Localization and Tracking of Implantable Biomedical Sensors

Abstract

Implantable sensor systems are effective tools for biomedical diagnosis, visualization and treatment of various health conditions, attracting the interest of researchers, as well as healthcare practitioners. These systems efficiently and conveniently provide essential data of the body part being diagnosed, such as gastrointestinal (temperature, pH, pressure) parameter values, blood glucose and pressure levels and electrocardiogram data. Such data are first transmitted from the implantable sensor units to an external receiver node or network and then to a central monitoring and control (computer) unit for analysis, diagnosis and/or treatment. Implantable sensor units are typically in the form of mobile microrobotic capsules or implanted stationary (body-fixed) units. In particular, capsule-based systems have attracted significant research interest recently, with a variety of applications, including endoscopy, microsurgery, drug delivery and biopsy. In such implantable sensor systems, one of the most challenging problems is the accurate localization and tracking of the microrobotic sensor unit (e.g., robotic capsule) inside the human body. This article presents a literature review of the existing localization and tracking techniques for robotic implantable sensor systems with their merits and limitations and possible solutions of the proposed localization methods. The article also provides a brief discussion on the connection and cooperation of such techniques with wearable biomedical sensor systems.

UWB RSS-Based Localization for Capsule Endoscopy Using a Multilayer Phantom and In Vivo Measurements

“…Results show how the receivers selected for localization impact the accuracy of the results. Particularly, the combination of receivers 2,4 and 3, taken as reference, leads to lower relative error values compared to the other combinations, as it is experiencing on average the highest level of received power [35], [36]. Similar results were obtained for the same combinations of receivers in a narrower frequency band (3.1-4.1 GHz) [32].…”

Location and Tracking for Ultra-WideBand In-Body Communications in Medical Applications

“…Results show how the receivers selected for localization impact the accuracy of the results. Particularly, the combination of receivers 2,4 and 3, taken as reference, leads to lower relative error values compared to the other combinations, as it is experiencing on average the highest level of received power[81],[82]. Similar results were obtained for the same combinations of receivers, when considering the same measurements but in a narrower frequency band (3.1-4.1 GHz)[83].…”

In-body backscatter communication and localization

“…Similarly, interest in deep tissue localization is on the rise. Localization of deep tissue sensors like capsule endoscope can enable physicians to isolate the parts of the GI tract with abnormalities, adapt video frame rates based on location, and deposit biomarkers at specific locations [49,58]. The localization requirements for such capsules are on the order of a few centimeters [49].…”