Portable Oxygen Concentrator Needed

Please help. My dad was forced in to early retirement because of a pulmonary embolism. ( Blood clot that restricts the flow of clean oxygen to the body.) Social Security pays such a small retirement benefit that he can't afford the cost of medicaid, pay his small house payment, utilities and buy food. He used his savings to buy an oxygen concentrator machine for his home but is almost a prisoner in his home because the machine isn't portable. It makes it almost impossible and could be deadly for him to go grocery shopping etc.  All of us need an oxygen concentration level in our bodies between 95 and 100 percent. Without his machine he is around 85 to 90 percent and less at times of exertion.  Sometimes he has that 'stood up too fast,dizzy,light head feeling', that comes on unexpectedly and is very dangerous and can last for minutes at a time. All through his life he has been very helpful in many ways to many people but would never ask for financial help. With the help of your generous donations we can get him the portable machine he needs to stay mobile and somewhat physically independent. Please help me raise $2,500 to purchase a suitable battery operated 1 to 6 liter oxygen concentrator machine. Thank you.