Design and optimization of an aperiodic ultrasound phased array for intracavitary prostate thermal therapies
Design and optimization of an aperiodic ultrasound phased array for intracavitary prostate thermal therapies
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DOI：
10.1118/1.597741
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发表时间：
1996-05-01
期刊：
影响因子：
3.8
通讯作者：
Hynynen, K
中科院分区：
文献类型：
--
作者：
Hutchinson, EB;Buchanan, MT;Hynynen, K
为探讨经直肠超声热疗治疗前列腺癌和前列腺增生症的可行性，设计并制作了57元非周期性相控阵列。介绍了一种利用不等尺寸元件的优化随机分布来降低栅瓣电平的方法。使用这种技术，避免了阵列周期性，使得使用更大的元件并因此使用更少的元件和放大器通道成为可能，同时仍然实现可接受的功率场图案。声功率场模拟确定与所选非周期性元件分布相关联的栅瓣水平比与周期性元件间隔和相同平均元件宽度相关联的栅瓣水平小大约30%-45%。或者通过使用非周期性而不是周期性元件分布，平均元件宽度可以增加大约20%-35%（类似于λ/4.4），同时保持恒定的栅瓣水平。在构造57单元阵列之前，用16单元非周期相控阵列证明了这种类型阵列的功率能力，该相控阵列在聚焦时每厘米阵列长度提供超过28 W的声功率。由57个元件阵列产生的功率场图案与模拟中使用的理论模型预测的场图案紧密匹配。除了同时产生多个焦点外，阵列还为距离中心轴最多5 cm和最多2 cm的焦点产生了可接受的功率场图案。基于功率能力和场模式，这种非周期性阵列设计有可能被纳入临床加热设备中，作为向前列腺和靠近体腔的其他目标体积提供热治疗的手段。(C)1996年美国医学物理学家协会。
A 57 element aperiodic linear phased array was designed and constructed to investigate the feasibility of using transrectal ultrasound for the thermal therapeutic treatment of prostate cancer and benign prostatic hyperplasia. A method of reducing grating lobe levels by using optimized random distributions of unequally sized elements is introduced. Using this technique, array periodicity is avoided, making it feasible to use larger elements and hence fewer elements and amplifier channels, while still achieving acceptable power field patterns. Acoustic power field simulations determined that the grating lobe levels associated with selected aperiodic element distributions were approximately 30%-45% less than those associated with periodic element spacing and the same average element width. Or by using aperiodic rather than periodic element distributions, the average element width could be increased by approximately 20%-35% (similar to lambda/4.4), while maintaining a constant grating lobe level. Prior to construction of the 57 element array, the power capabilities of this type of array were demonstrated with a 16 element aperiodic phased array, which delivered over 28 W of acoustical power per cm of array length while focused. The power field patterns produced by the 57 element array closely matched the field patterns predicted by the theoretical model used in the simulations. The array produced acceptable power field patterns for foci at depths up to 5 cm and up to 2 cm off the center axis, in addition to producing multiple foci simultaneously. Based on the power capabilities and field patterns, this aperiodic array design has the potential to be incorporated into a clinical heating device as a means of delivering thermal therapies to the prostate and other target volumes close to body cavities. (C) 1996 American Association of Physicists in Medicine.