Conclu- sion Peak velocities and VTI of SVC of health adult changed regularly in respiration cycle, which could conduce to elaborate study on SVC in clinical ultrasonography.

• 结论健康成年人SVC频谱各波峰值及VTI随生理呼吸出现规律性变化,对这种变化规律的认知,有助于SVC超声检查临床应用价值的深入研究。