Abstract
Objectives
The endoscope for inspection of body cavities has improved the accuracy of diagnosis. However, the magnification changes as the distance between the scope and object is varied. Changes in magnification make it impossible to measure surface distances for staging of lesion or to determine the displacement of structures. The objective of this invention is to develop a new device that provides a simple and noninvasive method of measuring accurate lesion size through an endoscope.
Methods
The invention incorporates a built-in laser diode that projects auto-parallel beams into the optical path of the rigid laryngoscope to form 2 spots in the field of view.
Results
The interspot distance is constant despite changes in focal plane, magnification, or viewing angle of laryngoscope. The interspot distance of being projected to even surface is constantly 4 mm.
Conclusions
This device enables the laryngologist to easily measure the distance between landmarks, or the size of vocal fold lesions in the outpatient setting.
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