(HVL) The attenuation of ultrasound waves in human tissue is characterized as the half value layer, or the half power distance. Half value layer means the distance the sound beam will travel in a tissue before its amplitude or energy is attenuated to half its original value. Air and lung tissue have extremely short half-power distances and represent severe obstacles to the transmission of acoustic energy.

From GE Healthcare.;
Versatile High Performance System 'The LOGIQ 5 Expert ultrasound system delivers the premium performance advantage of TruScan architecture in a versatile high performance package. Advanced capabilities for outstanding clinical performance are available with the efficiency and productivity needed to meet clinical demands.'

From GE Healthcare.;
'The System of Choice for General Imaging
Imagine a leading-edge ultrasound system so versatile that it can meet the demands of virtually any clinical setting. With the LOGIQ® 9, you'll have a high-performance system capable of multi-dimensional imaging for a full range of clinical applications - from abdominal to breast to vascular imaging. And an ergonomic design that improves scanning comfort and clinical work flow. Now, imagine what LOGIQ® 9 could do for you and your patients.'

(ESWL) Extracorporeal shock wave lithotripsy is a special use of kidney ultrasound, where high intensity focused ultrasound pulses are used to break up calcified stones in the kidney, bladder, or urethra. Pulses of sonic waves pulverize dense renal stones, which are then more easily passed through the ureter and out of the body in the urine. The ultrasound energy at high acoustic power levels is focused to a point exactly on the stone requiring an ultrasound scanning gel for maximum acoustic transmission.
Air bubbles in the ultrasound couplant, regardless of their size, degrade the performance of Lithotripsy and have the following effect:
Air bubbles smaller that 1/4 wavelength cause scattering of the sound waves as omni directional scatterers and less acoustic energy reaches the focal point. The result is less acoustic power at the focal point to disintegrate the kidney stone.
Air bubbles larger than 1/4 wavelength act as reflectors and deflects the acoustic energy off in a different direction. These results in less acoustic energy at the focal point.
Microbubbles dispersed throughout the ultrasound couplant layer change the average acoustic impedance of the gel layer (which reduces the total transmitted energy) and, due to refraction, change the focal point.

From Philips Medical Systems;
'The powerful system...
The SD 260 is a powerful B/W ultrasound system that offers standard all major scan techniques: curved, linear and annular phased array. The user has a choice of no less than 12 probes and can connect up to three probes simultaneously, regardless of their technique. The SD 260 is perfectly suited for use in either a busy hospital or clinic.'
This product is not available in the US, Australia, or New Zealand from Philips Medical Systems.

Specifications for this system will be available soon.