3D Localization of Miniaturized Devices for Precision Medicine: Enabling wireless surgical navigation, health monitoring, and targeted drug delivery

The localization and real-time tracking of devices in vivo with high precision are critical for many surgical and medical diagnostic procedures. For instance, in orthopedic surgeries, the precise alignment and control of implants and surgical tools can significantly impact the outcome. A common example is intramedullary nailing, in which long bone fractures are fixed by putting a metal rod into the bone and holding the two together using screws. It is crucial to know the precise locations of the screw holes, which are found by using X-ray fluoroscopy, before drilling into the fractured bone [1] . Although fluoroscopy provides ${100}{-}{200}{\mu}{\text{m}}$ of localization accuracy, it causes high levels of radiation exposure to the patient and the surgical team. Another example is capsule endoscopy, in which a pill-shaped camera is sent through the gastrointestinal (GI) tract of a patient, taking images of different regions of the stomach and intestines. It is important to know the real-time location of the pill as it goes through the GI tract in order to provide a quantitative assessment of the GI transit time and to enable targeted therapeutic interventions [2] . Currently, X-ray imaging is used to find the pill’s location at a given time. Other applications where the localization and tracking of devices in vivo are critical include robotic surgeries, minimally invasive surgeries, and endovascular procedures.