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This paper presents an energy-efficient and high-accuracy sampling synchronization approach for real-time synchronous data acquisition in wireless sensor networks (saWSNs). A proprietary protocol based on time-division multiple access (TDMA) and deep energy-efficient coding in sensor firmware is proposed. A real saWSN model based on 2.4 GHz nRF52832 system-on-chip (SoC) sensors was designed and experimentally tested. The obtained results confirmed significant improvements in data synchronization accuracy (even by several times) and power consumption (even by a hundred times) compared to other recently reported studies. The results demonstrated a sampling synchronization accuracy of 0.8 µs and ultra-low power consumption of 15 µW per 1 kb/s throughput for data. The protocol was well designed, stable, and importantly, lightweight. The complexity and computational performance of the proposed scheme were small. The CPU load for the proposed solution was <2% for a sampling event handler below 200 Hz. Furthermore, the transmission reliability was high with a packet error rate (PER) not exceeding 0.18% for TXPWR ≥ -4 dBm and 0.03% for TXPWR ≥ 3 dBm. The efficiency of the proposed protocol was compared with other solutions presented in the manuscript. While the number of new proposals is large, the technical advantage of our solution is significant.
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The area of military operations is a big challenge for medical support. A particularly important factor that allows medical services to react quickly in the case of mass casualties is the ability to rapidly evacuation of wounded soldiers from a battlefield. To meet this requirement, an effective medical evacuation system is essential. The paper presented the architecture of the electronically supported decision support system for medical evacuation during military operations. The system can also be used by other services such as police or fire service. The system meets the requirements for tactical combat casualty care procedures and is composed of following elements: measurement subsystem, data transmission subsystem and analysis and inference subsystem. The system, based on the continuous monitoring of selected soldiers' vital signs and biomedical signals, automatically proposes a medical segregation of wounded soldiers (medical triage). The information on the triage was visualized using the Headquarters Management System for medical personnel (first responders, medical officers, medical evacuation groups) and for commanders, if required. All elements of the architecture were described in the paper.
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Militares , Ferimentos e Lesões , Humanos , Triagem/métodos , Guerra , Técnicas de Apoio para a DecisãoRESUMO
Artery stiffness is a risk factor for cardiovascular disease (CVD). The measurement of pulse wave velocity (PWV) between the carotid artery and the femoral artery (cfPWV) is considered the gold standard in the assessment of arterial stiffness. A relationship between cfPWV and regional PWV has not been established. The aim of this study was to evaluate the influence of gender on arterial stiffness measured centrally and regionally in the geriatric population. The central PWV was assessed by a SphygmoCor XCEL, and the regional PWV was assessed by a new device through the photoplethysmographic measurement of multi-site arterial pulse wave velocity (MPPT). The study group included 118 patients (35 males and 83 females; mean age 77.2 ± 8.1 years). Men were characterized by statistically significantly higher values of cfPWV than women (cfPWV 10.52 m/s vs. 9.36 m/s; p = 0.001). In the measurement of regional PWV values using MPPT, no such relationship was found. Gender groups did not statistically differ in the distribution of atherosclerosis risk factors. cfPWV appears to be more accurate than regional PWV in assessing arterial stiffness in the geriatric population.
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Análise de Onda de Pulso , Rigidez Vascular , Masculino , Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Artérias Carótidas , Artéria Femoral , Fatores de RiscoRESUMO
Information about blood arterial oxygen saturation (SpO2) is crucial in critical care settings or home health monitoring during the COVID-19 pandemic. Also, we need to identify the factors that affect the SpO2 measurement. In this paper, the effect of compression of the cuff during noninvasive blood pressure (NIBP) measurement on the SpO2 results was investigated. A custom-made system was used for simultaneous measurement of NIBP and SpO2. The study was conducted on 213 subjects aged between 21 and 93, with a systolic blood pressure of (94 to 194) mmHg, diastolic blood pressure of (52-98) mmHg, and 994 NIBP readings were used for the analysis. During the NIBP measurement, momentary changes in SpO2 can reach ±17% and are in most cases positive (mean 2.9%). The change was not correlated with sex, age, height, body weight, BMI, HR and blood pressure. The obtained results show that frequent NIBP measurements may lead to wrong conclusions about SpO2. In our study, pressure measurements mainly caused the increase of blood oxygenation level.
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Measurement of pulse wave velocity (PWV) is a simple and noninvasive way to assess stiffness of the arteries. PWV measurement can refer to both the aorta and peripheral arterial vessels. Currently, the most clinically significant is the measurement of PWV between the carotid artery and the femoral artery, which is defined as the speed of the aortic pulse wave. Numerous studies have demonstrated the significance of prognostic PWV aortic measurement as a recognized exponent of subclinical organ damage both among the general population as well as among patients with increased cardiovascular risk, examining patients in detail with hypertension, diabetes, chronic renal failure. The prognostic value of PWV aortic measurement was reflected in the guidelines of the European Society of Cardiology (ESC) and the European Society of Hypertension (ESH). In clinical trials, the repeatability and reproducibility of PWV measurements were also evaluated, both parameters being considered satisfactory. The paper presents reports from studies on the significance of pulse wave velocity results in the prognosis assessment in different disease entities as well as in age groups.
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Hipertensão , Análise de Onda de Pulso , Rigidez Vascular , Aorta , Artérias Carótidas , Humanos , Hipertensão/diagnóstico , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Brachial aortic Pulse Wave Velocity (baPWV) and bone mineral density (BMD) are important indicators of cardiovascular health and bone strength, respectively. However, the gender-specific association between baPWV and BMD remains unclear. The aim of our study is to evaluate the relationship between baPWV and BMD in men and women populations METHODS: A comprehensive search was conducted in electronic databases for relevant studies published between the 1th and 30rd of April 2023. Studies reporting the correlation between baPWV and BMD in both males and females were considered. A random-effects model was used to calculate pooled correlation coefficients (r). RESULTS: Relevant data for both genders were found in six articles. In all publications included in the meta-analysis, the total number of studied individuals was 3800, with 2054 women and 1746 men. Pooled correlation coefficient was -0,24 (95 % CI: -0.34; -0.15) in women population, and -0.12 (95 %CI: -0.16, -0.06) in men. CONCLUSIONS: Based on the published data, we found that baPWV is negatively correlated with bone density in women. However, in men we do not find such a relationship. These findings suggest the importance of considering gender-specific factors when assessing the cardiovascular and bone health relationship.