目的 研制一种检测心肌生物力学属性的介入超声硬度检测仪,可直接、定量检测活体心肌组织硬度,为心肌病变提供力学相关资料.方法 仪器由介入超声硬度检测导管、生理信号单元和主机组成.检测时,在X线透视下,将导管通过犬外周动脉血管进入左心室,印压左室壁,超声检测心肌厚度形变值,压力传感器获得印压力值,根据应力-应变关系,计算得到表征组织硬度的参量.结果 应用该仪器进行活体犬心肌硬度检测,成功获取了舒张末期左室心尖部和游离壁心肌硬度值,其值分别为(40.55±4.75) kPa、(36.02±7.03) kPa.结论 该仪器为直接定量检测活体心肌硬度提供了方法,可为临床判断心脏的整体和局部舒张、收缩功能异常提供定量检测技术,同时,也可检测其他深部组织硬度改变.
Objective To acquire myocardium associated mechanical properties by directly quantifying stiffness of myocardium in vivo. An intervention stiffness detection system for biomechanics assessment of myocardium in vivo was established. Methods The equipment was composed of intervention ultrasound stiffness detection catheter, physiological signal unit and mainframe. Under X-ray perspective, catheter passed through peripheral artery and entered into left-ventricle of dog, and then impressed left-ventricle wall. Tissue thickness deformation was determined from the ultrasound echo and the pressure value was also gained by pressure transducer. According to strain-stress relation, the term of myocardium tissue stiffness may be obtained. Results By using the equipment, myocardium stiffness of left-ventricle apex and free wall were (40.55± 4.75) kPa and (36.02±7.03) kPa respectively. Conclusion The equipment offered a method for directly quantifying myocardium stiffness in vivo and clinical application for detecting local or whole myocardium diastolic and systolic insufficiency. Meanwhile it may be also used for detecting deep tissue stiffness.