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At least 19 recordsLinked to original sources
PubMed1975

Acoustical holography: physical parameters and potential clinical applications.

Acoustical holography achieves real-time imaging of bodily structures through ultrasound. The fundamentals of acoustical holography and a description of a prototype unit undergoing trials at the authors' institution are presented. Physical parameters and means of calibrating the acoustic beam are discussed, and results of preliminary experimental and clinical studies reviewed. Acoustical holography has the potential for providing complementary diagnostic information which, after further technical developments, may furnish clinically useful information.

Accident Prevention↗
PubMed1977

Holography in dentistry.

Holograms were made that recorded on a single piece of film an entire study case in three dimensions. Other applications of holography in dentistry are discussed. On a qualitative basis, it appears that holography has potential application in many fields of dentistry. However, a number of problems must be resolved before holography will find its way into the dental practice.

Dentistry↗
PubMed1977

Optical and long wave holography: potential applications in ophthalmology.

The first part of this paper describes the process of optical holography, and discusses the possibilities and some of the merits of the application of optical holographic techniques in the field of ophthalmology, such as: 1. Holographic observation of the eye and the light-path through the cornea and the lens, leading to the evaluation of the optical constants of the eye. 2. Holographic interferometric measurements of the configuration changes which accompany accommodation or changes in the intra-ocular pressure. 3. Three-dimensional observations of the fundus. The second part of the paper is devoted to long wave holography, which has attained special attention in electromagnetic (non-optic) and ultrasonic wave propagation. Although these two forms of wave propagation differ in their physical properties, there are many similarities in their signal processing techniques, the collection of wave fronts emerging from the object, and in the visualization of images.

Electromagnetic Phenomena↗
PubMed1992

Observation of surfaces by reflection electron holography.

Reflection electron holography is described as a method to observe sub-A surface morphology. Phase shift of a Bragg-reflected electron wave was measured by means of holographic interferometry using an electron microscope equipped with a field emission electron gun and an electron biprism. A short wavelength of high energy electrons is the essential key to the high vertical sensitivity of this method, since geometrical path differences produced by the surface topography are measured in units of wavelengths in interferometrical measuring. Phase shift at a monoatomic step and the displacement field around a dislocation emerging on the surface were observed.

Electrons↗
PubMed1986

Initial displacements and variations of eight human child skulls owing to high-pull headgear traction determined with laser holography.

In this study eight macerated, human child skulls (dental age approximately 9.5 years) were subjected to a standardized high-pull headgear traction system. Tensile forces from 0.5 to 3.5 N (1 N = 0.1 kgf) per side were produced to the maxillae. Displacements of skeletal components were determined at 22 indicator points per skull by means of laser holography. Coordinated displacements and variations in amount and direction were established in all skulls. The overall amount of displacements was primarily a characteristic of an individual skull, not of a particular displacement. On the average, the maxillae were displaced in a slightly downward and posterior direction almost parallel to the occlusal plane. No deformations of skeletal components were seen. Results indicated that initial displacements of the maxillae and other skeletal components are not in the same direction as the direction of applied forces.

Cephalometry↗
PubMed1991

Implementation of double-pulsed holography in evaluation of whole-body vibration.

This study used a unique holographic technique to evaluate the effects of vibration on soft tissues and bones. It was possible to record forced whole-body vibration in humans by holograph interferometry using a double-pulsed ruby laser. The study investigated the manner in which the muscles of the back and vertebral column are affected by vibrations applied to the human buttocks in the sitting position. The subject was exposed to vibration at two frequencies: 40 and 60 Hz (vertical Z axis). Transmission of the vibrations along the subject's back was recorded by means of double-pulsed holography and electromyography. Evaluation of the vibration pattern showed that the vibrations are transmitted along the back all the way up to the neck and head. The pattern of vibration in the muscles of the back and vertebral column showed that the greatest effect was exerted on the lumbar region of the back and the area of transition between the thoracic and cervical regions.

Adult↗
PubMed1975

Ultrasonic transmission holography of the eye.

Ocular ultrasonic transmission holography of the eye using equipment capable of real-time imaging has not previously been described. A method using pulsed ultrasound focused on an air/liquid interface is used to demonstate normal ocular structures including lens, optic nerve, and sclera. Intraocular foreign bodies imaged include radiopaque and nonradiopaque materials. A limit of resolution of at lease 1 mm. is demonstrated.

Eye Foreign Bodies↗
PubMedDate not supplied

[Some problems in the use of holography in medical-biological studies].

Various fields of the holographic methods application in medico-biological investigations are discussed. Special consideration is given to the methods of holographic interferometry, holographic microscopy, ultrasonic holography and to the technique of optic filtration of images. The paper sets forth brief characteristics of diverse holographic methods, technical possibilities of each one of them and a review of some practical work done in this field.

Holography↗
PubMed1976

[Holography and the possibility of its use in applied anatomy].

The article deals with some methods of holography (holograms with inclined reference beam, in three-dimensional media after Yu. N. Denisiuk, holographic interferometry) as applied to studying anatomical objects. Approximate optical schemes and photographic copies of holograms of separate objects are presented. The comparative analysis of different methods enabled the authors to recommened for practical use the method of obtaining holograms in three-dimensional media for documentation of anatomical investigation and storage of information, holographic method of obtaining contour maps of the surface for quantitative characteristics of individual properties of the object and the method of double exposure for studying static and dynamic deformities.

Anatomy↗
PubMed1975

Optical holography in ultrasonography.

Three techniques for producing three-dimensional ultrasonograms have been investigated. Of these, the optical holographic technique appears to have the advantages of simultaneous viewing of all levels and directions. The effects of magnification, gray scale manipulation, and more expeditious means of producing such holograms remain to be investigated.

Breast Neoplasms↗
PubMed1990

Holography in artificial neural networks.

The dense interconnections that characterize neural networks are most readily implemented using optical signal processing. Optoelectronic 'neurons' fabricated from semiconducting materials can be connected by holographic images recorded in photorefractive crystals. Processes such as learning can be demonstrated using holographic optical neural networks.

Algorithms↗
PubMedDate not supplied

Holography of 3D surface reconstructed CT images.

A multiplex hologram (cylindrical holographic stereogram) was successfully made from three-dimensional (3D) surface reconstruction CT images of a child with plagiocephaly. This method appears to be suitable as one of the projectional aids of 3D surface reconstruction CT images that are proving useful in plastic and reconstructive surgery. The principle of the method is described. Also discussed is the possibility of developing a computer-aided hologram synthesizing system that could be used for images obtained with U-arm X-ray equipment (by either cinefilm, or videotape, or digital subtraction angiography) or by CT as well as MR. For practical use, it is necessary for the hologram to be synthesized in a short time. One of the key problems in developing such a machine is the need for an incoherent-to-coherent image converter.

Child↗
PubMed1979

Interferometric laser holography for determination of the localization and extent of bladder tumor.

In male giant rabbits (n = 10) with and without bladder carcinomas, holographic interferometric investigations with a double impulse rubin laser were made for testing the sensitivity of this method in detection of elasticity changes of the bladder wall caused by tumors. It could be shown that the holographic interferometry enables a distinction to be made between healthy and tumorous regions of the bladder wall by the various interference patterns.

Animals↗