Smart phone-based automatic QT interval measurement

A smart phone-based automatic QT interval measurement system was developed. The system can assist pharmaceutical company in QT prolongation assessment prior to new drug approval. The ECG signal is captured by wearable sensor and processed on the smart phone. The processed results are sent using cellular network to the internet server. Cardiologist can quickly analyze the results. It shortens the time for data collection. Besides, it is convenient for the test subjects as they do not need to visit the lab frequently. The embedded algorithm on smart phone first detects QRS complex using slope-based method. Next the Q-wave onset and T-wave offset are detected using wavelet-based method. Subsequently, heart rate and QT interval are calculated. We combined the robustness of slope-based QRS detector and accuracy of wavelet-based feature point detector. The algorithm and user interface have been implemented on a smart phone with ARM OMAP 730 processor running at 200 MHz. Alive Technologies ECG sensor with Bluetooth communication is used to capture the ECG signal. The QT interval measurement system runs in real-time.