歌词
From VOA Learning English,
this is the Health Report.
Researchers have developed a medical device
which they say can find malaria infections in the human body.
The laser beam scanner is the first device
that can find the sometimes deadly disease
without going inside the body.
The test is painless, does not need blood from a person,
and appears to be right every time it is done.
At the present time,
a trained medical worker needs costly equipment,
a person's blood and a lot of time to know
if a person has been infected with malaria.
Trained workers, equipment and time
are not always available in poor parts of the world.
The newly developed device only needs a person
to place a finger on a laser device.
Doctor Dmitri Lopotko is a researcher
at the department of biochemistry and cell biology
at Rice University in Houston, Texas.
"We shine a very short light pulse through the skin.
And this light pulse is absorbed only by malaria parasites
because of the wavelength we use.
And in response to this short light pulse,
the parasite literally explodes," he said.
The light pulse comes from a low-powered laser.
It has less power than a laser point.
It shines on a very tiny particle called the hemozoin
once it has infected red blood cells.
Hemozoin crystals are not found in red cells
that are not infected with malaria.
As the crystals are heated by the laser,
they create small bubbles inside infected cells.
Doctor Lopotko says the bubbles exploded,
and then make a sound that scientists can hear and count.
"You can detect just a few infected cells
in a million normal cells," he said.
Doctor Lopotko says when researchers tested the device,
it was never wrong.
And it was able to find malaria infection early
when treatment is very important.
The device can be carried and uses its batteries.
It costs about 10,000 to 20,000 dollars to make.
But Doctor Lopotko says
considering the number of people it can test,
that is not a lot of money.
"Each device will be capable to screen more than 200,000 people per year.
So the cost of analysis for each patient
will be less than 50 cents," he said.
People without medical training can use the device
to discover whether people are infected with malaria.
Doctor Lopotko says the light beam used by the device is safe.
Researchers will now test the device at a hospital in Houston
that cares for patients infected with malaria.
If those tests are successful,
researchers will test the device throughout the world this year.
An article describing the malaria detection device
was published in the journal
Proceedings of the National Academy of Sciences.
And that's the VOA Learning English Health Report.
I'm Christopher Cruise.
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