Construction of an Intravascular Ultrasound Catheter with a Micro Piezoelectric Motor Internally Installed
Junjian Zhang, Shaowei Lu, Xinxin Liao, Zhihua Feng
Link:https://aip.scitation.org/doi/abs/10.1063/5.0020260
DIO:10.1063/5.0020260
ABSTRACT
Intravascular ultrasound (IVUS) has become a useful tool in the detection of coronary artery disease. However, non-uniform rotation distortion (NURD) reduces image quality.To suppress the influence of NURD, a piezoelectric motor that can meet the requirements of IVUS catheters has been proposed.The motor has a diameter of 1mm and a length of 10mm, using the new polarization direction proposed in the paper. A 45-degree mirror is fixed on the top of the motor to reflect the ultrasound transmitted from the transducer. The manufacture and drive of the piezoelectric motor is simple, and the maximum speed of the piezoelectric motor can reach 6450 rpm under the voltage of 20Vp-p. The minimum power required by the rotating motor is only 0.038W, which can be directly driven by the signal generator without a power amplifier. The motor can operate at a low voltage, and still has a high and stable speed.Meanwhile, the speed of the motor is controllable and has satisfactory stability with a maximum angular error of 8 degrees. The images detected by the cooperation of the motor and the ultrasonic transducer are also shown,which indicates the motor has the rotational stability that meets the imaging requirements and the potential for application in the IVUS catheter to help improve the image quality of the coronary arteries, prevent and help treat potential diseases.
文章摘要
血管内超声（IVUS）已成为检测冠状动脉疾病的有用工具。但是，非均匀旋转失真（NURD）会降低图像质量。为了抑制NURD的影响，提出了一种可以满足IVUS导管要求的压电马达。该马达直径为1mm，长度为10mm，采用了新的极化方向。45度反射镜固定在马达的顶部，以反射从换能器发射的超声波。压电电动机的制造和驱动很简单，在20Vp-p的电压下，压电电动机的最大速度可以达到6450 rpm。旋转电机所需的最小功率仅为0.038W，可以由信号发生器直接驱动，而无需功率放大器。电动机可以在低电压下运行，且仍具有高且稳定的速度。同时，电动机的速度是可控的，具有令人满意的稳定性，最大角度误差仅为8度。电动机具有满足成像要求的旋转稳定性以及在IVUS导管中应用的潜力，有助于改善冠状动脉的图像质量。
图1 电机工作原理图
图片显示了压电陶瓷管在一阶弯振模态下工作一周的过程，当把安装有反射镜的转子压在定子端面时，转子即在定子端面的行波作用下发生旋转，以达到反射以及接收超声波的目的。
图2 13组电机工作周期的最大值，平均值，最小值以及标准方差
图片显示了制作的压电马达的稳定性测试结果，可以看到电机每个旋转周期的一致性较好，这有利于降低非线性旋转失真（NURD），改善图片质量。
亮点：
1.结构简单，易于制造，有利于降低制造成本。
2.优化了压电陶瓷管的极化方向，简化了激励方式，也减少了所需信号源的数量。
3.电机所需要的输入功率很低，可直接使用信号发生器驱动。
