Biomedical subjects

M S Obaidat

Publications and source records attributed to M S Obaidat.

3 recordsLinked to original sources

PubMed1990

Architecture and design of a computerised stereogram generator for vision test.

A new microcomputer-based stereogram generator was designed and implemented to generate various visual stimuli that are used for testing the binocular vision system. The system is capable of generating static and dynamic stereoscopic stereograms that can be varied in size, shape, speed and disparity. It can also be used to generate a luminous stimulus on a dark background which, except for the depth parameters, can be varied in a similar way to the stereoscopic stimulus. A 16/32-bit microprocessor has been employed for the overall control of the stereogram parameters, which provides flexibility, versatility, compactness and speed at reduced cost. We have applied this system to the measurement of eye movement and computer vision.

Diagnosis, Computer-Assisted↗

PubMedDate not supplied

A real-time video pattern generator for use in ophthalmology.

An automated real-time microcomputer-based video pattern generator for use in optometry and ophthalmology is presented. The system can generate various vision pattern tests including a static and dynamic random dot stereogram that can be used to test depth perception. The patterns are generated in real time, which provides the ability to generate programmable images with objects that can move at different speeds. This feature is very useful in testing depth perception among infants and non-communicative people by correlating the movement of the eye with the movement of the object. The system also can generate other patterns such as checkerboards, vertical and horizontal bars, and provide the ability to sweep the size of the checkers and bars. These patterns are also useful for testing visual acuity. The system hardware is based on the TMS34010 graphics processor and hardware circuits and is connected to a host computer through a RS-232C serial communication port. Both control and application programs are written in assembly language. The system is fast, versatile and flexible with affordable cost.

Computer Graphics↗

PubMedDate not supplied

Phonocardiogram signal analysis: techniques and performance comparison.

This paper presents the applications of the spectrogram, Wigner distribution and wavelet transform analysis methods to the phonocardiogram (PCG) signals. A comparison between these three methods has shown the resolution differences between them. It is found that the spectrogram short-time Fourier transform (STFT), cannot detect the four components of the first sound of the PCG signal. Also, the two components of the second sound are inaccurately detected. The Wigner distribution can provide time-frequency characteristics of the PCG signal, but with insufficient diagnostic information: the four components of the first sound, S1, are not accurately detected and the two components of the second sound, S2, seem to be one component. It is found that the wavelet transform is capable of detecting the two components, the aortic valve component A2 and pulmonary valve component P2, of the second sound S2 of a normal PCG signal. These components are not detectable using the spectrogram or the Wigner distribution. However, the standard Fourier transform can display these two components in frequency but not the time delay between them. Furthermore, the wavelet transform provides more features and characteristics of the PCG signals that will help physicians to obtain qualitative and quantitative measurements of the time-frequency characteristics.

Aortic Valve↗