We report the development of an optical technique for noninvasive imaging of in vivo blood flow dynamics and tissue structures with high spatial resolution (2-10 microm) in biological systems. The technique is based on optical Doppler tomography (ODT), which combines Doppler velocimetry with optical coherence tomography to measure blood flow velocity at discrete spatial locations. The exception...

Selcuk University, Meram Faculty of Medicine, Departments of Obstetrics and Gynecology1 and Pediatry2, Konya, Turkey Aim: To propose optimal management of intrauterine growth restriction (IUGR) cases associated with severe preeclampsia at 28-34 weeks of gestation. Methods: Two hundred pregnant women with severe preeclampsia associated with growth restricted fetuses were followed with doppler ve...

Objective: To evaluate the value of Doppler velocimetry of umbilical and middle cerebral arteries and amniotic fluid volume in the surveillance of post term pregnancies. Design: Cross sectional study. Setting: Kasr El-Aini Hospital. Materials and Methods: Forty pregnant ladies with a gestational age of more than 41 weeks were compared to 40 pregnant ladies with gestational age ranging from 37 t...

Colloidal particles in a liquid medium are transported with constant velocity, and dynamic light scattering experiments are performed on the samples by self-mixing laser Doppler velocimetry. The power spectrum of the modulated wave induced by the motion of the colloidal particles cannot be described by the well-known formula for flowing Brownian motion systems, i.e., a combination of Doppler sh...

HKJGOM 2009; 9 (1) 28 Introduction Fetuses born with significant growth restriction have an increased risk of adverse perinatal outcomes1. Moreover, increased perinatal morbidity and mortality was often associated with the presence of abnormal Doppler waveforms in the umbilical arteries (UAs), either in the form of absent or reversed end-diastolic flow2,3. In fetuses with abnormal umbilical art...

Doppler velocity measurement has been extensively applied in prenatal diagnosis for more than two decades. Blood flow in numerous vessels has been investigated to predict fetal condition, especially in the umbilical artery [1–7]. Histopathologic studies suggest that abnormal umbilical artery Doppler velocimetry is correlated with a pathologic lesion of the placenta characterized by obliteration...

For longtime, the investigation of flow regimes has been achieved using fluorescent particles or anisotropic reflective particles. Fluorescent particles are suitable for open flows (Van Dyke, 1982) such as flows in channels (Peerhossaini et al., 1988) or flows behind a cylinder (to visualize Benard-von Karman street) (Provansal et al., 1986; Mutabazi et al., 2006). For closed flows such as flow...

Laser Doppler Velocimetry (LDV) has been employed to determine pseudo-turbulence characteristics of the flow field around bubble train forming in non-Newtonian caboxymethylcellulose (CMC) aqueous solution at low gas flow rate condition. The Reynolds stress and turbulent intensity of the liquid were investigated by means of Reynolds time-averaged method. The experimental results show that ax...

Ultrasonic sensors are commonly used for a wide variety of non-contact presence, proximity or distance measuring applications in industry, especially the automotive branch. This paper shows how the radiation properties of bending-type ultrasonic transducers with rotational symmetry depend on shape, dimensions and material parameters. In order to determine their dependencies, the behaviour of su...