Leadless Cardiac Pacemakers (LCP) have the potential to revolutionize Cardiac Rhythm Management (CRM). Current LCPs can only pace a single location of the heart limiting their use to patients requiring single-chamber stimulation. A Multi-node system of synchronized LCPs could be used in a significantly larger patient population. Synchronization using standard communication techniques involves high power consumption decreasing the longevity of the device. In this work, we investigate Galvanic Intra Body Communication (IBC) as a method to synchronize multi-node LCP systems. First, an accurate computational torso model was used for quasi-static simulations to estimate channel pathloss in the frequency range [40 kHz–20 MHz]. The model was then verified with in-vivo measurements using a novel experimental setup, where two LCP devices were placed in the right atrium, right ventricle and left ventricle. All channels involved in a potential multi-node LCP system were characterized. The orientation of the transducers relative to each other had a great impact on the results, with the attenuation level ranging between 55 dB and 70 dB between the best and worst orientations. The best results were achieved in the MHz range. Coupled with the fact that it does not require additional electrodes, this study suggests Galvanic IBC be superior to conventional communication methods for LCP devices. This analysis defines a methodology for galvanic IBC channel characterization for LCP systems, which is an important step for the design of efficient transceivers for IBC applications. More experiments with larger datasets are needed to bring this method to practice.

中文翻译：

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无引线起搏器体内通信的宽频特性

无引线心脏起搏器 (LCP) 具有彻底改变心律管理 (CRM) 的潜力。当前的 LCP 只能对心脏的单个位置起搏，将其用于需要单腔刺激的患者。同步 LCP 的多节点系统可用于更大的患者群体。使用标准通信技术的同步涉及高功耗，从而降低了设备的使用寿命。在这项工作中，我们研究了电流体内通信 (IBC) 作为一种同步多节点 LCP 系统的方法。首先，使用精确的计算躯干模型进行准静态仿真，以估计频率范围 [40 kHz–20 MHz] 内的信道路径损耗。然后使用新的实验装置通过体内测量验证模型，其中两个 LCP 装置分别放置在右心房、右心室和左心室。对潜在多节点 LCP 系统中涉及的所有通道进行了表征。换能器相对于彼此的方向对结果有很大影响，最佳和最差方向之间的衰减水平介于 55 dB 和 70 dB 之间。在 MHz 范围内取得了最好的结果。再加上它不需要额外的电极，这项研究表明 Galvanic IBC 优于传统的 LCP 设备通信方法。该分析定义了 LCP 系统的电流 IBC 通道表征方法，这是为 IBC 应用设计高效收发器的重要步骤。需要对更大的数据集进行更多的实验才能将这种方法付诸实践。