Study of erythrocyte sedimentation in human blood through the photoacoustic signals analysis.

Introduction: In this study, we utilized the pulsed photoacoustic (PA) technique to analyze globular sedimentation in whole human blood, with a focus on distinguishing between healthy individuals and those with hemolytic anemia.

Methods: Blood samples were collected from both healthy individuals (women and men) and those with hemolytic anemia, and temporal and spectral parameters of PA signals were employed for analysis.

Results: Significant differences (p < 0.

Image reconstruction algorithm for laser-induced ultrasonic imaging: The single sensor scanning synthetic aperture focusing technique.

This paper aims to implement a laser-induced ultrasound imaging reconstruction method based on the delay-and-sum beamforming through the synthetic aperture focusing technique (SAFT) for a circular scanning, performed with a tomograph that had one acoustic sensor and a system that rotates the sample around a fixed axis. The proposed method, called the Single-sensor Scanning Synthetic Aperture Focusing Technique, considers the size of the sensor and the detection procedure inside the SAFT's algebra. This image reconstruction method was evaluated numerically, using the Green function for the laser-induced ultrasound wave equation to generate a forward problem, and experimentally, using a solid object of polylactic acid, and a Sprague-Dawley rat heart located in a tissue-mimicking phantom.

Laser-induced sound pinging for the rapid determination of total sugar or sweetener content in commercial beverages.

We recently reported on fixed-path length laser-induced sound pinging (FPL-LISP) as a rapid photoacoustic technique employing an inexpensive benchtop tattoo-removal laser for reliably determining the speed of sound in low-volume fluids. In this contribution, we demonstrate the capacity of FPL-LISP to analyze representative commercial beverages for their natural or artificial sweetener contents. As a benchmark, the speed of sound was determined for solutions of sugars (glucose, fructose, sucrose), mock high fructose corn syrup (HFCS-55), and 12 household sweeteners (culinary sugars, syrups, honey, molasses) across the concentration range of 1-20% w/v in water, simulating the typical sweetener range found in commercial soft drinks.

Quantitative Photoacoustic Method for the Measurement of Absorption Coefficients of Highly Absorbing Samples.

In this study, we present a quantitative photoacoustic (PA) method for performing absorption measurements on highly absorbing samples. Based on the thermoelastic mechanism, the relative changes in PA signal amplitude allowed the determination of absorption coefficients of materials in the 0.19-2500-cm range, with no prior knowledge of the material's optoacoustic properties required.

Spectrophotometric analysis at the single-cell level: elucidating dispersity within melanic immortalized cell populations.

It is widely held that the melanosome is an exemplar of the absorption features of melanin-containing cells, which are assumed to be uniform in both size and optical characteristics. In recent years, however, it has become increasingly apparent that this is a strikingly poor assumption. Indeed, melanin extracted from natural sources and synthetic melanin both show wide variability in their degree of polymerization (molecular weight) and spectroscopic characteristics.

Dye-doped organosilicate nanoparticles as cell-preserving labels for photoacoustic signal generation.

Nanoparticle-assisted ultrasound generation by pulsed laser or photoacoustic (PA) techniques has been employed in the study of several tissues both in vivo and in vitro. Among the many applications of this technology, the detection of few cells in vitro is of particular interest. However, the toxicity induced by laser irradiation used for PA signal generation, whether in the absence or the presence of PA enhancers, within single isolated cells has not yet been investigated in detail.

Detection of melanoma cells in vitro using an optical detector of photoacoustic waves.

Background And Objective: Circulating tumor cells have been shown to correlate positively with metastatic disease state in patients with advanced cancer. We have demonstrated the ability to detect melanoma cells in a flow system by generating and detecting photoacoustic waves in melanoma cells. This method is similar to flow cytometry, although using photoacoustics rather than fluorescence.