Impedance Analyzer Design Based on EMI and Lamb Wave

2014 ◽  
Vol 529 ◽  
pp. 506-510 ◽  
Author(s):  
Yu Xiang Zhang ◽  
Xin Zhang ◽  
Shi Yi Chen ◽  
Jia Zhao Chen
Keyword(s):  
Health Monitoring ◽  
Lamb Wave ◽  
Detection Method ◽  
Specific Structure ◽  
Impedance Analyzer ◽  
Wave Technology ◽  
Damage Monitoring ◽  
Single Method ◽  
Active Detection

EMI and the Lamb Wave technology are two kinds of mainstream active detection method in health monitoring , which have a long-term development. Health monitoring based on the combination of the EMI technology and Lamb wave, can be either a single method to conduct monitoring and analysis of specific structure ,or two methods together to conduct more comprehensive damage monitoring.

Application of Marginal Spectrum in Active Lamb Wave Damage Monitoring of Plate Structure

2014 ◽  
Vol 490-491 ◽  
pp. 1698-1701 ◽  
Author(s):  
Bao Chun Xu ◽  
Mu Lan Wang ◽  
Qian Jia
Keyword(s):  
Health Monitoring ◽  
Lamb Wave ◽  
Monitoring Technology ◽  
Plate Structure ◽  
Damage Monitoring ◽  
Before And After ◽  
Marginal Spectrum ◽  
Scattering Signal

In this study, the marginal spectrum based on instantaneous parameter is applied to the active Lamb wave-based health monitoring of plate structure to investigate the marginal spectrum variation of the signals after being added with damage scattering signal. First,the active Lamb wave monitoring technology is employed to obtain the Lamb wave signals of the plate before and after damage. Then the marginal spectra of the signals before and after damage are obtained using the HHT technology and compared with the spectrum of the signals. The results show that the marginal spectrum can better describe the variation of the signals before and after damage.

scholarly journals Long-Term IoT-Based Maternal Monitoring: System Design and Evaluation

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2281
Author(s):  
Fatemeh Sarhaddi ◽  
Iman Azimi ◽  
Sina Labbaf ◽  
Hannakaisa Niela-Vilén ◽  
Nikil Dutt ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Maternal Health ◽  
Pregnant Women ◽  
Health Monitoring ◽  
Quality Care ◽  
Well Being ◽  
Pregnancy And Postpartum ◽  
Comprehensive Framework ◽  
Specific Health

Pregnancy is a unique time when many mothers gain awareness of their lifestyle and its impacts on the fetus. High-quality care during pregnancy is needed to identify possible complications early and ensure the mother’s and her unborn baby’s health and well-being. Different studies have thus far proposed maternal health monitoring systems. However, they are designed for a specific health problem or are limited to questionnaires and short-term data collection methods. Moreover, the requirements and challenges have not been evaluated in long-term studies. Maternal health necessitates a comprehensive framework enabling continuous monitoring of pregnant women. In this paper, we present an Internet-of-Things (IoT)-based system to provide ubiquitous maternal health monitoring during pregnancy and postpartum. The system consists of various data collectors to track the mother’s condition, including stress, sleep, and physical activity. We carried out the full system implementation and conducted a real human subject study on pregnant women in Southwestern Finland. We then evaluated the system’s feasibility, energy efficiency, and data reliability. Our results show that the implemented system is feasible in terms of system usage during nine months. We also indicate the smartwatch, used in our study, has acceptable energy efficiency in long-term monitoring and is able to collect reliable photoplethysmography data. Finally, we discuss the integration of the presented system with the current healthcare system.

Selection of Materials and Sensors for Health Monitoring of Composite Structures

2003 ◽  
Vol 785 ◽  
Author(s):  
Seth S. Kessler ◽  
S. Mark Spearing
Keyword(s):  
Health Monitoring ◽  
Lamb Wave ◽  
Composite Structures ◽  
Structural Damage ◽  
Performance Metrics ◽  
Full Range ◽  
Transportation Systems ◽  
Health Monitoring Systems ◽  
The Relationship ◽  
Selection Of

ABSTRACTEmbedded structural health monitoring systems are envisioned to be an important component of future transportation systems. One of the key challenges in designing an SHM system is the choice of sensors, and a sensor layout, which can detect unambiguously relevant structural damage. This paper focuses on the relationship between sensors, the materials of which they are made, and their ability to detect structural damage. Sensor selection maps have been produced which plot the capabilities of the full range of available sensor types vs. the key performance metrics (power consumption, resolution, range, sensor size, coverage). This exercise resulted in the identification of piezoceramic Lamb wave transducers as the sensor of choice. Experimental results are presented for the detailed selection of piezoceramic materials to be used as Lamb wave transducers.

Dry Flexible Electrode Based on MWCNT for Long Term Health Monitoring

2021 ◽  
Author(s):  
Chiraz Naggara ◽  
Dhouha Bouchaala ◽  
Rajarajan Ramalingame ◽  
Nabil Derbel ◽  
Olfa Kanoun
Keyword(s):  
Health Monitoring ◽  
Flexible Electrode

Development of PZT fiber rosette to locate acoustic source

2021 ◽  
pp. 1045389X2199192
Author(s):  
Bao Chi Ha ◽  
Kevin Gilbert ◽  
Gang Wang
Keyword(s):  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Lamb Wave ◽  
Lead Zirconate ◽  
Acoustic Source ◽  
Mechanical Coupling ◽  
Monitoring Applications ◽  
Commercial Off The Shelf ◽  
Lamb Wave Propagation ◽  
Strain Direction

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.

Gray change detection method for damage monitoring in materials

2015 ◽  
Vol 54 (4) ◽  
pp. 934 ◽  
Author(s):  
Xiaochuan Zhang ◽  
Ge Yang ◽  
Nan Zhan ◽  
Hongwei Ji
Keyword(s):  
Change Detection ◽  
Detection Method ◽  
Damage Monitoring
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