weight × 3.5). In this embodiment, any instrument can be applied.

  The exercise load electrocardiograph 30 determines whether or not it is the timing for sampling the heart rate (step S8). Whether the timing of sampling of the heart rate is determined by, for example, a timer so that the heart rate is measured every predetermined time.

  If it is not time to sample the heart rate (step S8: NO), the process proceeds to step S12. When it is time to sample the heart rate (step S8: YES), the exercise electrocardiograph 30 acquires heart rate data through the electrode 32 and stores it in the storage unit 37 (step S9). The heart rate data is, for example, stored in a heart rate table in which the time from the start of the load test and the heart rate are associated with each other. Subsequently, the exercise load electrocardiograph 30 confirms the current load amount based on the load protocol, and stores it as exercise amount data obtained by converting the load amount into an exercise amount (step S10). The momentum data is stored in a momentum table in which, for example, the time from the start of the load test and the momentum are associated with each other. Here, the case where the exercise amount data is stored has been described, but the load amount before conversion into the exercise amount may be stored.

  The exercise electrocardiograph 30 calculates a predicted time (predicted arrival time) until the subject reaches the target heart rate based on the heart rate data and the exercise amount data (step S11). The detailed flow of step S11 will be described later.

  The exercise load electrocardiograph 30 displays the predicted arrival time on the display unit 38 (step S12). If the estimated arrival time is already displayed, it is updated.

  The exercise load electrocardiograph 30 determines whether the exercise load is ended based on the load protocol or the biological information (step S13). Whether or not to end the exercise load is determined by whether or not the end of the load is designated by the user from the input device or whether or not the end setting condition of the exercise load electrocardiograph 30 is met.

  If it is determined that the exercise load is not yet finished (step S13: NO), the process returns to step S7. When it is determined that the exercise load has ended (step S13: YES), a light load at the initial stage of the load inspection is applied, and the subject is caused to perform an organizing exercise for cooling down.

  The exercise load electrocardiograph 30 determines whether or not to end the cooling down (step S14). The determination of whether or not to end the cooling down is determined by whether or not the user has designated the end of the cooling down from the input device. Until the end of cooling down is input (step S14: NO), the exercise load electrocardiograph 30 continues to apply a cooling down load. When the user determines that the subject has sufficiently cooled down and inputs the end of cooling, the cooling down is terminated (step S14: YES).

  After receiving the end of the load test, the exercise electrocardiograph 30 records the report as the report mode and determines whether to end the report mode (step S15). Whether or not to end the report mode is determined by whether or not the report end is designated by the user from the input device. When the report mode is ended (step S15: YES), the next examinee is inspected or a power-off input by the user is accepted, and the end is determined (step S16). When the next subject is inspected (step S16: NO), the process returns to step S1 in order to accept input of subject information. When the end of the load test is input (step S16 :: YES), the exercise load electrocardiograph 30 is shut down.

  Next, step S11 will be described in detail.

  FIG. 4 is a flowchart showing the flow of calculating the predicted arrival time, FIG. 5 is a diagram showing the relationship of heart rate-Mets, FIG. 6 is a diagram showing the time-Mets relationship according to the load protocol, and FIG. It is a figure which shows the example by which estimated arrival time is displayed.

  First, the exercise electrocardiograph 30 reads a heart rate table storing the heart rate under load in step S9 into the memory 36 (step S21). Subsequently, the exercise load electrocardiograph 30 reads the exercise amount table storing the exercise amount (Mets) under load in step S10 into the memory 36 (step S22).

  Since both the heart rate table and the exercise amount table are associated with time, the relationship between the heart rate and the exercise amount at the same time is also known. The exercise electrocardiograph 30 plots (heart rate, Mets) coordinate points in the heart rate-momentum (Mets) coordinate system (step S23). A state in which the coordinate points are plotted is, for example, as shown by white circles in FIG. As in the graph shown in FIG. 5A, in the case of a step type load test, several coordinate points are arranged almost horizontally. This is because at the same stage of the step, the amount of exercise is almost the same, and the heart rate increases with time even with the same amount of exercise. As in the graph shown in FIG. 5B, in the case of the ramp type load test, since there is no stage, the coordinate points are continuous toward the upper right.

  The exercise load electrocardiograph 30 determines whether or not to use the resting heart rate data acquired in step S4 (step S24). The criteria for determining whether or not to use resting heart rate data is determined by whether or not sufficient (heart rate, Mets) coordinate points are plotted to create the heart rate-Mets regression linear equation described below. The For example, when the number of coordinate points is 2 or less, it is determined that heartbeat data at rest is also used.

  When the resting data is used (step S24: YES), the coordinate points based on the resting heart rate are also plotted in the heart rate-Mets coordinate system (step S25). Here, the amount of exercise at rest is 1 Mets, and the heart rate-Mets coordinates. When resting data is not used (step S24: NO), step S25 is skipped and the process proceeds to step S26.

  The exercise electrocardiograph 30 creates a heart rate-Mets regression linear equation as shown by a straight line in FIG. 5 by the least square method based on the plotted plural heart rate-Mets coordinate points (step S26). Here, it is known that the relationship between the amount of exercise (Mets) given to the subject and the heart rate (HR) is Mets = a × HR + b (a: coefficient, b: intercept).

  The exercise load electrocardiograph 30 substitutes the target heart rate into the generated heart rate-Mets regression linear equation, and calculates the scheduled exercise amount scheduled when the target heart rate is reached (step S27).

  Subsequently, the exercise electrocardiograph 30 is based on the load over time based on the load protocol and the subject information, and shows a time-Mets indicating a theoretical relationship between the time course scheduled by the load protocol and the amount of exercise. A relational expression is calculated (step S28). The time-mets relational expression is shown as a graph in FIG. In the case of the step type load test, the momentum increases step by step for each stage for a predetermined time, so that it becomes a step as shown in FIG. 6A, and in the case of the ramp type load test, the momentum increases linearly. As shown in FIG. 6B, it is shown in a straight line. Note that this time-Mets relational expression can be created any time after the load protocol is determined, so it may be created at an earlier or later stage.

  The exercise load electrocardiograph 30 substitutes the scheduled exercise amount calculated in step S27 for the time-Mets relational expression, and calculates the predicted arrival time for the heart rate to reach the target heart rate (step S29). In the case of the step type load test, as shown by an arrow in FIG. 6A, the scheduled momentum is reached between the stages, so the start time of the later stage is set as the predicted arrival time.

  The exercise load electrocardiograph 30 refers to the load protocol and determines whether or not the current load test is a step load test (step S30). When it is a step type load test (step S30: YES), the entire stage including the predicted arrival time is set as the predicted arrival time width (step S31).

  When it is not a step type load test (step S30: NO), the predicted arrival time is finely adjusted (step S32), and a predetermined time width is set from the adjusted predicted arrival time (step S33). The reason for finely adjusting the predicted arrival time is that when the amount of exercise increases, there is a slight delay for the effect to appear in the heart rate. For example, the calculated value is adjusted assuming that the predicted arrival time is delayed by a few seconds. A predetermined time width from the adjusted predicted arrival time, for example, 1 to 3 minutes, is set as the predicted arrival time width. Since the predicted arrival time width is set, fine adjustment of the predicted arrival time can be omitted.

  As described above, the predicted arrival time and the predicted arrival time width are set, and the process returns to step S11 in FIG. The display unit 38 may display the remaining time until the predicted arrival time. The expected arrival time is displayed together with a graph showing the relationship between the test elapsed time and the heart rate, for example, as shown in FIG. In the case of a step-type load test, the stage predicted to reach the target heart rate is also displayed. The set time width may be shown as shaded in FIG.

  As described above, according to the exercise load electrocardiograph 30 of the present embodiment, since the predicted arrival time until the target heart rate is reached is displayed on the display unit 38, the doctor empirically predicts the end time. There is no need to do. If it takes longer than necessary to reach the target heart rate, increase the load and shorten the examination time, or if it seems to reach the target heart rate abnormally early, reduce the load and increase the examination time. it can. Thus, a user such as a doctor can skip the stage or speed up the load according to the load plan of a general load test after knowing the time to the target heart rate. Therefore, the progress of the load adjustment can be surely understood by the doctor, which can be used for analysis after the test.

  In the case of a loaded myocardial scintigraphy, the thallium administration timing can be determined with reference to the time required to reach the target heart rate. Furthermore, since the subject can visually recognize the scheduled arrival time up to the target heart rate, he is freed from anxiety about how long the test will continue.

  Further, the relationship between the amount of exercise (Mets) given to the subject and the heart rate (HR) becomes Mets = a × HR + b (a: coefficient, b: intercept), and the heart rate-Mets regression linear equation. Have created. By substituting the target heart rate into the heart rate-Mets regression linear equation, the scheduled amount of exercise when the target heart rate is reached can be easily determined. The scheduled amount of exercise is substituted into the time-Mets relational expression, and the predicted arrival time for reaching the target heart rate is calculated. Therefore, the predicted arrival time is easily calculated.

  Moreover, in the said embodiment, it is judged whether the data at rest are used in step S24. Until the heart rate-momentum coordinates under examination are more than a predetermined number (for example, 3 points or more), the heart rate-Mets regression linear equation is also obtained using the heart rate measured by the electrode 32 at rest and the known momentum at rest. calculate. Therefore, the estimated arrival time can be calculated and displayed on the display unit 38 even when the heart rate information is still small. On the other hand, if a predetermined number or more of heart rate-momentum coordinates under examination are obtained, a heart rate-Mets regression linear equation is created using only the heart rate-momentum coordinates under examination without including resting data. Therefore, a regression line can be created more accurately than when resting data is included.

  On the display unit 38, the predicted arrival time width is set and displayed. Therefore, it is possible to determine how far the user reaches the target heart rate intuitively visually. In particular, if displayed together with a graph of the heart rate over time, the difference between the current heart rate and the target heart rate can be intuitively recognized visually.

  In the above embodiment, the time-mets relational expression is created in step S28, but the present invention is not limited to this. The time-Mets relational expression can be created any time after the time when the subject information and the load protocol are prepared. Since the time-Mets relational expression follows the load protocol, it is sufficient to create the time-Mets relational expression once outside the subroutine shown in FIG.

  Moreover, in the said embodiment, although the display part 38 is displayed regarding the estimated arrival time which reaches | attains a target heart rate, it is not limited to this. The estimated maximum oxygen uptake and predicted physical fitness may be calculated from each parameter of the load protocol, heart rate, subject information, etc., and these may be displayed.

10 Load test system,
20 load device,
30 Exercise electrocardiograph,
31 input section,
32 electrodes,
33 Dielectric code,
34 amplifier,
35 communication port,
36 memory,
37 storage unit,
38 CPU.

Claims (7)

A subject information input unit that accepts input of subject information;
A target heart rate determination unit for determining a target heart rate based on the subject information;
A load protocol storage unit for storing a load protocol indicating a plan over time for a load applied to the subject;
A heart rate measuring unit for measuring the heart rate of the subject;
On the basis of the movement amount at the heart rate measurement obtained based on the load of the load protocol measured the heart rate and when the heart rate measurement, prediction heart rate of the subject reaches the target heart rate A calculation unit for calculating the arrival time;
A display unit for displaying the predicted arrival time;
A target heart rate arrival time predicting device. The calculation unit includes:
Based on the subject information and the load of the load protocol at the time of heart rate measurement, determine the amount of exercise at the time of heart rate measurement, calculate a regression linear equation indicating the relationship between the amount of exercise and the measured heart rate,
Substituting the target heart rate into the regression line equation to calculate the planned exercise amount when the target heart rate is reached,
The target heart rate arrival time prediction device according to claim 1, wherein a time when an exercise amount becomes the scheduled exercise amount according to the load protocol is calculated as the predicted arrival time. The calculation unit includes:
Determine the momentum from the load and subject information of the load protocol, calculate a time-momentum relational expression indicating the theoretical relationship between the time course and the amount of exercise along the load protocol,
The target heart rate arrival time predicting apparatus according to claim 2, wherein the predicted arrival time for reaching the target heart rate is calculated by substituting the scheduled exercise amount into the time-exercise relational expression.   The calculation unit uses the heart rate measured by the heart rate measurement unit at rest and the known exercise amount at rest until the coordinates of the heart rate and the exercise amount under examination are obtained by a predetermined number or more. 3. The regression linear equation is calculated using only the coordinates of the heart rate and the momentum under load after calculating the formula and obtaining the predetermined number or more of the coordinates of the heart rate and the momentum under examination. The target heart rate arrival time prediction apparatus according to claim 3.   The target according to claim 1, wherein the calculation unit sets a predicted arrival time width having a time width from the predicted arrival time, and causes the display unit to display the predicted arrival time width. Heart rate arrival time prediction device.   6. The target heart rate arrival time prediction apparatus according to claim 1, wherein the display unit displays the predicted arrival time together with a graph indicating heart rate measurement results in time series. Receiving the input of the subject information;
Receiving an input of a load protocol indicating a relationship between the load applied to the subject and the passage of time;
Determining a target heart rate based on the subject information;
Measuring a heart rate of the subject;
Obtaining a momentum at the time of heart rate measurement from the load of the load protocol and subject information, and calculating a regression linear expression indicating a relationship between the measured heart rate and the amount of exercise from a plurality of heart rate-momentum coordinates ,
Substituting the target heart rate into the regression line equation to calculate a scheduled exercise amount when the target heart rate is reached;
Obtaining momentum from the load of the load protocol and subject information, calculating a time-momentum relational expression indicating a theoretical relationship between the time course and the amount of exercise according to the load protocol;
Substituting the scheduled momentum into the time-momentum relational expression to calculate a predicted arrival time to reach a target heart rate;
Displaying the predicted arrival time;
A target heart rate arrival time prediction method comprising: