Point and Line Source Laser Generation of Ultrasound for Inspection of Internal and Surface Flaws in Rail and Structural Materials

Kenderian, Shant; Djordjevic, B. Boro; Green, R. E.

doi:10.1080/09349840109409697

Cited by 37 publications

(6 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, with these measured phase-velocity values, we can calculate the Young modulus according to equation (2.1). The results are in good agreement with the literature [1,3,14,16,33,35]. Figure 12 presents the average and standard deviations of the calculated Young modulus from five subjects.…”

Section: Measurements and Resultssupporting

confidence: 88%

“…The stimulus was applied with an approximately 458 angle over the tissue surface, which provided equal longitudinal and shear energy to the sample. Compared with a point and a round source, the line source (provided by the metal rod) improved the SNR, and reduced the attenuation of the surface wave, which enabled the surface wave to propagate longer distances [33][34][35]. The shaker applied a tissue displacement of approximately 100 nm in the axial direction.…”

Section: Surface Wave Generation Induced By a Shakermentioning

confidence: 99%

See 1 more Smart Citation

Determining elastic properties of skin by measuring surface waves from an impulse mechanical stimulus using phase-sensitive optical coherence tomography

Guan

Reif

et al. 2011

J. R. Soc. Interface.

254

203

View full text Add to dashboard Cite

The mechanical properties of skin are important tissue parameters that are useful for understanding skin patho-physiology, which can aid disease diagnosis and treatment. This paper presents an innovative method that employs phase-sensitive spectral-domain optical coherence tomography (PhS-OCT) to characterize the biomechanical properties of skin by measuring surface waves induced by short impulses from a home-made shaker. Experiments are carried out on single and double-layer agar-agar phantoms, of different concentrations and thickness, and on in vivo human skin, at the forearm and the palm. For each experiment, the surface wave phase-velocity dispersion curves were calculated, from which the elasticity of each layer of the sample was determined. It is demonstrated that the experimental results agree well with previous work. This study provides a novel combination of PhS-OCT technology with a simple and an inexpensive mechanical impulse surface wave stimulation that can be used to non-invasively evaluate the mechanical properties of skin in vivo, and may offer potential use in clinical situations.

show abstract

Section: Measurements and Resultssupporting

confidence: 88%

Section: Surface Wave Generation Induced By a Shakermentioning

confidence: 99%

Determining elastic properties of skin by measuring surface waves from an impulse mechanical stimulus using phase-sensitive optical coherence tomography

Guan

Reif

et al. 2011

J. R. Soc. Interface.

254

203

View full text Add to dashboard Cite

show abstract

“…The shaker consisted of a signal generator and a single element piezoelectric ceramic with a metal rod attached at the end (length of ∼20 mm and diameter of ∼2 mm) as a line source, which improved the signal-to-noise ratio (SNR) and enhanced the detection of the SAW compared with a point source. [53][54][55] A ∼20 Hz pulse train with a ∼0.2% duty cycle was generated by the shaker, which produced frequency contents of up to ∼10 KHz in the SAW signals at the tissue surface. The detection of the shaker-induced SAW was accomplished by a PhS-OCT system.…”

Section: Generation and Detection Of Sawmentioning

confidence: 99%

Evaluating elastic properties of heterogeneous soft tissue by surface acoustic waves detected by phase-sensitive optical coherence tomography

Guan

et al. 2012

J. Biomed. Opt.

View full text Add to dashboard Cite

The combined use of surface acoustic wave (SAW) and phase-sensitive optical coherence tomography (PhS-OCT) is useful to evaluate the elasticity of layered biological tissues, such as normal skin. However, the pathological tissue is often originated locally, leading to the alternation of mechanical properties along both axial and lateral directions. We present a feasibility study on whether the SAW technique is sensitive to detect the alternation of mechanical property along the lateral direction within tissue, which is important for clinical utility of this technique to localize diseased tissue. Experiments are carried out on purposely designed tissue phantoms and ex vivo chicken breast samples, simulating the localized change of elasticity. A PhS-OCT system is employed not only to provide the ultra-high sensitive measurement of the generated surface waves on the tissue surface, but also to provide the real time imaging of the tissue to assist the elasticity evaluation of the heterogeneous tissue. The experimental results demonstrate that with PhS-OCT used as a pressure sensor, the SAW is highly sensitive to the elasticity change of the specimen in both vertical and lateral directions with a sensing depth of ∼5 mm with our current system setup, thus promising its useful clinical applications where the quantitative elasticity of localized skin diseases is needed to aid in diagnosis and treatment.

show abstract

“…If these defects are not detected in a timely manner, they can rapidly propagate and lead to the sudden catastrophic failure of the entire structure [4,5]. Therefore, the detection of surface microdefects, such as surface or near-surface cracks or incomplete fusion, especially through non-destructive evaluation methods, plays a crucial role in the industrial domain [6,7].…”

Section: Introductionmentioning

confidence: 99%

Depth Evaluation of Tiny Defects on or near Surface Based on Convolutional Neural Network

Fei,

Cao,

et al. 2023

Applied Sciences

View full text Add to dashboard Cite

This paper proposes a method for the detection and depth assessment of tiny defects in or near surfaces by combining laser ultrasonics with convolutional neural networks (CNNs). The innovation in this study lies in several key aspects. Firstly, a comprehensive analysis of changes in ultrasonic signal characteristics caused by variations in defect depth is conducted in both the time and frequency domains, based on discrete frequency spectra and original A—scan signals. Continuous wavelet transform (CWT) is employed to obtain wavelet time–frequency maps, demonstrating the consistent characteristics of this image with crack depth variations. A crucial innovation in this research involves the targeted design and optimization of the model based on the characteristics of ultrasonic signals and dataset size. This includes aspects such as data preparation, CNN architecture construction, and hyperparameter selection. The model is tested using a random validation set, which effectively demonstrates the CNN model’s validity and high precision. The proposed method enables the recognition and depth assessment of tiny defects on or near surfaces.

show abstract

Point and Line Source Laser Generation of Ultrasound for Inspection of Internal and Surface Flaws in Rail and Structural Materials

Cited by 37 publications

References 19 publications

Determining elastic properties of skin by measuring surface waves from an impulse mechanical stimulus using phase-sensitive optical coherence tomography

Determining elastic properties of skin by measuring surface waves from an impulse mechanical stimulus using phase-sensitive optical coherence tomography

Evaluating elastic properties of heterogeneous soft tissue by surface acoustic waves detected by phase-sensitive optical coherence tomography

Depth Evaluation of Tiny Defects on or near Surface Based on Convolutional Neural Network

Contact Info

Product

Resources

About