We studied the renal transplant blood flow using an ultrasonic contrast agent. The contrast medium was injected intravenously and produced blood flow enhancement for at least 60 seconds. Measurements were made from the recorded Doppler spectra. Fourteen renal transplant recipients were investigated by color Doppler echography. Blood flow in the interlobular artery could be analyzed in all patie...

The aim of this paper is to present a system that detects the hand gesture motions using the principle of Doppler Effect. Ultrasonic waves are transmitted by a sensor module and are reflected by a moving hand. The received waves are frequency shifted due to Doppler Effect. These frequency shifts in the ultrasonic waves are characterized to determine gestures. The gestures once recognized are ma...

Hepatic vein stenosis after liver transplantation is a relatively rare complication that could even result in graft loss. However, it is difficult to arrive at a definite diagnosis at the early stage of postoperation, and there are few researches on ultrasonic shear wave elastography in the diagnosis of hepatic vein stenosis. We report the case of an 11-year-old male patient with cirrhosis due ...

Although there are several indirect or noninvasive methods (i.e., oscillometric and Doppler) available, it is sometimes impossible to obtain a reading on exotic patients. The Doppler method is more versatile than the oscillometric method, and is the method used by the author for all exotic patients. The ultrasonic Doppler flow detector (Parks Medical Electronics Inc., Aloha, OR) uses ultrasonic...

BACKGROUND A diastolic coronary flow murmur has been reported for patients with coronary stenoses, yet is rarely appreciated during routine auscultation. We hypothesized that an ultrasonic Doppler method can detect the epicardial vibrations associated with this murmur. Ultrasonic Doppler vibrometry is a pulsed wave echocardiography phase demodulation technique designed for detecting vibrations....

A precision ultrasonic velocimeter and a new differential method of calculation of specific concentration increments were employed to study the nonlinear acoustic properties of aqueous solutions of ten amino acids and six proteins. The greater precision of the velocity measurements allows much more dilute solutions to be treated, providing for a wider range of amino acids and proteins to be stu...

Ultrasonic pulsed wave range Doppler sensors provide application in various fields, e.g. intruder alarm systems or autonomous vehicle steering, [1], [2], [3]. The timefrequency methods [4, 5] commonly used in these sensors, however, inhere the problem that, due to the transducer's non constant and direction-dependent transfer functions, the Doppler frequency cannot be determined with high accur...

In an effort to evaluate the effectiveness of the Doppler Ophthalmic Test (DOT) following carotid endarterectomy, a large group of patients was examined both pre- and postoperatively with non-invasive techniques. The DOT, which has proven to be a useful non-invasive diagnostic test for the determination of significant carotid artery stenosis, was found to be persistently abnormal in 46% of pati...