基础序列调制的Golay码研究长骨中的超声导波

发布时间：2018-01-06 05:39

本文关键词：基础序列调制的Golay码研究长骨中的超声导波　出处：《仪器仪表学报》2014年07期 　论文类型：期刊论文

【摘要】：利用超声导波评价长骨状况已引起越来越多的关注。长骨外附软组织使得接收到的导波信噪比(SNR)很低,因此难以应用在连体测量中。引入了一种超声编码信号作为激励,来提高对超声导波模式的识别。在附有表皮的长骨模型上,将基于基础序列调制的Golay码(BSGC)用于激励并产生超声弯曲导波信号。使得在远离换能器中心频率(200 kHz)的相对低频上(25~50 kHz),激励产生了幅度相对较大的导波信号,通过二维傅里叶变换(2D-FFT)得到了与皮质骨厚度变化敏感的弯曲导波模式的相速度值。研究结果表明这种编码激励方式提高了接收信号的SNR,为评价皮质骨的厚度提供了重要依据。
[Abstract]:More and more attention has been paid to the evaluation of the condition of long bone by ultrasonic guided wave. The signal-to-noise ratio (SNR) of the received guided wave is very low due to the soft tissue attached to the long bone. Therefore, it is difficult to be used in conjunctive measurement. An ultrasonic coded signal is introduced as an excitation to improve the pattern recognition of ultrasonic guided waves, in the long bone model with epidermis. Golay codes based on fundamental sequence modulation are used to excite and generate ultrasonic bending guided wave signals such that the relative low frequency is 200 kHz far away from the central frequency of the transducer (. 2550 kHz). The excitation results in a relatively large amplitude of guided wave signal. The phase velocities of the bending guided wave mode sensitive to cortical bone thickness change were obtained by two-dimensional Fourier transform (2D-FFTs). The results show that the coded excitation method improves the SNR of the received signal. It provides an important basis for evaluating the thickness of cortical bone.
【作者单位】：上海电力学院电子科学与技术系;复旦大学电子工程系;上海市医学图像处理与计算机辅助手术重点实验室;Jyvaskyla大学物理系;
【基金】：国家自然科学基金(11174060,11327405) 上海市科技支撑计划(13441901900) 教育部博士点基金(20110071130004,2013007110020)资助项目
【分类号】：TN911.7;TB559
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