PHYSICAL FITNESS ASSESSMENT USING BLOOD FLOW RESTRICTION

"Regular monitoring of the cardiovascular system is a recommended activity that may help to ensure adequate levels of health. Devices such as sphygmomanometers or blood pressure monitors, including inflatable cuffs, are used to measure blood pressure. This is usually done in a non-intrusive way. Blood flow studies can also be done on limbs using inflatable cuffs. For example, blood reperfusion studies can be done by applying a restriction on the limb and releasing pressure afterwards. The time it takes for blood to flow back into the blood vessels of the limb can be measured. These studies can be performed on patients or elite athletes. In the case of elite athletes, it is necessary to estimate their actual physical fitness and performance potential. Intrusive techniques can be used by introducing catheters to obtain blood samples and measure directly oxygen delivery and utilization, by assessing arteriovenous differences in oxygen content combined with the measurement of blood flow. The combined assessment of arterial and venous O2 content may allow the calculation of oxygen extraction, which, in itself, may be a significant variable related to health status and performance potential. Therefore, devices that are used to assess some aspects related to the performance or physical fitness of an athlete or a patient involve the use of intrusive devices and techniques. This entails discomfort for the athlete or patient and may require the presence of qualified personnel, with the results obtained after some delay. The proposed system makes possible the obtention by non-invasive measurements of venous oxygen data of the main vein draining the limb and/or one of its tributaries."