Ultrasonic imaging system

• US 5,952,577 A
• Filed: 07/21/1997
• Issued: 09/14/1999
• Est. Priority Date: 07/21/1997
• Status: Expired due to Fees

• Current Assignee: Boehringer Mannheim GmbH (Roche Holding AG), Sonotron Ltd.
• Original Assignee: Sonotron Ltd.
• Inventors: Passi, Garri S.
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): Kwok, Helen C.
• Application Number:
  US08/897,609
• Time in Patent Office: 785 Days
• Field of Search: 73/599, 73/600, 73/602, 73/624, 73/625, 73/626, 73/632, 73/633, 73/634, 73/618, 73/621, 600/444, 600/445, 600/463
• US Class Current: 73/618
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 2291/2675 Seam, butt welding
• CPC Class Codes: G01N 29/069 Defect imaging, localisation and sizing using, e.g. time of flight diffraction [TOFD], synthetic aperture focusing technique [SAFT], Amplituden-Laufzeit-Ortskurven [ALOK] technique
• CPC Class Codes: G01N 29/11 by measuring attenuation of acoustic waves
• CPC Class Codes: G01N 29/265 by moving the sensor relative to a stationary material
• CPC Class Codes: G01N 29/28 providing acoustic coupling , e.g. water impedance matching G10K11/02
• CPC Class Codes: G01S 15/8938 using transducers mounted for mechanical movement in two dimensions
• CPC Class Codes: G01S 5/18 using ultrasonic, sonic, or infrasonic waves
• CPC Class Codes: G01S 5/186 Determination of attitude using inertial means G01C9/00; control of attitude G05D1/49
• CPC Class Codes: G01S 5/20 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G01S 7/5205 Means for monitoring or calibrating

Abstract

An ultrasonic imaging system for imaging an object. The system includes a mechanism for designating an ultrasonic probe swiveling angle threshold beyond which the ultrasonic probe does not adequately image the scanned object, and an echo amplitude correction apparatus for correcting the amplitude of a received echo by normalizing such amplitude to the value of a previously recorded echo of higher amplitude. Furthermore, the system includes a mechanism for monitoring acoustic coupling, which includes a low frequency noise level selection apparatus for manually selecting the power at which a low frequency reference noise is generated by a vibrator, and a low frequency noise receiving crystal located in the probe holder of the ultrasonic probe, for receiving the low frequency reference noise signal. In addition, the system includes a probe location monitoring apparatus, including two mobile non-directional transceivers in the form of an air acoustic dipole, for determining ultrasonic probe location by triangulation; a mechanism for designating the displacement between the transceivers; and a mechanism for designating the radius of curvature of the object being scanned.

Claims

1. An ultrasonic imaging system for imaging an object, the system comprising:

(a) an ultrasonic probe for scanning the object;

(b) a probe location monitoring apparatus for monitoring a trajectory and orientation of said ultrasonic probe with respect to the object; and

(c) a mechanism for receiving, as an input into the system, a definition of an orientation threshold beyond which said ultrasonic probe will not adequately image the object.

2. The ultrasonic imaging system of claim 1, further comprising a trajectory display for displaying said trajectory of said ultrasonic probe, wherein said trajectory display provides a perceptible signal inditing when said ultrasonic probe is oriented at an orientation exceeding said defined orientation threshold received as an input into the system.

3. An ultrasonic imaging system for imaging an internal inhomogeneity in an object, the system comprising:

(a) an ultrasonic probe for scanning the object;

(b) a probe location monitoring apparatus for monitoring a trajectory and orientation of said ultrasonic probe with respect to the object;

(c) a monitor for displaying an image of the internal inhomogeneity in the object, said image being a graphic representation of ultrasound signals which have been reflected off of, and are representative of, the internal inhomogeneity in the object, and

(d) an echo amplitude correction apparatus for selecting for display, on said monitor, an ultrasound signal of greatest amplitude, wherein said ultrasoun signal of greatest amplitude is selected from amongst a plurality of said reflected ultrasound signals representative of the internal inhomogeneity, and wherein said ultrasound signal of greatest amplitude is displayed on said monitor instead of an ultrasound signal of lesser amplitude representative of the same internal inhomogeneity.

4. An ultrasonic imaging system for imaging an object with an ultrasonic probe including electrical circuitry, the system comprising:

(a) a vibrator for generating a reference signal;

(b) a detector, acoustically coupled to the ultrasonic probe, for detecting said reference signal;

(c) a selection apparatus for gradually varying a power output of said vibrator, said selection apparatus being operative to vary said power output between more than two power output gradations, and

(d) an indicator for indicating when said reference signal is being detected by said detector.

5. The system as in claim 4, wherein said detector is electrically separated from the electrical circuitry of the ultrasonic probe.

6. The system as in claim 4, wherein said detector includes a crystal acoustically coupled to the ultrasonic probe.

7. An ultrasonic imaging system for imaging an object, comprising:

(a) an ultrasonic probe for scanning the object, said ultrasonic probe including at least two transmitters for transmission of air acoustic signals; and

(b) an acoustic dipole for locating said ultrasonic probe by triangulation, said acoustic dipole including two non-directional acoustic transceivers for detecting said air acoustic signals transmitted by said transmitters.

8. The system as in claim 7, wherein a first of said transceivers is displaceable with respect to a second of said transceivers.

9. The system as in claim 8, further including a mechanism for designating a displacement between said transceivers.

10. The system as in claim 7, further including a mechanism for designating a degree of curvature of the object.

11. A method for verifying an acoustic coupling of an ultrasonic probe to a workpiece, comprising the steps of:

(a) introducing a reference signal into the workpiece, using a vibrator having a gradually adjustable power output level;

(b) providing a detector, acoustically coupled to the probe, for detecting said inference signal;

(c) providing a mechanism for indicating when said reference signal is detected by said detector; and

(d) gradually increasing said power output level through a plurality of gradations until said mechanism indicates that said reference signal is detected by said detector.

12. The method of claim 11, further comprising the step of:

(e) positioning the probe at a substantially maximal distance on the workpiece from said vibrator.

13. The method of claim 11, wherein said reference signal includes low frequency noise.