Monday, August 31, 2009

The Crisis is Near Now

A High Frequency Oscillatory Ventilator Design

Some of the news items I have been reading say that there will be a particular shortage of high frequency oscillatory ventilators. Many ICU units do not have any or may only have one. This type of ventilator is required to care for patients with the most damaged lungs.

I found a design for such a device in the IEEE transactions on Biomedical Engineering publication. Here is the drawing.















The link to the PDF is located at this link.
The PDF essentially gives instructions on how to build this ventilator.

This device is much more complex than the basic ventilators I have built, but it seems that it would possible to build such a ventilator from common valves, sensors and control systems substituting for some of the components that are listed. The diaphragm actuator for example could be a large bass (subwoofer) type speaker.

It would be great if someone could build one of these unists and get back to me about how feasible it is and how well it works in testing.

Next week an idea for using ECMO.
Don't know what ECMO is?
Have a look.
http://panvent.blogspot.com/2009/09/using-dialysis-machine-to-do-ecmo.html

Now My Rant
Many of the recent reports that I have read indicate that there is a high likelihood that the current H1N1 pandemic will result in very busy ICU units and shortages of ventilators this fall in Canada. Doctors that work in ICU units that have had to treat H1N1 patients with Acute Respiratory Distress Syndrome (ARDS) say that the patients may have to be on a ventilator for a longer time period than they have seen with patients that got lung function complications in normal seasonal flu.

Here is a link to one such news item from CP.
Intensive care units likely to be main battlegrounds in the war against H1N1
There have been many stories like it originating from hospitals in Canada, the US, India, Australia, UK, Brazil, etc.

When I first proposed the Pandemic Ventilator Project two years ago as a means to alleviate some of the needs for ventilators in a pandemic, I expected it might be used for the H5N1 Avian flu. It seemed like a good insurance plan for a pandemic that, if we were lucky, might not even happen. Things have changed a lot since then. Now it is H1N1, people have actualy died from it, and this pandemic might return stronger this fall and winter, killing even more people. The risk of ventilator shortages has gone from a remote possibility to more likely. A lot has changed in the last six months.

Unfortunately, something that has not changed is the development status of the Pandemic Ventilator Project. As I have said several times before, the project has largely reached the limits of what I can do on my own to develop it. I need people with more ideas, more technical knowledge, more clinical expertise and better management and organizational skills than I possess on my own to carry the project further than I have. It would be a shame if we reach the stage where we really could use a ventilator from he pandemic ventilator project, but no one worked on it beforehand to get it ready in time.