Dynamic electrocardiograph measurement technology characteristic measurement method based on image measurement

Abstract

The invention relates to the technical field of image measurement, and particularly discloses a dynamic electrocardiograph measurement technical feature measurement method based on image measurement, which comprises the steps of scale verification and feature measurement, in the step of scale verification, the number x of pixel points between picture straight lines and the actual size y input by a user are obtained, and the proportional relation x / y of pixels and the size is determined; characteristic measurement: according to the picture, measuring the measuring technical characteristics of the dynamic electrocardiograph, the technical characteristics including maximum input voltage, sensitivity, frequency response, overshoot, lag and tracing speed; pixel distances are converted into actual physical quantities through scale parameters, and then error analysis is carried out. According to the image measurement method, an image loading module, a dynamic scaling control module, a dynamic measurement module and a result analysis module are included in the measurement method, all the modules cooperatively work through event driving, and complete and efficient measurement from image loading to measurement result judgment is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of image measurement, and particularly relates to a method for measuring metrological technical characteristics of a dynamic electrocardiograph based on image measurement. Background Art

[0002] A dynamic electrocardiograph can continuously record three-channel or multi-channel electrocardiogram signals for 24 hours or longer in the natural state of a patient, and with the aid of a computer, it can be displayed, analyzed and processed to timely detect various arrhythmia events and abnormal ST segment changes, providing an important basis for clinical diagnosis and treatment. The dynamic electrocardiograph is widely used in medical clinics. Compared with multi-parameter monitors and ordinary electrocardiographs, the requirements for allowable errors of the metrological technical characteristics of the dynamic electrocardiograph are higher and the technical indicators are more stringent.

[0003] At present, for the measurement method of the metrological technical characteristics of a dynamic electrocardiograph, the dynamic electrocardiogram signal is printed by a printer, and then different metrological technical characteristics are measured on different characteristic signal papers using a scale and an optical magnifying glass, including items such as maximum input voltage, sensitivity, frequency response, overshoot, hysteresis, recording speed, etc. This traditional metrological test method will introduce large artificial visual errors, the process efficiency of measuring data with a scale is very low, and on-site manual error analysis and calculation are required to determine whether the technical characteristics of the instrument meet the national metrological technical requirements. The dynamic electrocardiograph is used very frequently in medical clinics, putting higher requirements on the time efficiency of on-site detection by metrological technicians.

[0004] In order to improve the metrological speed and metrological accuracy of the dynamic electrocardiograph, there is an urgent need for a method for measuring the metrological technical characteristics of a dynamic electrocardiograph with high precision and high efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for measuring the metrological technical characteristics of a dynamic electrocardiograph based on image measurement to solve the above technical problems.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A method for measuring the metrological technical characteristics of a dynamic electrocardiograph based on image measurement includes scale calibration and characteristic measurement, wherein: Scale calibration: Obtain the number of pixel points x between straight lines in the picture and the actual size y input by the user, and determine the proportional relationship between pixels and size as x / y; Characteristic measurement: According to the picture, measure the metrological technical characteristics of the dynamic electrocardiograph, and the technical characteristics include maximum input voltage, sensitivity, frequency response, overshoot, hysteresis and recording speed; convert the pixel distance into an actual physical quantity through the scale parameter, and then perform error analysis.

[0007] As a further solution of the present invention, the specific steps for obtaining the ratio relationship between pixels and dimensions are as follows: Select a picture file and load it into the picture box. Drag two straight lines to the preset positions on the picture and input the actual dimension between the two straight lines. Calculate according to the formula: calibration coefficient = (pixel distance / actual dimension) / (ruler length / ruler scale). Scale the ruler according to the calibration coefficient and save it after adjusting the ruler calibration coefficients on the interfaces where the ruler will be used to be the same.

[0008] As a further solution of the present invention, the specific steps for measuring the tracing speed are as follows: The user clicks the select picture button to trigger the Btn_SelectFile04_Click event to display the picture. When the user operates to change the position of the measurement line, it triggers the CeLiang_04 position change event, calls the JiSuanJJ method to calculate the distance in real time and update the measurement result. Click the verification button to trigger the button14 click event for error calculation and result display.

[0009] As a further solution of the present invention, the specific steps for overshoot measurement are as follows: The user clicks the select picture button to select a picture and load it into pictureBox02. When the value of the trackBar changes, adjust the BaseScale of the corresponding ruler and rescale the image for display. When the position of the measurement line changes, trigger the calculation of the longitudinal measurement result and display it in the corresponding text box.

[0010] As a further solution of the present invention, when using the slider to adjust the image scaling ratio, perform corresponding operations according to different TrackBar controls, mainly scaling the image and updating the relevant rulers and displays.

[0011] As a further solution of the present invention, click the button14_Click method, obtain the measurement result from CeLiangJG04.Text, divide it by 25 and display it with two decimal places reserved in textBox55. Calculate the error percentage from 7 and display it with one decimal place reserved in textBox56. According to whether the error is within ±5%, set textBox57 to display "Compliant" or "Non-compliant", and the color corresponds to green or red.

[0012] As a further solution of the present invention: Click the button12_Click event, calculate the difference between the maximum and minimum values of the two measurement lines, calculate the overshoot value according to the formula guochong = (difference / (2 * minimum value)) * 100, and display it in textBox31. According to whether the error is greater than 20%, set textBox37 to display "Compliant" or "Non-compliant", and the colors correspond to green or red respectively.

[0013] Advantages of the present invention: By calibrating the scale, the present invention obtains the calibration coefficient and realizes the high-precision unit conversion of the distance of the image feature position. By the method of image measurement, the measurement method includes four modules: an image loading module, a dynamic scaling control module, a dynamic measurement module, and a result analysis module. Each module works collaboratively through event-driven to achieve a complete and efficient measurement from image loading to measurement result determination. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below with reference to the accompanying drawings.

[0015] Figure 1 is a schematic diagram of the scale calibration of the present invention; Figure 2 is a schematic diagram of the maximum input voltage measurement of the present invention; Figure 3 is a schematic diagram of the sensitivity measurement of the present invention; Figure 4 is a schematic diagram of the frequency response measurement of the present invention; Figure 5 is a schematic diagram of the overshoot measurement of the present invention; Figure 6 is a schematic diagram of the hysteresis measurement of the present invention; Figure 7 is a schematic diagram of the tracing speed measurement of the present invention; Figure 8 is a flow chart of the scale calibration of the present invention; Figure 9 is a flow chart of the feature measurement of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] Please refer to Figures 1-9As shown, the present invention is a method for measuring the characteristics of the measurement technology of a dynamic electrocardiograph based on image measurement, which generally includes two major steps: the first step is scale calibration, and the second step is characteristic measurement.

[0018] Step 1: calibrate the scale: Basic principle: mutual conversion between pixels and actual size; The relationship between pixels and size on the user's current computer is: Assuming the distance between the straight lines is x pixels, and the size entered by the user is y (unit: mm), then on the user's current computer, the relationship between pixels and size is: x / y. Because the resolution of each computer is different, before using the image measurement method, the ruler must be calibrated first. The operation interface is as shown below ( Figure 1 ) is shown in the following figure. The scale calibration process is as follows Figure 8 shown.

[0019] Program implementation process: 1.1 File operation (Btn_SelectFile00_Click, a button method defined in programming, that is Figure 1 Clicking the "Calibrate Image" button in the program will trigger the "Btn_SelectFile00_Click" program. Use the SelectFile() method (a general function for loading images, which is called in the "Btn_SelectFile00_Click" program) to select an image file and load the selected image into the picture box pictureBox_DB (the control used to load images in the program).

[0020] 1.2 The user drags two straight lines ( Figure 1 There are two black straight lines in the image), move it to a specific position (this specific position is selected by the user, such as Figure 1 As shown, the black straight line is usually chosen to be just on the red straight line in the figure. This red line is Figure 1 The edge of the 5mm small square. Generally, the vertical distance between the two black measuring lines is an integer number of small squares, such as 10, 20, etc.).

[0021] The location of the two black lines is JiaoZhunZZ01.Location.X (represents Figure 1 The straight line on the left), JiaoZhunZZ02.Location.X (represents Figure 1 the position of the straight line on the right side of the middle); 1.3 The user enters the actual size between the two straight lines in millimeters.

[0022] 1.4 Calculate, adjust and save calibration coefficients: Input verification → Calculate calibration coefficient → Update the calibration coefficient of the scale control → Save the calibration coefficient; Core formula: Calibration coefficient = (Pixel distance / Actual size) / (Scale length / Scale graduations).

[0023] Program implementation steps: Read the actual size input by the user; Calculate the ratio of pixels to actual size, that is, how many pixel points are included in 1 mm; Calculate the ratio of the electronic ruler ( Figure 1 There are graduations on all four sides enclosed by the four black dots in it, and that is the electronic ruler. The electronic ruler is represented by ruler1 / ruler2 / ruler3 / ruler4 in the program respectively). The ratio of the control (ruler1.Width is the length of the ruler, and the unit is px (px is the abbreviation of pixel, which is the basic unit in digital images, screen displays, and graphic designs. It is the smallest unit that makes up a digital image and is used to represent the size and position of an image, screen display, or design element)), ruler1.RulerMax is the graduation of the ruler, and the unit is mm); Find the difference between the two ratios to obtain the calibration coefficient JiaoZhunXS; Scale the displayed ruler through BaseScale to ensure that the size of the ruler is the same as the actual size to assist the user in measurement; Adjust the calibration coefficients of all the scales on the interface to be consistent. The interfaces that use the scale include the measurement of items such as maximum input voltage, sensitivity, frequency response, overshoot, hysteresis, and tracing speed.

[0024] Save the calibration coefficient of the ruler to prevent the user from having to re-verify the scale every time they open it. One number corresponds to one calibration coefficient, which is theoretically unchanged, but it will also change if the software and the installed computer change.

[0025] Second step, Feature measurement: The measurement of the metrological technical characteristics of a dynamic electrocardiograph includes items such as maximum input voltage, sensitivity, frequency response, overshoot, hysteresis, and tracing speed, as shown in the following figure ( Figures 2-7 ), from the perspective of image measurement, it mainly includes measurements in two directions: the X coordinate and the Y coordinate. The X coordinate measurement selects the tracing speed measurement item for detailed analysis and description, and the Y coordinate measurement selects the overshoot measurement item for detailed analysis and description. The feature measurement process is as Figure 9 shown.

[0026] 1. Measurement method for the metrological technical characteristics of the tracing speed of a dynamic electrocardiograph: The implementation effect of the measurement method for the metrological technical characteristics of the tracing speed of a dynamic electrocardiograph is as Figure 7 shown.

[0027] Implementation process of the measurement method: [Select Picture] → [Display Picture] → [Drag Measurement Line] → [Calculate Distance in Real Time] → [Click to Verify] → [Display Measurement Results]; The measurement method includes four modules: an image loading module, a dynamic zoom control module, a dynamic measurement module, and a result analysis module. Each module works collaboratively through event-driven mechanisms to achieve a complete process from image loading to measurement result determination. The core lies in converting the pixel distance into the actual physical quantity through the scale parameter and then performing error analysis.

[0028] 1.1 Image loading module: Use the button click event handler. The program SelectFile() is used to obtain the file name. If the file name is not empty, a Bitmap object (which is used in the program to assign the user-selected picture to the originalImage04 image variable) is created and assigned to originalImage04 (originalImage04 is a custom variable. The statement in the program is: private Bitmap originalImage04;), and then it is displayed on pictureBox04 (pictureBox04 is the control used in the tracing speed program to load and display the user-selected picture). The function of this part is to allow the user to select a picture and display it in the corresponding PictureBox control. The program implementation process is as follows: The user clicks the button to trigger the Btn_SelectFile04_Click event; Call the SelectFile() method to obtain the file path; Load the picture and display it on the pictureBox04 control; Store the original image in the originalImage04 variable; 1.2 Dynamic zoom control module: The scanned speed picture is clear enough without magnification. The default magnification factor is 1, corresponding to the trackBar04.Value parameter.

[0029] 1.3 Dynamic measurement module: When any one of the two measurement lines changes its position, the CeLiang_04_LocationChanged method event is triggered. The event calls the JiSuanJJ method, and finally the result is assigned to CeLiangJG04.Text. The parameters passed here are "horizontal", two DraggableLine objects (CeLiang_04_1 and CeLiang_04_2 represent the left and right lines respectively), the value of trackBar04, and a ruler_04_4 ruler object. The JiSuanJJ method returns a string result to display the measurement result. The function of this module is to calculate the vertical distance between the two measurement lines when the position of the measurement lines changes and update the display.

[0030] The JiSuanJJ method performs different calculations based on the category parameter (vertical or horizontal). Whether it is vertical or horizontal, a conversion coefficient ZhuanHua is calculated, and then the result is obtained by multiplying the position difference between the two measurement lines by this coefficient. Vertically, the difference in Y coordinates is calculated, and horizontally, the difference in X coordinates is calculated. Calibration coefficient (BaseScale) , and the calculation of the conversion coefficient involves three attributes of rulerBase: RulerMax, Width, and BaseScale. The meanings of these three parameters are the ruler scale (unit: mm), the ruler length (unit: px), and the calibration coefficient respectively. These three parameters are known. According to the calibration coefficient (BaseScale) formula, only by dragging the two measurement lines on the image can the vertical distance (unit: px) be obtained, and then the actual distance between the two lines (unit: mm) can be calculated.

[0031] Program implementation process: When the position of the CeLiang_04 control changes, the CeLiang_04_LocationChanged method is triggered. The method code: CeLiangJG04.Text = JiSuanJJ("horizontal", CeLiang_04_1, CeLiang_04_2, trackBar04.Value, ruler_04_4); Call the JiSuanJJ method to calculate the measurement result: The first step: Parameter passing: measurement type (horizontal / vertical), two draggable lines, zoom value, and ruler reference; The second step: Conversion coefficient calculation: Calculate the conversion coefficient ZhuanHua, which is used to convert the pixel distance to the actual distance. The method code: double conversionFactor = 0.1f * 10 * Math.Floor(rulerBase.RulerMax) / rulerBase.Width / rulerBase.BaseScale; Step 3: Distance conversion: Take the absolute value of the X - coordinate difference according to the direction and multiply by the conversion factor. Method code: result = (0 + (Math.Abs(line01.Location.X - line02.Location.X)) * conversionFactor).ToString("0.0"); Step 4: Return the formatted result (rounded to one decimal place).

[0032] 1.4 Result analysis module: The button14_Click method processes the calculation of time error. Obtain the measurement result from CeLiangJG04.Text, divide it by 25 and round to two decimal places, and display it in textBox55. Then calculate the percentage error from 7, round to one decimal place and display it in textBox56. According to whether the error is within ±5%, set textBox57 to display "Compliant" or "Non - compliant", with the corresponding colors green or red. The program verifies whether the time measurement meets the national technical requirements for ambulatory electrocardiographs. The theoretical value is 7 seconds, and the allowable error for the actual result is ±5%.

[0033] Program implementation process: Click the button to trigger the button14_Click event (corresponding to Figure 7 the "Scan speed" button.); Data conversion: Divide the measured value by 25 and round; Error calculation: (Measured value - 7) / 7 * 100%; Result judgment: If the error is within ±5%, display green and "Compliant"; If it exceeds the range, display red and "Non - compliant"; 2. Measurement method for overshoot measurement technical characteristics of ambulatory electrocardiographs: The implementation effect of the measurement method for overshoot measurement technical characteristics of ambulatory electrocardiographs is as Figure 5 shown.

[0034] Measurement method implementation process: [Select picture] → [Display picture] → [Drag measurement line] → [Real - time calculate distance] → [Click to verify] → [Display measurement result]; The user clicks the button to select an image, which is then loaded into pictureBox02. When the value of the trackBar changes, it adjusts the BaseScale of the corresponding scale ruler and rescales the image for display. When the position of the draggable line of CeLiang changes, it triggers the calculation of the longitudinal measurement result and displays it in the corresponding text box. The JiSuanJJ method is responsible for converting the position difference of the line and the scale ruler parameters into actual physical values. The measurement method consists of four modules: an image loading module, a dynamic scaling control module, a dynamic measurement module, and a result analysis module. Each module works collaboratively through event-driven mechanisms to achieve a complete process from image loading to measurement result determination. The core lies in converting the pixel distance into actual physical quantities through scale ruler parameters and then performing error analysis.

[0035] 2.1 Image Loading Module: Use the Btn_SelectFile02_Click method.

[0036] Function: When the user clicks the "Select File" button, it calls the SelectFile() method to select a file and loads the selected image into pictureBox02.

[0037] Program Implementation Process: 1. Call the SelectFile() method to obtain the file path.

[0038] 2. If the file path is not empty, use the Bitmap class to load the image and assign it to originalImage02.

[0039] 3. Display originalImage02 in the pictureBox02 control.

[0040] 2.2 Dynamic Scaling Control Module: Use the TrackBar_ValueChanged method: Function: When the user adjusts the image scaling ratio using the trackbar (slider), it performs corresponding operations according to different TrackBar controls, mainly scaling the image and updating the relevant scale rulers and displays.

[0041] Program Implementation Process: 1. Obtain the name (indexName) of the TrackBar control that triggered the event. Enter different case branches based on indexName.

[0042] Figure 5The control for the magnification of the middle image. Since the measurement of the technical characteristics of the Holter electrocardiograph includes items such as the maximum input voltage, sensitivity, frequency response, overshoot, hysteresis, and recording speed, and there is a TrackBar control in each item, a variable is needed to identify which slider is recognized, and this variable is indexName; In each branch: Step 1: Check whether the corresponding original images (originalImage01 to originalImage07) exist. If not, return directly.

[0043] Step 2: Obtain the current values (value01 to value07) of the TrackBar.

[0044] Step 3: Update the BaseScale property of the corresponding rulers (ruler_01_1 to ruler_07_4) according to the values of the TrackBar.

[0045] Step 4: Calculate the sizes of the scaled images (newWidth and newHeight).

[0046] Step 5: Create the scaled images (zoomedImage01 to zoomedImage07) using the Bitmap class.

[0047] Step 6: Display the scaled images in the corresponding PictureBox controls (pictureBox01 to pictureBox07).

[0048] Step 7: Update the corresponding scaling ratio displays (Scaling01 to Scaling07).

[0049] 2.3 Dynamic measurement module: [[ID=2,7]]2.3.1: CeLiang_02_Hmin_LocationChanged method; CeLiang_02_Hmax_LocationChanged method; Function: These two methods are used to update the displayed results when the positions of the minimum measurement line and the maximum measurement line change. When the positions of the CeLiang_02_Hmin or CeLiang_02_Hmax controls change, the JiSuanJJ method is called to calculate and update the measurement results.

[0050] Program implementation process: 1. Call the JiSuanJJ method and pass in relevant parameters (measurement type (horizontal / vertical), two draggable lines, zoom value, and ruler base).

[0051] 2. Update the calculation result to the text of the CeLiangJG02_min or CeLiangJG02_max control.

[0052] 2.3.2. JiSuanJJ method: Function: Calculate the vertical distance between two lines according to the measurement type (vertical or horizontal), and return the formatted result.

[0053] Program implementation process: First step: Parameter passing: measurement type (horizontal / vertical), two draggable lines, zoom value, and ruler base; Second step: Calculate the conversion coefficient ZhuanHua, which is used to convert the pixel distance to the actual distance.

[0054] double ZhuanHua = 0.1f * 10 * Math.Floor(rulerBase.RulerMax) / rulerBase.Width / rulerBase.BaseScale; Third step: Calculate the vertical distance between two lines according to the measurement type, and multiply by ZhuanHua to get the actual distance.

[0055] result = (0 + (Math.Abs(line01.Location.Y - line02.Location.Y)) * ZhuanHua).ToString("0.0"); Fourth step: Return the formatted result (retain one decimal place).

[0056] 2.4 Result analysis module: The button12_Click method processes the calculation overshoot error. First, calculate the difference between the maximum value maxValue and the minimum value minValue of the two measurement lines, then calculate the overshoot value and display it in textBox31. According to whether the error is greater than 20%, set textBox37 to display "Compliant" or "Non-compliant", and the color corresponds to green or red. The program verifies whether the overshoot measurement meets the relevant technical requirements of the dynamic electrocardiograph.

[0057] Program implementation process: Click the button to trigger the button12_Click event (corresponding to the Figure 5 "Calculate overshoot" button in Overshoot calculation: Difference = Maximum value - Minimum value; Overshoot = (Difference / (2 * Minimum value)) * 100; Result judgment: textBox37.Text = Overshoot <= GUOCHONG_THRESHOLD? "Compliant" : "Non-compliant"; textBox37.ForeColor = Overshoot <= GUOCHONG_THRESHOLD? Color.Green : Color.Red; Result display: When the error is within 20%, it shows green and "Compliant". When it exceeds the range, it shows red and "Non-compliant"; Result analysis: As Figure 5 the overshoot measurement and Figure 7 the measurement results of the tracing speed shown, the measurement results obtained by using the method based on image measurement in this article, compared with the measurement method using traditional scale and optical magnifier, the results are consistent, indicating that the method is feasible. However, the relative expanded uncertainty value of the measurement results evaluated by using this method is smaller. Therefore, the overall measurement results have higher credibility and accuracy. At the same time, the entire measurement process takes less time, has a low error rate, and high measurement efficiency.

[0058] The above has described an embodiment of the present invention in detail, but the content described is only a preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A measurement method for the metrological technical characteristics of a dynamic electrocardiograph based on image measurement, characterized in that, Including scale calibration and feature measurement, where: Scale calibration: Obtain the number of pixel points x between the straight lines in the picture and the actual size y input by the user, and determine the proportional relationship between pixels and size as x / y; Feature measurement: Based on the picture, measure the metrological technical features of the dynamic electrocardiograph, and the technical features include maximum input voltage, sensitivity, frequency response, overshoot, hysteresis, and recording speed; convert the pixel distance into the actual physical quantity through the scale parameter, and then perform error analysis.

2. A measurement method for the metrological technical features of a dynamic electrocardiograph based on image measurement according to claim 1, characterized in that, The specific steps to obtain the proportional relationship between pixels and size are as follows: Select the picture file and load it into the picture box, drag two straight lines to the preset positions in the picture, and input the actual size between the two straight lines; Calculate according to the formula: calibration coefficient = (pixel distance / actual size) / (scale length / scale division), and scale the scale according to the calibration coefficient, and save after adjusting the scale calibration coefficient of the interface where the scale will be used to be consistent.

3. A measurement method for the metrological technical features of a dynamic electrocardiograph based on image measurement according to claim 1, characterized in that, The specific steps for the recording speed measurement are as follows: The user clicks the select picture button to trigger the Btn_SelectFile04_Click event to display the picture. The user's operation causes the position of the measurement line to change, triggering the CeLiang_04 position change event. Call the JiSuanJJ method to calculate the distance in real time and update the measurement result. Click the verification button to trigger the button14 click event to perform error calculation and result display.

4. A method for measuring the metrological technical features of a dynamic electrocardiograph based on image measurement according to claim 1, characterized in that, The specific steps for the overshoot measurement are as follows: The user clicks the select picture button to select the picture and load it into pictureBox02. When the value of the trackBar changes, adjust the BaseScale of the corresponding scale and rescale the image for display. When the position of the measurement line changes, trigger the calculation of the longitudinal measurement result and display it in the corresponding text box.

5. A method for measuring the metrological technical features of a dynamic electrocardiograph based on image measurement according to claim 4, characterized in that, When using the slider to adjust the image scaling ratio, perform corresponding operations according to different TrackBar controls, mainly scaling the image and updating the relevant scale and display.

6. A measurement method for the metrological technical features of a dynamic electrocardiograph based on image measurement according to claim 3, characterized in that, Click the button14_Click method, obtain the measurement result from CeLiangJG04.Text, divide it by 25 and retain two decimal places for display in textBox55, calculate the error percentage from 7 and retain one decimal place for display in textBox56, and set textBox57 to display "Compliant" or "Non-compliant" according to whether the error is within ±5%, with the color corresponding to green or red.

7. A measurement method for metrological technical features of a dynamic electrocardiograph based on image measurement according to claim 4, characterized in that, Click the button12_Click event, calculate the difference between the maximum and minimum values of the two measurement straight lines, calculate the overshoot value according to the formula guochong = (difference / (2 * minimum value)) * 100 and display it in textBox31, and set textBox37 to display "Compliant" or "Non-compliant" according to whether the error is greater than 20%, with the color corresponding to green or red.

Images