Development of a bio-radar system for non-contact detection of vital signs

Non-contact remote sensing of objects is among the topics that humanity has been working on for nearly a century. In the last two decades, beyond the sensing of the object, it is aimed to extract the properties of the determined object. Thanks to the features of the radar, many applications can be made today such as vehicle speed measurements, classification of underground objects, even identification of living things behind obstacles and tracking meteorological events. In addition, radar also finds itself a place in the medical field. Especially traditionally, the fact that information obtained by contact with the patient can be received via radar in a contactless manner makes it extremely reasonable. Because this situation allows the patient to move comfortably and prevents extra injury. It also makes the job of experts easier. Therefore, it shows that the radar can be used in situations such as the vital signs detection, sleep tracking and mental stress detection. Radars used for these purposes are called bio-radar. In this thesis study, a bio-radar system is developed according to two different radar types. First, simulation studies have been carried out for bio-radars. Then, Continuous Wave (CW) bio-radar structure was constituted and its working principle has been explained. As a result of experimental studies with the constituted bio-radar structure, vital signs have been obtained with two different algorithms. Due to the lack of range of the CW radar, the frequency modulated continuous wave (FMCW) bio-radar structure has been also generated to eliminate the range disadvantage. In consequence of experimental studies, both the range of the human subject has been determined and vital signs is obtained. The performance of the FMCW bio-radar generated by performing multiple human subject measurements has been presented. In studies, the effect of range on the accuracy of detecting vital signs has been observed. High accuracy has been achieved by determining the respiration rate with almost one beat error rate within both bio-radar structures. However, the results obtained in determining the heart rate are not sufficiently consistent compared to the reference values due to the extremely small chest wall motion due to heart rate. According to the obtained results, it is foreseen that in the future, bio-radars will replace the devices that make measurements performed by body contact in the field of medicine.