说明：  实现了心电曲线的实时绘制，正常QT间期范围设置、QT间期、QR间期的实时显示、可以显示一分钟之内的平均QT间期、QT间期状态一栏可实现间期预警，如果QT间期大于正常QT间期范围则状态颜色由绿色变成红色。用了一个100ms的定时器，每次100ms之后触发一次画图，让曲线往右移一格，由于100ms很短，所以在视觉上形成了连续移动的效果
(The real-time rendering of the ECG curve is realized. The normal QT interval setting, the QT interval, the real-time display of the QR interval, the average QT interval in one minute and the QT interval state can realize the interval warning. If the QT interval is larger than the normal QT interval, the state color is turned from green to red. A 100ms timer is used, and a drawing is triggered every time after 100ms to move the curve to the right. Because the 100ms is very short, the effect of continuous movement is formed in the vision.)