Indoor navigation applied to the detection of allergic reactions during provocation tests

The current method to detect allergies obliges the patient to stay within a room under the observation of the nurse during the allergy tests. Such tests last up to 4 hours. The authors have developed an allergy detection system based on the heart rate variability, which is monitored through electrocardiogram sensors. The detector is based on the correlation between variations of the heart rate and allergic reactions. However, heart rate variations are also due to the patient's physical activity, being necessary to discriminate them. The pocket navigation system will be used to enhance the performance of the allergy detection algorithm, as it is able to identify different physical activities. Additionally, the patient can walk out of the testing room because a 3D localization solution is possible. The experiments described in this article show that it is possible identifying the most important patient's physical activities to avoid false allergic reaction alarms. Moreover, the patient is allowed to move within the hospital during the allergy tests and can be located in case of a severe allergic reaction occurs. The experiments show also long duration walks to assess that our unaided inertial-based navigation system is suited to this particular medical application.