Most usual ultrasound machines are 2D real-time systems. This types of ultrasound scanners allow to assess both motion and anatomy, including the motion of heart valves, the movement of intestines and lungs and also to guide interventions, like for example a biopsy or a laparoscopic ultrasound.
A standard real-time scanner consists of a mobile console with the monitor on the top and rows of small containers at the bottom to accommodate a variety of scanner probes. The linear, curved or phased array transducers are usually equipped with multiple crystals or in some cases with a moving crystal. A real-time scanner may be e.g., a mechanical scanner or electronic array scanner.

See also Musculoskeletal and Joint Ultrasound.

Transducers used for the real-time mode are different than for the A-mode, B-, or M-modes. A linear array transducer with multiple piezoelectric crystal elements that are different arranged and fired, transmits the needed larger sound beam.
A subgroup of x adjacent elements (8-16; or more in wide-aperture designs) is pulsed simultaneously; the inner elements pulse delayed with respect to the outer elements. The interference of the x small divergent wavelets generates a focused beam. The delay time determining the focus depth of a real-time transducer can be changed during imaging.
Similar delay factors applied during the receiving phase, result in a dynamic focusing effect on the return. This forms a single scan line in the real-time image. To produce the following scan line, another group of x elements is selected by shifting one element position along the transducer array from the previous group. This pattern is then repeated for the groups along the array, in a sequential and repetitive way.

Different sound velocities in tissue are causing refraction artifacts. With convex elastomer lens transducers, sound beam refraction at the skin interface can alter the transducer's focusing characteristics and beam profile, cause element to element nonuniformity, and cause phase changes in the acoustic wave. These cumulative refraction induced errors degrade the image quality through distortion and loss of resolution. Because the amount of refraction is proportional to the velocity mismatch, the greater the mismatch, the greater the refraction.

From Philips Medical Systems;
'The perfect practice system...
The SD 240E is a compact and ergonomically designed system, standard equipped with two probe connectors. The user has a choice out of more than 12 linear, curved and annular phased array probes which can be used with this perfect office unit. Total Image Focus and cine memory technology are just the icing on the cake.'
This product is not available in the US, Australia, or New Zealand from Philips Medical Systems.'

Specifications for this system will be available soon.

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.