EAGER: Network Protocol Stack for Galvanic Coupled Intra-body Sensors

植入的传感器将通过原位检测异常生理状况、个性化医疗和主动给药，实现下一代医疗保健。这些功能需要通过身体组织在植入物之间进行高能效的数据通信，由于射频（RF）波在体内的高衰减，这很难通过射频波实现。该项目涉及网络协议栈的设计，使用弱电流作为底层通信机制，而不是传统的射频波来连接植入物。与射频相比，这种模式节省了两个数量级的能源。这项研究将有助于实现由连接的植入物网络产生的各种应用，使运动员、军事人员和其他高危人群受益。主动报告体内生理变化的能力将增加人类的寿命。该项目包括针对K-12学生的拓展部分，基于计算机模拟的项目设计，以及在科学博物馆等公共场所的演示。本项目计划的研究是第一次系统地设计基于电信号电耦合的网络协议。它有以下目标：(i)探索传输频率和功率对多播通信组织边界处信号反射和折射的影响；（ii）设计无干扰媒体接入方案，该方案考虑了所有同时有源的收发器对在信号路径交叉处产生的热量，适用于基于CSMA和tdma的方法；（iii）研究新的策略，并对皮肤上中继节点的最佳放置进行性能分析，以便在受可行的身体位置限制的情况下，从身体的位置检索传感器数据，最大限度地减少数据收集延迟；（iv）使用ns-3进行电偶通信的第一个模拟器和试验台，并将提出通过非接触磁耦合线圈对植入传感器充电的方法。

Implanted sensors will enable the next generation of healthcare by in-situ testing of abnormal physiological conditions, personalized medicine and proactive drug delivery. These functions require energy efficient communication of data between implants through the body tissues, which is difficult to achieve via radio frequency (RF) waves owing to their high attenuation within the body. The project involves the design of a network protocol stack using weak electrical currents as the underlying communication mechanism, instead of conventional RF waves to connect the implants. This paradigm results in energy savings of two orders of magnitude compared to RF. This research will help in realizing diverse applications arising out from a network of connected implants that benefit athletes, military personnel, and other at-risk populations. The ability to proactively report physiological changes within the body will increase longevity of human life. The project incorporates outreach components targeting K-12 students, design of computer-simulation based projects, and demonstrations at public venues like science museums.The research planned in the course of this project is the first effort to systematically devise networking protocols based on galvanic coupling of electric signals. It has the following goals: (i) explore the impact of the transmission frequency and power on signal reflection and refraction at the tissue boundaries for multicast communication, (ii) design of interference-free medium access schemes that take into account heat generated at the crossings of the signal paths for all simultaneously active transceiver pairs, for both CSMA and TDMA-based approaches, (iii) research new strategies and conduct performance analysis for optimal placement of on-skin relay nodes for retrieving the sensor data from locations in the body that minimize the data gathering latency while being constrained by feasible on-body locations, and (iv) the first simulator and testbed for galvanic coupled communication using ns-3, and will also propose ways to charge the implanted sensors through contact-less magnetically coupled coils.