Ultrasound Department, Fraunhofer-Institute for Biomedical Engineering, 66280 Sulzbach, Germany.
Sensors (Basel). 2021 Jan 9;21(2):421. doi: 10.3390/s21020421.
The aim of this work was to extend conventional medical implants by the possibility of communication between them. For reasons of data security and transmitting distances, this communication should be realized using ultrasound, which is generated and detected by capacitive micromachined ultrasonic transducers (CMUTs). These offer the advantage of an inherent high bandwidth and a high integration capability. To protect the surrounding tissue, it has to be encapsulated. In contrast to previous results of other research groups dealing with the encapsulation of CMUTs, the goal here is to integrate the CMUT into the housing of a medical implant. In this work, CMUTs were designed and fabricated for a center frequency of 2 MHz in water and experimentally tested on their characteristics for operation behind layers of Polyether ether ketone (PEEK) and titanium, two typical materials for the housings of medical implants. It could be shown that with silicone as a coupling layer it is possible to operate a CMUT behind the housing of an implant. Although it changes the characteristics of the CMUT, the setup is found to be well suited for communication between two transducers over a distance of at least 8 cm.
这项工作的目的是通过在医学植入物之间实现通信的可能性来扩展传统的医学植入物。出于数据安全性和传输距离的考虑，这种通信应该使用超声来实现，而超声是由电容式微机械超声换能器（CMUT）产生和检测的。CMUT 具有固有带宽高和集成能力强的优势。为了保护周围的组织，它必须被封装。与其他研究小组以前在 CMUT 封装方面的研究结果不同，这里的目标是将 CMUT 集成到医学植入物的外壳中。在这项工作中，CMUT 被设计并制造用于水中的中心频率为 2MHz，并在聚醚醚酮（PEEK）和钛层后面的操作特性上进行了实验测试，PEEK 和钛是医学植入物外壳的两种典型材料。结果表明，使用硅作为耦合层，CMUT 可以在植入物外壳后面进行操作。虽然这改变了 CMUT 的特性，但该设置被发现非常适合在至少 8cm 的距离内进行两个换能器之间的通信。
