The most recent oxygen generators are technically designed devices to emit oxygen-enriched air up to 90-95%, with variations not exceeding ± 3% depending on the magnitude of the flow. They are divided into fixed hubs (whose power source is represented by the normal power grid) and mobile hubs (with battery power source). Check
www.novairindustries.com if you wish to know more information about oxygen generators and oxygen production.
Safety of an oxygen generator
For safety reasons, these devices are equipped with an alarm system that activates while, for any reason, the emission of oxygen-enriched air drops to a concentration of less than 82%. Also for safety reasons, the patient who uses the device at home, without any sanitary control, is informed that he must use a bottle of oxygen gas in case of emergency and request qualified assistance for the control and maintenance of the concentrator. The weight and dimensions of these devices are rather reduced: the units currently on the market hardly exceed 25 kg.
These characteristics represent a real limit to achieving workflows and particularly high concentrations. However, even with these limitations, these units provide excellent performance for a wide range of requirements. In particular, in patients with reduced mobility, in accordance with certain clinical characteristics, the use of fixed concentrators is indicated and particularly advantageous both at home and in certain hospital or territorial health structures (for example in some hospitals), rehabilitation care centers or assisted nursing homes -RAS).
Oxygen treatment from a distribution system should be considered oxygen enriched air treatment. In other words, the percentage of oxygen is different from that which can be obtained with liquid oxygen (concentration of O2 not less than 99.5%) and generally, if certain variations of manufacturer to manufacturer, reaches 90-95% and in any case never goes below 82%. The main construction standards also provide for a tolerance of ± 3% compared to the concentrations declared by the manufacturer.
Models of oxygen generators
Beyond the small variations from one model to another, it should be remembered that the oxygen concentration provided by this type of device can also vary depending on the air flow that is desired to reach the mouth of the patient. For example, if a flow of 1 liter / minute is compatible with a generator O2 concentration equal to about 95%, increasing the flow up to 5 liters / minute, the concentration of O2 decreases until about 90%. Normally, this drop in oxygen concentration has no major significance, however, it is still a good standard to re-evaluate oxygen saturation (SpO2) and PaO2 even after adequate period (about half an hour) breathing with the flow prescribed by the doctor and issued by the home generator. The oxygen concentration is also reduced due to other factors, among which essentially the malfunctions or problems of the filters, in particular the bacterial filter. That is why it is advisable to carry out an appropriate maintenance of the device once a month or every two months. The use of the oxygen generator obviously involves a cost for the consumption of electrical energy. This cost, calculated for a 400-watt device that runs for 20 hours a day, reaches about 25-30 euros a month. In some European countries these costs are reimbursed by the health service. According to some guidelines for long-term oxygen therapy, it is not advisable to use an oxygen generator if the patient needs flows greater than 5 liters per minute. Below this limit, the use of the oxygen generator is certainly possible, although it is still necessary to evaluate the particular clinical characteristics of the patient. According to some studies, the best results with this type of device are obtained for oxygen fluxes of about 2 liters / minute, or flows that allow O2 concentrations of not less than 95%.
Technological progress favors the development of many portable type generators powered by rechargeable internal batteries that produce a flow of non-medicinal oxygen (whose concentration is less than 99.5%) with intermittent flow, in pulsed mode ( ie oxygen emission during the first part of the inspiration) or on demand (oxygen emitted during all the inspiration).