<qa>  What is the distance of the 6-min walk recorded?1. A 6-minute.walk: oximetry tests of 20 healthy volunteers simultaneously tested using Oxitone oximeter and standard fingertip pulse oximeter in accordance with the industry Medical standards of 6-min walk protocol. Measurements are collected and recorded continuously prior to test, during the test and after 6 minutes the test. The distance of the 6-min walk will be recorded CRF. 