Cardiovascular patient risk assessment system and method based on cardiopulmonary exercise test

Abstract

The invention relates to the technical field of cardiopulmonary exercise tests, in particular to a cardiovascular patient risk assessment system and method based on a cardiopulmonary exercise test, and the system comprises a physiological data acquisition module, a blood oxygen fluctuation analysis module, an exercise load adjustment module, a cardiopulmonary recovery assessment module and a risk grading module. By monitoring and synchronizing multi-dimensional data in a cardiopulmonary exercise test in real time, the accuracy and credibility of the data are improved, close association between physiological indexes and exercise loads is strengthened, and a doctor can more accurately evaluate the blood oxygen stability and find key physiological changes in time through detailed blood oxygen fluctuation analysis; by integrating heart rate, expiration frequency and stride frequency data, dynamic exercise load adjustment is provided, optimized exercise suggestions for individuals are achieved, then prevention and evaluation strategies are refined, real-time monitoring on the recovery ability of a patient is increased by adding cardiopulmonary recovery evaluation, and intervention is more transparent.

Description

Technical Field

[0001] The present invention relates to the technical field of cardiopulmonary exercise testing, and in particular to a cardiovascular patient risk assessment system and method based on cardiopulmonary exercise testing. Background Art

[0002] Cardiopulmonary exercise testing (CPET) is a medical technology that evaluates cardiopulmonary function and endurance by measuring physiological parameters such as breathing, heart rate, and oxygen consumption during exercise. This technology is widely used in the study of cardiovascular and respiratory diseases and exercise physiology. It can provide information about the interaction between the patient's heart, lungs, blood vessels and other systems. By monitoring and analyzing the patient's physiological responses under standardized exercise tests, doctors can determine whether their cardiopulmonary function is normal and identify potential disease risks.

[0003] Among them, the cardiovascular patient risk assessment system of cardiopulmonary exercise test uses cardiopulmonary exercise test technology combined with physiological data analysis to assess the disease risk of cardiovascular patients. The system monitors and analyzes various physiological indicators of patients during exercise, assesses the working status of their heart, lungs and other organs, and helps doctors judge the cardiovascular health status and potential risks of patients in daily activities, which is of great significance for preventing cardiovascular events in advance and guiding clinical treatment.

[0004] Existing technologies rely on standardized exercise test results and fail to fully capture immediate changes during exercise, thus affecting the timeliness and detail of cardiovascular disease risk assessment. In addition, insufficient support is provided for the adjustment of individualized exercise load, resulting in the inability to develop the best exercise test plan for each patient. Cardiopulmonary function recovery assessment mostly relies on long-term observations and lacks immediate data support, which limits the rapid feedback and adjustment of patients' recovery capabilities, resulting in a lack of sufficient data basis when formulating assessment plans, reducing the accuracy and efficiency of the assessment, making patients' cardiovascular risk assessment untimely and increasing the occurrence of potential health risks. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a cardiovascular patient risk assessment system and method based on cardiopulmonary exercise test.

[0006] In order to achieve the above-mentioned object, the present invention adopts the following technical scheme: a cardiovascular patient risk assessment system based on cardiopulmonary exercise test, the system comprising:

[0007] The physiological data acquisition module monitors the patient's current exercise frequency, stride length and exercise speed based on the patient's real-time exercise stage type, records blood pressure, heart rate and blood oxygen saturation data at multiple time points through a blood pressure monitor and a blood oximeter, implements data synchronization, and obtains a multi-dimensional physiological data set;

[0008] The blood oxygen fluctuation analysis module analyzes the change in blood oxygen saturation at adjacent moments based on the multidimensional physiological data set, calculates the offset ratio between the change and the average blood oxygen value at the current stage, determines whether there is a critical blood oxygen fluctuation, and obtains blood oxygen stability assessment data;

[0009] The exercise load adjustment module extracts the heart rate and expiratory frequency of the current period according to the blood oxygen stability assessment data, combines and analyzes them with the step frequency data, identifies the interactive effects of physiological parameters, determines the metabolic load during exercise, adjusts the patient's exercise step frequency and stride, and obtains an exercise intensity adjustment index;

[0010] The cardiopulmonary recovery assessment module calls the exercise intensity adjustment index, analyzes the heart rate and blood oxygen recovery data after exercise, calculates the ratio of heart rate and blood oxygen recovery rate, assesses the adaptability and recovery efficiency of the cardiopulmonary system, and determines the cardiopulmonary recovery difference index.

[0011] The present invention has improvements in that the multidimensional physiological data set includes physiological indicators, exercise load records, and time point matching results; the blood oxygen stability assessment data includes fluctuation amplitude analysis results, offset ratio measurement, and stability level; the exercise intensity adjustment index includes metabolic load value, cadence adjustment coefficient, and stride adjustment coefficient; the cardiopulmonary recovery difference index includes recovery rate ratio, adaptability index, and recovery efficiency level.

[0012] The present invention is improved in that the physiological data acquisition module comprises:

[0013] The gait monitoring submodule monitors the patient's current cadence, stride length and speed based on the patient's real-time motion stage type, determines whether the change in cadence and stride length exceeds the motion stage standard, and identifies gait feature data that meets the motion stage characteristics;

[0014] The physiological data recording submodule calls the gait feature data, detects the blood pressure, heart rate and blood oxygen saturation data collected by the blood pressure meter and the oximeter, matches and compares the blood pressure value with the heart rate value according to the exercise time point, and identifies the physiological data whose heart rate change range is consistent with the blood pressure change range;

[0015] The multi-dimensional data calculation submodule synchronizes the physiological data in real time using the formula:

[0016] ;

[0017] Calculation of multidimensional coupling strength values , and associate physiological indicators with exercise load to obtain a multidimensional physiological data set, where Representative Heart rate value at all times, Representative Blood pressure value at any time, Representative The speed of movement at any time, Representative The step frequency at the moment, Representative Time stride, Represents the total number of measurements.

[0018] The present invention is improved in that the blood oxygen fluctuation analysis module comprises:

[0019] The blood oxygen change extraction submodule extracts the blood oxygen saturation values ​​at consecutive moments based on the multidimensional physiological data set, calculates the difference in blood oxygen saturation at adjacent moments, and identifies the blood oxygen change amount whose blood oxygen difference exceeds the basic change range;

[0020] The offset ratio calculation submodule extracts the average value of the blood oxygen saturation in the corresponding time period based on the blood oxygen change, and calculates the offset ratio of the blood oxygen saturation to the average value, using the formula:

[0021] ;

[0022] Get blood oxygen deviation ratio ,in, Representative The blood oxygen saturation value at the moment, Represents the average blood oxygen level. Represents the total number of measurements;

[0023] The stability assessment submodule compares the blood oxygen deviation ratio with the physiological stability index to determine whether there is a critical blood oxygen fluctuation and obtain blood oxygen stability assessment data.

[0024] The present invention is improved in that the exercise load adjustment module comprises:

[0025] The cardiopulmonary interaction extraction submodule extracts the heart rate and exhalation frequency of the current period according to the blood oxygen stability evaluation data, combines and analyzes them with the step frequency data, identifies the time period when the heart rate change interval is greater than the exhalation frequency change interval, and obtains the cardiopulmonary interaction influence interval value;

[0026] The metabolic load calculation submodule uses the formula according to the cardiopulmonary interaction interval value:

[0027] ;

[0028] Calculate metabolic load estimate ,in, Represents the difference between heart rate and exhalation rate. Represents the total cadence value, represents the total exercise time;

[0029] The exercise intensity adjustment submodule compares the heart rate energy consumption standard based on the metabolic load estimation value, identifies the interval that exceeds the energy consumption benchmark, and adjusts the patient's exercise frequency and stride to obtain an exercise intensity adjustment index.

[0030] The present invention is improved in that the cardiopulmonary recovery assessment module comprises:

[0031] The exercise intensity analysis submodule calls the exercise intensity adjustment index, analyzes the heart rate and blood oxygen recovery data after the exercise, calculates the ratio of the heart rate and blood oxygen recovery rate, and obtains the heart rate recovery rate and the blood oxygen recovery rate;

[0032] The recovery rate ratio calculation submodule performs rate comparison based on the heart rate recovery rate and the blood oxygen recovery rate, using the formula:

[0033] ;

[0034] Calculate the recovery rate ratio ,in, Represents the maximum heart rate recovery rate value, that is, the maximum value of the heart rate recovery rate recorded during the monitoring period. Represents the heart rate fluctuation range, which refers to the fluctuation range of heart rate during the recovery period. Represents the maximum blood oxygen recovery rate value, that is, the maximum value of the blood oxygen recovery rate recorded during the monitoring period. Represents the fluctuation range of blood oxygen, which refers to the fluctuation range of blood oxygen during the recovery period. It stands for Exercise Adjustment Index;

[0035] The recovery difference determination submodule compares the recovery rate ratio with the recovery standard of the difference exercise stage according to the recovery rate ratio, evaluates the adaptability and recovery efficiency of the cardiopulmonary system, and determines the cardiopulmonary recovery difference index.

[0036] The present invention is improved in that the system further comprises:

[0037] The risk grading module analyzes the fluctuations of heart rate and blood oxygen data in each exercise stage according to the cardiopulmonary recovery difference index, combines the fluctuation trend of heart rate with the lowest point of blood oxygen, compares the health risk assessment baseline, identifies the overlapping area of ​​data, determines the corresponding risk level, and evaluates the health risk of the patient to obtain the staged health risk level;

[0038] The staged health risk level includes heart rate fluctuation characteristics, low blood oxygen value analysis results, and risk level classification.

[0039] The present invention is improved in that the risk grading module comprises:

[0040] The heart rate fluctuation calculation submodule identifies the fluctuation of heart rate and blood oxygen data in each exercise stage according to the cardiopulmonary recovery difference index, compares and analyzes the fluctuation trend of heart rate and the lowest point of blood oxygen, and obtains the analysis results of heart rate and blood oxygen fluctuation data;

[0041] The blood oxygen baseline comparison submodule compares the heart rate and blood oxygen fluctuation data analysis results with the health risk assessment baseline using the formula:

[0042] ;

[0043] Get your cardio load ratio ,in, Represents the intensity of heart rate fluctuation. Represents the heart rate baseline value. Represents the blood oxygen baseline value, Represents the lowest blood oxygen value;

[0044] Based on the cardiopulmonary load ratio, the overlapping areas of the data are identified, the overlapping range is judged and the corresponding level interval is determined, and then the patient's health risk is evaluated to obtain the staged health risk level.

[0045] A cardiovascular patient risk assessment method based on cardiopulmonary exercise test, wherein the cardiovascular patient risk assessment method based on cardiopulmonary exercise test is performed based on the above-mentioned cardiovascular patient risk assessment system based on cardiopulmonary exercise test, and comprises the following steps:

[0046] S1: Based on the patient's real-time exercise stage type, monitor the patient's current exercise frequency, stride length and exercise speed, record blood pressure, heart rate and blood oxygen saturation data at multiple time points through a blood pressure monitor and a blood oximeter, implement data synchronization, and obtain a multidimensional physiological data set;

[0047] S2: Based on the multidimensional physiological data set, analyze the changes in blood oxygen saturation at adjacent moments, calculate the offset ratio between the changes and the average blood oxygen value at the current stage, and determine whether there is a critical blood oxygen fluctuation by comparing the offset ratio with the physiological stability index, and obtain blood oxygen stability evaluation data;

[0048] S3: analyzing the blood oxygen stability assessment data in combination with the step frequency data, identifying the interactive effects of physiological parameters, determining the metabolic load during exercise, adjusting the patient's exercise step frequency and stride, and obtaining an exercise intensity adjustment index;

[0049] S4: calling the exercise intensity adjustment index, analyzing the heart rate and blood oxygen recovery data after the exercise, calculating the ratio of the heart rate and blood oxygen recovery rate, comparing the ratio with the recovery standard of the difference exercise stage, evaluating the adaptability and recovery efficiency of the cardiopulmonary system, and determining the cardiopulmonary recovery difference index;

[0050] S5: According to the cardiopulmonary recovery difference index, the fluctuations of heart rate and blood oxygen data in each exercise stage are analyzed, and the overlapping areas of the data are identified by combining the fluctuation trend of the heart rate and the lowest point of blood oxygen, and the corresponding risk level is determined. The health risk of the patient is evaluated to obtain the staged health risk level.

[0051] Compared with the prior art, the advantages and positive effects of the present invention are:

[0052] In the present invention, by real-time monitoring and synchronization of multi-dimensional data in cardiopulmonary exercise tests, the accuracy and credibility of the data are improved, and the close relationship between physiological indicators and exercise load is strengthened. The detailed blood oxygen fluctuation analysis enables doctors to more accurately evaluate blood oxygen stability and timely discover key physiological changes. By integrating heart rate, expiratory frequency and step frequency data, dynamic exercise load adjustment is provided, and optimized exercise recommendations for individuals are achieved, thereby refining prevention and evaluation strategies. The addition of cardiopulmonary recovery assessment increases real-time monitoring of patients' recovery ability, making intervention more transparent so that doctors can take preventive or intervention measures at an early stage to improve patient safety and avoid potential risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 The module diagram of the cardiovascular patient risk assessment system based on cardiopulmonary exercise test is proposed for the present invention;

[0054] Figure 2 is a flow chart of the physiological data acquisition module in the present invention;

[0055] Figure 3 This is a flow chart of the blood oxygen fluctuation analysis module in the present invention;

[0056] Figure 4 It is a flow chart of the exercise load adjustment module in the present invention;

[0057] Figure 5 This is a flow chart of the cardiopulmonary recovery assessment module of the present invention;

[0058] Figure 6 It is a flow chart of the risk grading module in the present invention. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0060] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating positions or positional relationships, are based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0061] Example

[0062] See also Figure 1 The present invention provides a technical solution: a cardiovascular patient risk assessment system based on cardiopulmonary exercise test comprises:

[0063] The physiological data acquisition module monitors the patient's current exercise frequency, stride length and exercise speed based on the patient's real-time exercise stage type, records blood pressure, heart rate and blood oxygen saturation data at multiple time points through a blood pressure monitor and a blood oximeter, implements data synchronization, and associates physiological indicators with exercise load to obtain a multi-dimensional physiological data set;

[0064] The blood oxygen fluctuation analysis module analyzes the changes in blood oxygen saturation at adjacent moments based on a multi-dimensional physiological data set, calculates the offset ratio between the changes and the average blood oxygen value at the current stage, and determines whether there are key blood oxygen fluctuations by comparing the offset ratio with the physiological stability index, thereby obtaining blood oxygen stability evaluation data.

[0065] The exercise load adjustment module extracts the heart rate and exhalation frequency of the current period based on the blood oxygen stability assessment data, combines and analyzes them with the cadence data, identifies the interactive effects of physiological parameters, determines the metabolic load during exercise, and compares the heart rate energy consumption standard to adjust the patient's exercise cadence and stride length to obtain the exercise intensity adjustment index;

[0066] The cardiopulmonary recovery assessment module calls the exercise intensity adjustment index, analyzes the heart rate and blood oxygen recovery data after exercise, calculates the ratio of heart rate and blood oxygen recovery rate, compares the ratio with the recovery standard of the difference exercise stage, evaluates the adaptability and recovery efficiency of the cardiopulmonary system, and determines the cardiopulmonary recovery difference index;

[0067] The risk grading module analyzes the fluctuations in heart rate and blood oxygen data in each exercise stage based on the cardiopulmonary recovery difference index, combines the fluctuation trend of heart rate with the lowest point of blood oxygen, compares the health risk assessment baseline, identifies overlapping areas of data, determines the corresponding risk level, and evaluates the patient's health risk to obtain a stage-by-stage health risk level.

[0068] The multidimensional physiological data set includes physiological indicators, exercise load records, and time point matching results. The blood oxygen stability assessment data includes fluctuation amplitude analysis results, offset ratio measurement, and stability level. The exercise intensity adjustment index includes metabolic load value, cadence adjustment coefficient, and stride adjustment coefficient. The cardiopulmonary recovery difference index includes recovery rate ratio, adaptability index, and recovery efficiency level. The stage-by-stage health risk level includes heart rate fluctuation characteristics, blood oxygen low value analysis results, and risk level classification.

[0069] The cardiopulmonary recovery difference index is an indicator used to quantitatively evaluate the difference in the recovery capacity of the cardiopulmonary system after exercise. It measures the recovery efficiency of the cardiopulmonary system by comparing the recovery rate of heart rate and blood oxygen after exercise. This index reflects the difference in the recovery of cardiopulmonary function of patients after different exercise stages and is used to judge the adaptability and recovery speed of the patient's cardiopulmonary system.

[0070] For example, the heart rate recovery rate is obtained by calculating the time it takes for the heart rate to drop from the highest value to a target value (such as resting heart rate) after exercise. The faster the recovery rate, the stronger the cardiopulmonary function and the better the recovery ability; the blood oxygen recovery rate is similar to the heart rate recovery. It measures the change in blood oxygen saturation after exercise. It usually refers to the speed at which blood oxygen saturation recovers from the lowest value during exercise to the normal level. A faster recovery rate indicates that the lungs and vascular system have better oxygen delivery capacity and stronger recovery ability;

[0071] Calculate the recovery ratio. By calculating the ratio of heart rate recovery rate to blood oxygen recovery rate, a comprehensive recovery index can be obtained. This ratio is used to evaluate the difference between the two, and then determine the cardiopulmonary recovery difference index. According to the recovery standards of different exercise stages, the deviation value between the calculated cardiopulmonary recovery difference index and the standard is used to judge the difference in recovery ability.

[0072] See also Figure 2 , the physiological data acquisition module includes:

[0073] The gait monitoring submodule monitors the patient's current cadence, stride length and speed based on the patient's real-time motion stage type, determines whether the change in cadence and stride length exceeds the motion stage standard, and identifies gait feature data that meets the motion stage characteristics;

[0074] Obtain the patient's cadence, stride and exercise speed in real time. By presetting the standard range of cadence and stride in different exercise stages, call the currently collected cadence and stride data, compare them with the standard values ​​of the corresponding stage, and calculate the cadence change rate and stride rate , set the standard change rate threshold and ,like or If the gait exceeds the corresponding threshold, it is judged as abnormal gait, otherwise the gait data is included in the normal gait data set. In this example, suppose a patient's standard gait frequency range is 150-170 steps / minute and the standard stride range is 0.8-1.2 meters during the jogging stage. The current collected data is 160 steps / minute and 1.1 meters. The calculation result is , If you set , ,but and None of them exceeds the threshold, and the gait data meets the characteristics of the motion stage and is identified as gait feature data.

[0075] The physiological data recording submodule calls the gait feature data, detects the blood pressure, heart rate and blood oxygen saturation data collected by the blood pressure monitor and the oximeter, matches and compares the blood pressure value with the heart rate value according to the exercise time point, and identifies the physiological data whose heart rate change range is consistent with the blood pressure change range;

[0076] Real-time detection of blood pressure, heart rate and blood oxygen saturation data recorded by the blood pressure monitor and oximeter. According to the change trend of physiological data at adjacent time points, the blood pressure value and heart rate value are matched and compared, the physiological data that meets the exercise stage standards are selected, and the blood pressure change rate is calculated. and heart rate variability For example, if a patient is in the brisk walking stage, the normal range of heart rate is 100-120bpm, and the normal range of blood pressure is 110-130mmHg. The current data is heart rate 115bpm and blood pressure 125mmHg. The calculation is , If you set the heart rate change threshold , blood pressure change threshold ,but and All of them were within a reasonable range and the data were included in the physiological data.

[0077] The multi-dimensional data calculation submodule synchronizes the real-time data based on the physiological data using the formula:

[0078] ;

[0079] Calculation of multidimensional coupling strength values , and associate physiological indicators with exercise load to obtain a multidimensional physiological data set, where Representative Heart rate value at all times, Representative Blood pressure value at any time, Representative The speed of movement at any time, Representative The step frequency at the moment, Representative Time stride, Represents the total number of measurements;

[0080] The actual monitoring data is 3 times, specifically: , , , , , substitute the formula and calculate each item in turn:

[0081] ;

[0082] ;

[0083] ;

[0084] calculate :

[0085] ;

[0086] ;

[0087] The results show that the overall coupling degree of the patient's physiological parameters during exercise is 1953.86. If the normal interval is 1800-2500, this value is within the normal range, indicating that the relationship between the physiological indicators and the exercise load during the current exercise process is stable, and a multidimensional physiological data set can be generated for subsequent analysis.

[0088] See also Figure 3 , the blood oxygen fluctuation analysis module includes:

[0089] The blood oxygen change extraction submodule extracts the blood oxygen saturation values ​​at consecutive moments based on the multidimensional physiological data set, calculates the difference in blood oxygen saturation at adjacent moments, and identifies the blood oxygen change amount when the blood oxygen difference exceeds the basic change range;

[0090] The blood oxygen saturation data point values ​​at each moment are obtained in sequence. For example, if the monitored object is a patient, the blood oxygen saturation value is collected every second within 10 minutes to form 600 data points, specifically, the blood oxygen saturation at the 1st second is 98, the 2nd second is 97, the 3rd second is 96, the 4th second is 97, and the 5th second is 95. The data is collected continuously until the 600th second. The data is obtained by the oximeter. Then the blood oxygen saturation data sequence is called to subtract the blood oxygen values ​​from the 2nd second to the 600th second from the previous second, and the difference of the blood oxygen saturation at adjacent moments is calculated. The difference at the 2nd second is 97 minus 98, which is equal to -1, at the 3rd second is 96 minus 97, which is equal to -1, at the 4th second is 97 minus 96, which is equal to 1, and at the 5th second is 95 minus 97, which is equal to -2 , and so on, the blood oxygen changes whose absolute values ​​exceed the basic change range are screened out. The basic change range is set to 2. According to the fluctuation range of the sampled data under multiple normal exercise conditions, combined with the statistical analysis results, it is determined that the sampling range is 1 to 3 and the fluctuation is normal. 2 is set as the threshold. If the absolute value of the blood oxygen difference is greater than 2, it is determined to be the blood oxygen change. During the calculation process, the change of -2 in the 5th second reaches the threshold. Subsequently, if the blood oxygen value drops from 98 to 95 in the 120th second, the change is -3, which is also determined to be the blood oxygen change. After completing the judgment of 600 blood oxygen differences, all qualified blood oxygen changes are extracted to obtain a data set with an absolute value greater than 2 in the blood oxygen difference list, and generate a blood oxygen change value.

[0091] The offset ratio calculation submodule extracts the average value of blood oxygen saturation in the corresponding time period based on the blood oxygen change, and calculates the offset ratio of blood oxygen saturation to the average value using the formula:

[0092] ;

[0093] Get blood oxygen deviation ratio ,in, Representative The blood oxygen saturation value at the moment, Represents the average blood oxygen level. Represents the total number of measurements;

[0094] The sampling is performed 4 times in total. The first blood oxygen saturation value is 97, the second is 95, the third is 96, and the fourth is 98. The average blood oxygen value is calculated based on the cumulative sum of the sampling data. The calculation process is 97 plus 95 plus 96 plus 98, which equals 386. The total number of samples is 4 times, calculate the average blood oxygen value Equal to 386 divided by 4, we get , then calculate the deviation ratio of blood oxygen saturation to the average value. If the first deviation is |97-96.5|, which is equal to 0.5, the second deviation is |95-96.5|, which is equal to 1.5, the third deviation is |96-96.5|, which is equal to 0.5, and the fourth deviation is |98-96.5|, which is equal to 1.5, the cumulative absolute deviation is 0.5+1.5+0.5+1.5=4. Substitute it into the formula for calculation:

[0095] ;

[0096] Get blood oxygen deviation ratio The value is 0.0104, and the blood oxygen deviation ratio value is obtained.

[0097] The stability assessment submodule compares the blood oxygen deviation ratio with the physiological stability index to determine whether there is a critical blood oxygen fluctuation and obtain blood oxygen stability assessment data;

[0098] Compared with the physiological stability index, the physiological stability index is set to 0.02, which is derived from the statistical offset ratio fluctuation range setting during normal human movement. The blood oxygen saturation fluctuation does not exceed ±3 as the standard. Combined with the sampling data, it is calculated that the offset ratio is less than 0.02 for stability and equal to or greater than 0.02 for instability. The blood oxygen offset ratio value of 0.0104 is called and directly compared with the stability index of 0.02. It is judged that 0.0104 is less than 0.02, and it is judged that there is no critical blood oxygen fluctuation, and the blood oxygen stability evaluation data is generated.

[0099] See also Figure 4 , the exercise load adjustment module includes:

[0100] The cardiopulmonary interaction extraction submodule extracts the heart rate and exhalation frequency of the current period based on the blood oxygen stability assessment data, combines it with the cadence data for analysis, identifies the time period when the heart rate change interval is greater than the exhalation frequency change interval, and obtains the cardiopulmonary interaction influence interval value;

[0101] The blood oxygen saturation value of the patient during exercise was obtained in real time and the change curve was recorded. Then, the continuous blood oxygen saturation stable interval was screened out from the recorded time series, and the blood oxygen fluctuation was set to no more than 2% as the stable threshold. The interval in which the patient's blood oxygen saturation was stable at more than 95% was used as the basis for extracting effective data. Then, the heart rate data and expiratory frequency data of the corresponding period were extracted in the screened blood oxygen stable interval. The calculation formula was the sum of each sampling value divided by the number of sampling times. If the heart rate values ​​collected within 5 seconds were 88, 92, 95, 90 and 93 times / min, the mean was (88+92+95+90+93) / 5=91.6 times / min, and the expiratory frequency values ​​collected within 5 seconds were 18, 20, 19, 21 and 20 times / min, the mean was (18+20+19+21+20) / 5=19.6 times / min. Combined with the cadence data collection, the cadence was recorded by the accelerometer The number of steps per second is synchronized to the heart rate and expiratory frequency timeline. The step frequency collection values ​​are 120, 125, 122, 118 and 123 steps / minute, with an average of 121.6 steps / minute. After completing the basic data extraction, the heart rate change interval and the expiratory frequency change interval are calculated, respectively, in the form of interval maximum minus minimum value. If the heart rate change interval value is greater than the expiratory frequency change interval value, the interval is included in the valid interval. For example, in a certain interval, the maximum heart rate is 98 times / minute, the minimum is 85 times / minute, the change interval is 13 times / minute, the maximum expiratory frequency is 22 times / minute, the minimum is 18 times / minute, and the change interval is 4 times / minute, then the interval is determined to be valid. Finally, during the exercise process, multiple valid intervals that meet the requirement that the heart rate change interval is greater than the expiratory frequency change interval are identified, and the heart rate, expiratory frequency and step frequency data in each valid interval are integrated to obtain the cardiopulmonary interaction interval value.

[0102] The metabolic load calculation submodule uses the formula based on the cardiopulmonary interaction interval value:

[0103] ;

[0104] Calculate metabolic load estimate ,in, Represents the difference between heart rate and exhalation rate. Represents the total cadence value, represents the total exercise time;

[0105] Extract the mean heart rate and the mean expiratory frequency within the effective interval, and calculate the difference between the two as the cardiopulmonary difference For example, within a valid interval, the sampled heart rate data are 92, 96, 100, 97 and 95 (beats / minute), and the mean heart rate is calculated as follows:

[0106] ;

[0107] The exhalation frequency data are 18, 20, 21, 19, 20 (times / minute). Calculate the mean exhalation frequency:

[0108] ;

[0109] Get the cardiopulmonary difference:

[0110] ;

[0111] Next, extract the total step frequency , count all the cadence cumulative values ​​within the valid range, for example, the cadence data is 120, 122, 118, 125 and 124 (steps / minute), calculate the total cadence value:

[0112] ;

[0113] Count the total exercise time within the effective interval , if the duration of the interval is 10 seconds, substitute it into the formula to calculate:

[0114] ;

[0115] The estimated metabolic load value of 14712.9 is obtained. This result shows that the estimated metabolic load value in the current interval is 14712.9. If the baseline value is 20000, it is lower than the baseline value, indicating that the current metabolic load is within the normal range.

[0116] The exercise intensity adjustment submodule compares the heart rate energy consumption standard based on the estimated metabolic load, identifies the interval that exceeds the energy consumption benchmark, and adjusts the patient's exercise frequency and stride length to obtain the exercise intensity adjustment index;

[0117] Based on the estimated metabolic load, it is first compared with the heart rate energy consumption standard. The heart rate energy consumption standard is set as a metabolic load baseline value of 20,000. This baseline value is calculated based on the average metabolic load level of healthy people during moderate and brisk walking. The heart rate and exercise duration are collected by energy metabolism monitoring equipment and combined with power calculation. In this example, the average heart rate collected during 10 minutes of moderate and brisk walking is 120 beats / min, and the power output is 80 watts, which gives an average metabolic load of 20,000. The metabolic load estimate is then identified. Whether the calculated value is higher than the benchmark value, the current 14712.9<20000, it is determined that the metabolic load in the current interval is not exceeded. The patient's exercise frequency and stride length are adjusted according to the metabolic load exceeding the standard. The adjustment factor coefficient is 0.8. The adjusted frequency is the current average frequency of 121.8×0.8=97.44 steps / minute, and the stride length is adjusted to the original stride length of 0.75 meters×0.8=0.6 meters, that is, 97.44×0.6=58.464. After adjustment, the exercise intensity is reduced, and the exercise intensity adjustment index is obtained.

[0118] See also Figure 5 , the cardiopulmonary recovery assessment module includes:

[0119] The exercise intensity analysis submodule calls the exercise intensity adjustment index, analyzes the heart rate and blood oxygen recovery data after exercise, calculates the ratio of heart rate and blood oxygen recovery rate, and obtains the heart rate recovery rate and blood oxygen recovery rate;

[0120] Get the recovery data of heart rate and blood oxygen after exercise. Use wearable devices or medical monitoring instruments, such as heart rate monitors and blood oxygen saturation meters, to record the heart rate and blood oxygen change values ​​per second after exercise. Establish time series data, store the data in a database or cache system, extract the data and preprocess it, remove signal noise, outliers and equipment errors, use sliding average method or median filtering method to smooth the heart rate and blood oxygen data to make their fluctuation trend more stable, and then calculate the heart rate recovery rate. Select the key time points of heart rate data such as the first 10 seconds, 30 seconds, 60 seconds, and 120 seconds after the end of exercise, and calculate the heart rate drop rate at adjacent time points. Use the formula: ,in, Indicates time Heart rate recovery rate at and Respectively indicate time points and The heart rate value at and For the corresponding time point, the heart rate recovery rate at different time points after the exercise is calculated by this formula. Similarly, the blood oxygen recovery rate is calculated. The blood oxygen data at the same time point is used to calculate the change in the blood oxygen recovery rate to obtain the blood oxygen recovery rate.

[0121] The recovery rate ratio calculation submodule compares the heart rate recovery rate and the blood oxygen recovery rate using the formula:

[0122] ;

[0123] Calculate the recovery rate ratio ,in, Represents the maximum heart rate recovery rate value, that is, the maximum value of the heart rate recovery rate recorded during the monitoring period. Represents the heart rate fluctuation range, which refers to the fluctuation range of heart rate during the recovery period. Represents the maximum blood oxygen recovery rate value, that is, the maximum value of the blood oxygen recovery rate recorded during the monitoring period. Represents the fluctuation range of blood oxygen, which refers to the fluctuation range of blood oxygen during the recovery period. It stands for Exercise Adjustment Index;

[0124] Set the exercise intensity adjustment index for different individuals and use the baseline recovery data for calibration. For example, for individuals with low-intensity exercise, set , and for individuals with high-intensity exercise, , and then substitute the actual value, if , , , , substitute into the formula to calculate:

[0125] ;

[0126] The results show that the individual's recovery rate ratio is 4.63, which can be compared with the known population baseline data to determine his cardiopulmonary recovery.

[0127] The recovery difference determination submodule compares the recovery rate ratio with the recovery standard of the differential exercise stage according to the recovery rate ratio, evaluates the adaptability and recovery efficiency of the cardiopulmonary system, and determines the cardiopulmonary recovery difference index;

[0128] Call the standard recovery ratio interval of the different exercise stages to obtain the standard recovery rate ratio interval under different exercise modes. For example, the recovery rate ratio after a short run is usually between 3.5-5.5, while the recovery rate ratio after a long run is usually between 2.0-3.5. Compare the individual calculated recovery rate ratio with the standard ratio interval. If the ratio is higher than the upper limit of the standard interval, it means that the cardiopulmonary adaptability is strong. If the ratio is lower than the lower limit of the standard interval, it means that the cardiopulmonary system has weak recovery capacity. Combined with the data change trend at different time points after exercise, calculate the recovery trend change rate, further refine the evaluation of the individual's cardiopulmonary recovery capacity, and determine the cardiopulmonary recovery difference index.

[0129] See also Figure 6 , the risk grading module includes:

[0130] The heart rate fluctuation calculation submodule identifies the fluctuation of heart rate and blood oxygen data in each exercise stage according to the cardiopulmonary recovery difference index, compares and analyzes the fluctuation trend of heart rate and the lowest point of blood oxygen, and obtains the analysis results of heart rate and blood oxygen fluctuation data;

[0131] Obtain the heart rate and blood oxygen data of each exercise stage, continuously record the patient's heart rate and blood oxygen saturation, and then analyze the fluctuation of the data. Specifically, calculate the heart rate change rate of each stage, that is, the difference between the current heart rate and the heart rate at the previous moment divided by the heart rate at the previous moment, calculated as: change rate = (current heart rate-previous heart rate) / previous heart rate. For example, if the heart rate at the previous moment is 150 beats / minute and the current heart rate is 160 beats / minute, then the change rate is (160-150) / 150=0.0667. At the same time, record the lowest blood oxygen value of this stage, such as 95%. Then, analyze the trend of the heart rate change rate to determine whether it is rising, falling or stable. Compare the heart rate change trend with the lowest blood oxygen value to identify the relationship between the two. For example, if the heart rate change rate continues to rise and the lowest blood oxygen value decreases, it indicates that the exercise intensity is too high. Through the above analysis, the analysis results of the heart rate and blood oxygen fluctuation data are obtained, which provides a basis for adjusting the exercise intensity.

[0132] The blood oxygen baseline comparison submodule compares the heart rate and blood oxygen fluctuation data analysis results with the health risk assessment baseline using the formula:

[0133] ;

[0134] Get your cardio load ratio ,in, Represents the heart rate fluctuation intensity value, which indicates the intensity of heart rate fluctuation in a specific exercise stage. stands for Heart Rate Baseline, which represents the expected heart rate level under normal or safe conditions. Stands for blood oxygen baseline value, which represents the expected blood oxygen concentration level under normal or safe conditions. Stands for Blood Oxygen Minimum, which refers to the lowest blood oxygen concentration value recorded during a specific exercise phase;

[0135] Based on the analysis results of heart rate and blood oxygen fluctuation data, the results are compared with the health risk assessment baseline. The health risk assessment baseline is usually formulated based on a large number of population data, including heart rate baseline values ​​and blood oxygen baseline values. For example, if a 35-year-old patient has a heart rate baseline value of 75 beats / minute and a blood oxygen baseline value of 97%, during a high-intensity training, the monitoring shows that the heart rate fluctuation intensity value is 15 beats / minute and the lowest blood oxygen value in the stage is 94%. If the following data is available , , , , substitute into the formula to calculate:

[0136] ;

[0137] The cardiorespiratory load ratio obtained was 51.39, which was used for subsequent health risk level determination.

[0138] Based on the cardiopulmonary load ratio, the overlapping areas of the data are identified, the overlapping range is determined and the corresponding level interval is determined, and then the health risk of the patient is evaluated to obtain the staged health risk level;

[0139] Based on the calculated cardiorespiratory load ratio, it is necessary to determine the overlapping area with the health risk assessment baseline to determine the corresponding risk level. The health risk assessment baseline usually divides the cardiorespiratory load ratio into different risk level intervals, for example: low risk (-50 to 50), medium risk (51 to 100), high risk (greater than 100). By comparing the individual's cardiorespiratory load ratio (51.39) with the interval, it is found that it falls in the medium risk. Therefore, the individual's health risk is assessed as medium risk, and the staged health risk level is obtained.

[0140] The cardiovascular risk assessment method for patients based on cardiopulmonary exercise testing includes the following steps:

[0141] S1: Based on the patient's real-time exercise stage type, monitor the patient's current exercise frequency, stride length and exercise speed, record blood pressure, heart rate and blood oxygen saturation data at multiple time points through a blood pressure monitor and a blood oximeter, implement data synchronization, and obtain a multidimensional physiological data set;

[0142] S2: Based on the multi-dimensional physiological data set, analyze the changes in blood oxygen saturation at adjacent moments, calculate the deviation ratio between the changes and the average blood oxygen value at the current stage, and determine whether there is a critical blood oxygen fluctuation by comparing the deviation ratio with the physiological stability index, and obtain blood oxygen stability evaluation data;

[0143] S3: Based on the blood oxygen stability assessment data, combined with the cadence data, the interactive effects of physiological parameters are identified, the metabolic load during exercise is determined, the patient's exercise cadence and stride length are adjusted, and the exercise intensity adjustment index is obtained;

[0144] S4: Call the exercise intensity adjustment index, analyze the heart rate and blood oxygen recovery data after exercise, calculate the ratio of heart rate and blood oxygen recovery rate, compare the ratio with the recovery standard of the difference exercise stage, evaluate the adaptability and recovery efficiency of the cardiopulmonary system, and determine the cardiopulmonary recovery difference index;

[0145] S5: According to the cardiopulmonary recovery difference index, analyze the fluctuations of heart rate and blood oxygen data in each exercise stage, combine the fluctuation trend of heart rate and the lowest point of blood oxygen, identify the overlapping areas of data, judge the corresponding risk level, and evaluate the health risk of the patient to obtain the staged health risk level.

[0146] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A cardiovascular patient risk assessment system based on cardiopulmonary exercise testing, characterized in that: The system comprises: The physiological data acquisition module monitors the patient's current exercise frequency, stride length and exercise speed based on the patient's real-time exercise stage type, records blood pressure, heart rate and blood oxygen saturation data at multiple time points through a blood pressure monitor and a blood oximeter, implements data synchronization, and obtains a multi-dimensional physiological data set; The blood oxygen fluctuation analysis module analyzes the change in blood oxygen saturation at adjacent moments based on the multidimensional physiological data set, calculates the offset ratio between the change and the average blood oxygen value at the current stage, determines whether there is a critical blood oxygen fluctuation, and obtains blood oxygen stability assessment data; The exercise load adjustment module extracts the heart rate and expiratory frequency of the current period according to the blood oxygen stability assessment data, combines and analyzes them with the step frequency data, identifies the interactive effects of physiological parameters, determines the metabolic load during exercise, adjusts the patient's exercise step frequency and stride, and obtains an exercise intensity adjustment index; The cardiopulmonary recovery assessment module calls the exercise intensity adjustment index, analyzes the heart rate and blood oxygen recovery data after exercise, calculates the ratio of heart rate and blood oxygen recovery rate, assesses the adaptability and recovery efficiency of the cardiopulmonary system, and determines the cardiopulmonary recovery difference index.

2. The cardiovascular patient risk assessment system based on cardiopulmonary exercise test according to claim 1, characterized in that: The multidimensional physiological data set includes physiological indicators, exercise load records, and time point matching results; the blood oxygen stability assessment data includes fluctuation amplitude analysis results, offset ratio measurement, and stability level; the exercise intensity adjustment index includes metabolic load value, cadence adjustment coefficient, and stride adjustment coefficient; the cardiopulmonary recovery difference index includes recovery rate ratio, adaptability index, and recovery efficiency level.

3. The cardiovascular patient risk assessment system based on cardiopulmonary exercise test according to claim 1, characterized in that: The physiological data acquisition module comprises: The gait monitoring submodule monitors the patient's current cadence, stride length and speed based on the patient's real-time motion stage type, determines whether the change in cadence and stride length exceeds the motion stage standard, and identifies gait feature data that meets the motion stage characteristics; The physiological data recording submodule calls the gait feature data, detects the blood pressure, heart rate and blood oxygen saturation data collected by the blood pressure meter and the oximeter, matches and compares the blood pressure value with the heart rate value according to the exercise time point, and identifies the physiological data whose heart rate change range is consistent with the blood pressure change range; The multi-dimensional data calculation submodule synchronizes the physiological data in real time using the formula: ； Calculation of multidimensional coupling strength values , and associate physiological indicators with exercise load to obtain a multidimensional physiological data set, where Representative Heart rate value at all times, Representative Blood pressure value at any time, Representative The speed of movement at any time, Representative The step frequency at the moment, Representative Time stride, Represents the total number of measurements.

4. The cardiovascular patient risk assessment system based on cardiopulmonary exercise test according to claim 1, characterized in that: The blood oxygen fluctuation analysis module includes: The blood oxygen change extraction submodule extracts the blood oxygen saturation values ​​at consecutive moments based on the multidimensional physiological data set, calculates the difference in blood oxygen saturation at adjacent moments, and identifies the blood oxygen change amount whose blood oxygen difference exceeds the basic change range; The offset ratio calculation submodule extracts the average value of the blood oxygen saturation in the corresponding time period based on the blood oxygen change, and calculates the offset ratio of the blood oxygen saturation to the average value, using the formula: ； Get blood oxygen deviation ratio ,in, Representative The blood oxygen saturation value at the moment, Represents the average blood oxygen level. Represents the total number of measurements; The stability assessment submodule compares the blood oxygen deviation ratio with the physiological stability index to determine whether there is a critical blood oxygen fluctuation and obtain blood oxygen stability assessment data.

5. The cardiovascular patient risk assessment system based on cardiopulmonary exercise test according to claim 1, characterized in that: The exercise load adjustment module comprises: The cardiopulmonary interaction extraction submodule extracts the heart rate and exhalation frequency of the current period according to the blood oxygen stability evaluation data, combines and analyzes them with the step frequency data, identifies the time period when the heart rate change interval is greater than the exhalation frequency change interval, and obtains the cardiopulmonary interaction influence interval value; The metabolic load calculation submodule uses the formula according to the cardiopulmonary interaction interval value: ； Calculate metabolic load estimate ,in, Represents the difference between heart rate and exhalation rate. Represents the total cadence value, represents the total exercise time; The exercise intensity adjustment submodule compares the heart rate energy consumption standard based on the metabolic load estimation value, identifies the interval that exceeds the energy consumption benchmark, and adjusts the patient's exercise frequency and stride to obtain an exercise intensity adjustment index.

6. The cardiovascular patient risk assessment system based on cardiopulmonary exercise test according to claim 1, characterized in that: The cardiopulmonary recovery assessment module includes: The exercise intensity analysis submodule calls the exercise intensity adjustment index, analyzes the heart rate and blood oxygen recovery data after the exercise, calculates the ratio of the heart rate and blood oxygen recovery rate, and obtains the heart rate recovery rate and the blood oxygen recovery rate; The recovery rate ratio calculation submodule performs rate comparison based on the heart rate recovery rate and the blood oxygen recovery rate, using the formula: ； Calculate the recovery rate ratio ,in, Represents the maximum heart rate recovery rate value, that is, the maximum value of the heart rate recovery rate recorded during the monitoring period. Represents the heart rate fluctuation range, which refers to the fluctuation range of heart rate during the recovery period. Represents the maximum blood oxygen recovery rate value, that is, the maximum value of the blood oxygen recovery rate recorded during the monitoring period. Represents the fluctuation range of blood oxygen, which refers to the fluctuation range of blood oxygen during the recovery period. It stands for Exercise Adjustment Index; The recovery difference determination submodule compares the recovery rate ratio with the recovery standard of the difference exercise stage according to the recovery rate ratio, evaluates the adaptability and recovery efficiency of the cardiopulmonary system, and determines the cardiopulmonary recovery difference index.

7. The cardiovascular patient risk assessment system based on cardiopulmonary exercise test according to claim 1, characterized in that: The system further comprises: The risk grading module analyzes the fluctuations of heart rate and blood oxygen data in each exercise stage according to the cardiopulmonary recovery difference index, combines the fluctuation trend of heart rate with the lowest point of blood oxygen, compares the health risk assessment baseline, identifies the overlapping area of ​​data, determines the corresponding risk level, and evaluates the health risk of the patient to obtain the staged health risk level; The staged health risk level includes heart rate fluctuation characteristics, low blood oxygen value analysis results, and risk level classification.

8. The cardiovascular patient risk assessment system based on cardiopulmonary exercise test according to claim 7, characterized in that: The risk grading module includes: The heart rate fluctuation calculation submodule identifies the fluctuation of heart rate and blood oxygen data in each exercise stage according to the cardiopulmonary recovery difference index, compares and analyzes the fluctuation trend of heart rate and the lowest point of blood oxygen, and obtains the analysis results of heart rate and blood oxygen fluctuation data; The blood oxygen baseline comparison submodule compares the heart rate and blood oxygen fluctuation data analysis results with the health risk assessment baseline using the formula: ； Get your cardio load ratio ,in, Represents the intensity of heart rate fluctuation. Represents the heart rate baseline value. Represents the blood oxygen baseline value, Represents the lowest blood oxygen value; Based on the cardiopulmonary load ratio, the overlapping areas of the data are identified, the overlapping range is judged and the corresponding level interval is determined, and then the patient's health risk is evaluated to obtain the staged health risk level.

9. A cardiovascular patient risk assessment method based on cardiopulmonary exercise testing, characterized in that: The cardiovascular patient risk assessment system based on cardiopulmonary exercise test according to any one of claims 1 to 8 comprises the following steps: S1: Based on the patient's real-time exercise stage type, monitor the patient's current exercise frequency, stride length and exercise speed, record blood pressure, heart rate and blood oxygen saturation data at multiple time points through a blood pressure monitor and a blood oximeter, implement data synchronization, and obtain a multidimensional physiological data set; S2: Based on the multidimensional physiological data set, analyze the changes in blood oxygen saturation at adjacent moments, calculate the offset ratio between the changes and the average blood oxygen value at the current stage, and determine whether there is a critical blood oxygen fluctuation by comparing the offset ratio with the physiological stability index, and obtain blood oxygen stability evaluation data; S3: analyzing the blood oxygen stability assessment data in combination with the step frequency data, identifying the interactive effects of physiological parameters, determining the metabolic load during exercise, adjusting the patient's exercise step frequency and stride, and obtaining an exercise intensity adjustment index; S4: calling the exercise intensity adjustment index, analyzing the heart rate and blood oxygen recovery data after the exercise, calculating the ratio of the heart rate and blood oxygen recovery rate, comparing the ratio with the recovery standard of the difference exercise stage, evaluating the adaptability and recovery efficiency of the cardiopulmonary system, and determining the cardiopulmonary recovery difference index; S5: According to the cardiopulmonary recovery difference index, the fluctuations of heart rate and blood oxygen data in each exercise stage are analyzed, and the overlapping areas of the data are identified by combining the fluctuation trend of the heart rate and the lowest point of blood oxygen, and the corresponding risk level is determined. The health risk of the patient is evaluated to obtain the staged health risk level.

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