Apparatus for the scanning of objects by means of ultrasound echography

Claim 1

Apparatus for scanning objects by ultrasound echography which comprises: a mosaic of ultrasound transducer elements; transmitter means connected to the transducer elements which cause the elements to repeatedly transmit ultrasound signals; receiver means connected to the transducer elements for receiving and processing echo signals which are produced when the transmitted ultrasound signals are reflected; and display means for displaying images which are processed and reconstructed from the signals produced in the receiver means; wherein, as an improvement: the elements of the mosaic are grouped into 2 n subwindows, where n is a positive integer greater than one, and each subwindow is a group of adjacent transducer elements which are sufficient to form an echogram of an area of the object, and the receiver means comprise, in functional series connection: focusing and image scanning means for controlling directional characteristics of the mosaic; .sup. n parallel signal channels, each channel processing signals from a subwindow and comprising controllable delay means and a first memory for storing a delay value correction factor which controls the delay means; adder means which combine the outputs of the channels; evaluation circuit means, the output of the evaluation circuit means being connected to the delay stage; and additionally comprising 2 n -1 correlation means which operate to determine correction factors by adaptively correlating signals which are derived from progressive binary subgroupings of subwindows of elements, where a first subset of the 2 n -1 of the correlation means process signals from respective pairings of the subwindows and other correlation means compare signals from progressive pairings of the pairs of subwindows.