Clin Exp Otorhinolaryngol.  2011 Dec;4(4):199-203.

Development of Laser Ruler in Rigid Laryngoscope

• Lee YO
• Kim BC
• Lee JH
• Lee JC
• Lee BJ
• Wang SG
• Ro JH
• Jeon GR
• Shin BJ

Abstract

OBJECTIVES
The objective of this study was to develop a new device that provides a simple, noninvasive method of measuring accurate lesion size while using an endoscope.
METHODS
We developed a rigid laryngoscope with a built-in laser-ruler using a one-light emitting diode and an acrylic plate. The invention incorporates a built-in laser diode that projects an auto-parallel beam into the optical path of the rigid laryngoscope to form two spots in the field of view.
RESULTS
While the interspot distance remains consistent despite changes in focal plane, magnification, or viewing angle of the laryngoscope, projection to an uneven surface introduces certain variations in the shape, and size of the spots, and the distance between the two spots.
CONCLUSION
The device enables a laryngologist to easily measure the distance between landmarks, as well as the change in real size, and the progressive change of vocal fold lesions in an outpatient setting.

Keyword

Laser; Ruler; Laryngoscope

MeSH Terms

Enzyme Multiplied Immunoassay Technique
Humans
Inventions
Laryngoscopes
Outpatients
Vocal Cords
Natural Resources

Figure

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  Fig. 1 Rigid videolaryngoscope. This device is consisted of the guiding part and the grip.

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  Fig. 2 A schematic image of the laser ruler on the tip of rigid digital videolaryngoscope. This shows the distal end of an endoscope built-in laser ruler. The distal end of this device is composed of ① crystal glass, ② light-emitting diode (LED), ③ charge-coupled device (CCD) camera system, ④ acryl plate, ⑤ body, ⑥ laser diode.

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  Fig. 3 A schematic drawing of automatic parallel beam.

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  Fig. 4 The dual laser spots on the even surface and uneven surface. (A) shows that the interspot distance of being projected to even surface is consistently 4.5 mm. (B) shows that two spots of being projected to uneven surface is various in shape and size, and that interspot distance is not constant.

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  Fig. 5 Printed image of the dual laser spots projecting onto the vocal fold of normal larynx using author's rigid digital videolaryngoscope built-in laser ruler. The inter-spot distance was exactly 4.5 mm.

Reference

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