The Defence Research & Development Organisation (DRDO) has started serving the nation in more ways than one. In an ingenious move, the Defence Bio-Engineering & Electro-Medical Laboratory (DEBEL), a lab under DRDO has modified the On-Board Oxygen Generation System used in Tejas for Medical use.
One of the symptoms as well as consequence of being infected by Coronavirus is lack of oxygen level in the body of the host. The demand from extremely high number of cases emerging daily has put an unforeseen pressure on the supply of medical oxygen. There is a dreadful shortage of oxygen in almost all parts of the country & the entire supply chain is somehow managing to make the ends meet.
In another discussion, DRDO has developed a system planned to be used in Tejas Mk2 or MWF which can generate infinite amount of oxygen for the pilots who are required to stay for extended periods of time in the air while flying the aircraft. When flying above 25,000 feet, due to thin air & lack of oxygen, pilots without a continuous supply of oxygen can only stay conscious for 3–6 minutes before slipping into Hypoxia. Traditionally this task of providing oxygen in the cockpit has been done by carrying heavy oxygen cylinders in the aircraft. This has a limitation of weight & time. Standard oxygen tanks on the Tejas allows a flight time of somewhat more than an hour. After that the aircraft has to land on the base to refill oxygen. This creates additional load on ground & increases the turn around time of the aircraft, not to mention managing the logistics of oxygen cylinders. On a bigger picture, the aircraft’s range & endurance is limited not only by the fuel it carries, but also by the oxygen available in tanks for the pilot to breathe. Tejas can refuel in the air for extended duration missions but there is no way the aircraft can get oxygen if it runs out of it.
Here comes in the On-board Oxygen Generation System (OBOGS) developed by DEBEL of DRDO. Firstly this system has no tanks at all & is a very small & portable system. The system takes the bleed air from the atmosphere, separates the oxygen from it using a process called Pressure Swing Absorption Technology, supplies it to the pilot’s O2 mask & discards the rest of the oxygen deficient air back into the atmosphere. This eliminates the need of carrying oxygen cylinders (though the aircraft still has smaller backup oxygen cylinder in case the OBOGS malfunctions). This allows the aircraft to stay longer in the air with only the fuel constraining its range & endurance.
Now there is an urgent need of oxygen for COVID infected patients & there is a parallel technology available that can generate oxygen out of thin air. DRDO decided to fuse the two. The organization has designed a plant based on the Tejas Mk2’s OBOGS technology that can generate up to a maximum of 1,000 litres of oxygen per minute round the clock. This can cater to at least 50 ventilators in ICU for an unlimited time.
Now producing the oxygen is one thing & delivering that oxygen to the patients is completely another. In the cockpit where the OBOGS & the pilot are in the vicinity of each other, oxygen can be directly transported as produced but doing that in a hospital scenario is not feasible. Here comes in another system by the same organization. DEBEL has developed the portable cylinder based SpO2 (Blood Oxygen Saturation) supplemental oxygen delivery system which is used to deliver the oxygen to soldiers posted at extreme high altitude areas.
In the human body, haemoglobin binds the oxygen & carries it through the blood stream to organs & tissues. Normal oxygen saturation is between 96 to 98% in a healthy body. This supplemental oxygen delivery system automatically detects the low blood oxygen saturation level in the body & delivers the oxygen from the system, thus preventing the soldier from sinking into a state of Hypoxia. The same system will be used to transport the oxygen generated from OBOGS based plant & deliver it to the patients.
These technologies have been transferred to a private industry already. UP has already ordered 5 units of the OBOGS based plant to address the COVID wave in the state.
Still, challenges at the operational level exist. Channelizing the oxygen in cryogenic tanks in the right quantity & at right time remains a crucial pain area. Nevertheless, this is a noble effort by DRDO to serve the country. We wish these efforts will be fruitful, we will save as many lives as we can in these difficult times & come out of this pandemic stronger than ever.
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