摘要:
The invention relates to a method for determining the structural organization of a target object comprising the steps of: - transmitting a signal; - receiving reflection and/or transmission and/or diffraction and/or matter excitation signal or signals generated by structures and/or interfaces of the object in response to said signal, - extracting a phase signal of such response signal or signals; - determining discontinuities in such phase signal, such discontinuities being related to the spatial distribution of such structures and/or interfaces of the object. Also a corresponding device is disclosed.
摘要:
The method decomposes the radio frequency signal into sub-bands by filtering, for example with a time-frequency transform. From the coefficients acquired through decomposition a matrix of spectral coefficients is obtained, from which local estimators are obtained, constituted in particular by the coefficients of the interpolating polynomials. The statistical distribution of the local estimators is evaluated in windows overlaid on the ultrasound frame. The conformation of the distribution histograms of the spectral coefficients provides a parameter which, combined with the local estimators, provides weighted local estimators, which contain spectral information useful in the identification of specific structures in the organ subjected to ultrasound analysis.
摘要:
A description is given of a method of spectral analysis of a radio frequency ultrasonic signal reflected by a structure subjected to echographic examination, comprising the steps of: a) transmitting an ultrasonic excitation signal into a portion of said structure under examination; b) receiving a radio frequency response signal from said structure; c) applying a time-frequency transform to said radio frequency response signal, dividing the radio frequency response signal into a plurality of frequency bands; d) calculating a local spectral parameter from the values of the time-frequency transform.
摘要:
A method is described, for detecting the presence of a foreign first material (N) randomly applied on an object (BA) under examination formed by a second material, wherein the foreign first material (N) is transparent or semi-transparent and the second material is absorbent and/or scattering at at least one wavelength of an optical radiation. The method provides for lighting a first area (Zl) of the object (BA) by means of at least one optical source (1). The method also provides for framing a second area (Z2) of the object (BA) by means of an optical receiver (3). The optical receiver (3) and the optical source (1) are designed and arranged so that the first area (Zl), lighted by the optical source (1), is different from the second area (Z2) framed by the optical receiver (3). The presence of the foreign first material (N) on a surface of the object (BA) is detected through a change in the optical signal on the optical receiver (3) due to optical radiation emitted by the optical source (1) and conveyed through the foreign first material (N) from the first area (Zl) up until the second area (Z2).
摘要:
The invention relates to a method for determining local characteristics of a target object comprising the following steps: - transmitting a signal into said object; - receiving reflection and/or transmission and/or scattering and/or diffraction and/or matter excitation signal or signals generated by the object in response to said signal; - extracting the phase or a parameter correlated to the phase of such response signal or signals; - applying one or more mathematical operators to such phase or parameter to determine one or more local parameters; - identifying area or areas of the object having common propagation properties from one or more of such local parameters; - determining direct or indirect local quantitative information on the physical properties of the target from at least one of said local parameters or a combination thereof as a function of the type of propagation identified in such area or areas. Also a corresponding device is disclosed.
摘要:
A description is given of a method of spectral analysis of a radio frequency ultrasonic signal reflected by a structure subjected to echographic examination, comprising the steps of: a) transmitting an ultrasonic excitation signal into a portion of said structure under examination; b) receiving a radio frequency response signal from said structure; c) applying a time-frequency transform to said radio frequency response signal, dividing the radio frequency response signal into a plurality of frequency bands; d) calculating a local spectral parameter from the values of the time-frequency transform.