Acoustic Doppler velocity meters �ADVMs� provide an alternative to more traditional flow measurement devices and proce­ dures such as flumes, weirs, and stage rating for irrigation and drainage canals. However, the requirements for correct calibration are extensive and complex. A three-dimensional computational fluid dynamics �CFD� model was used to design a subcritical rapidly varied flow cont...

A new method for estimating the measurement depth and volume in laser Doppler flowmetry (LDF) is presented. The method is based on Monte Carlo simulations of light propagation in tissue. The contribution from each individual Doppler shift is calculated and thereby multiple Doppler shifts are handled correctly. Different LDF setups for both probe based (0.0, 0.25, 0.5, and 1.2 mm source-detector...

The continuity equation suggests that a ratio of velocities at two different cardiac valves is inversely proportional to the ratio of cross-sectional areas of the valves. To determine whether a ratio of mitral/aortic valve orifice velocities is useful in determining aortic valve area in patients with aortic stenosis, 10 control subjects and 22 patients with predominant aortic stenosis were exam...

References 1. Curry GR, White DN: Color coded ultrasonic differential velocity arterial scanner (Echoflow). Ultrasound Med Biol 4: 27-35, 1978 2. Barnes RW, Russell HE, Bone GE, Slaymaker EE: Doppler cere­ brovascular examination: Improved results with refinements in tech­ nique. Stroke 8: 468-71, 1977 3. Gee W, Mehigan JT, Wylie EJ: Measurement of collateral cerebral hemispheric blood pressure...

1. Rudski LG . Point: can Doppler echocardiography estimates of pulmonary artery systolic pressures be relied upon to accurately make the diagnosis of pulmonary hypertension? Yes . Chest . 2013 ; 143 ( 6 ): 1533 1536 . 2. Rich JD . Counterpoint: can Doppler echocardiography estimates of pulmonary artery systolic pressures be relied upon to accurately make the diagnosis of pulmonary hypertension...

Transesophageal echocardiography (TEE) has advanced the role of the cardiovascular anesthesiologist and increased his/her active role and obligations during perioperative patient care. Assessment of global and regional left ventricular (LV) function consists of two-dimensional (2D) or Doppler evaluation of cardiac structures and their interaction with blood flow. The techniques used are mostly ...

In this paper a novel technique for flow measurement which is based on the photoacoustic (PA) Doppler effect is described. A significant feature of the proposed approach is that it can be implemented using tone burst optical excitation thus enabling simultaneous measurement of both velocity and position. The technique, which is based on external modulation and heterodyne detection, was experime...