EAGER: Flexible wireless joint sensing system for knee arthroplasty

本研究的目的是开发一种使用新型二维纳米材料的低功耗柔性无线关节传感器系统。该传感器可用于全膝关节置换术，这是一种取代膝关节承重面的外科手术，以减轻疼痛和残疾。约20%的全膝关节置换术可能存在软组织失衡或假体跟踪不良，导致僵硬或微妙的不稳定。目前，外科医生通常完全依靠他们的最佳判断力来确定什么感觉像是平衡和稳定的膝盖。因此，膝关节置换术中的韧带平衡是假体寿命的关键步骤。本研究开发的智能传感器系统可以在手术过程中提供软组织调整和种植位置的实时信息，从而帮助骨科医生。由于它不是一次性传感器，即使在手术后，它也会继续提供实时数据来监控人工膝关节的性能。这使外科医生能够诊断潜在的故障，并在后续访问期间调整人工膝关节的对准。灵活的无线联合传感器系统将使用石墨烯和MoS2等智能材料以及高能效的无线传感技术来开发。设计了一种新型的基于二维材料的有源传感器，并对其进行了表征。柔性二维传感器阵列将连接到可编程电源单元进行电信号扫描，以测量每个单元的电导率随压力变化的差异。它将以低功耗、高灵敏度和快速响应的方式检测节理压力分布信号。测量到的压力分布信号将无线传输到控制系统，并将结果实时呈现在地图上。无线传感器系统的电路将进行优化，以实现低功耗、面积消耗和精度。组装好的传感器单元将在人工膝关节模型上进行现场测试。植入物的生物兼容性也将被系统地评估，以使材料满足作为骨植入物的最低生物安全性标准。这一研究项目将在材料、机械、生物医学和电气工程等更广泛的领域以综合和跨学科的方式显著加强本科生和研究生教育和研究培训。这一跨学科项目将为女性学生和来自代表性不足群体的学生提供巨大的教育和研究机会。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The objective of this research is to develop a low power flexible wireless joint sensor system using novel two dimensional (2D) nanomaterials. The sensor can be used for total knee arthroplasty which is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve pain and disability. Approximately 20% of total knee arthroplasty may have soft tissue imbalance or mal-tracking components resulting in stiffness or subtle instability. Currently, surgeons generally relied solely on their best judgment in determining what felt like a balanced and stable knee. Therefore, ligament balancing during knee arthroplasty is a critical procedure necessary for the longevity of the prosthesis. The smart sensor system developed in this research can help orthopedic surgeons by providing real-time information about soft tissue adjustments and implant position during the surgical procedure. Since it is not a disposable sensor, it continues to provide real-time data to monitor the performance of the artificial knee even after the surgery. This enables surgeons to diagnose potential malfunction and adjust the alignment of the artificial knee during follow-up visits. The flexible wireless joint sensor system will be developed using smart materials such as graphene and MoS2, and power-efficient wireless sensing techniques. A new design of active sensor based on 2D materials will be fabricated and characterized. The flexible 2D sensor array will be connected to the programmable power unit for sweeping electric signal to measure the difference of conductivity of each unit with pressure change. It will detect joint pressure distribution signals with high sensitivity and rapid response with low power consumption. The measured pressure distribution signal will be transmitted to the control system wirelessly, and the results will be presented on a map at real-time. The circuitry for wireless sensor system will be optimized for low power, area consumption, and accuracy. The assembled sensor unit will be tested in situ by applying it in an artificial knee model. Biocompatibility of implants will also be evaluated systematically so that the materials meet the minimal biosafety criteria as bone implants. This research project will significantly enhance undergraduate and graduate education and research training in an integrative and interdisciplinary manner in the broader areas of materials, mechanical, biomedical, and electrical engineering. This interdisciplinary project will provide great educational and research opportunities to female students and students from underrepresented groups.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.