Development of the support system od dysphagic patients using automatic analyzing system of dysphagia

本研究旨在建立吞咽困难的客观诊断系统，利用从颈部检测到的吞咽和呼气声音的声学分析技术。研制了一种新型有源噪声控制器检测仪。并结合视频透视数据，研制了吞咽呼气声信号采集系统。声学信号分析系统包括250赫兹、500赫兹、1/3倍频程和1倍频程分析，以及声学信号输入电平的自动分析系统和调制传递功能。当患者吞咽5mlBaS(180%w/v)时，用我们的方法检测吞咽后即刻的呼气声音，并将这些吞咽和呼气事件的视频荧光(VF)图像输入VHS录像机。从VF数据中，在吞咽后没有吸入或穿透时产生92种呼气声音，在吞咽困难时有吸气或穿透时产生118种呼气声音。呼气音信号临界值为0~250 Hz的诊断结果与室颤诊断结果有显著的一致性。敏感性为83.2%，特异性为82.6%，符合率为82.9%。

This study was designed to establish the objective diagnosing system for dysphagia using the acoustic analyzing techniques of swallowing and expiratory sounds detected from the neck. New detecting instrument with active noise controller was developed. Acquisition system of acoustic signal of swallowing and expiratory sounds combined with the videofluorographic data was also developed. Analyzing system of the acoustic signals consists of the 250 Hz, 500 Hz, one-third octave, and 1 octave band analyses besides the automatically nomalyzing system of input level of the acoustic signals and the moduration transfer function.In this study, forty-three mixed pre-and post-surgical head and neck cancer patients with informed consent were examined. While patients swallowed 5 ml of barium (180% w/v), the expiratory sounds immediately after the swallows were detected using our method and fed to a VHS video recorder with videofluorographic (VF) images of these swallows and expiratory events.From the VF data, 92 exiratory sounds were produced after the swallow without aspiration or penetration and 118 exiratory sounds were produced after dysphagic swallows with aspiration or penetration.Acoustic signals of the expiratory sounds were analyzed by our computed acoustic analyzing system. Comparison of the diagnosis using the critical magnitude from 0 to 250 Hz band of expiratory sound siganals with the VF diagnosis showed significant agreement. Sensitivity was 83.2%, specificity 82.6% and percent agreement was 82.9%.