Abstract
For surgical precedures of stroboscopic microsurgery of the larynx, a monitoring system with acoustic analysis of patient's voice obtained during the operation has been developed.
In this system, coefficient of variation of the fundamental frequency (Fcv) of the voice for periodicity and the ratio of averaged difference of amplitude and effective in-put level are obtained. The result is displayed on a monitor display and also printed out by digital printer.
The results of normal cases of 6 males and 6 females are as follows;
1) In male group, Fcv of /a/ is 0.73% and that of /e/ is 0.72%
2) In female group, both Fcv of /a/ and /e/ are 1.00%.
3) Larger score is obtained in female group than in male group while no difference between /a/ and /e/ is obtained.
4) In male group, Vsus of /a/ is 21.15% while that of /e/ is 17.47%.
5) In female group, VSUB of /a/ is 16.48% while that of /e/ is 12.52%. 6) Smaller score in female group and also in /e/ is shown than in male group and in /a/.
Pre-and post-operative phonatory examinations as sustained vowels in 40 clinical cases with various laryngeal lesions were performed. In addition, voices obtained through a direct laryngoscope were acoustically analyzed pre-and post-operatively while vibratory patterns were simultaneously observed by use of a laryngostroboscope.
The results are as follows;
1) The score of Fcv of voices through a direct laryngoscope is larger than that of voiced vowels.
2) In regard to estimation of phonatory funtion of the larynx, there is no significant difference between an acoustical analysis by this system and a stroboscopic observation of vibratory patterns.
3) It is revealed that there is significant relationship between phonarory functions immediately after the operation and that of long thrm after the operation.
In addition, for 15 clinical cases, this system has been employed as a monitoring system for functional microsurgery of the larynx.
We would say that for this system it is very important to perform anesthetic procedures and extension of the larynx resorablly in order to obtain good voices abaiable for acoustic analysis.
It seems most likely that the operation may be accomplished when the score of Fcv reaches under the level of 1.7% and Vsus is under 30% while the stroboscopic vibratory pattern is normally restored.
By use of this system, prevision of the result of the operation can be obtained.
