Sunday, April 26, 2009

Possible Swine Flu Pandemic Brewing

It has been a while since I have posted. I have had other priorities and this project has been left on the back burner. The events of this week seem to have made the Pandemic Ventilator Project a priority once again.

For the sake of those that are visiting this blog for the first time I will summarize the goals of the Pandemic Ventilator project. I will then discuss the work that has been done to date. I will then relate the project to the current swine flu outbreak that could possibly become a worldwide pandemic requiring many ventilators, possibly more than are currently available.

In February of 2007, I became aware of concerns by the World Health Organization that a worldwide influenza pandemic was imminent. One of the problems that will almost certainly be encountered if there is even a moderately severe pandemic is a shortage of ventilators. I had the idea that using modern industrial control devices such as PLCs (Programmable Logic Controllers), readily available solenoid valves and other readily available components, a functioning emergency use ventilator could be constructed. I came up with an initial design that I published on this blog and invited others to improve on the design or come up with better, different designs.

The project has had some success but is not complete. So far three different prototypes have been built by two other persons, and myself but there has been limited testing done. There have also been projects started by students at Michigan Tech University and two different groups in India that have used some of the ideas presented here develop different ventilators for use in pandemics or third world situations. If you follow through the blog postings from the first one, you can see the development of the project. In addition to working on my ventilator design, I have also written postings that encourage greater participation by government agencies in increasing the stockpiles of ventilators set aside for pandemic use. There are also several postings defending the use of non-commercially made ventilators in emergency situations. These postings mainly chronicle the brave individuals that built home made ventilators during the last polio epidemic. There are also reviews of other publications and videos.

It is difficult to predict if this outbreak will develop into a worldwide pandemic that is bad enough to cause a severe shortage of ventilators. Two factors cause it to be hard to predict. One, it is difficult to get good information because government authorities want to control panic and reduce economic disruption, and two, the nature of outbreaks themselves is unpredictable.

So what do we know? First the people that are dying are not the typical elderly and very young. They are mainly healthy young and middle aged adults. The death rate seems fairly high, perhaps as great as 10%. Death rates early on in a pandemic however are very difficult to pin down, as we really do not know how many people were infected but in fact had very mild symptoms and were not counted. The virus is spreading to many geographical locations quickly. The WHO has already stated that it’s first line defense against pandemic outbreaks, which is containment, is no longer possible. The reason that there are no major travel restrictions imposed by governments is not that they think the threat is too minor, but that it is past the point where travel restrictions will help. What is still unknown is how severe it will eventually be, and how readily it will spread.

In the region that I live in, there are about 50 ventilator equipped ICU stations. The population served is about 500,000. If we had an pandemic that struck 10 percent of the population in each wave, and the virus was severe enough that 1 percent of those infected in each wave required a ventilator, then the number of ventilators required would be 500. Let us hope and pray that this pandemic is a very, very mild one.

Here is a link to a BBC News Link on Mexico Flu Experiences