Guan Xiying, Seale Thomas W, Gan Rong Z
School of Aerospace and Mechanical Engineering and Biomedical Engineering Center, University of Oklahoma, Norman, OK, USA.
School of Aerospace and Mechanical Engineering and Biomedical Engineering Center, University of Oklahoma, Norman, OK, USA.
Hear Res. 2017 Jul;350:22-31. doi: 10.1016/j.heares.2017.04.003. Epub 2017 Apr 10.
Acute otitis media (AOM) is a rapid-onset infection of the middle ear which results in middle ear pressure (MEP), middle ear effusion (MEE), and structural changes in middle ear tissues. Previous studies from our laboratory have identified that MEP, MEE, and middle ear structural changes are three factors affecting tympanic membrane (TM) mobility and hearing levels (Guan et al., 2014, 2013). Sound energy reflectance or absorbance (EA) is a diagnostic tool increasingly used in clinical settings for the identification of middle ear diseases. However, it is unclear whether EA can differentiate these three factors in an AOM ear. Here we report wideband EA measurements in the AOM model of chinchilla at three experimental stages: unopened, pressure released, and effusion removed. These correspond to the combined and individual effects of the three factors on sound energy transmission. AOM was produced by transbullar injection of Haemophilus influenzae in two treatment groups: 4 days (4D) and 8 days (8D) post inoculation. These time points represent the relatively early and later phase of AOM. In each group of chinchillas, EA at 250-8000 Hz was measured using a wideband tympanometer at three experimental stages. Results show that the effects of MEP, MEE, and tissue structural changes over the frequency range varied with the disease time course. MEP was the primary contributor to reduction of EA in 4D AOM ears and had a smaller effect in 8D ears. MEE reduced the EA at 6-8 kHz in 4D ears and 2-8 kHz in 8D ears and was responsible for the EA peak in both 4D and 8D ears. The residual EA loss due to structural changes was observed over the frequency range in 8D ears and only at high frequencies in 4D ears. The EA measurements were also compared with the published TM mobility loss in chinchilla AOM ears.
急性中耳炎（AOM）是中耳的一种快速发作的感染，会导致中耳压力（MEP）、中耳积液（MEE）以及中耳组织的结构变化。我们实验室之前的研究已经确定，MEP、MEE和中耳结构变化是影响鼓膜（TM）活动度和听力水平的三个因素（关等人，2014年，2013年）。声能反射率或吸收率（EA）是临床环境中越来越多地用于识别中耳疾病的一种诊断工具。然而，尚不清楚EA能否区分AOM耳中的这三个因素。在此，我们报告了在三个实验阶段对龙猫AOM模型进行的宽带EA测量：未开放、压力释放和积液清除。这些分别对应于这三个因素对声能传输的综合和单独影响。通过经鼓膜注射流感嗜血杆菌在两个治疗组中诱发AOM：接种后4天（4D）和8天（8D）。这些时间点代表AOM的相对早期和后期阶段。在每组龙猫中，在三个实验阶段使用宽带鼓室计测量250 - 8000Hz的EA。结果表明，在整个频率范围内，MEP、MEE和组织结构变化的影响随疾病病程而变化。MEP是4D AOM耳中EA降低的主要因素，而在8D耳中的影响较小。MEE在4D耳中降低了6 - 8kHz的EA，在8D耳中降低了2 - 8kHz的EA，并且是4D和8D耳中EA峰值的原因。在8D耳的整个频率范围内以及4D耳仅在高频处观察到由于结构变化导致的残余EA损失。还将EA测量结果与已发表的龙猫AOM耳中的TM活动度损失进行了比较。
