Biomedical subjects
Publications and source records attributed to G W van Marle.
A disadvantage of commercially available averagers is the time needed for the output routine. This paper describes a microcomputer, programmed as an averager, with additional features to obtain an examination time as short as possible, which indeed is important for clinical application. Through this apparatus, the time needed for a standard ERG and VECP examination could be reduced from 50 to 25 min.
The use of television systems to generate patterned stimuli for the examination of EPs has disadvantages due to the frame frequency of 50Hz of television sets. Because of this, changes in the pattern last 20 msec, with the result that the variability in EP latencies is larger than in the results obtained by projector systems. Furthermore, 50 Hz noise on the recordings, transmitter through the visual system, may be seen.
Application of TV systems for generating patterned stimuli for the examination of the electrical cortical potentials has disadvantages caused by the frame frequency of 50 Hz of TV sets. Apart from a larger variability in latency times of the electrical potentials as compared to the results obtained by projector systems, a 50-Hz noise on the recordings mediated through the visual system may be seen. These disadvantages can be ameliorated by increasing the frame frequency of the TV set.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.