Flexible Non-contact Electrodes for Wearable Biosensors System on Electrocardiogram Monitoring in Motion.

Electrocardiogram (ECG) is a critical physiological indicator that contains abundant information about human heart activities. However, it is a kind of weak low-frequency signal, which is easy to be interfered by various noises. Therefore, wearable biosensors (WBS) technique is introduced to overcome this challenge. A flexible non-contact electrode is proposed for wearable biosensors (WBS) system, which is made up of flexible printed circuits materials, and can monitor the ECG signals during exercise for a long time. It uses the principle of capacitive coupling to obtain high-quality signals, and reduces the impact of external noise through active shielding; The results showed that the proposed non-contact electrode was equivalent to a medical wet electrode. The correlation coefficient was as high as 99.70 ± 0.30% when the subject was resting, while it was as high as 97.53 ± 1.80% during exercise. High-quality ECG could still be collected at subjects walking at 7 km/h. This study suggested that the proposed flexible non-contact electrode would be a potential tool for wearable biosensors for medical application on long-term monitoring of patients' health and provide athletes with physiological signal measurements.

The Effects of Different Reference Methods on Decision-Making Implications of Auditory Brainstem Response.

Hearing loss is a common disease affecting public health all around the world. In clinic, auditory brainstem response (ABR) has been widely used for the detection of hearing loss based on its convenience and accuracy. The different reference methods directly influence the quality of the ABR waveform which in turn affects the ABR-based diagnosis. Therefore, in this study, a reference electrode standardization technique (REST) was adopted to systematically investigate and evaluate the effect of different reference methods on the quality of ABR waveform in comparison with the conventional average reference (AR) and mean mastoid (MM) methods. In this study, ABR signals induced by click stimulus were acquired via an EEG electrode cap arrays, and those located on the six channels along the midline were compared systemically. The results showed that, when considering the different channels, the ABR in the Cz channel showed the best morphology. Then, the ABR waveforms acquired via the REST method possessed better morphologies with large amplitude (0.06 ± 0.02 µV for wave I, 0.07 ± 0.02 µV for wave III, and 0.21 ± 0.04 µV for wave V) when compared with the traditional method. Summarily, we found that the REST and MM methods improved the quality of ABR on both amplitude and morphology under different stimulation rates and levels without changing the latencies of ABR when compared with the conventional AR method, suggesting that the REST and MM methods have the potential to help physicians with high accurate ABR-based clinical diagnosis. Moreover, this study might also provide a theoretic basis of reference methods on the acquisition of electroencephalogram over public health issues.

A review of NOx and SOx emission reduction technologies for marine diesel engines and the potential evaluation of liquefied natural gas fuelled vessels.

Due to intensive marine activities and the use of low-quality fuel oils, the marine transport accounts for a considerable part of air pollution in the transportation sector. Although ships provide the convenient transportation, they exhaust a large number of hazardous pollutants, especially nitrogen oxides (NOx) and sulfur oxides (SOx), which have a significant side effect on environment and human health. To alleviate the impact of global shipping on the environment, international maritime organization established the more stringent emission regulations from Tier I to Tier III in order to reduce emissions from ships. As a result, various emission reduction technologies need to be developed in order to meet more stringent regulations in the future and reduce the pollutant emissions. Under this background, it is indispensable to examine the existing emission reduction technologies when exploring another possible method to reduce the pollutant emissions. Based on a significant number of related literatures, it is general to utilize the marine alternative fuels to reduce the pollutant emissions. Especially, liquid natural gas (LNG) is considered to be one of the most promising marine alternative fuels due to its economy and environmentally friendly features. This review thus aims to summarize the different emission reduction technologies of marine diesel engines through three reduction paths of fuel optimization, pre-combustion control and exhaust after-treatment. Furthermore, the utilization of LNG in the marine diesel engines are evaluated comprehensively from three aspects of environmental protection, energy structure and economic benefits. At the end, some suggestions on the future research are given based on the extensive review on the state-of-the-art literature.