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

全膝关节置换术（TKR）主要用于恢复关节活动度并缓解疼痛， 患有骨关节炎的患者。虽然耐用性大大提高，但 植入物仍然可能过早失效，特别是由于软组织平衡不当， 如果患者超过运动限制，则会出现超负荷。这些故障可以通过以下方式缓解： 分别为术中和术后负荷感知。传感器系统的开发 能够测量和报告通过TKR传输的力量是下一个逻辑之一 这些植入物的演变。虽然已经提出了一些传感器系统，但是它们都需要 通过感应线圈或内部电池提供的外部电源， 耗尽了我们建议能量可以从通过关节的载荷中获得 在日常生活活动中使用摩擦电效应。摩擦电效应是一种新的 发现了将机械能转换成电能的转换机制。它 具有比其他机制，如电磁和压电更高的功率密度 换能，并且因此允许较小的整体形状因子。这意味着传感器可以 安装在任何TKR的胫骨托和UHMWPE关节面部件之间， 修改. 拟议研究的目的是创建一个自供电的负载测量 TKR系统。研究将集中在i）开发一个模型，可以准确地预测 能量采集器的输出功率，ii）制造物理原型作为能量采集器的输出功率的证明， （三）全面测试。该模型将能够优化能量采集器 设计以最大限度地发电。我们将把能量采集器整合到一个低功耗的 传感和遥测系统，其能够将所测量的数据无线地传输到 外部接收器该集成系统将通过典型膝关节下的关节模拟器进行测试 加载中将量化传感器测量载荷的准确度。负载不平衡，例如 将模拟不适当的软组织张力或植入物组件错位， 将确定传感器检测这些问题的能力。因为传感器会连接到 我们还将进行长期耐久性研究， 排除由于引入我们的 传感器.一旦开发和测试，我们的传感器将提供一个选择， 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.