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Rehovot, Israel

Fine I.,Elfi Tech
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2014

PPG volumetric model is frequently adopted to explain the pulsatile nature of optical response for arterial pulsation. In this article we show that the pulsatile fluctuation of optical response can be explained in terms of the light scattering related changes. According to this assumption, these fluctuations are driven by the modulation the scattering coefficient associated with the blood flow hemodynamic effects. There was shown that the proposed model yields a good correspondence with the pulse-oximetry related parameters. Moreover, it was found that the experimental relationship between the red blood concentration in the blood (hematocrit) and the parameters being derived from the in vivo measured optical signals can be described in terms of this scattering driven model. There was demonstrated that the commonly used volumetric assumption fails to provide a reasonable description of the experimental results. The last fact can be used as a decisive argument in favor of the scattering driven model. This model can be used for better understanding of the pulse oximetry as well as for the guidance for the algorithmic development of the blood hemoglobin/ hematocrit in vivo. © 2014 SPIE. Source

Rubinstein I.A.,Moscow State University | Kaminskiy A.V.,Elfi Tech | Tolokonnikova A.A.,Russian Academy of Sciences | Kolombet V.A.,Russian Academy of Sciences | Shnoll S.E.,Russian Academy of Sciences
Biophysics (Russian Federation) | Year: 2014

Basic phenomena of the "macroscopic fluctuations" are repeated on the light beams generated by lasers or light-emitting diodes. Study of the light beams fluctuations look promissory. © 2014 Pleiades Publishing, Inc. Source

A system, method and medical tool are presented for use in non-invasive in vivo determination of at least one desired parameter or condition of a subject having a scattering medium in a target region. The measurement system comprises an illuminating system, a detection system, and a control system. The illumination system comprises at least one light source configured for generating partially or entirely coherent light to be applied to the target region to cause a light response signal from the illuminated region. The detection system comprises at least one light detection unit configured for detecting time-dependent fluctuations of the intensity of the light response and generating data indicative of a dynamic light scattering (DLS) measurement. The control system is configured and operable to receive and analyze the data indicative of the DLS measurement to determine the at least one desired parameter or condition, and generate output data indicative thereof.

A method and apparatus are presented for non-invasive determination of blood clotting related and blood circulation related parameters of a mammal. At least one stimulus ST is non-invasively induced in a blood containing medium in the mammal for a preset period of time t

Fine I.,Elfi Tech | Kuznik B.I.,Chita State Medical Academy | KuznikKaminsky A.V.,Elfi Tech | Shenkman L.,Tel Aviv University | And 2 more authors.
Journal of Biomedical Optics | Year: 2012

We conducted a study on 861 healthy and sick subjects and demonstrated that some calculated parameters based on measurement of the dynamic light scattering (DLS) signal from the finger correlate highly with chronological age ranging from 1.5 to 85 years old. Measurements of DLS signals were obtained during both occlusion and nonocclusion of blood flow in the finger. For the nonocclusion case we found that the low-frequency component of the DLS signal significantly correlates with the biological age while the high-frequency component of the DLS signal resembles the arterial pulse-wave and does correlate with age. However, the most prominent correlation between the DLS characteristics and age was noted with the stasis stage measurements. We propose that the observed age-related phenomena are caused by alterations in local blood viscosity and interactions of the endothelial cells with erythrocytes. Further, a new noninvasive index based on the age-related optical characteristics was introduced. This noninvasive index may be used as a research and diagnostic tool to examine the endothelial and thrombolytic properties of the vascular system. © 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). Source

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