Kassanos Panagiotis, Hourdakis Emmanouel
School of Electrical and Computer Engineering, National Technical University of Athens, 15772 Athens, Greece.
Sensors (Basel). 2024 Dec 28;25(1):133. doi: 10.3390/s25010133.
In recent years, implantable sensors have been extensively researched since they allow localized sensing at an area of interest (e.g., within the vicinity of a surgical site or other implant). They allow unobtrusive and potentially continuous sensing, enabling greater specificity, early warning capabilities, and thus timely clinical intervention. Wireless remote interrogation of the implanted sensor is typically achieved using radio frequency (RF), inductive coupling or ultrasound through an external device. Two categories of implantable sensors are available, namely active and passive. Active sensors offer greater capabilities, such as on-node signal and data processing, multiplexing and multimodal sensing, while also allowing lower detection limits, the possibility to encode patient sensitive information and bidirectional communication. However, they require an energy source to operate. Battery implantation, and maintenance, remains a very important constraint in many implantable applications even though energy can be provided wirelessly through the external device, in some cases. On the other hand, passive sensors offer the possibility of detection without the need for a local energy source or active electronics. They also offer significant advantages in the areas of system complexity, cost and size. In this review, implantable passive sensor technologies will be discussed along with their communication and readout schemes. Materials, detection strategies and clinical applications of passive sensors will be described. Advantages over active sensor technologies will be highlighted, as well as critical aspects related to packaging and biocompatibility.
近年来，可植入传感器得到了广泛研究，因为它们能够在感兴趣的区域（例如手术部位或其他植入物附近）进行局部传感。它们可以实现不引人注意且可能是连续的传感，从而具有更高的特异性、预警能力，进而能够及时进行临床干预。植入式传感器的无线远程询问通常通过外部设备利用射频（RF）、感应耦合或超声来实现。有两类可植入传感器，即有源传感器和无源传感器。有源传感器具有更强的功能，如节点上的信号和数据处理、复用和多模态传感，同时还能实现更低的检测限、对患者敏感信息进行编码的可能性以及双向通信。然而，它们需要能源来运行。尽管在某些情况下可以通过外部设备无线提供能量，但电池植入和维护在许多可植入应用中仍然是一个非常重要的限制因素。另一方面，无源传感器提供了无需本地能源或有源电子设备即可进行检测的可能性。它们在系统复杂性、成本和尺寸方面也具有显著优势。在这篇综述中，将讨论可植入无源传感器技术及其通信和读出方案。将描述无源传感器的材料、检测策略和临床应用。将突出无源传感器相对于有源传感器技术的优势，以及与封装和生物相容性相关的关键方面。
