(07-03-2014 08:34 PM)becker44a Wrote:
(07-03-2014 01:42 PM)SuperSleeper Wrote: Just from watching the video, the only concern I would have is the durability of the flexible "membrane" that covers the tubing. It just "looks" thin and fragile on video and I'm wondering at what point the tubing would develop cracks and leak-points.
I watched the video - very interesting idea. A couple other concerns come to mind. I use a ResMed S9 Autoset, and it is pre-programmed to use either of 2 diameters of hose: 15mm (Slimline), and 22mm (standard). Someone will correct me if I'm wrong, but I believe the Climateline heated host is the 22mm diameter. It is necessary when setting up the machine to designate the type of tubing, which implies the diameter. Your video does not indicate the diameter of your product, except to say it has "a larger bore". The machine's programming expects and supports only 2 sizes of tubing. What will be the effect on the data collection and therapy functions of the machine from using a replacement tubing if it does not match one of the "standard" diameters?
Also, part of the programming of the S9 Autoset includes an (FOT) algorithm for detecting the difference between Obstructive and Central (or Clear Airway) apneas, and adjusting the machine's behavior accordingly. If the machine is operating as an Auto-PAP, it can respond to an Obstructive event by increasing the pressure. It does not increase pressure when it detects a Central event. So the correct performance of the FOT algorithm is critical to the S9's treatment. The FOT algorithm sends 4 hz pressure pulses down the tubing, and watches the pressure and flow sensors for indications that the airway is open or not. A traditional PAP tube will always have a (nearly) circular cross-section during use, regardless of the twists or turns in its path. The TravelHose will not - its cross-section will vary based on the flexible covering. I am concerned that the TravelHose might have quite different fluid dynamics than a traditional hose, and might influence or impair the FOT detection. This could be very detrimental for a patient who is susceptible to pressure-induced Central events. I am much less aware of the PR equipment, but I imagine they also have a means to differentiate between Central and Obstructive events, so a similar issue may exist for those machines.
Good luck with your project.
Your concern is certainly in place, but I think it is not as significant as it may appear. I can list several reasons for that:
A. First , the Travelhose is only slightly larger in diameter than the standard hose (23-24 instead of 22 mm). So no huge difference there.
B. Thanks to the internal spring support, the bore (or lumen) through which the air flow is mostly circular. It is certainly smoother along much of the length of the hose than some of the lower cost hoses on the market.
C. I've tested the Travelhose resistance to flow, and validated that even under the worst situation of being folded 180 degrees (right back in itself) on a zero radius (something standard hoses simply can't do), pressure drop is only about 1cmH2O at 80l/s! This is comparable to the best hoses.
D. The Travelhose is not intended as a replacement for your everyday hose, but rather for use during travel. I think the extra comfort of having a collapsible hose outweighs the slightly compromised (if at all, this remains to be tested) performance for a few days.
I hope you find my answers reasonable, and will support me buy pre-ordering one or more Travelhoses for your next vacation, OK?
Can you help me find more CPAP users forums like this one?