<$free info on the Origin of Pranayam$>

Pranayama has been treated as the part of Yoga. And was practiced by saints. But it was too much importance to given to do hard and difficult yogasanas which resulted in the neglect of exercises for the inner organs of the body and the cells within. But Patanjali, modern yogis like Baba ramdev and Baba lalitji recognized the pranayama and its importance in good health. They both followed the father of yogic science in india that is saint Patanjali's yoga sutras ( the principles of Yoga) .
Baba Ram dev has did research on this pranayama and understood its properties of curing and controlling of human ailments and diseases through his yogic camps. However it is practices in different yogic camps by different yogic gurus. Popularly ramdev's yoga is called "Divya Yoga".

Anyway with the yogic principles laid down by the saint Patanjali Baba Ram dev discovered it and made more popular through his television channel shows. He is just regarded as the father of modern yoga in the modern times of India. The whole credit goes to him for making pranayam as the independent science for providing health for all.