Eriksson R, Persson H W, Dymling S O, Lindström K
Department of Electrical Measurements, Lund Institute of Technology, Sweden.
Ultrasound Med Biol. 1995;21(1):49-57. doi: 10.1016/0301-5629(94)00087-5.
Due to its sensitivity to measurement artifacts, the ultrasonic Doppler technique has not yet become a clinically useful tool for blood perfusion measurements. One of these measurement artifacts is caused by ultrasonic wave interference in combination with the small changes of structures inside the ultrasonic field. These changes are a result of variations in blood pressure, small movements in muscles, and involuntary movements of the transducer. The changes alter the ultrasonic interference pattern, causing fluctuations in the measured perfusion value. In this paper a new multifrequency technique for blood perfusion measurement is presented. The technique is based on a multifrequency setup, with four ultrasonic frequencies simultaneously transmitted with the same transducer. It is shown that by averaging the measured values obtained from each frequency, the sensitivity to ultrasonic wave interference can be lessened. Measurement results from both in vitro and in vivo experiments are presented.
由于对测量伪像敏感，超声多普勒技术尚未成为临床上用于血液灌注测量的有用工具。这些测量伪像之一是由超声波干扰与超声场内结构的微小变化共同引起的。这些变化是血压变化、肌肉微小运动以及换能器非自愿运动的结果。这些变化改变了超声干涉图样，导致测量的灌注值出现波动。本文提出了一种用于血液灌注测量的新的多频技术。该技术基于多频设置，同一换能器同时发射四个超声频率。结果表明，通过对从每个频率获得的测量值进行平均，可以降低对超声波干扰的敏感度。文中给出了体外和体内实验的测量结果。
