Bio-tissue structure monitoring under shock wave treatment

Abstract

Real-time maps showing the intensity of the subskin blood flux reconstructed by the contrast variation in single-exposure (prolonged-exposure) speckle photography (left) and isolines of these maps (right)The dynamic bio-speckle patterns were generated by illumination of living tissue via laser light and were recorded using a standard digital CCD camera (768 x 494 pixels) at a frame rate of 25 frames/second. The exposure time varied from 10 Ps (for cross-correlation analysis of subsequent frames) to 1/60 s (for a single exposure mode). Speckle patterns were recorded as a distribution of gray values I(m,n) in digital form for each pixel (m,n) of the CCD matrix. In real-time operation the image analysis is performed during the time interval between subsequent (two or more) frames.

Real-time suppression of turbidity of biological tissues in motion by three-wave mixing phase-conjugation

“…Since the position of the scatterers did not change between forward and backward propagation, the image resolution was preserved. Because of the strong absorption of the 532 nm wavelength used in the experiments, the thickness was limited to 0.7 mm, and the acquisition time in the minute range did not allow studying in vivo biological media, which typically have a decorrelation time of 0.1 ms [10].…”

A non-invasive method for the assessment of hemostasis in vivo by using dynamic light scattering

“…The dynamic speckles deals with soft and hard bio tissues as well as with visualization of the blood flow [8][9][10]. In some cases the speckle imaging is used as a second modality for visualization of blood vessels [11,12].…”

“…For the autocorrelation function of signal g 1 (τ) the C (2) will be given by (7) In case of the single scattering from the uncorrelated Brownian particles the measured covariance is expressed in terms of the diffusion coefficient and optical parameter q: (8) A is dependents on the geometry, where q is defined by: (9) λ 0 is the wavelength in the vacuum, n is the refractive index of the surrounding medium, θ is the angle between the incident light and the detection axis.…”