Wearable and mobile approach to stress and fatigue monitoring

Thesis type: 



Gonçalo de Oliveira Pimentel


João Paulo Trigueiros da Silva Cunha


Wearable and mobile approach to stress and fatigue monitoring


There is a growing concern about the health problems that occur due to stress and fatigue at work. Around the world, workers suffer from this disorders and this undoubtedly affects their performance and health. Stress, for example, is the cause of various cardiovascular and neurological diseases. Furthermore, fatigue has been widely reported to cause several work and car accidents.

With this in mind, this work aims to use state of the art wearable and mobile technology to monitor parameters of stress and fatigue during normal routines of different professionals. Surveys already validated in the literature were also used to assess the subject’s cognitive function which is also important in studies in this area.

To better study events that can induce stress and fatigue, an Android app (called VJ E-Diary) to enable the registration of events in the phone so that later they can be synchronized with other data was developed. Furthermore, a small computer application (VJ Assembly) was developed to synchronize data from different sensors and present it to the user efficiently. This tool was
also designed to accept the files generated by the VJ E-Diary so that the registered events can be automatically synchronized with the other data.

Studies with 3 different types of professionals (6 Police Officers, 3 Neurosurgeons and 4 Firefighters) were developed with the goal of monitoring both Stress and Fatigue.

Police Officers were monitored during their work routines and days off. Two events were detected as being stressful, but only one was reported by the officer. Significant changes in the ratios between Low Frequencies and High Frequencies (LF/HF) values were observed between work days and day offs. Neurosurgeons were monitored during intracranial aneurysm procedures and different stressful events were identified. Results also support the fact that a more stressful procedure induces higher mental fatigue in the surgeon. Four Firefighters underwent a protocol where they had to complete different tasks which were mentally and physically demanding, so that their psychological and physiological responses could be studied. The Trial Social Stress Test (TSST) and Fitness tasks seem to fulfill their roles as stress and physical fatigue inducers. However, some changes need to be done to the protocol to reliably obtain unbiased baseline data.

It was possible to draw important conclusions which may be of enormous importance for the design of effective interventions in order to reduce stress and fatigue levels in different professionals. The tools developed also shown great potential in improving this type of studies and several goals were proposed as future work to achieve this. Furthermore, various suggestions are also presented with the aim of improving the developed studies.