Device for the examination of objects by ultrasonic echography with angular focusing

• US 4,677,981 A
• Filed: 09/20/1985
• Issued: 07/07/1987
• Est. Priority Date: 09/25/1984
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Coursant, Roger H.
• Primary Examiner(s): Howell, Kyle L.
• Assistant Examiner(s): Smith, Ruth S.
• Application Number:
  US06/778,634
• Time in Patent Office: 655 Days
• Field of Search: 128/660, 73/625, 73/628, 310/334, 310/358, 310/359, 310/317
• US Class Current: 600/447
• CPC Class Codes: G01S 7/52046 Techniques for image enhancement involving transmitter or receiver image enhancement by image data processing G06T5/00
• CPC Class Codes: G10K 11/32 characterised by the shape of the source
• CPC Class Codes: G10K 11/345 using energy switching from one active element to another

Abstract

A device for examining objects by ultrasonic echography comprising a focusing network of n ultrasonic transducers and in which the ultrasonic transducers (a,b,c, . . . i, . . . , n-1,n) are made of an electrostrictive material with non-remanent polarization, and the said polarization is effected by a polarization stage comprising: (1) a source (501) of p polarization direct voltages, (2) a demultiplexing and branching circuit (502) receiving, on the one hand, the p polarization voltages and, in the other, combinations of m bits selecting the said voltages in order to supply them to the transducers, (3) a circuit for the determination of a law of sensitivity (503), consisting of a counter (522) whose number of states corresponds at least to the numbers of directions to be explored and of a memory (521), intended to provide the n respective digital combinations corresponding to each state of the counter, and (4) a sequencer (520).

Claims

1. A device for the examination of objects by ultrasonic echography comprising a focusing network of n ultrasonic transducers associated with a transmission stage for the repeated transmission of ultrasonic waves across the region to be explored and with a reception stage for the processing of the return echoes received, wherein:

said ultrasonic transducers are made of an electrostrictive material with non-remanent polarisation and further comprising

(1) a source of p polarisation direct voltages;

(2) demultiplexing and branching circuit means which include n demultiplexers each of which receives the p polarisation direct voltages selects one of the said voltages and supplies, via a series polarisation resistor the selected voltage to one of said ultrasonic transducers;

(3) a circuit means which determines a law of sensitivity corresponding to two phase states and to p/2 or (p+1)/2 amplitude states when p is even or odd, respectively, said circuit means comprising a counter having a number of states which correspond at least to the number of different directions in which it is desired to perform an examination by focusing the ultrasonic waves, and a memory which supplies to the n demultiplexers, in response to any particular state of the counter, n respective digital combinations corresponding to the said state thereby indicating to each demultiplexer one of the direct voltages which it has to select for the polarisation of the transducer associated with it;

(4) sequencer means comprising a clock circuit which fixes the duration of the transmission and reception periods and the rate of change of state of the counter.