Patent ID: 6687625
Filing Date: 2004-02-03
Classification: G01L

Abstract:
A method for determining localized strain in a target body comprising:a. acoustically coupling at least one ultrasound source to a target body; b. emitting a first pulse of ultrasound energy of a known wavelength from said source along a first radiation axis into the target body; c. recording a first echo sequence having at least one echo segment arriving in response to said first pulse of ultrasound energy; d. locating at least one level crossing in said first echo sequence arriving in response to said first pulse of ultrasound energy as a function of time to form a first level crossing; e. displacing the target body along said first radiation axis by a known displacement; f. emitting a second pulse of ultrasound energy from said source along said first radiation axis into the target body; g. recording a first echo sequence having at least one echo segment arriving in response to said second pulse of ultrasound energy; h. locating at least one level crossing in said first echo sequence arriving in response to said second pulse of ultrasound energy as a function of time to form a second level crossing; i. comparing said first level crossing to said second level crossing to determine a set of time shift values as a function of time; and j. determining the local strain in the target body along portions of said first radiation axis from said set of time shift values.