A new evaluation method for dependence of width of transmitted waves on accuracy in multipoint simultaneous ultrasonic measurements of cardiac wall vibration waveform

It has been revealed that the ultrasound measurement with high temporal resolution is useful for diagnosis of myocardial tissue properties. However, it is considered that the dynamic measurement of the target tissue is affected by the motion of neighbor tissues because of the wide width of the transmitted wave. For this reason, the measurement error is affected by spatial and temporal factors. In the present study, we constructed an experimental system for measuring these effects quantitatively and investigated the accuracy of the velocity measurement using some transmitted waves such as focused, plane, and diverging waves. In the conditions of the present study, the measurement error is minimized at 9° of the angular width of the transmitted wave. This method is useful for evaluating the conditions of transmitted waves for measurements of other targets which need a high temporal resolution such as shear wave, cardiac blood flow, and so on.