Closed loop maximum likelihood phase aberration correction in ph

Details Closed loop maximum likelihood phase aberration correction in ph Closed loop maximum likelihood phase aberration correction in ph

1994-09-26

1996-07-02

Williams, Hezron E.

Measuring and testing

Vibration

By mechanical waves

73626, 73628, 12866006, 12866101, G01N 2918

Patent

active

055311172

ABSTRACT:
A phased array ultrasonic imaging system performs a scan in which beamforming time delay errors due to nonuniformity in ultrasound speed within the transmission medium are corrected by estimating and correcting phase aberrations in accordance with the maximum likelihood theory. The system employs a multiple-channel transmitter and receiver, and estimates phase values, not phase difference values, thereby eliminating any need to perform an integration to produce the phase aberration profile. The method can be implemented in real-time, allowing correct data to flow out of the circuit which at the same time can be receiving new input data. Delays can be added to allow for phase aberration correction of past measurements. The method allows tracking, to some extent, of variations that may occur in the phase aberrations. Depending on the number of channels that are simultaneously considered, different closed loop circuits can be employed. A one-dimensional closed loop circuit, for example, estimates the phase aberration affecting one single channel, while a two dimensional closed loop circuit jointly estimates the phase aberrations affecting two of the channels.

REFERENCES:
patent: 4817614 (1989-04-01), Hassler et al.
patent: 4989143 (1991-01-01), O'Donnell et al.
patent: 5172343 (1992-12-01), O'Donnell
patent: 5235983 (1993-08-01), Iida et al.
patent: 5388461 (1995-02-01), Rigby
Flax et al., "Phase-Aberration Correction Using Signals from Point Reflectors and Diffuse Scatters: Basis Principles", IEEE Trans. on Ultrasonics, Ferroelectrics and Frequency Control, vol. 35, No. 6, Nov. 1988, pp.758-767.

Affiliated with

Also associated with

Rating

Closed loop maximum likelihood phase aberration correction in ph does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Closed loop maximum likelihood phase aberration correction in ph, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Closed loop maximum likelihood phase aberration correction in ph will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1498215