Tuning a New ECG and Breath Monitoring System Through Cardiopulmonary Exercise Test Comparison: The Case of IUTA Athletes

Heart Rate (HR) and Breath Rate (BR) are important parameters that define the physiological state of the subject during life and are suitable for the evaluation of the athlete training or performances during a race or a match. In particular for runners, these are two indexes that can be easily monitored during the performance for the athlete to understand their physical state as well as for the trainer or the coach to improve the athlete deep knowledge and better design the subject specific training.

The HR can be typically acquired by lots of different technologies. For example, there are lot of smartwatches and HR monitors that can acquire and display the HR but just a few of these devices can acquire correct ElectroCardioGram waveform (ECG), without the possibility to detect the BR. All these devices can be bought and are ready to use.

In this paper, a simple and fast fitting new device for ECG and BR acquisition is presented. This device is a first optimized prototype that use a reduced number of electrodes on the torso to acquire both the ECG waveform and a BR signal that are sent via Bluetooth connection to a processing and visualizing device.

In order to evaluate the reliability and precision of this device we have defined an experimental campaign. Two IUTA athletes (a man and a woman) have been selected to wear the device during a Cardio Pulmonary Exercise Test (CPET). IUTA is the Italian Ultramarathon and Trail Association and the two athletes are ultrarunners that compete in 24 hour run, where the goal is to reach the longest distance possible. The athletes have been informed and have given their consent.

CPET enables to assess the performances of heart and lungs at rest and during exercise with non-invasive techniques. In particular, it provides an assessment of the integrative exercise responses involving the pulmonary, cardiovascular and skeletal muscle systems, which are not adequately reflected through the measurement of individual organ system function. CPET includes the measurements of respiratory oxygen uptake (Vo2), carbon dioxide production (Vco2), and ventilation during a symptom‐limited exercise test.

During the experimental campaign the proposed device is fitted on the athlete along with the CPET apparatus. The athlete has to run at 7 kilometers per hour in the warm up phase for two minutes while the speed increases to 12 kilometers per hour during the exercise phase which lasts until the HR reach the 90-95 % of the maximum HR value or it stabilizes on an acceptable one.

The BR track and ECG waveform acquired by the CPET are compared to the ones acquired with the new device to confirm the reliability and precision of the system and define some athletes’ characteristics.

Thus, even though the proposed system is at an early stage and further development is still needed, it demonstrated to provide data with similar accuracy to the ECG and BR of the CPET instrument, while having the option to wear it during the routine training and performance of the athlete. Therefore, the data that can be acquired are more realistic and are referring to the athlete specific gesture and motions.