An implantable self-powered load sensor for total knee replacement health monitoring

全膝关节置换术(TKR)可恢复活动范围并缓解疼痛，主要用于 患有骨性关节炎的患者。虽然耐用性有了显著提高，但这些 植入物仍然可能过早失败，特别是因为软组织平衡不当或 如果患者超过了运动限制，就会超负荷。这些故障可以通过以下方式得到缓解 分别在术中和术后进行负荷感应。一种传感器系统的研制 能够测量和报告通过TKR传输的力是下一个逻辑之一 这些植入物的进化。虽然已经提出了一些传感器系统，但它们都需要 通过感应线圈或内部电池提供的外部电力最终将成为 耗尽了。我们认为能量可以从通过接头的负载中获得。 在日常生活活动中利用摩擦电效应。摩擦电效应是一种新的 发现了将机械能转化为电能的转换机制。它 具有比电磁和压电等其他机制更高的功率密度 转导，因此允许更小的整体外形系数。这意味着传感器可以 安装在任何TKR的胫骨托盘和UHMWPE承载部件之间，没有任何 修改。 拟议的研究的目标是创建一种自供电的负载测量 TKR系统。研究的重点将是i)开发一种能够准确预测 能量收集机的输出功率，ii)制造物理原型作为证明- 概念，以及iii)综合测试。该模型将使优化能量收割机成为可能 设计以最大限度地提高发电量。我们将把能量收集器集成到一个低功率 传感和遥测系统，能够将测量数据无线传输到 外部接收器。集成系统将在典型膝关节下通过关节模拟器进行测试 正在装车。传感器测量负载的精度将被量化。负载不平衡，例如 将模拟不适当的软组织张力或种植体组件错位，并 传感器检测这些问题的能力将被确定。因为传感器会连接到 我们还将直接与其他植入物组件一起进行长期耐用性研究，以 排除任何潜在的有害影响种植体寿命的结果 传感器。一旦开发和测试，我们的传感器将提供持续监测的选项 TKR健康。

A total knee replacement (TKR) restores range of motion and provides pain relief primarily for patients suffering from osteoarthritis. While durability has improved significantly, these implants can still fail prematurely, especially because of improper soft tissue balancing or overloading if the patient exceeds exercise limitations. These failures could be mitigated by intra- and post-operative load sensing, respectively. The development of a sensor system capable of measuring and reporting forces transmitted through TKR is one of the next logical evolutions of these implants. While some sensor systems have been proposed, they all require external power provided via induction coils or an internal battery that will eventually become depleted. We propose that energy can be harvested from the loads passing through the joint during the activities of daily living using the triboelectric effect. The triboelectric effect is a newly discovered transduction mechanism for converting mechanical energy into electrical energy. It has a higher power density than other mechanisms such as electromagnetic and piezoelectric transduction, and therefore allows a smaller overall form factor. This means the sensor can be installed between the tibial tray and UHMWPE bearing component of any TKR without any modifications. The objective of the proposed research is to create a self-powered load measurement system for TKR. Studies will focus on i) developing a model that can accurately predict the output power of the energy harvester, ii) manufacturing a physical prototype as a proof-of- concept, and iii) comprehensive testing. The model will enable optimizing the energy harvester design to maximize power generation. We will integrate the energy harvester into a low-power sensing and telemetry system capable of transmitting the measured data wirelessly to an external receiver. The integrated system will be tested by a joint simulator under typical knee loading. The sensor accuracy in measuring the load will be quantified. Load imbalances such as improper soft tissue tensions or implant component misalignment will be simulated and the sensor's capability in detecting these issues will be determined. Because the sensor will interface directly with other implant components, we will also perform long-term durability studies to rule out any potential detrimental effects on implant longevity as a result of introducing our sensor. Once developed and tested, our sensor will offer an option for continuous monitoring of TKR health.