Abstract
1-Introduction
2-System structure
3-Result
4-Conclusion
Acknowledgement
References
Abstract
In recent years, many studies have focus on health care. We designed a non-invasive wearable device that not only equipped with BLE to detect vital signals but also combining an intelligent terminal to develop healthcare IoT. In most studies, an electrode potential is used in ECG, while for PPG, heart rates are measured by the amount of reflected LED light. However, in this paper, we detect heart vibration signals based on radial artery vibration signals by the wrist PVDF piezo film sensor that the user wears to detect his/her heart rate. The device can also reduce power consumption. In order to promote Signal to Noise Ratio (SNR), we adopt filter circuit design and peak detection algorithm to eliminate noise by using the intelligent terminal, then we are able to achieve high accuracy heart rate calculation. Furthermore, the intelligent terminal will upload the data to the cloud, so not only the user can monitor self-vital information anytime but also medical institutions can access the data in case of an emergency.
Introduction
Normally, we measure heart rates on ECG and PPG. When applying ECG, we need to stick many electrodes on the user’s skin which is not comfortable and convenient for the user [1]. As for PPG, it utilities LED to detect blood flow to measure heartbeat. So the battery energy will be exhausted soon [1] [2]. In this paper, we will not only compare ECG, PPG and PVDF (please refer to Table1) but also adopt PVDF sensor to measure heart rates and can get slightly vibration which come from arterial wall’s jumping of wrist[5]. In order to get heart rate easily, we add op-amp (operational amplifier) circuit and Butterworth filter circuit to enhance SNR. Moreover, we adopt PAN TOMPKINs algorithm [6] to peak searching when using an intelligent terminal device in order to eliminate noise and increase heart rate detection accuracy. Apart from having Wi-Fi and BLE functions, the intelligent terminal also equips with a powerful CPU to process raw data immediately and share the workload of the cloud server.