Stroboscopic laryngoscopy currently plays an important role in clinical assessment of voice function and diagnosis of throat and voice diseases. It is mainly used to observe the vibration characteristics of the vocal cords during vocalization. It is the only inspection that can see the movement of the mucosal waves of the vocal cords. It can observe the vibration law of the vocal cords, and provide an objective basis for the diagnosis of vocal cord diseases (such as vocal cord cysts, early vocal cord cancer) and the comparison before and after vocal cord surgery. With the advancement of electronic technology, it has been realized that the image of the dynamic laryngoscope can be analyzed by the electronic computer, so that the dynamic laryngoscope examination can eliminate more subjective factors and develop towards quantification. It occupies an important position in the fields of laryngology, pathological phonology, and artistic phonology.
The working principle of strobe laryngoscope:
The vocal cords vibrate rapidly during pronunciation, which can be 80 to 1000 times per second, or even as high as 2000 times, which is indistinguishable by the human eye. In order to observe the vibration of the vocal cords in detail, it is necessary to resort to some method to relatively slow down the rapid vibration. This is the principle of the strobe laryngoscope technology. If a regularly vibrating object is illuminated by a flash of the same frequency, the object will be fixed in the vibration period, producing a still image. If the frequency of the flash is slightly different from the frequency of the vibrating body, that is, every time the phase of the flash on the vibrating body moves backward or forward, a slow moving image is produced, which is caused by the 0.2 second visual residual of the human eye. Optical illusion. Applying this principle to the vibrating vocal cords makes the rapidly vibrating vocal cords appear to be stationary or greatly slowed down. This technique allows us to see complex images of vocal cord vibrations.
Stroboscopic laryngoscopy method:
The inspection method of the strobe laryngoscope is basically the same as that of the straight tube magnifying laryngoscope. The difference is that the light source is an intermittent flash light source, that is, the straight tube magnifying laryngoscope and the cold light source of the flash laryngoscope are connected through an optical fiber. The endoscope camera system can record the real vibration state of the vocal cords at the eyepiece end of the straight tube magnifying laryngoscope, and then replay the video to observe the vibration of the vocal cords and the condition of the laryngeal lesions in detail. According to clinical needs, check the dynamic phase, the static phase and the phase from 0 to 360 degrees, and the vibration form of the vocal cords when the real sound, false sound, low pitch, high pitch, weak pitch, and strong pitch are produced, and video recording is performed as needed.
The significance of strobolaryngoscopy:
1. Diagnosis of subtle lesions By observing the mucosal waves, it is helpful to find lesions that are difficult to find under ordinary light sources, such as vocal cord grooves, tiny cysts in the vocal cords, and vocal cord scars.
2. Identify the extent of the lesion. For lesions on or below the free edge of the vocal cords, such as wide base polyps, vocal cord prismatic bulge, etc., the width of the base of the lesion can be understood by observing the mucosal waves, and the scope of surgical resection can be guided.
3. In terms of noise surgery, according to the vibration of the vocal cords and mucosal waves, it can identify similar morphological hyperplastic lesions or find the changes in the subtle structure of the vocal cords to determine the surgical method.
4. Dynamic observation of the progress of the lesion. Superficial vocal cord lesions only affect the mucosal wave. When the lesion develops to the deep layer, it affects both mucosal waves and vocal cord vibration.
Strobe laryngoscope and its video equipment have become an indispensable instrument for checking laryngeal function. It can display vocal cord vibrations and mucosal fluctuations that cannot be observed by other laryngoscopes on the fluorescent screen, and can be recorded and saved for permanent preservation, for the diagnosis and differential diagnosis of laryngeal diseases (including early laryngeal cancer), to determine the effect of surgery, and the disease Provide basis for consultation, follow-up, teaching, and scientific research.