Design and analysis of a compliant non-invasive real-time localization system for nasogastric intubation

Nasogastric intubation is one of the most commonly performed clinical procedures. Real-time placement confirmation of the NG tube passage at the laryngeal region into the esophagus is crucial for safety, but is lacking in current practice. In this paper, we present a compliant non-invasive real-time localization system using passive magnetic tracking method. With minimal modification to the nasogastric tube, this system allows non-radiographic localization and confirmation of the nasogastric tube tip; and the compliant design allows the system to ergonomically conform to the patients' necks for maximum comfort. Two compliant deformation models were analyzed to facilitate prediction of the changes in the sensor locations due to the system compliance, which allows the system parameters to be updated in real-time for accurate compensation. Simulation and experimental results demonstrate that the proposed system is capable of localizing the tube insertion, and distinguishing the NG tube placement at esophagus or trachea. A neck attachment prototype was designed and built to validate the feasibility of the proposed approach.