The Embedded System Integrated ECG Monitoring and Low Energy Led Light Stimulation

Abstract

Background: Nowadays people usually have higher work pressure and faster life rhythm. In the long-term stress environment, easily lead to autonomic nervous system (ANS) disorders and lead to physiological or psychological problems. To resolve the problem, we propose an embedded system which integrates ANS monitoring and low energy light stimulation. When the ANS was detected abnormal, a recommended low energy infrared light was activated to stimulate the subject to balance ANS. Materials and Methods: The experiment instruments included electrocardiogram (ECG) module, LED array and the embedded system. ECG module received ECG signal, and then transferred analog signal to digital data. The microprocessor calculated time-domain and frequency-domain data of heart rate variability (HRV), and analyzed the time-domain data, and power spectral density data. The autonomic nervous system (ANS) of the user can be monitored by this device we developed. When the calculated values are out of the criteria, the system will alert the user to turn on infrared light to stimulate and balance ANS. LED wavelength is 850 nm, the default output power is 10 mW, and the default repetition rate is 10 Hz. Result: Wu et al. proposed that using low level laser to stimulate on Neiguan point (PC6) was used to adjust the ANS of the night shift workers. And in other studies, Laser array and LED array were used to stimulate the palm of the subjects with open eyes in different clinical trial, the alpha powers were both increased significantly. So the combination of ANS monitoring and light therapy was useful and feasible. Besides ECG monitoring, LED irradiation and HRV calculation, the data of the embedded system can be transmitted by UART to the remote PC for storage, display and analysis. Furthermore, the embedded system can receive the setting value from PC. For example, adjusting the irradiated dosage, LED operation rate and duty cycle to find out the influence factor of the ANS. Conclusion: an embedded system with ECG monitoring and LED infrared stimulation was realized, it combined physiological state monitoring and light stimulation, it make the ANS feedback and real time adjustment possible.