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Biomedical subjects

N Rohde

Publications and source records attributed to N Rohde.

11 recordsLinked to original sources
PubMed1976

EOG: light test and dark test.

The EOG test is divided into two parts: a light and a dark test. The adaptation period is extended to 30 min. During this adaptation period the luminance in the cabin decreases (or increases) slowly to the starting value of the light or dark step. In a model, we studied the influence of this ramplike luminance course on the results. Standard values for the test were calculated with 30 test persons. Our test results show a lower relative standard deviation (V = 10%) compared with earlier published results.

Adaptation, Ocular↗
PubMed1976

ERG of humans without C-wave.

Three out of 18 healthy persons investigated with the DC-ERG do not show a c-wave. By varying the adaptation levels and intensities of the stimuli four components in the human ERG can be isolated, the cone and rod late receptor potentials, the positive DC response, and a c-wave in most subjects. It is suggested that investigation of these components reveals a more detailed understanding of the pathophysiologic mechanisms in some retinal diseases.

Action Potentials↗
PubMed1976

Experiments concerning the human C-wave.

The dependence of the human c-wave from the step amplitude was studied qualitatively. The maximum of the c-wave is achieved with light stimuli longer than 10 sec. After a dark period of 10 sec a fully developed c-wave appears. Also, in response to a brilliant photoflash a c-wave could be recorded. The influence of a mobile pupil on the response in the DC-ERG is demonstrated. Responses of the retinal potential to square wave and sinusoidal stimuli of different period times have been registered.

Action Potentials↗
PubMed1976

A method for DC-ERG recording of alert humans.

We developed a technique for DC-coupled ERG recording of the alert human. The equipment consists of three units: a new cornea suction glass, a separate electrode, and a vacuum control device. We get stable recordings of more than one-half hour. By comparison with the EOG the identity of the EOG "on"-peak and ERG c-wave is assured. A fine structure of DC-ERG recording of 100 muV amplitude is closely correlated to the variation of the blood pressure in the ophthalmic artery. It may either be caused by the variable electric conductivity of the eyeball due to the blood pressure or it may reflect a variation of the retinal potential itself.

Attention↗