270
3 Holographic Interferometry for Studying …
study of artificial cardiac valve deformation during its creation, the investigation of
the middle ear membrane during transmission of sounds using holography with time
averaging and successful implementation of double-pulse holographic interferometers in dentistry, possibilities of the “dark reconstruction” method for the study of
tremor, breathing, etc.
In particular, the work [218] concerns the development of a non-destructive
noncontact highly sensitive method using holographic interferometry. The valve is
placed in the test cell with holes for visual observation. Cusp deformations under
pressure are recorded with the holographic interferometry. The finite interferogram
gives the possibility to establish some defects or structural abnormalities, which can
also present in the material, of which the valve is made. Meanwhile, in the work [218],
three types of changes are described, which can be determined with screening-tests.
The suggested method is expected to become an effective means of detecting
hidden defects of heart valves for replacement. It has already been considered as a
promising means of quality control, especially while producing artificial heart valves
that will help to detect first signs of calcinosis. Thus, the application of holographic
test without destroying the sample can significantly improve the quality and lifetime
of artificial heart valves.
In the works [216, 219], oscillations of the ear tympanic membrane were investigated with holographic interferometry that gave the possibility to determine pathologies in this area. It is difficult to study, for example, inner part of the ear cavity using
this method. But, it is possible to determine behavior of the membrane in its depth
where the pathology can be localized. Ultrasonic holography can be used to study
inner organs, parts which are situated behind the nontransparent membrane.
During the experiments [220], a new method of estimation of holographic interferograms with circular shift was developed and tested. The dispersed phase distribution
index was calculated, and brightness modulation of interference fringes was determined. Besides the framing, mask was produced during analyses of histograms and
determination of the local minimum of brightness modulation distribution a binary.
The mask is used for valid and non-valid dispersed phase distribution areas during
further phase unwrapping and interpolation as well as its path. Estimation of the
obtained holographic interferograms with circular shift shows that this method can
be successfully applied for processing of a complex interference pattern even if there
are heterogeneous interference fringes and dark areas.
The article [221] shows that to measure deformations in medical and technical
spheres with highly sensitive methods of holographic interferometry the methods of
research of real-time dynamic processes, for example, during analyses of the environmental impact on biological and other objects, are of special interest. Unfortunately,
most traditional materials used for holographic interferometry measurements have a
number of disadvantages: long processing time (halogenide-silver materials) or bad
resolution of lines. An important problem emerges in the case of implementation
of real-time classical inteferometry: After processing of the object, its position and
surface should not be changed in the boundaries of the interferometry series. This
requirement is rather difficult to meet especially with biological objects or in real
3 Holographic Interferometry for Studying …
study of artificial cardiac valve deformation during its creation, the investigation of
the middle ear membrane during transmission of sounds using holography with time
averaging and successful implementation of double-pulse holographic interferometers in dentistry, possibilities of the “dark reconstruction” method for the study of
tremor, breathing, etc.
In particular, the work [218] concerns the development of a non-destructive
noncontact highly sensitive method using holographic interferometry. The valve is
placed in the test cell with holes for visual observation. Cusp deformations under
pressure are recorded with the holographic interferometry. The finite interferogram
gives the possibility to establish some defects or structural abnormalities, which can
also present in the material, of which the valve is made. Meanwhile, in the work [218],
three types of changes are described, which can be determined with screening-tests.
The suggested method is expected to become an effective means of detecting
hidden defects of heart valves for replacement. It has already been considered as a
promising means of quality control, especially while producing artificial heart valves
that will help to detect first signs of calcinosis. Thus, the application of holographic
test without destroying the sample can significantly improve the quality and lifetime
of artificial heart valves.
In the works [216, 219], oscillations of the ear tympanic membrane were investigated with holographic interferometry that gave the possibility to determine pathologies in this area. It is difficult to study, for example, inner part of the ear cavity using
this method. But, it is possible to determine behavior of the membrane in its depth
where the pathology can be localized. Ultrasonic holography can be used to study
inner organs, parts which are situated behind the nontransparent membrane.
During the experiments [220], a new method of estimation of holographic interferograms with circular shift was developed and tested. The dispersed phase distribution
index was calculated, and brightness modulation of interference fringes was determined. Besides the framing, mask was produced during analyses of histograms and
determination of the local minimum of brightness modulation distribution a binary.
The mask is used for valid and non-valid dispersed phase distribution areas during
further phase unwrapping and interpolation as well as its path. Estimation of the
obtained holographic interferograms with circular shift shows that this method can
be successfully applied for processing of a complex interference pattern even if there
are heterogeneous interference fringes and dark areas.
The article [221] shows that to measure deformations in medical and technical
spheres with highly sensitive methods of holographic interferometry the methods of
research of real-time dynamic processes, for example, during analyses of the environmental impact on biological and other objects, are of special interest. Unfortunately,
most traditional materials used for holographic interferometry measurements have a
number of disadvantages: long processing time (halogenide-silver materials) or bad
resolution of lines. An important problem emerges in the case of implementation
of real-time classical inteferometry: After processing of the object, its position and
surface should not be changed in the boundaries of the interferometry series. This
requirement is rather difficult to meet especially with biological objects or in real