Still stuck in my 4 meter rut. It has in a way become worse because I am now more dependent upon the oxygen than before. It used to be that I would take several hours a day off of it and sit at my computer. My problem is that you can't reduce it slowly, eventually you reach the point where there is a period of "cold turkey" where I feel like I no longer can breathe.
During that time I need to sit still, take deep breaths and wait while I readjust to the thinner air. The fact that the air is around 12% lower in pressure here in Jerusalem than at sea level hardly helps.
Even switching to the portable tank is an adjustment, the air flow is reduced. Using the oxygen concentrator, I need to set it to between two and three liters a minute of air flow, while the tank, i use at one half liter per minute. It's not a real comparison, the regulator on the tank puts out the oxygen at a high enough pressure that hose length, as far as I have gone, 6 meters, is irrelevant, it still comes out at that flow rate.
The oxygen concentrator uses a bouncing ball indicator, which really reads pressure and it is calibrated with a 2 meter hose. So to get the equivalent of one half liter per minute of oxygen from the tank, with a 2 meter hose I need to set the output of the concentrator to 1.5-2 liters per minute, 2.5-3 for a 4 meter hose and at 5, the maximum for a 6 meter hose.
So switching from the concentrator to the tank requires some getting used to, and even more to nothing at all. With nothing at all, eventually things settle down, but not at 99% saturation, so it is far less comfortable, and leaves me with a prolonged sense of being unable to breathe, no matter how hard and fast I suck the air in.
This also is a problem switching the other way, as I tend to gulp air through my mouth and the oxygen is coming in through my nose. More air, no improvement.
I have not even tried to address the issue of a gas mask, as we turned our old ones in and never got new ones. Now it looks like we may need them, and there isn't enough money for the state to buy new ones. I still have no idea of how it will work, if at all. I guess I could buy one privately that includes a drinking hose (to be connected to a special canteen), and connect it to the oxygen tank instead.
I have two tanks, one is a 5 liter portable tank, which I mentioned before. It will provide me with 1/2 a liter per minute (sitting still) for 8-10 hours. I also have a large one used for emergencies when the concentrator stops working (which is relatively often, every three months or so) which will provide 30-35 hours. It's impossible to tell as the pressure gauges are approximate and calibrated in pounds per square inch, which is not exact. My estimate is that at 2000 pounds per square inch (the nominal fill amount of the tanks), they provide one liter per minute for an hour per liter of tank. It's a guess, but seems to be close with my actual usage.
The hose itself has its own challenges. The most obvious is to not get it caught on anything. The second was not to pull too hard or loop it because it disconnects from the machine. Th first few times I did it, I wasn't aware I had and ended up wondering why I suddenly could not breathe. It's hard to tell, the hose I use goes not to the unit itself, but to a water bottle.
The water bottle provides some humidity to prevent my nose and throat from drying out completely while I use it. There is a small curved hose from the water bottle to the output of the machine, and if I am not careful it gets kinked or wrapped around the bottle and pulled off of the machine.
It also has to be removed when I turn the machine off, one of the failures I had of the machine was that when it was turned off there was a vacuum and water was drawn out of the bottle into the machine itself.
So far the rental company has replaced them free, without complaint, but I would prefer that they would just come by every other month and swap it out with another machine and take the one I have back the shop and PM it (perform preventive maintenance)
I guess is they figure it is cheaper to fix the when they break instead of PM them.
On the computer front, I tried one last time to upgrade the BIOS in the ThinkPad 770 and found a way to do it without the battery. Now it is up to date (if you consider 2001 up to date) with the correct BIOS, but it still has the problem. Oh well, back to the drawing board as it were.