Ophthalmoscope densitometer.

A densitometer for quantitative autoradiography.

A low cost spot densitometer system is described. This system is useful for quantitative autoradiography of local cerebral glucose utilization, blood flow, receptor binding and other applications requiring densitometry on films. The densitometer can be used alone or interfaced to a microcomputer. The densitometer consists of a photographic enlarger, a digital multimeter, and the densitometer el...

The Ophthalmoscope

Miniature binocular indirect ophthalmoscope.

The optical principles of indirect ophthalmoscopy were mastered by Gullstrand (I 9 I I) although his ophthalmoscope did not achieve wide popularity because of its complexity and limited field of view. Schepens (I947) demonstrated his binocular indirect ophthalmoscope 2I years ago in the United States of America. The instrument described here is a further stage in simplification (Figs I and 2). ...

A Photoelectric Densitometer for Use with Suspensions

A device for quickly and accurately measuring the population density of a suspension of microorganisms, permitting the preparation of yeast suspensions of known density to within 1 per cent error, was constructed with two Visitron photoelectric cells, a single light of high intensity and a good Wheatstone bridge for balancing the currents from the two photoelectric cells. A large Pyrex milk cul...

Simplified Indirect Ophthalmoscope.

INDIRECT ophthalmoscopy is one of the most important methods of fundus examination, especially in cases of detachment of the retina. The advantages of this method over direct ophthalmoscopy include a larger field of view, a more brilliant image, and a greater depth of focus. It is especially valuable for the examination of the highly myopic eye. The stereoscopic view obtained with the binocular...