Early screening of developmental dysplasia of hip by acoustical technique

Abstract

目的: 开发一种非侵入性数字声波技术 ,反映髋关节的结构特征 ,用于新生儿髋发育不良的早期筛查。方法: 应用包括有刺激系统、传导系统和带有双通道数字过滤程序数据分析系统的数字声波技术 ,测量分析了 90例正常新生儿两侧髋关节声波信号相关性 (CF)和声强差异 (D) ,并初步对 16例 1～ 60个月婴幼儿进行相应测量 ,并与正常组进行比较。结果: 在 160～ 3 15Hz范围 ,两侧髋关节声波信号相关性 :正常组CF >0 .94 ;髋发育不良组中有 6例CF <0 .8。声强差异 :正常组D<2dB ;髋发育不良组均明显大于正常 ,差异有显著性意义 (P <0 .0 0 1)。统计学处理还表明 ,以声强差异 2dB为临界点 ,灵敏度可以达到 10 0 %。结论: 该声波技术提供了一个用数字客观评估髋关节声波信号的实用方法 ,可用于新生儿髋发育不良的早期筛查。 Objective: To search for non invasive acoustical technique reflecting the dynamic response of the observed structure for early screening of developmental dysplasia of the hip (DDH) in neonates. Methods: The special testing instruments included an excitation system, a transduction system and the data acquisition and analysis system with a program of dual channel digital filter for measuring the power of acoustic signals.The baseline for 90 normal neonates has been established. Sixteen cases of unilateral DDH were examined by the acoustical technique. Results: The most optimal and effective testing frequencies were found in the range of 200～ 315?Hz ,in which there was a high coherence (CF> 0.94 ) and a small discrepancy (D<2?dB) in normal group. The results suggested that the coherence of the signals in 6 cases were below 0.8 in at least one of these three frequency bands. The discrepancy estimated for the patients were found to be clearly different from the normal figures ( P < 0.001 ). By setting the cut off discrepancy at 2.0 dB,the best sensitivity of 100% would be achieved. Conclusion: This study shows that the development of the acoustical technique providing a practical method with objective measure of sound signals across hip joints for early screening of DDH in neonates.