High-efficiency oxygen enrichment unit may help treat COVID patients

The device concentrates oxygen from air by selectively removing nitrogen. Using the unit, oxygen-rich air can be delivered to patients with lung complications caused by coronavirus

Representative photo

In a development that could provide crucial support to COVID-19 patients, the Central Mechanical Engineering Research Institute (CMERI), Durgapur, has developed an oxygen enrichment unit (OEU) that is nearly three times more efficient than its competitors and also works well at high altitudes.

An apex R&D institute for mechanical engineering that functions under the aegis of the Council of Scientific and Industrial Research (CSIR), the West Bengal-based institute has transferred the technology for this OEU to Zen Medical Technologies Pvt. Ltd, a private company based in Ranga Reddy district of Telangana.

OEU is a device that concentrates oxygen from the air by selectively removing nitrogen. Using this device, oxygen-rich air can be delivered to patients with respiratory problems like lung complications caused by COVID-19, using an oxygen mask or nasal cannula, stated the Ministry of Science and Technology on Thursday (April 8).

The material cost of the device is approximately Rs 35,000 per unit. The sub-systems of the OEU are compressor, solenoid operated 3/2 valves, flow meter and pre-filter. The compressor feeds pressurized air into the module and oxygen is enriched on the permeate side due to its preferential permeation over nitrogen. Suspended particles, viruses, bacteria present in the air are filtered out by a HEPA filter.


The device could be used in remote places, homes or hospital-like facilities for patients with chronic obstructive pulmonary diseases (COPD), chronic hypoxemia and pulmonary edema. It may also be used as an adjunct treatment for severe sleep apnea (in conjunction with a continuous positive airway pressure unit).

According to Prof Harish Hirani, Director of CSIR-CMERI, the indigenously developed OEU will be very useful for homes, hospitals, and defense forces, particularly in high altitude terrain and remote rural localities. The device can be more effective and crucial for treating COVID-19 patients, he was quoted in the statement issued by the Ministry.

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Dr Hirani feels this device may help reduce the demand for oxygen cylinders and ventilators that has been on the rise due to spread of Coronavirus infections. Since air pollution is also increasing, demand for this OEU is expected to grow very rapidly as it is also useful for maintaining proper oxygen levels for a healthy environment indoors.

The CSIR-CMERI device works on the principle of pressure swing adsorption (PSA) and utilizes zeolite columns to selectively remove nitrogen from air under certain pressure, thereby increasing the oxygen concentration, the statement said. The unit has been tested at TUV Rheinland India, located at Bangalore, according to IEC 60601-1 3.1 edition: 2012 standard for electrical safety compliance whereas the oxygen enrichment percentage vis-a-vis outflow has been tested with CSIR-CMERI in-house facility.

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The OEU is capable of delivering up to 30 LPM Oxygen enriched air, which is absent in units that are commercially available now. The machine can regulate flow with accuracy 0.5 Ipm. This facility will help in high flow oxygen therapy that is proven to be a better method in treatment and management of COVID-19 patients, the statement said.

OEU that are available in the medical devices market in the country generally work till 8,000 feet from sea level. With an optional plug-in module, this unit can work up to the altitude of 14,000 feet with a penalty on flow rate, thereby making it very handy for the usage at high altitude by defences forces in case of contingencies.

Though some other research establishments in the country have also developed similar devices, the CSIR-CMERI system having an outflow at 93% oxygen concentration level and 5 LPM is far ahead than those that merely give the outflow of around 27-35%. The performance benchmarking of the unit found it to be at par with the similar devices marketed by reputed multinational companies, the statement said.