Video Stroboscopy

Videostro­boscopy ful­fills sev­er­al impor­tant require­ments of a com­plete voice exam­i­na­tion. It pro­vides use­ful, real-time infor­ma­tion con­cern­ing the nature of vibra­tion, an image to detect vocal pathol­o­gy, and a per­ma­nent video record of the exam­i­na­tion. As impor­tant as any of these aspects, stro­boscopy sub­stan­tial­ly improves the sen­si­tiv­i­ty of sub­tle laryn­geal diag­noses over tech­niques, such as rigid or flex­i­ble transnasal laryn­goscopy, with con­tin­u­ous light sources.

A videostrobe unit con­sists of a stro­bo­scop­ic unit (light source and micro­phone), a video cam­era, an endo­scope, and a video recorder. Stro­boscopy can be per­formed by using either rigid or flex­i­ble endo­scopes; each has its own ben­e­fits and drawbacks.

Although flex­i­ble endoscopy is ide­al for observ­ing unal­tered laryn­geal behav­ior from var­i­ous angles and for view­ing the glot­tis through a nar­row supra­glot­tic aper­ture, it suf­fers from the low inte­si­ty of light car­ried through the long fiberop­tic bun­dle to the tip of the nar­row endo­scope. With stan­dard endo­scopes, the light bounc­ing off objects being observed must then trav­el the length of the endo­scope back to a cam­era or the oper­a­tor’s eye to be detect­ed. Rigid tran­so­ral endoscopy pro­duces a mag­ni­fied bright image ide­al for stro­boscopy but requires hold­ing of the patien­t’s tongue through­out the exam­i­na­tion, which dis­torts the nat­ur­al phona­to­ry pos­ture of the phar­ynx and lar­ynx. More­over, the patient must have suit­able anato­my and the phys­i­cal tol­er­ance to allow the clin­i­cian to visu­al­ize the entire glottis.