Our healthy lifestyle requires a personalized healthy diet and balanced physical activities. All of these will in principle be possible with personal trainers and dietologists. Why the development of continuous monitoring of human health and activity wireless wearable devices will be one of the key technologies in the ubiquitous sensor network society for years to come. The wearable device developed is based on laser Doppler flowmetry, which is used for functional evaluation of the circulatory system. We here present wearable laser Doppler flowmetry sensors based on compact VCSEL with Wi-Fi/Bluetooth data transfer in examining health, diabetic, and smoking volunteers. The developed wearable devices consist of three channels for recording blood perfusion, skin temperature, and movements. This allows for measurement at any desirable point of the human body. The system also comprises a wireless data acquisition module. Signal processing based on wavelet transformation has shown that the proposed sensor can detect five frequency rhythms by analysis of the small arteries blood flow oscillations: endothelial, neurogenic, myogenic, respiratory, and pulse rhythm. Overall, a series of studies of healthy volunteers, non- and smoking, at different gravity position, and diabetic patient have shown that wearable device(s) is capable of differentiating cardiovascular parameters with high sensitivity. Our promising results demonstrate the robustness of both the data acquisition and the spectral analysis methods employed to characterise measured optical data.
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