CONTINUOUS WAVE DOPPLER AND PDA: THE VELOCITY INDEX

نویسندگان
چکیده

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Continuous wave ultrasonic Doppler tomography.

In continuous wave ultrasonic Doppler tomography (DT), the ultrasonic beam moves relative to the scanned object to acquire Doppler-shifted frequency spectra which correspond to cross-range projections of the scattering and reflecting structures within the object. The relative motion can be circular or linear. These data are then backprojected to reconstruct the two-dimensional image of the obje...

متن کامل

estimation of carotid artery pulse wave velocity by doppler ultrasonography

background: pulse wave velocity (pwv) is widely used for estimating the stiffness of an artery. v arious invasive and non-invasive methods have been developed to determine pwv over the years. in the present research , the non-invasive estimation of the pwv of large arteries was used as an index for arterial stiffness. methods: a dynamic model based on the navier-stokes equations coupled to elas...

متن کامل

Quantification of mitral regurgitation with amplitude-weighted mean velocity from continuous wave Doppler spectra.

Amplitude-weighted mean velocity from continuous wave (CW) Doppler spectra was used to measure aortic flow (QAo) and left ventricular mitral inflow (QLVin). These flows were used to quantify mitral regurgitation fraction: RFm = (QLVin-QAo).QLVin-1.100(%).QLVin was calculated from the diastolic time integral of amplitude-weighted mean velocity that was derived from CW spectra with the transducer...

متن کامل

The difference between Doppler velocity and real wind velocity in single scattering from refractive index fluctuations

Scattering of electromagnetic waves by turbulence is considered. It is shown that Doppler velocity (the ratio of Doppler shift and Bragg wave number) includes two terms: The first is the mean radial velocity in the scattering volume, and the second is what we call the “correlation velocity,” caused by a correlation between the fluctuations of velocity and those of refractive index. The correlat...

متن کامل

Continuous-Wave Doppler in the Evaluation of Intracranial Collateral Circulation

Adequate intracranial collateral circulation reduces risk of stroke in carotid artery surgery. To evaluate their relative accuracies in assessing intracranial collateral blood flow, we prospectively compared transcranial Doppler and continuous-wave Doppler of the cervical carotid arteries combined with compression of the common carotid artery in 28 consecutive patients before carotid endarterec...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Pediatric Research

سال: 1984

ISSN: 0031-3998,1530-0447

DOI: 10.1203/00006450-198404001-00154