Kidney cancers can be cystic, and differentiating between a single benign cyst of the kidney and a kidney cancer can occasionally be a problem. When many cysts are present, as in polycystic renal disease, the distinction is easier. Cysts may also be caused by some parasitic infections.
It will actually collect the oxygen in the ambient air (~21%) and convert it into a concentration of around 85-94%. One of the main reasons you would want a concentrator over a tank and regulator would be when you are using a lot of oxygen for taking ozone saunas or ozonating oils.
The flow rate o f oxygen is usually adjusted to increase or decrease the amount of oxygen that patients are receiving. Standard oxygen sources can deliver from Â½ liter per minute of O2 to 5 liters/minute (L/min). Every liter/minute of oxygen increases the percentage of O2 the patient breathes by 3 â 4 %. Room air is 21% O2. So if a patient is on 4 L/min O2 flow, then he or she is breathing air that is about 33 â 37% O2. The normal practice is to adjust O2 flow for patients to be comfortably above an oxygen blood saturation of 90% at rest. It is often, however, the case that patients need more oxygen for exercise.