多面的観察による声帯振動の基礎的研究

抄録

The vibratory pattern of the vocal fold was observed and analysed using excised canine larynges. X-ray stroboscopy and ultra-high speed cinematography were utilized to clarify the three dimensional movements of the vocal fold vibration. As contrasting media, three lead pellets were inserted into the epithelium of the so-called free edge of the vocal fold with same distance. Their movements during vocal fold vibration were observed and recorded with an X-ray stroboscope and ultra-high speed camera from three dimensional aspects.
The experiments were mainly carried out on normal larynges. In addition, some pathological conditions were artificially produced on the vocal folds used for the same experiment. A small piece of muscle was attached to the vocal fold simulating a vocal polyp. And small amount of glue was injected into the fold to make it stiff.
The trajectory of each point was found almost circular only in frontal plane. On the other hand, their movements were observed to be almost linear in superior and lateral planes.
From these observations, the three-dimensional movement of the vocal fold was considered to be spindle-shaped along the longitudinal line of the folds.
A small mass loaded vocal fold showed almost normal vibratory pattern with larger amount of air flow. However, in stiffened folds only small wave motion was observed. Moreover, if inferior surface of the fold became stiffened, the vibratory pattern was obviously affected. This fact suggests that phonosurgical procedure on the inferior surface of the fold must be carefully carried out as much as possible to avoid undesirable injury on this area.