扫频耳声发射快速检测系统的设计与实现

发布时间：2018-04-24 05:09

  本文选题：扫频刺激声 + 耳声发射　； 参考：《东北大学》2014年硕士论文

【摘要】：耳声发射现象的发现是近年来耳科研究的一项重要进展,耳声发射是耳蜗主动产生的一种非常微弱的声能量,它可以客观无损地检测耳蜗功能状态,因此在耳科临床和听力筛选有着非常广泛的应用。目前,已经有很多款耳声发射检测设备问世,但都有着检测时间过长,效率不高,且只能检测出某些离散频率点的听力损失情况的缺点。本文针对畸变产物耳声发射(DPOAE)的提取,设计了一套扫频耳声发射检测系统,能够很好地解决上述问题。本文首先对耳声发射的概念及其特点进行了探讨,并引入扫频刺激声替换现有的纯音刺激声,使得耳声发射检测效率大为提升。系统主要分为扫频刺激声的产生、DPOAE信号放大、滤波和采集,USB数据传输,信号提取与分析四大模块,采用TI公司的DSP芯片TMS320VC5509A作为系统中央处理器。其次,介绍了双通道可控音量刺激声播放电路的设计,通过D/A变换和功率放大器将刺激声数据转换刺激声,为用于诱导人耳产生DPOAE信号,提出“三段式”扫频刺激声播放组合,经过线性变换,滤除刺激声。刺激声诱导产生DPOAE信号后,通过信号放大、滤波及其A/D采样电路,得到24位高精度信号。随后,采用USB数据接口,完成USB固件和上位机软件编程,实现扫频刺激声及其A/D采样信号的传输,即上位机将扫频刺激声数据传输到：DSP, DSP将A/D采集得到的数据传输到上位机,并将数据保存。最后介绍了线性变换和阈值截取算法滤除扫频刺激声与脉冲噪声,并通过短时傅里叶变换得到DPOAE信号的时频曲线,并完成对系统噪声优越性等性能测试。
[Abstract]:The discovery of otoacoustic emission is an important development in recent years. Otoacoustic emission is a very weak acoustic energy produced by cochlea initiative, and it can be used to detect the functional state of cochlea objectively. Therefore, it is widely used in ear clinic and hearing screening. At present, there are many otoacoustic emission detection devices, but all have the shortcomings of long detection time, low efficiency, and can only detect the hearing loss of some discrete frequency points. Aiming at the extraction of distortion product otoacoustic emission (DPOAE), a frequency sweep otoacoustic emission detection system is designed in this paper, which can solve the above problems well. In this paper, the concept and characteristics of otoacoustic emission (OAE) are discussed, and the efficiency of otoacoustic emission detection is greatly improved by introducing frequency-sweep stimuli to replace the existing pure acoustic stimuli. The system is mainly divided into four modules: signal amplification, filtering and collecting USB data transmission, signal extraction and analysis. TI's DSP chip TMS320VC5509A is used as the central processor of the system. Secondly, the design of two-channel controllable volume stimulation sound playing circuit is introduced. The stimulatory sound data is converted into stimulatory sound by D- A transform and power amplifier. In order to induce human ear to produce DPOAE signal, a "three-segment" sweep stimulation sound playback combination is proposed. The stimulated sound is filtered by linear transformation. After the DPOAE signal is generated by sound stimulation, the 24 bits high precision signal is obtained by amplifying, filtering and sampling A / D circuits. Then, the USB data interface is used to complete the programming of the USB firmware and the upper computer software, which realizes the transmission of the sweep sound and its A / D sampling signal, that is, the upper computer transmits the scan sound data to the USB, and the DSP transmits the data collected by the A / D to the upper computer. And save the data. Finally, the linear transform and threshold truncation algorithm are introduced to filter the sweep sound and pulse noise. The time-frequency curves of DPOAE signal are obtained by short-time Fourier transform, and the performance of the system noise superiority is tested.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP274;R764
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本文编号：1795273