Vinegar, a salad spinner and a toilet plunger are some of the everyday materials being used in a low-tech medical revolution that is transformomg healthcare off-grid and in the third world.
The new developments come as a reaction to the increasing complexity of modern medical technology which is not only expensive, but can only work in large centralised hospitals. Great if you live in a city. Not so great if you live in the boondocks, or in a country without medical infrastructure.
Salad spinner centrifuge
This week two students from Rice University, Houston Texas, launched a centrifuge for analysing blood and urine samples made from an ordinary garden salad spinner.
Using plastic lids, cut-up combs, yogurt containers and a hot-glue gun, sophomore Lauren Theis, and freshman Lila Kerr constructed their robust centrifuge to identify anaemia, the most widespread blood disorder.
The centrifuge costs about US$30 in parts, (including the spinner!) making it perfect for use in medical clinics in developing countries around the world.
When tiny capillary tubes containing 15 microliters of blood are spun in the device for 10 minutes, the blood separates into heavier red blood cells and lighter plasma. The hematocrit, or ratio of red blood cells to the total volume, measured with a gauge held up to the tube, can tell clinicians if a patient is anaemic. That detail is critical for diagnosing malnutrition, tuberculosis, HIV/AIDS and malaria.
Powered by a hand pump, the device spins tubes at up to 950 rpm. Results compare favourably to those obtained with conventional centrifuges –but it has significant advantages.
First, it requires no electricity -just a little muscle. “We’ve pumped it for 20 minutes with no problem,” said Theis. “Ten minutes is a breeze.” Second, it can spin up to 30 samples at a time. Third, it is robust. “It’s all plastic and pretty durable,” Kerr said. “We haven’t brought it overseas yet, of course, but we’ve trekked it back and forth across campus in our backpacks and grocery bags, and it’s held up fine.” And of course it is cheap and easy to construct.
Later this year Kerr will test the spinner in Ecuador, Theis will take one to Swaziland and a third BTB team will take one to Malawi.
Another deadly medical problem in the third world is cervical cancer. In Ethiopia for instance it accounts for 60 percent of all referrals to the country’s only cancer centre. According to Stamford-based gynaecologist Paul Blumenthal, at least 6,000 Ethiopian women die of the disease each year. And that’s a very conservative estimate, as the country has way of tracking the disease.
In response to the problem, Blumenthal has developed an approach to diagnosing cervical cancer that could not be simpler or cheaper. “I’ve never been to a country where they told me 60 percent of the total number of cancer referrals were for cervical cancer. I was incredulous,” said Blumenthal.
His miracle cure? Household vinegar. A caregiver swabs the woman’s cervix with vinegar and then examines the result. Pre-cancerous lesions show up as an opaque raised white patch.
The technique is an alternative to the ‘pap smear’ which requires special equipment, laboratories and trained personnel. Because it is so cheap and easy to use, it is more likely to catch a cancer early, when it can still be treated. Blumethal has also developed a slightly less low-tech treatment using cryotherapy, or freezing of tissue.
But there’s no doubt that for millions of women who don’t have access to the Pap test, the low-tech screening test could be a godsend – the difference between life and death.
Toilet plunger wound healer
Open wounds are yet another mass killer in the third world. Dr Robert Riviello of the Division of Trauma, Burn and Surgical Critical Care at Brigham and Women’s Hospital in Boston, reckons that every year between 50 million and 60 million people in low-income countries suffer from acute and chronic wounds,
For reasons that are not fully understood, healing can be accelerated by applying suction to the wound under a tightly-sealed bandage. It helps draw bacteria and fluid away from a wound, keeping it cleaner and hence, encouraging faster healing. It also allows dressings to be left in place much longer than traditional dressings which need to be removed and replaced several times a day.
Negative pressure has been an effective treatment in the developed world for decades. The problem is that, yet again, the treatment is expensive. A negative pressure pump costs up to $100 a day to rent – a year’s income in some countries.
And of course it needs an electricity supply.
Now Danielle Zurovcik, an engineering student at Massachusetts Institute of Technology (MIT) engineering class has invented a basic suction pump that doesn’t require electricity, is cheap to manufacture, lightweight to transport and can be left in place for days.
I was walking through Kmart and saw a row of plungers,” Zurovcik told AOL News. “I just thought, ‘Wow, that’s exactly what I can use.”
A month later , Zurovcik had designed and built a device that uses a bellows pump, a plastic tubing and a fitting to enclose a wound. It is, basically a watered down version of a commercial negative-pressure pump, which is already a staple in American hospitals to treat bed sores and quicken burn relief.
Almost unbelievably, her pump costs just $3 to make. The device is squeezed to create the suction, and then left in place, connected to the underside of the wound dressing by a thin plastic tube.
“It holds its pressure for as long as there’s not an air leak,” said Zurovcik.
To basically take a toilet plunger and produce negative pressure over a prolonged period of time, that is really great,” Kristian Olson, a physician at Massachusetts General Hospital, told MIT’s Technology Review. “Not only do I see it answering this need in developing countries, I think it could really enhance home therapy for chronic wounds in the U.S.” she said.
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