Design, Development, and Validation of Medical Wearable Devices: Challenges and Solutions for Technology Integration, Industrialization and Certification

[eng] Due to the advances in the field of medical care, worldwide life span has increased over the past decades. This rise in longevity comes hand in hand with an increase in health expenditure as aging-associated diseases are becoming more prevalent. Aging associated diseases are normally chronic illnesses that need constant attention from medical personnel, as patients need continuous monitoring and specific treatment to palliate the effects of their illnesses. Given this situation, new tools are required to assist healthcare professionals in their work. Wearable devices have proven to be a useful tool for medical personnel, as they allow for continuous and remote monitoring of patients, eliminating the need for doctors and nurses to carry out tracking tasks. By reducing workload, resources can be utilized more efficiently, making the healthcare system more sustainable. Although the usefulness of these devices, most of these systems are not reliable because they are consumer electronics devices, which are not certified as medical equipment. Medical certification is essential to utilize a system in a clinical environment and it ensures that the equipment has a high standard of quality, and it is safe for both patients and healthcare personnel. To assess an individual’s health status, multiple parameters can be measured, although vital sign monitoring is the most common method. Vital signs are a set of physiological parameters that reflect the essential functions of the body. These parameters are within a well-defined range when the individual health is optimal. Despite monitoring vital signs is very useful, they do not show the complete picture. To complement the information provided by these parameters, the biochemical data, such as the level of glucose in blood, must be collected and analyzed. Blood tests are the gold standard method for biochemical analysis, but it has several drawbacks that limit its use. These tests are invasive, require trained personnel, and only allows to know the state of the patient at the moment of the extraction. An alternative analysis that has gained a lot of interest during the past few years is based on the use of sweat as the sample to be analyzed. Sweat analysis is non-invasive, does not require a professional to collect the sample, and can be performed continuously, as this fluid is always present on the skin due to the body's thermoregulation. The goal of this thesis is to develop wearable devices for a comprehensive health monitoring system. These devices are capable of measuring a patient's vital signs and analyzing their sweat. Monitoring both parameters allows for a precise and complete assessment of an individual's health status. On one hand, the development of a medical-grade wearable device capable of monitoring patients' vital signs is presented. Not only the device has been developed, but the certification and industrialization of this system have also been carried out, giving as an outcome a robust product ready to be utilized in clinical environments. This new monitoring tool allows healthcare institutions to remotely assess each patient's health status and improve the care provided through efficient resource management. On the other hand, a novel system capable of capturing and analyzing an individual’s sweat content in a non-invasive and continuous manner has been developed. This device can be an invaluable tool for medical personnel, as it can provide information only available through invasive methods such as blood analysis. Monitoring both vital signs and multiple biomarkers in sweat provides a precise and complete assessment of the patient's condition. This system formed by these two devices has the potential to revolutionize the field of healthcare, as non-invasive, continuous, and comprehensive patient monitoring can be carried out.