A patch-sized wearable ECG/respiration recording platform with DSP capability

In this paper, a healthcare platform is designed to establish a mobile telecare environment with the digital signal processing (DSP) ability. Although mobile health (mHealth) is not an innovative research topic, the improvements of wearable sensing technologies and today´s mobile devices can make such systems more consummate and powerful than before. In the proposed platform, an electrocardiography (ECG)/respiration (RESP) prototype is developed to record single-lead ECG signal and thorax impedance variation caused by respiration of the users. The prototype weights about 8 g, and the size of prototype, which is 25×35×6 mm³, is smaller than electrode. With easy-to-use user interface (UI), it could be applied in many kinds of platform such as mobile phone and tablet as a monitoring device. The recorded data can be uploaded to Dropbox automatically. The other thing that´s worth mentioning is the ability to process digital data. With discrete wavelet transform (DWT) we can not only preprocess the biomedical signals for noise reduction but also detect P wave, QRS complex and T wave in real-time. By verifying with MIT-BIH QT database, the results show that the sensitivity of R peak achieves to 99.5%, P wave 97.87% and T wave 92.91%. Ignoring the data recorded from sudden death, the sensitivity of T wave can be up to 98.38%. Equipped with the developed DSP algorithms, the system can provide noise cancellation and motion artifact removal when moving , stretching and sleeping in user´s daily life. According to the experiment results, the sensitivity of R wave still performs well even running on treadmill at speed of 15km/h. Therefore, our design can be applied in various fields such as art, sport and medical care.