TFG: Development of algorithms for monitoring physiological parameters to assist drivers

One of the main problems that we face today is traffic accidents. In recent years there have been more than 1000 deaths per year in Spain due to this reason, however, it is extremely difficult to find products on the market that assist the driver to deal with this problem.

In order to provide a solution to the problem outlined, at the B105 Electronic Systems Lab, a bracelet wearable was designed, which monitors the driver’s body temperature, stress level, heart rate, blood pressure, and the level of alcohol in the air.  This device is intended to provide a tool for the drivers to assist them to check if they are physically good and mentally ready to drive. However, the reliability expected in this device was not achieved, to use it as an end system in a user, due to a lack of time. For this reason, the main objective of this TFG has been to achieve the greatest performance of the electronic device designed in the previous project.

The first step has been to carry out a study of other similar products that can be found in the market, as well as the design of the device.

Then, an analysis of the parameters obtained with the bracelet has been conducted, to understand what aspects need to be known about them to measure them, and the different methods that exist to obtain them. In addition, the measurement method used by the device for each of them has been analysed in further detail, focusing on what problems it could present, and which factors could affect them.

Afterwards, tests have been carried out in all the modules in a separate way, in which the previous analysis has been considered. Different measurements have been performed on all the sensors during the tests, to calibrate them and to check their behaviour towards the factors that affect them.Through these tests, it has been concluded which is the optimal method to obtain each one of the parameters, the design problems that the device presents, and how it could be improved.

Lastly, the integration of all the modules has been carried out, in which besides obtaining all the parameters considering the conclusions obtained from the tests, an alarm system has been carried out. This system warns the user by the vibration of the bracelet, if a value out of a healthy range is detected in any of the measurements on the parameters. This integration has also been tested and depurated using the debugger.

Finally, it can be concluded that the main objective of the project has been achieved, although some changes would be necessary to improve its functionality, in order to be used as an end device.

TFM: Development of an electronic system for monitoring people’s parameters

Road safety is one of the objectives of the European Union due to the high number of infractions committed every year by drivers and pedestrians, and the large amount of accidents with fatalities registered in Europe year by year. Therefore, any step taken in order to deal with this problem is beneficial for everyone.

Current technology allows increasing the security measures of vehicles, which, together with consciousness-raising of drivers and pedestrians, take us one step closer to the reduction of these figures. Every day more people decide to use biosensors for controlling their vital signs. The transfer and adaptation of the aforementioned systems to the situation in which a driver is, permit to complement both legal actions accomplished and consciousness-raising measures, improving road safety.

The main objective of this Master’s thesis consists of the development of an electronic system that allows drivers to notice the indisposition to drive, permitting to avoid an accident and also an infraction.

After analyzing the parameters that affect driving and are related to the driver, those that can be monitored in a non-intrusive way and without using disposable material were chosen: body temperature, blood pressure, pulse, stress level, and alcohol level.

All of that has been gathered in a single module formed by three PCBs. Both hardware and software have been designed. The proposal has been assembled and the case and the band have been 3D-printed in order to form the final device with a smart bracelet form factor. This module has been designed with the purpose of having small dimensions and low consumption since it is powered by a battery.

Finally, several tests have been carried out to verify the proper functioning of the system. The biggest challenge was found while obtaining blood pressure based on the photoplethysmography signal. Through those tests, the developed software could be adapted according to the results obtained, since offset values that have to be applied and the times that sensors need could be known. This also permitted to discover errors committed during previous stages of the development process.

Therefore, it can be confirmed that the general objectives set have been accomplished.

Technical viability of the proposal could be proved, and this informs of the existence of several application fields that the project could have, as is the case of professional drivers.