Both diagnostic and therapeutic ultrasound applications require an understanding of the directivity patterns on the transducers to design ultrasound equipment and faithfully characterize the acoustic output from medical ultrasound devices. Since each ultrasound transducer has its own specific directivity pattern, the measurement of the directivity pattern is necessary. The objectives of this wo...

conclusions noninvasive assessment of the patient hydration condition using the ultrasound is a simple and practicable measure in emergency. with regard to the considerations, it is possible to estimate cvp via diameter measurement and cross-section of the central veins. results twenty patients with the mean age of 60.3 were studied. the main reason for cardiac catheterization was shock. there ...

Conventional two-dimensional intracoronary ultrasound enables the extent, distribution, and therapy of atherosclerotic plaques to be studied as it provides a unique tomographic visualization of both the vascular lumen and wall'". The most important limitation of two-dimensional intracoronary ultrasound in pre/poststudies is the matching of the target sites for serial measurement. This problem i...

The non-invasive assessment of cardiovascular changes with spaceflight often involves the measurement of blood vessel dimension using ultrasound imaging. However, many commonly used measurement techniques are often manually intensive and dependent on the individual making the measurements. We propose a new automated method for measuring the vessel dimensions which involves creating a smoothed e...

We describe a case of a lingual thyroglossal duct cyst diagnosed prenatally by ultrasound at 26 weeks of gestation. The follow-up ultrasound scans revealed no changes in the cyst measurement. Surgical treatment was performed without any complication 72 hours after delivery with good results.

In 100 eyes of 50 patients central corneal thickness was measured comparing optical to ultrasound pachymetry. With optical pachymetry the values were 1 to 40 micrometer (microns) lower in 64 eyes compared to ultrasound pachymetry. With ultrasound pachymetry the values were 1 to 18 microns lower in 26 eyes compared to optical pachymetry. In 10 cases no difference in pachymetry readings was seen ...

In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration...

The total output power from a medical ultrasound transducer has to be measured due to various reasons but in general they are related to assessment of performance and safety of equipment. The objective of this work was to develop a primary level ultrasonic power measurement system to establish standards for ultrasonic power measurement in Thailand. This system is being set up at the National In...