Gita 04.27 explained
sarvāṇi — of all; indriya — the senses; karmāṇi — functions; prāṇa–karmāṇi — functions of the life breath; ca — also; apare — others; ātma–saṁyama — of controlling the mind; yoga — the linking process; agnau — in the ﬁre of; juhvati — offer; jñāna–dīpite — because of the urge for self-realization.
Others, who are interested in achieving self-realization through control of the mind and senses, offer the functions of all the senses, and of the life breath, as oblations into the ﬁre of the controlled mind.
Sarvan-Indriya-karmani -> Karma of all the senses are offered;
also offered is Prana-karmani -> the activities of Prana Yau. -> In pranayam the breathing is regulated and as a means to regulate the breathing turn the consciousness inward.
In the process of astanga yoga there is a stage called Pratyahara where one cuts-off all the senses, Gyan yogis also in many ways wanted to have sadhana of astanga yoga because there process is also to turn consciousness inward, some Gyan yogi may also use sadhana of Bhakti Yoga, sometimes they may think about impersonal Brahman, or practice Neti-neti, so in whatever way they wanted to turn their consciousness inward. ātma-saṁyama-yogāgnau, they are self-controlled they are trying to turn inwards in the fire of inward mind. juhvati jñāna-dīpite – because they are illuminated by knowledge and because of the urge of self-realization, because of knowledge they realise that real knowledge is not outward but is inward.
Srila Prabhupad purport: In the Yoga-sūtra of Patañjali, the soul is called pratyag-ātmā and parāg-ātmā. As long as the soul is attached to sense enjoyment it is called parāg-ātmā, but as soon as the same soul becomes detached from such sense enjoyment it is called pratyag-ātmā.
Parag -> rag means attachment Parag means when the attachment is attracted outward, attached to things is Parag atam.
Pratyag-atma -> the soul turns inwards and soul becomes detached like pratayahar. To become pratyag atma is ultimate goal.
Srila Prabhupad Purport:
(explanation of prāṇa-karmāṇi cāpare)
The yoga system conceived by Patañjali is referred to herein. In the Yoga-sūtra of Patañjali, the soul is called pratyag-ātmā and parāg-ātmā. As long as the soul is attached to sense enjoyment it is called parāg-ātmā, but as soon as the same soul becomes detached from such sense enjoyment it is called pratyag-ātmā. The soul is subjected to the functions of ten kinds of air at work within the body, and this is perceived through the breathing system. The Patañjali system of yoga instructs one on how to control the functions of the body’s air in a technical manner so that ultimately all the functions of the air within become favorable for purifying the soul of material attachment. According to this yoga system, pratyag-ātmā is the ultimate goal. This pratyag-ātmā is withdrawn from activities in matter. The senses interact with the sense objects, like the ear for hearing, eyes for seeing, nose for smelling, tongue for tasting, and hand for touching, and all of them are thus engaged in activities outside the self. They are called the functions of the prāṇa-vāyu. The apāna-vāyu goes downwards, vyāna-vāyu acts to shrink and expand, samāna-vāyu adjusts equilibrium, udāna-vāyu goes upwards – and when one is enlightened, one engages all these in searching for self-realization
Prana vayu is one of the vayu and Prana is also generic word to describe all the five vayus, just like mind is referred as one of the settle element in the settle body but sometimes mind may be generically used to refer to settle body. We have matter mind and consciousness, mind is generically used to refer to settle body of which mind is one component. Similarly Pran vayu is generically used to refer all the pran vayus or it is used to refer to one of the five vayu. E.g. saman vayu, sometime when we move round and round we feel vertigo or giddiness, we feel like that because vayu is disrupted, disinclined. Whole system of analyzing the system based on vayu is sophisticated system of analysis, when we look at the body there are different ways of looking it, modern scientists offers a one ways of looking the body, vedic culture offers different ways of looking the body it involves Prana, it involves Shakti, avuravada offers other it is related to Cough, Vata & Pita. Prana and Shakti vedic system and ayurveda are connected.
Important principle is whole process of vyau is directed inwards, now a days people use lom-vilom by practicing this respiratory disorder will go away, similarly by doing something else other deceases go away, these things may be happening and these may be beneficial also, but the point is that it is not the primary goal of doing all these activities. All these regulation of life air is to turn our consciousness inwards.