[Equipment] DIY CPAP

[aviB]

  Easy to build and affordable CPAP device for adult.pdf (Size: 265.44 KB / Downloads: 950)

Hi Forum!
As you know many struggle to attain the diagnosis of OSA let alone afford and tolerate the therapy. I am thoroughly impressed by the community of users within this forum and the DIY spirit that should transcend more of medicine. I am a sleep physician and would be happy to collaborate with folks.
Please see this attached article on DIY CPAP.

[DeepBreathing]

Hi aviB. Welcome to Apnea Board.

The thinking behind this device is excellent. I could see all sorts of troubles getting it registered in a "western" country but for some developing nations it could be a lifesaver. Do you know if trials have been done to guarantee the safety and efficacy of the device?

Another thought that occurs to me is that in some of the poorer nations I've visited (eg Myanmar and Laos) I don't think sleep apnea is even on the radar as a health problem. Many of these places are still struggling for clean water and very basic medical services.

[Dog Slobber]

Within the document is a link to a more detailed PDF including pictures, schematics and code.

http://www.ub.edu/biofisica/dwn/CPAP%20d...iption.pdf

[zzzZorro]

Hi Forum!
As you know many struggle to attain the diagnosis of OSA let alone afford and tolerate the therapy. I am thoroughly impressed by the community of users within this forum and the DIY spirit that should transcend more of medicine. I am a sleep physician and would be happy to collaborate with folks.
Please see this attached article on DIY CPAP.

Somehow I would suspicion a 'technical challenge' to building such a sophisticated [microchip/printed circuit] device by people who are confused about the kind of water to use would not gain a lot of traction.

[Perchas]

With an Arduino, a three-phase turbine controlled by frequency variator, an LCD display and a 20W medical Power Supply would be more accurate, simple and much cheaper to manufacture.

Value this possibility

By the names of the authors I think they are Spaniard, is that right?

[aviB]

That's true. These countries have enough health issues that sleep apnea isn't a priority. This group focused on health care institutions and/or universities building their own devices to use PAP for critically ill patients, especially if ventilators are not available. 
In the spirit of open source health and public health - software and hardware need to be closely intertwined.

[slowriter]

I love this idea. Would seem to be the next step.

Is there any hardware difference between CPAP and bilevel machines? Do the latter need a different kinds of blower?

Occurs to me that if not, or there's not a significant cost difference, an initiative like this should target bilevel, and then innovate on the software side to provide different functionality, algorithms, etc.

[RNeil]

This is very interesting. I was surprised to see an analog PI controller. A digital controller would be more flexible and could be integrated in the Arduino.

I think a fixed pressure device would be easy to implement. Beyond that, I do not know anything about the algorithm. Do we want to provide any information for Oscar? I don't know how to do that either.

[hearsay73]

Excellent idea. I can see application for this in countries where a CPAP machine is cost prohibitive.

I'm wondering about the cost of building it though as I couldn't find it in the documents. Building the box is around 15 euros (around 16usd) as indicated. For the rest of the components?

[eecharlie]

Interesting!

I'd second the comment about it being strange to use a hardware analog PI controller, especially when there's an Arduino in there just to update the LCD! The entire control algorithm can and should be implemented in the microcontroller. The difference between a CPAP, BiPAP, APAP, etc is just the control algorithm, not the hardware. 

The Raspberry Pi Zero (and other Pi variants) now costs less than an Arduino and can be web-connected easily, so probably makes more sense as the computing platform. You could optionally skip the display and use a mobile phone for the interface to cut costs (though, this is meant for places people are much less likely to have smartphones).

To get the level of comfort that I imagine has a big impact on compliance (usage) that we enjoy with modern machines, you need a good control algorithm as well as comfy face masks.

With some effort it would be possible to identify most of the specific control algorithms used on modern CPAPs by feeding a data set through some system identification signal processing.

This design could be updated and simplified to the point where it can be contract manufactured and sold by Tindie