HAPO CHAMBER DEVELOPED BY DRDO

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High Altitude Pulmonary Oedema (HAPO) chamber has been developed by Defence Research and Development Organisation (DRDO). The chamber has been designed as a portable first aid device that provides emergency treatment for varying degrees of Acute Mountain Sickness including HAPO by Defence Bio-Engineering and Electromedical Laboratory (DEBEL), Bangalore. It works on a simple but effective principle of increasing the atmospheric pressure around the patient thereby simulating descent in altitude. The patient is kept inside the chamber and can be inflated to a maximum pressure of 130 mm Hg thereby simulating a descent of about 8000 feet without any physical movement.

The HAPO chamber is lightweight cylindrical bag weighing about 5 kg only. It is fabricated using a double ply nylon fabric with neoprene coat, which is durable and cold resistant. The foot pump provided with the chamber is 1.2 kg in weight and has the stroke output of 3 litres. The time taken to inflate the chamber is approximately 5 minutes. A simple adjustable leakage valve is provided for wide range of control of ventilation to the chamber.

In automatic model, the pressure is maintained with Automatic Pressure Control (APC) unit, which is connected to 12 volt DC supply. Batteries (both primary and rechargeable) specifically designed to work at sub zero temperatures have been identified for supply of power to this APC unit. APC unit with a compressor working on AC power supply for inflation of chamber is also offered.

The HAPO chamber was earlier used to be imported. The indigenously developed chamber is four to five times cheaper and also of better quality than the imported version. The chamber is already in-use with the Armed Forces.