We live in an era of wearable sensing, where our movement through the world can be continuously monitored by devices. Yet, we lack a portable sensor that can continuously monitor muscle, tendon, and bone motion, allowing us to monitor performance, deliver targeted rehabilitation, and provide intuitive, reflexive control over prostheses and exoskeletons. Here, we introduce a sensing modality, magnetomicrometry, that uses the relative positions of implanted magnetic beads to enable wireless tracking of tissue length changes. We demonstrate real-time muscle length tracking in an in vivo turkey model via chronically implanted magnetic beads while investigating accuracy, biocompatibility, and long-term implant stability. We anticipate that this tool will lay the groundwork for volitional control over wearable robots via real-time tracking of muscle lengths and speeds. Further, to inform future biomimetic control strategies, magnetomicrometry may also be used in the in vivo tracking of biological tissues to elucidate biomechanical principles of animal and human movement.

我们生活在一个可穿戴传感的时代，我们在世界各地的运动可以被设备持续监控。然而，我们缺乏能够持续监测肌肉、肌腱和骨骼运动的便携式传感器，从而使我们能够监测性能、提供有针对性的康复，并提供对假肢和外骨骼的直观、反射性控制。在这里，我们介绍了一种传感方式，即磁显微测量法，它使用植入磁珠的相对位置来实现对组织长度变化的无线跟踪。我们通过长期植入的磁珠在体内火鸡模型中展示实时肌肉长度跟踪，同时研究准确性、生物相容性和长期植入稳定性。我们预计该工具将通过实时跟踪肌肉长度和速度为对可穿戴机器人的意志控制奠定基础。此外，为了为未来的仿生控制策略提供信息，磁显微测量也可用于生物组织的体内跟踪，以阐明动物和人类运动的生物力学原理。