Translational and Brownian motion in laser-Doppler flowmetry of large tissue volumes
| Autor: | Terence S. Leung, D. T. Delpy, Tiziano Binzoni, Mohamed L. Seghier |
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| Rok vydání: | 2004 |
| Předmět: |
Erythrocytes
ddc:616.0757 Sensitivity and Specificity Flow measurement Diffusion Optics Laser-Doppler Flowmetry Animals Humans Computer Simulation Radiology Nuclear Medicine and imaging Diagnosis Computer-Assisted Brownian motion Organ Size/physiology Physics Erythrocytes/physiology Blood Volume Models Statistical Radiological and Ultrasound Technology Scattering business.industry Blood Flow Velocity/physiology Mathematical analysis Models Cardiovascular Reproducibility of Results Spectral density Organ Size Blood flow Laser Doppler velocimetry Blood Physiological Phenomena ddc:616.8 Blood Volume/physiology Nonlinear system Diagnosis Computer-Assisted/methods Scattering theory Laser-Doppler Flowmetry/methods business Blood Flow Velocity |
| Zdroj: | Physics in Medicine and Biology, Vol. 49, No 24 (2004) pp. 5445-5458 |
| ISSN: | 1361-6560 0031-9155 |
| DOI: | 10.1088/0031-9155/49/24/004 |
| Popis: | This study reports the derivation of a precise mathematical relationship existing between the different p-moments of the power spectrum of the photoelectric current, obtained from a laser-Doppler flowmeter (LDF), and the red blood cell speed. The main purpose is that both the Brownian (defining the 'biological zero') and the translational movements are taken into account, clarifying in this way what the exact contribution of each parameter is to the LDF derived signals. The derivation of the equations is based on the quasi-elastic scattering theory and holds for multiple scattering (i.e. measurements in large tissue volumes and/or very high red blood cell concentration). The paper also discusses why experimentally there exists a range in which the relationship between the first moment of the power spectrum and the average red blood cells speed may be considered as 'linear' and what are the physiological determinants that can result in nonlinearity. A correct way to subtract the biological zero from the LDF data is also proposed. The findings should help in the design of improved LDF instruments and in the interpretation of experimental data. |
| Databáze: | OpenAIRE |
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