From ALOKA Co., Ltd.;
'A Platform for Pure Harmonic Detection
Harmonic Echo™ technology constructs images using second harmonic components, which contain far less artifacts and noise than fundamental-frequency components.
Pure Harmonic Detection is a technology to transmit distortion-free, fundamental-frequency ultrasound beams. And when the fundamental-frequency ultrasound beam is a pure sinusoidal wave, both the fundamental-frequency image and the Harmonic Echo™ image are much clearer with less noise. This technology is especially effective for obese patients and in a variety technically difficult scanning conditions.'

Annular arrays are transducer assemblies with circular or ringlike elements, used to focus the beam. Annular arrays must be steered mechanically since they can only be fired in an outward-inward progression due to the rings. Annular arrays reduce section thickness artifacts.

The wider the ultrasound beam, the more severe the problem with volume averaging and the beam-width artifact, to avoid this, the ultrasound beam can be shaped with lenses.
Different possibilities to focus the beam:

Conventional multi-element transducers are electronically focused in order to minimize beam width. This transducer type can be focused electronically only along the long axis of the probe where there are multiple elements, along the short axis (elevation axis) are conventional transducers only one element wide. Electronic focusing in any axis requires multiple transducer elements arrayed along that axis. Short axis focusing of conventional multi-element transducers requires an acoustic lens which has a fixed focal length.
For operation at frequencies at or even above 10 MHz, quantization noise reduces contrast resolution. Digital beamforming gives better control over time delay quantization errors. In digital beamformers the delay accuracy is improved, thus allowing higher frequency operation. In analog beamformers, delay accuracy is in the order of 20 ns.
Phased beamformers are suitable to handle linear phased arrays and are used for sector formats such as required in cardiography to improve image quality. Beamforming in ultrasound instruments for medical imaging uses analog delay lines. The signal from each individual element is delayed in order to steer the beam in the desired direction and focuses the beam.
The receive beamformer tracks the depth and focuses the receive beam as the depth increases for each transmitted pulse. The receive aperture increase with depth. The lateral resolution is constant with depth, and decreases the sensitivity to aberrations in the imaged tissue. A requirement for dynamic control of the used elements is given. Since often a weighting function (apodization) is used for side lobe reduction, the element weights also have to be dynamically updated with depth.

See also Huygens Principle.

From Verathon Inc.;
'The BladderScan® is a portable, noninvasive ultrasound instrument that measures bladder volume. It is battery-operated, easy to use, and quickly provides accurate results. In less than five minutes, you can use the BladderScan® to obtain a precise reading of a patient's bladder volume. The BladderScan® supplies the information that caregivers need to diagnose, treat and manage urinary conditions.'

See also Urologic Ultrasound, Mirror Artifact, Pelvic Ultrasound, Transrectal Sonography and Ultrasonography.

From Verathon Inc.;
'The BladderScan® BVI 6100 is a handheld, noninvasive ultrasound instrument that measures bladder volume. It is easy to operate, so any staff member can scan patients quickly and accurately. To view ultrasound images from exams and print BVI 6100 exam results for patient records and reimbursement, just log on to ScanPoint®, Verathon Inc.'s (formerly Diagnostic Ultrasound Corp.) innovative online service. The BVI 6100 makes it easier to provide the best care for your patients.'

See also Urologic Ultrasound, Mirror Artifact, Pelvic Ultrasound, Transrectal Sonography and Ultrasonography.