Thursday, September 9, 2010

Researchers develop tea bag filter that cleans water






A group of researchers in South Africa has developed a filter that can purify water straight from the bottle.
It sits inside a tube that can be fitted on top of a bottle and purifies water as it is poured on a cup.


The designer behind the filter, Dr Eugene Cloete, from the Stellenbosch University in South Africa, says the filter is only as big as an ordinary tea bag.


He says the product is cost-effective and easy to use.
"We are coming in here at the fraction of the cost of anything else that is currently on the market," says Dr Cloete on BBC World Service.
According to him the filter will not only stop harmful bacteria from getting into the water, it will also kill them.


"We cover the tea bag material with nano-structured fibres, and instead of tea inside the tea bag, we incorporate activated carbon.
"The function of the activated carbon is to remove most of the dangerous chemicals that you would find in water."


He says that the function of the fibres is to create a filter where harmful bacteria is physically filtered out and killed.

According to the World Health Organisation the number of people who can access clean drinking water has been improving steadily across the globe. But there are millions of people - many in Sub-Saharan Africa - who still do not have access to drinkable water.
via:BBC

Salad Spinner Centrifuge: A Cheap, Ingenious Health Care Tool


We already know that we need to eat plenty of leafy greens to stay healthy, but who knew that a salad spinner itself could help save lives?

As we learn from EurekAlert, Rice University undergraduates Lila Kerr and Lauren Theis were presented with an assignment in their Introduction to Bioengineering and World Health class.
As Theis explains:

"We were essentially told we need to find a way to diagnose anemia without power, without it being very costly and with a portable device."

In a solution short on cost but long on ingenuity, the duo modified a basic, everyday salad spinner into an easy to use and transport centrifuge that successfully separates blood to allow diagnosis of anemia with no electricity. The device costs about $30, can process 30 individual 15 microliter blood samples at a time, and can separate blood into its component red cells and plasma in about 20 minutes.
"Sally Centrifuge," as the innovation has been dubbed by its creators, is undergoing a series of field tests this summer in places that will benefit from the availability of effective but low-tech solutions and adaptations. As part of Rice University's Beyond Traditional Borders (BTB), a global health initiative focused primarily on developing countries, Kerr and Theis are traveling along with their device to Ecuador, Swaziland and Malawi, where rural clinics will provide real-world testing of the surprising diagnostic tool.

In rural, under-served and impoverished parts of the world, a positive diagnosis for anemia is a critically important clue when looking for other health problems such as malnutrition, or serious chronic infectious diseases such as malaria and HIV/AIDS. Until now, blood samples taken in the field would have to be sent to a distant location complete with expensive laboratory centrifuges and electricity, while patients would be left waiting for the results — a lapse in time that can be deadly. Being able to diagnose the condition in real time with "Sally Centrifuge" would allow appropriate treatment to begin before before an illness progresses and a patient's condition deteriorates too drastically.

Maria Oden, engineering professor and co-adviser to the team, reflects on how successfully the two young women approached the assignment by providing something that may literally save lives as it is brought to bear on pressing health challenges in rural and economically under-developed regions of the world:


"The students really did an amazing job of taking very simple, low-cost materials and creating a device their research shows correlates nicely with hematocrit levels in the blood. Many of the patients seen in developing world clinics are anemic, and it's a severe health problem. Being able to diagnose it with no power, with a device that's extremely lightweight, is very valuable."


source via:Eurekalert and Shine