The knee replacement is one of the most common orthopedic surgical interventions in the United States; however, recent studies have shown up to 20% of patients are dissatisfied with the outcome. One of the key issues to improving these operations is a better understanding of the ligamentous balance during and after surgery. The goal of this paper is to investigate the feasibility of embedding piezoelectric transducers in the polyethylene bearing of a total knee replacement to act as self-powered sensors to aid in the alignment and balance of the knee replacement by providing intra- and postoperative feedback to the surgeon. A model consisting of a polyethylene disc with a single embedded piezoelectric ceramic transducer is investigated as a basis for future work. A modeling framework is developed including a biomechanical model of the knee joint, a finite element model of the knee bearing with encapsulated transducer, and an electromechanical model of the piezoelectric transducer. Model predictions show that a peak voltage of 2.3 V with a load resistance of 1.01 MΩ can be obtained from a single embedded piezoelectric stack, and an average power of 12 μW can be obtained from a knee bearing with four embedded piezoelectric transducers. Uniaxial compression testing is also performed on a fabricated sample for model validation. The results found in this paper show promising potential of embedded piezoelectric transducers to be utilized for autonomous self-powered in vivo knee implant force sensors.

中文翻译：

---

膝关节植入物中嵌入式压电陶瓷的能量收集和传感

膝关节置换术是美国最常见的整形外科手术方法之一。但是，最近的研究表明，多达20％的患者对治疗结果不满意。改善这些手术的关键问题之一是更好地了解手术期间和术后的韧带平衡。本文的目的是研究在全膝关节置换术的聚乙烯轴承中嵌入压电换能器作为自供电传感器，以通过向膝关节提供术中和术后反馈来帮助膝关节置换术的对准和平衡的可行性。外科医生。研究了由带有单个嵌入式压电陶瓷换能器的聚乙烯盘组成的模型，作为将来工作的基础。开发了一个建模框架，其中包括膝关节的生物力学模型，带有封装换能器的膝关节轴承的有限元模型和压电换能器的机电模型。模型预测表明，可以从单个嵌入式压电叠堆中获得2.3 V的峰值电压，负载电阻为1.01MΩ，而从带有四个嵌入式压电换能器的膝关节轴承中可以获得12μW的平均功率。还对制造的样本执行单轴压缩测试，以进行模型验证。本文发现的结果表明，嵌入式压电换能器有望用于自主自供电的体内膝关节植入力传感器。单个嵌入式压电叠层可以得到3 V，负载电阻为1.01MΩ，而带有四个嵌入式压电换能器的膝关节轴承可以得到12μW的平均功率。还对制造的样本执行单轴压缩测试，以进行模型验证。本文发现的结果表明，嵌入式压电换能器有望用于自主自供电的体内膝关节植入力传感器。单个嵌入式压电叠堆可提供3 V的负载电阻，为1.01MΩ，而具有四个嵌入式压电换能器的膝关节轴承可提供12μW的平均功率。还对制造的样本执行单轴压缩测试，以进行模型验证。本文发现的结果表明，嵌入式压电换能器有望用于自主自供电的体内膝关节植入力传感器。