The equipment specifications may be reproduced
with appropriate acknowledgement to IBUS
Transducer frequency of 7.5 MHz or higher
Good spatial and contrast resolution
(uniform characteristics throughout the field of view are desirable)
An electronic linear array transducer
or a mechanically driven sectoring annular array transducer can be used,
and should have a penetration depth better than 4 cm at 7.5 MHz
Good near field resolution should be provided
either by using an acoustic stand-off or by signal processing methods
which may include variable aperture and variable frequency techniques