Opto-acoustic trace analysis in liquids with the frequency-modulated beam of an argon ion laser

Lahmann, W.; Ludewig, H.; Welling, H.

doi:10.1021/ac50012a012

Cited by 77 publications

(20 citation statements)

References 9 publications

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“…A key advantage of the technique is that it exploits the strong optical contrast of tissues enabling differentiation of anatomical features that would be indistinguishable using other radiological modalities. A broad range of potential applications have emerged including detection of breast [3] [4], skin and oral cancers3 The aim of the work described in this paper was to exploit the increased optical absorption in maligned tissue, reported by others for discrimination purposes. For this reason, laser pulses at 308 nm were used to generate photoacoustic signatures in tumor tissue.…”

Section: -1 Physiology Of Malignant Breast Massesmentioning

confidence: 99%

Laser-induced photoacoustic imaging for breast cancer detection using multivariate image analysis.

El-Sharkawy

Hussein

Abbass

2010

The International Conference on Applied Mechanics and Mechanica

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Time-resolved photoacoustic imaging has been used to characterize breast tissue for the purpose of discriminating between normal and maligned areas of the tissue. Ultrasonic thermoelastic waves were generated in breast tissue by the absorption of nanosecond laser pulses at 193 nm produced by Q-switched Excimer laser in conjunction with a Michelson interferometer used to detect the thermoelastic waves and plot the 2-D and the 3-D image through IR-CCD. The concepts behind the use of photo-acoustic techniques for off-line detection of breast cancer tumor features were presented in earlier research papers [1][2]. This paper illustrates the application of multivariate image analysis (MIA) techniques to detect the presence of tumor features of breast cancer. MIA is used to rapidly detect the presence and quantity of common tumor features as they scanned by an RGB camera. Multiway principal component analysis is used to decompose the acquired three-channel tumor images into a two dimensional principal components (PC) space. Masking score point clusters in the score space and highlighting corresponding pixels in the image space of the two dominant PCs enables isolation of tumor defect pixels based on contrast and color information. The technique provides a qualitative result that can be used for early tumor detection. The proposed technique can potentially be used on-line to prescreen the existence of tumors through vision based systems.

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Section: -1 Physiology Of Malignant Breast Massesmentioning

confidence: 99%

Laser-induced photoacoustic imaging for breast cancer detection using multivariate image analysis.

El-Sharkawy

Hussein

Abbass

2010

The International Conference on Applied Mechanics and Mechanica

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“…This approach was especially useful for the detection of trace gases, which was partly due to the high sensitivity of a microphone in the air. This technique was also applied to condensed phase samples, in which a piezoelectric transducer was used for better impedance matching [10,11]. When the laser beam is focused into the sample, the local temperature increases.…”

Section: Landmark Papers From the 1970'smentioning

confidence: 99%

Laser spectroscopy on organic molecules

Imasaka

1996

Analytical and Bioanalytical Chemistry

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Various laser spectrometric methods have been developed until now. Especially, laser fluorometry is most sensitive and is frequently combined with a separation technique such as capillary electrophoresis. For non-fluorescent compounds, photothermal spectrometry may be used instead. A diode laser is potentially useful for practical trace analysis, because of its low cost and long-term trouble-free operation. On the other hand, monochromaticity of the laser is essential in high-resolution spectrometry, e.g. in low temperature spectrometry providing a very sharp spectral feature. Closely-related compounds such as isomers can easily be differentiated, and information for assignment is obtained from the spectrum. Multiphoton ionization mass spectrometry is useful for soft ionization, providing additional information concerned with molecular weight and chemical structure. A short laser pulse with a sufficient energy is suitable for rapid heating of the solid surface. A matrix-assisted laser desorption/ion-ization technique is recently employed for introduction of a large biological molecule into a vacuum for mass analysis. In the future, laser spectrometry will be developed by a combination with state-of-the-art laser technology. In the 21st century, new laser spectrometry will be developed, which may be based on revolutionary ideas or unexpected discoveries. Such studies will open new frontiers in analytical laser spectroscopy.

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“…Dual-wavelength excitation was used in order to eliminate background absorption by the solvent (Lahmann et al, 1977). The cadmium content in the metal-tolerant fungus Penicilium ochrochloron was determined using a moddated Ar+ laser and a piezoelectric detector (Oda et al, 1978).…”

Section: Modulated Excitationmentioning

confidence: 99%

Photo Acoustic and Photothermal Methods Applied to the Study of Radiationless Deactivation Processes in Biological Systems and in Substances of Biological Interest

Braslavsky

1986

Photochem & Photobiology

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Opto-acoustic trace analysis in liquids with the frequency-modulated beam of an argon ion laser

Cited by 77 publications

References 9 publications

Laser-induced photoacoustic imaging for breast cancer detection using multivariate image analysis.

Laser-induced photoacoustic imaging for breast cancer detection using multivariate image analysis.

Laser spectroscopy on organic molecules

Photo Acoustic and Photothermal Methods Applied to the Study of Radiationless Deactivation Processes in Biological Systems and in Substances of Biological Interest

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