I-Corps: Networking Medical Implants Through Ultrasounds

截至目前，现有的无线医疗植入物通过射频（RF）电磁波连接。基于RF的解决方案倾向于几乎盲目地缩小传统无线技术（例如，Wi-Fi、蓝牙、Zigbee）应用于体内环境，很少或根本不关注人体的特殊特性和安全要求。人体实际上由高达65%的水组成，这是一种RF波不能很好传播的介质。此外，RF频谱是稀缺的，并且已经挤满了许多相互干扰的设备。因此，基于RF的技术引起了对现有RF通信系统的潜在干扰的严重关注，这些干扰可能会无意中破坏植入式网络的可靠性和安全性，并最终破坏患者的安全性。 该团队开发了超声波宽带（UsWB）技术，这是一种通过超声波实现无线通信的网络平台（即，非可听频率的声波）。超声波无线通信和联网技术（即，基于非可听频率的声波）相对于人体中基于射频（RF）的解决方案具有显著的优点。超声波在人体组织中比RF波传播得更好，导致（i）更低的能量消耗和（ii）减少的组织加热。超声波也长期用于医学成像，并被证明是安全的。而且，与RF波不同，超声波在低传输功率下不会从体外穿透到体内，反之亦然。因此，超声波通信链路可能更安全，因为它们不太容易受到无意或恶意干扰。在这个阶段，该团队开发了第一个非集成和非植入式UsWB原型，该原型使用现成的高频超声换能器，通过模拟生物组织中高保真声传播的介质来实现超声波的传输和接收，即，所谓的超声波幻象

As of today, existing wireless medical implants are connected through radio frequency (RF) electromagnetic waves. RF-based solutions tend to almost blindly scale down traditional wireless technologies (e.g., Wi-Fi, Bluetooth, Zigbee) to the intra-body environment, with little or no attention to the peculiar characteristics and safety requirements of the human body. The human body is in fact composed up to 65% of water, a medium through which RF waves do not propagate well. In addition, the RF frequency spectrum is scarce and already crowded with many devices interfering with one another. Therefore, RF-based technologies raise serious concerns about potential interference from existing RF communication systems that can unintentionally undermine the reliability and security of the implantable network, and ultimately the safety of the patient. This team has developed the ultrasonic wideband (UsWB) technology, a networking platform that enables wireless communications through ultrasounds (i.e., acoustic waves at non-audible frequencies).Ultrasonic wireless communications and networking technology (i.e., based on acoustic waves at non-audible frequencies) is proven to have significant advantages with respect to radio-frequency (RF)-based solutions in the human body. Ultrasounds propagate better than RF waves in human tissues, leading to (i) lower energy consumption and (ii) reduced heating of tissues. Ultrasounds have also been long used for medical imaging and are proven to be safe. And, unlike RF waves, ultrasonic waves do not penetrate from outside-the-body to inside-the-body, and vice versa, at low transmission powers. Therefore, ultrasonic communication links are potentially more secure as they are less prone to unintentional or malicious interference. At this stage, the team has developed the first, non-integrated and non-implantable UsWB prototype that uses off-the-shelf high-frequency ultrasonic transducers to enable transmission and reception of ultrasonic waves, through media that emulate with high fidelity acoustic propagation in biological tissues, i.e., so-called ultrasonic phantoms.