Ultrasound scanning of inferior vena cava to study the hydration condition during sport

Water is essential for our body: more than 60% of our weight is made up of liquids. The analysis of fluid loss during sports performance is crucial for an athlete, as intense sweating can cause dehydration. It can lead to worsening of sports performance, cardiovascular fatigue and, if prolonged and in extreme situations, even hyperthermia, failure of the gastrointestinal system, heat cramps and death. Fluid balance, i.e. the optimal ratio between fluid intake and loss, is critical to athlete performance and safety during exercise, especially in extreme environmental conditions such as high-temperature environments. Being able to perform a fluid loss analysis in a short time and with precision is certainly useful to optimize training and physiological recovery. The aim of this master's thesis is therefore to investigate the fluid dynamic response of the athlete after an effort, noting its effects on the IVC. Currently, methods are used that require long processing times and, consequently, also lengthen the time to know the results, making timely intervention impossible. The ultrasound analysis of the inferior vena cava (IVC), on the other hand, is immediate and allows to verify in real time the volume status of the sports subject, providing an estimate of the hydration status. The main objective of the project is precisely to study the level of hydration of athletes during sports activities and during recovery, to monitor them and improve their performance through real-time control of the diameter of the IVC, using a portable ultrasound probe and a segmentation software owned by Viper s.r.l. To this end, some candidates were subjected to sweating activity. In detail, the dataset is composed of 21 subjects, 9 women and 12 men, and contains healthy subjects differentiated into sportsmen (14) and non-athletes (7), with an age of 24 +/- 2 years and a weight of 70.3 +/- 11.8 kg. The test protocol provided for subjecting candidates to a sporting activity, i.e. 4 sloping walks on a treadmill lasting 10 minutes each, with slope and speed parameters varying according to the amount of weight lost. During the activity, a POLAR band was worn for ECG monitoring and ultrasound scans of the IVC were performed to observe the variation in the diameter of the IVC, assuming a reduction during the activity. At the end of the acquisition phase and after obtaining the average diameter in the different frames of the ultrasound video, three parameters were calculated that indicate the collapsibility of the IVC: caval index (CI), respiratory caval index (RCI) and cardiac caval index (CCI). By correlating these parameters and segmented diameters with initial patient data by means of statistical tests (two-sample t-test, one-way ANOVA, multi-way ANOVA), any significant differences in the dataset were evaluated, but were not highlighted. However, the initial assumption on the diameter trend was respected. During exercise, a gradual reduction in the diameter of the veins was noted, while an increase was observed during hydration. The demonstration of these trends was obtained by interpolation between values using linear regression.