Determination of a palatal lift prosthesis to decrease levator muscle fatigue.

目的：为了阐明语音矫治器制作过程中的关键因素，以减少肌肉疲劳，防止说话者连续发言。方法和对象：1998年，构建了可变比例的腭部假体语音矫治器。当每种实验语音器具被取出并插入时，记录下在语音任务中的腭帆提肌的肌电图。在1998年的研究中，选择了5名正常说话者作为研究对象。1999年：每个受试者在插入和取出各自的语音器具时被指示进行200次/PU/的制作。在每种实验条件下，记录提升肌肌电。在快速傅立叶变换的基础上计算平均功率频率，以检验1)S语音矫治器是否可以减少肌肉疲劳，2)哪种类型的腭部假体可以最有效地减少肌肉疲劳。Res…结果：1)腭咽闭合功能语音储备容量的变化大于矫治器宽度的变化。语音储备容量定义为语音任务中提肌活动与可能的最大活动之间的差异活动。也就是说，当膜被提升到腭面的水平时，储备能力可能会变得比任何其他垂直位置都大。2)对于正常说话者，在200次连续产生/PU/的过程中，语音矫治器减轻提肌疲劳的效果在放置和移除条件下没有差别。另一方面，对于伴有腭咽闭合不全的腭裂说话者，与位置相关的语音储备能力表现出更大的增加的受试者，肌肉疲劳表现出更大的减少。结论：可将舌膜提升至腭面水平的假体可以最有效地减轻肌肉疲劳，从而使说话者能够在不降低腭咽闭合功能的情况下进行连续的语音产生。这种影响在扬声器中可能更为显著，对于扬声器来说，随着矫治器的放置，所需的提肌活动明显减少。较少

Purpose : This research was conducted to clarify crucial factors in construction procedure of a speech appliance to decrease muscle fatigue, which prevent speakers from performing continuous speech.Methods and Subjects : 1998 : Experimental speech appliances with variable portion of a palatal lift prosthesis were constructed. Electromyography of the levator veli palatini muscle during speech tasks was recorded when each type of experimental speech appliances was removed and inserted. Five normal speakers were selected as subject in the study of 1998. 1999 : Each subjects was instructed to perform 200 productions of/pu/when respective speech appliances were inserted and removed. In each experimental condition, levator EMG was recorded. Mean power frequency (MPF) were calculated on the basis of Fast Fourier Transfer (FFT) so as to examine 1) whether s speech appliance can decrease the muscle fatigue, 2) what type of a portion of a palatal lift prosthesis can decrease most effectively.Res … More ults : 1) Change in reserve capacity for velopharyngeal function for speech, which is defined as differential activity between levator activity during speech tasks and possible maximum activity, was greater in association with alteration of length and angle of a velum portion of an experimental palatal lift prosthesis than the condition of alteration of width of the appliances. That is, when the velum is elevated up to the level of the palatal plane, reserve capacity could become greater than any other vertical positions. 2) For normal speakers, the effect of a speech appliance to decrease levator muscle fatigue during 200 continuous productions of/pu/was not different between placement and removal conditions. On the other hand, in case of speakers with cleft palate with velopharyngeal incompetence, subjects, who showed greater increase in reserve capacity for speech in association with placement, exhibited greater decrease in muscle fatigue. Conclusion : The results obtained here can suggest that a palatal lift prosthesis which can elevate the velum up to the level of the palatal plane could decrease muscle fatigue most effectively, which might enable speakers to perform continuous speech production without collapse in velopharyngeal function. The effect might be more remarkable in speakers, for whom decrease in required levator muscle activity is marked in association with placement of the appliance. Less