Wei Luxi, Boni Enrico, Ramalli Alessandro, Fool Fabian, Noothout Emile, van der Steen Antonius F W, Verweij Martin D, Tortoli Piero, De Jong Nico, Vos Hendrik J
IEEE Trans Ultrason Ferroelectr Freq Control. 2022 Oct;69(10):2798-2809. doi: 10.1109/TUFFC.2022.3204118. Epub 2022 Sep 27.
Two-dimensional (2-D) arrays offer volumetric imaging capabilities without the need for probe translation or rotation. A sparse array with elements seeded in a tapering spiral pattern enables one-to-one connection to an ultrasound machine, thus allowing flexible transmission and reception strategies. To test the concept of sparse spiral array imaging, we have designed, realized, and characterized two prototype probes designed at 2.5-MHz low-frequency (LF) and 5-MHz high-frequency (HF) center frequencies. Both probes share the same electronic design, based on piezoelectric ceramics and rapid prototyping with printed circuit board substrates to wire the elements to external connectors. Different center frequencies were achieved by adjusting the piezoelectric layer thickness. The LF and HF prototype probes had 88% and 95% of working elements, producing peak pressures of 21 and 96 kPa/V when focused at 5 and 3 cm, respectively. The one-way -3-dB bandwidths were 26% and 32%. These results, together with experimental tests on tissue-mimicking phantoms, show that the probes are viable for volumetric imaging.
二维（2-D）阵列无需探头平移或旋转即可提供容积成像功能。一种以逐渐变细的螺旋模式分布元件的稀疏阵列能够与超声设备实现一对一连接，从而允许采用灵活的发射和接收策略。为了测试稀疏螺旋阵列成像的概念，我们设计、实现并表征了两款原型探头，其中心频率分别为2.5兆赫兹低频（LF）和5兆赫兹高频（HF）。两款探头采用相同的电子设计，基于压电陶瓷并利用印刷电路板基板进行快速成型，以便将元件连接到外部连接器。通过调整压电层厚度实现了不同的中心频率。低频和高频原型探头的工作元件分别占88%和95%，在分别聚焦于5厘米和3厘米时，产生的峰值压力分别为21千帕/伏和96千帕/伏。单向-3分贝带宽分别为26%和32%。这些结果以及对仿组织体模的实验测试表明，这些探头对于容积成像而言是可行的。
