Repairing Oxyhealth Vitaeris 320 Hyperbaric Chamber With a Window Leak and a Splitting Zipper

My Oxyhealth Vitaeris 320 hyperbaric chamber is old, and last fall the window seal started coming apart. I spent hours and hours researching it on the Internet. There was a fellow who sold chambers who had a web page claiming he had found a glue that would hold, but when I contacted him, he told me that it came apart after about a month. Like me he spent hours and hours testing different glues without success. He finally put the broken unit in storage thinking perhaps a rigid (not soft like the chamber) porthole solution might work. I attempted to glue it with various glues based on recommendations found on the Internet, always without permanent success. It is very difficult to glue the fiberglass impregnated nylon the chamber is made of because it seeps an oil that makes the bond only last a short time. I had a mishap and melted a hole in the clear plastic of the window. That was very worrying to me, but I found ordinary hot glue adheres to it nicely. The original problem remained. If you haven't ruined it by trying glues that can't be removed, you can send your chamber back to Oxyhealth and they will repair it using the original plastic welding technique, but the shipping and repair are very expensive. I found using strong magnets that holding the flaps of nylon together tightly worked after a fashion. The chamber has an exhaust valve that vents air after the chamber reaches 4 psi above atmospheric pressure, so some leakage is tolerable. However, the air escaping just further eroded the plastic weld that originally held it in place separate more, and the window started coming apart a lot more.
This chamber seems to help my glaucoma, so it was important to me that I get this repaired in a permanent fashion so I kept at it. My final (I hope) solution is shown below. I ordered some square steel washers (M3x1x20) (dimensions in mm) and some M3 nuts and bolts. I then ground the sides of some of the washers so they were trapezoidal and would fit the curves of the window. Then I drilled holes (just smaller than the M3 bolts) through the chamber so I could bolt it together where it was coming apart using the bolts and washers on each side. So far, it is working well. I can't even hear any air escaping by the window now. I also have some Harbor Freight cargo straps holding the pressure. I might be fine removing these but at least for now, I'm leaving them on. The newer chambers come with similar straps, and now I know why. Some photos are shown below.
The repaired chamber from the outside The repaired chamber from the inside
About a year after the repair, I had to add a few more bolts and washers to seal where the window split had expanded. It was an easy and quick repair, because I still had some square washers, nuts and bolts left over.
Since this repair, my friend with a smaller chamber was able to repair a window leak with HH-66 vinyl adhesive. I actually bought a bottle before I knew of his success, but was too afraid to try it, for fear it was an irreversible process.

Oxyhealth 320 Zipper Repair

My outer zipper popped apart one day. It just split as I was inflating the chamber. This was a circumstance I feared would happen someday. I have tried to be very careful, but zippers are not forever. To repair it, I carefully unzipped the slider so it was open again. Then I put a cargo strap around the outside of the chamber holding the zipper together. It is adjusted so it does squeeze the chamber a little when inflated. I have been running it this way for several months now without a problem. Recently I was worried that this strap was squeezing the chamber too much, so I loosened it. The inner zipper popped apart the first time I inflated the chamber. I very careful zipped the slider back over the split area to reopen the zipper. Evidently loosening it was a bad move, so I tightened it back up like it was and the chamber reinflated without the zipper popping. I'm so thankful! Here is how it looks on the inside with the strap tightened back up with the zipper holding.
Photo of the strap indentation in the chamber....

I did some googling, and found that Summit to Sea uses a German oil for their zippers. I also contacted Trevor at Oxyhealth, who has been very helpful in tho past. He said not to put the oil on the zipper. He also said to be very careful to unzip the chamber all the way after every use. So I haven't applied oil and am now careful to unzip the chamber all the way. I hope to get more years of use from this unit. I heard it was $1,600 to have Oxyhealth put a new zipper in the unit.

Further zipper tips after another year or more running the chamber: I started having problems with the inner zipper popping open intermittently. I would have to reverse the zipper over the open split to the beginning and rezip it. Recently this didn't work anymore. Careful investigation revealed there was still a tiny place near the start of the zipper where the coil zipper was not meshing. I reversed back over that to the beginning of the zipper, and took a set of pliers, and pinched the zipper pull so it was tighter around the zipper. I didn't remove the rings in mine that make pulling the zipper easier, but next time I would remove them before trying to pinch the zipper pull as it was in the way. It now zips with more difficulty, but I haven't had the problem with the inner zipper popping open with a loud bang.
After doing the pinch fix for about a year, the inner zipper started needing it more and more often. It was down to almost every week. Finally, the zipper pulled broke from the metal fatigue. Fortunately, Trevor from Oxyhealth had a replacement zipper pull, and he sent it to me. First I removed the white zipper stop that keeps you from unzipping it too far. I put this aside. I then took a seam ripper and cut the threads that were holding the tail of the zipper in the tight place where it is sewed in at the end. I had to cut the two stitching lines across the end and then about half an inch down the side, so I could slide the zipper ends out of the tight spot. I was then able to carefully put the new zipper pull on the old zipper with in the correct orientation. (I didn't want to get it upside down.) Then I put the white zipper stop back in and attempted to crimp it down. It wasn't really great, so I put a piece of gaffer's tape over it to keep it in place. If I do it again, I might put it slightly inside the pocket, so the pressure holds it in. I was able to stuff the zipper back in it's pocket and put the ring back on the pull. Without even trying to sew it back up, it is holding the 4 psi just fine. Thank you Trevor!!

O2 Concentrator Replacement

In 2020 I was considering taking my chamber overseas for use on a three month assignment. The shipping was going to be expensive, as there was a lot of equipment to ship. I had the chamber, which could be packed up into a big box, but my O2 concentrator was an external unit that was large and not as easy to pack. I got to wondering why it had to be so big. The reason is that the O2 concentrator outside the unit needs to work against the back pressure of the chamber. I decided to try a small concentrator obtained from Amazon for about $300. (These are harder to buy now, probably due to Covid.) This unit had a smaller liters per minute rating, but I put it inside the chamber and run an extension cord in the hole where the oxygen tube used to go. You have to slow the output down to get a high concentration of oxygen, but it seems to work just fine. This is a cheaper way to replace your oxygen concentrator at the sacrifice of a little room inside. I prefer it as the concentrator sits nicely at my feet, and I have a lot of space saved outside the chamber where the old concentrator used to be. Now I have a power strip for powering my laptop and charging my noise canceling headphones inside, which is a big benefit.

My Visual Field Tests and Their Implications for Hyperbaric Oxygen Treatment of Open Angle Glaucoma

This is not medical advice, because my doctorate is in electrical engineering, not medicine. I will tell you what happened to me though. I have open angle glaucoma. I have been taking Latanoprost for years. In June, 2019 my visual field test caused doctor great concern. I had failed with my left eye. I still remember having all kinds of difficulty seeing the flashes, and I was trying hard to see them. My doctor wanted to know what had changed in my lifestyle. She said my eye needed more oxygen. I wasn't quite sure just then in her office, but as I rode my bike home, I figured it out. I normally spend about an hour a day in the hyperbaric oxygen chamber. I do this because I feel better and think I can concentrate better if I do. I'm an engineering professor, and the last two quarters before my test in June, 2019, were very busy making videos and other things I could not easily do in the chamber, so I discontinued its use. After doing a little research, I started up again, getting in a couple weeks of treatment. I had a vacation scheduled, so the next several weeks there was no chamber time. I came back and did another visual field test. See my results below. The last two columns are the interesting ones.
My visual field test results
An article I found in PubMed on a clinical study for using hyperbaric oxygen to treat open angle glaucoma encouraged me to get back on hyperbaric oxygen.. I probably would have done it anyway, but it was nice to have the encouragement. My results seem to me, even more striking than theirs.