Method of and device for determining the internal structure of a body by means of acoustic beams
First Claim
Patent Images
1. In a method for determining the internal structure of a body comprising the steps of:
- passing a plurality of acoustic beams through a body in different directions from one or more acoustic transmission elements to one or more separate acoustic reception elements;
measuring the value of the transit time of each of said beams through the body; and
utilizing the measured transit time values to calculate the value of the acoustic refractive index at points in a matrix associated with the body;
the improvement comprising the steps of;
first assuming a distribution of acoustic refractive index values at preselected points in the matrix, which approximate known body structure, said assumed distribution taking into account the geometry of the transmission and reception elements;
using said assumed distribution to calculate the path of each of said beams throught the body;
calculating an assumed transit time for each beam along the determined paths; and
then comparing the assumed transit time with the measured value of the transit time to generate step-wise corrections for the calculated value of the acoustic refractive index at points in the matrix.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and device for determining the internal structure of a body by means of acoustic beams. Transit times and intensities of acoustic beams passing through the body in different spatial directions are measured to establish the refractive index distribution and the acoustic absorption coefficient distribution, respectively at the points of a point matrix associated with the body. The non-rectilinear course of the acoustic beams is taken into account in this respect. This results in reconstructed images of higher quality.
45 Citations
17 Claims
-
1. In a method for determining the internal structure of a body comprising the steps of:
-
passing a plurality of acoustic beams through a body in different directions from one or more acoustic transmission elements to one or more separate acoustic reception elements;
measuring the value of the transit time of each of said beams through the body; and
utilizing the measured transit time values to calculate the value of the acoustic refractive index at points in a matrix associated with the body;
the improvement comprising the steps of;first assuming a distribution of acoustic refractive index values at preselected points in the matrix, which approximate known body structure, said assumed distribution taking into account the geometry of the transmission and reception elements; using said assumed distribution to calculate the path of each of said beams throught the body; calculating an assumed transit time for each beam along the determined paths; and then comparing the assumed transit time with the measured value of the transit time to generate step-wise corrections for the calculated value of the acoustic refractive index at points in the matrix. - View Dependent Claims (2, 3, 4, 5)
-
-
6. In a device for determining the internal structure of a body of the type comprising:
- an acoustic converter disposed around the body which includes separate acoustic transmission elements and acoustic reception elements;
means for selectively activating the transmission and reception elements for the transmission and reception, respectively, of acoustic beams;
means for measuring the value of the transit time of the acoustic beams between the transmission elements and the reception elements; and
means for calculating the acoustic refractive index at points in a matrix which is associated with the body from the measure values of the transit time;
the improvement comprising;means for determining the paths of the acoustic beams through the body on the basis of an assumed distribution of the values of the acoustic refractive index in the body and for determining theoretical transit time values for acoustic beams following those determined paths; and means for comparing the measured transit time values with the theoretical transit time values and for correcting the calculated values of the acoustic refractive index at points in the matrix on the basis of the results of the comparison. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
- an acoustic converter disposed around the body which includes separate acoustic transmission elements and acoustic reception elements;
Specification