scholarly journals A Smartphone Step Counter Using IMU and Magnetometer for Navigation and Health Monitoring Applications

Sensors ◽  
2017 ◽  
Vol 17 (11) ◽  
pp. 2573 ◽  
Author(s):  
Maan Khedr ◽  
Nasser El-Sheimy
Author(s):  
Bao Chi Ha ◽  
Kevin Gilbert ◽  
Gang Wang

Because of their electro-mechanical coupling property, Lead-Zirconate-Titanate (PZT) materials have been widely used for ultrasonic wave sensing and actuation in structural health monitoring applications. In this paper, a PZT rosette concept is proposed to conduct Lamb wave-based damage detection in panel-like structures by exploring its best directional sensing capability. First, a directivity study was conducted to investigate sensing of flexural Lamb wave propagation using a PZT fiber having d33 effects. Then, commercial off-the-shelf PZT fibers were polarized in-house in order to construct the PZT rosette configuration, in which three PZT fibers are oriented at 0°, 45°, 90°, respectively. Since Lamb wave responses are directly related to measured PZT fiber voltage signals, a simple interrogation scheme was developed to calculate principal strain direction in order to locate an acoustic source. Comprehensive tests were conducted to evaluate the performance of the proposed PZT rosette using an aluminum plate. It is shown that the PZT rosette is able to sense Lamb wave responses and accurately locate an acoustic source. We expect to further evaluate the PZT rosette performance when damages are introduced.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 518
Author(s):  
Hasan Borke Birgin ◽  
Antonella D’Alessandro ◽  
Simon Laflamme ◽  
Filippo Ubertini

Multifunctional structural materials are very promising in the field of engineering. Particularly, their strain sensing ability draws much attention for structural health monitoring applications. Generally, strain sensing materials are produced by adding a certain amount of conductive fillers, around the so-called “percolation threshold”, to the cement or composite matrix. Recently, graphite has been found to be a suitable filler for strain sensing. However, graphite requires high amounts of doping to reach percolation threshold. In order to decrease the amount of inclusions, this paper proposes cementitious materials doped with new hybrid carbon inclusions, i.e., graphite and carbon microfibers. Carbon microfibers having higher aspect ratio than graphite accelerate the percolation threshold of the graphite particles without incurring into dispersion issues. The resistivity and strain sensitivity of different fibers’ compositions are investigated. The electromechanical tests reveal that, when combined, carbon microfibers and graphite hybrid fillers reach to percolation faster and exhibit higher gauge factors and enhanced linearity.


Author(s):  
Ida Syafiza M. Isa ◽  
Mohamed O. I. Musa ◽  
Taisir E. H. El-Gorashi ◽  
Ahmed Q. Lawey ◽  
Jaafar M. H. Elmirghani

Sensors ◽  
2017 ◽  
Vol 17 (2) ◽  
pp. 265 ◽  
Author(s):  
Jun Zhang ◽  
Gui Tian ◽  
Adi Marindra ◽  
Ali Sunny ◽  
Ao Zhao

2021 ◽  
Vol 110 ◽  
pp. 05001
Author(s):  
Nataliya Apatova ◽  
Oleg Korolyov ◽  
Sergey Ivanov

Personal health monitoring is especially necessary in a pandemic of COVID19 and based on objective and subjective data. Modern medicine uses numerous diagnostic devices, many of which are for personal health monitoring. Applications for mobile phones are becoming more widespread, they make a possibility constantly monitor vital signs for a person. However, the consolidation into a single personalized database of information on daily mobile monitoring and examination results from various doctors in various medical organizations not yet carried out. Proposed to build a blockchain from this data and results of data analysis add subjective sensations and indicators to it, which clarified during the conversation with the doctor and not always fully and correctly transmitted by the patient. Using an integrated approach to personal health monitoring, building a blockchain from official data and personal objective and subjective indicators makes it possible to identify at the early stages of the disease, to have a complete and reliable picture of the state of health.


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