A new respiratory valve system for measuring oxygen uptake during swimming

Abstract

We describe a new respiratory valve system with minimal dead space, which allows measurement of ventilation and oxygen uptake during swimming. The device offers considerable advantages in efficiency and accuracy over current equipment, and can be used in conjunction either with a miniaturized telemetry system for oxygen uptake measurement or with a conventional system. The valve has a low airflow resistance, a small dead space (15 ml), and an electrically operating, closed-circuit pump to remove excess water from the expiratory tube. The external form and the buoyancy of the valve have been hydrostatically and hydrodynamically designed to reduce drag and to ensure a correct mass in the water. To obtain this result a very sophisticated material, carbon fibre, has been utilized. Our studies showed that this respiratory system is ideal for obtaining valid and reliable values of oxygen uptake during swimming, even at high speed and in endurance swimming tests.

Adaptação da máscara do analisador de gases VO2000 para mensuração de parâmetros cardiorrespiratórios em natação

“…Although the drag coefficient had not been measured, the air tube of the SNK developed in the present investigation was designed in front of the swimmer's face and not on his side, as it is observed in conventional snorkels. Such design was based on the snorkels elaborated by Toussaint et al (10) and Dal Monte et al (7) since they present reduced drag values. The results of all parameters measured were highly correlated (0.88 to 0.99) and except for the VE, they did not present significant differences.…”

“…The SNK was based so that the air tube was projected to the front of the participant's face and not to his side, as it is observed in conventional snorkels. This sketch was based on the snorkels elaborated by Toussaint et al (10) and Dal Monte et al (7) since they present reduced drag coefficients. The whole system weights 360 grams and has a dead space of 250 ml.…”

“…Toussaint et al (10) , developed a specific snorkel for swimming evaluation with the advantage to generate a low drag in relation to conventional snorkels. Dal Monte et al (7) presented a snorkel similar to the one proposed by Toussaint et al (10) , but with lower dead space. These snorkels were designed however for Douglas bag.…”

“…Although the technological advance has made this kind of test performance easier, especially in swimming, it is extremely difficult to obtain a valid estimation for cardiorespiratory parameters (7) . However, the importance of these data is crucial, since the technique applied during swimming can considerably modify the energy spent for the individual to move in the liquid environment (3,8) .…”

“…However, the importance of these data is crucial, since the technique applied during swimming can considerably modify the energy spent for the individual to move in the liquid environment (3,8) . Dal monte et al (7) reported that the power generated by the swimmer to win the drag may be affected by the use of maladjusted equipment, resulting hence in higher energy expenditure to perform swimming at a given velocity (8)(9) . Toussaint et al (10) , developed a specific snorkel for swimming evaluation with the advantage to generate a low drag in relation to conventional snorkels.…”