Three Key Criteria for choose portable oxygen concentrator:
Criteria A: Portable oxygen concentrator must have bigger flow than our requirements. If doctor prescribe 2 l/min. We must choose a device which should provide 3 liters flow at least. We will need more oxygen when we stand up and walk. When emergency happen, we also need more oxygen than usual. We must take it into consideration.
Criteria B: Portable oxygen concentrator must produce 90% saturation oxygen at flow you required. Doctors don't write oxygen purity in prescription. Doctors prescribe oxygen dose according to oxygen therapy we received in hospital. Hospitals standard is above 90% purity oxygen.
For example: If doctor prescribe 2LPM for us, we need to make confirmation that portable oxygen concentrator could produce above 90% oxygen at 2 liters. This is lowest standard. If device could provide 90% oxygen above 2 liters, that will be better.
There are some devices designed for pregnant use and sport use. They don't need to meet medical grade. These devices just provide 93% oxygen at 1 liters. When you turn up flow, oxygen saturation will decrease to 70% at 2 liters, 60% at 3 liters, 40% at 5 liters. There is one type small oxygen concentrator just produce 30% oxygen at 1 to 3 liters flow. Please don't get confused by these devices. Insufficient oxygen will worsen illness and be harmful to our health)
Criteria C: Portable oxygen concentrator must have low oxygen alarm to monitor oxygen purity. Low oxygen alarm activate when oxygen purity decrease to less than 82%. If alarm activate, we can call Lovego service station to check machine.
If portable oxygen concentrator doesn't have low oxygen alarm, we won't know whether it is producing oxygen or normal air. If device has problem in oxygen concentration, it still looks working normally. Actually it just deliver normal air. It is great potential dangerous to our health. We will feel suffocating when we inhal normal air. It will worsen our situation and cause syncope and death in emergency situation.