A Medical Device Can Find Malaria Infections-英语听力

[00:00.10]From VOA Learning English, [00:01.69]this is the Health Report. [00:04.18]Researchers have developed a medical device [00:07.38]which they say can find malaria infections in the human body. [00:13.12]The laser beam scanner is the first device [00:17.05]that can find the sometimes deadly disease [00:20.36]without going inside the body. [00:23.34]The test is painless, does not need blood from a person, [00:27.51]and appears to be right every time it is done. [00:31.37]At the present time, [00:33.14]a trained medical worker needs costly equipment, [00:37.52]a person's blood and a lot of time to know [00:41.57]if a person has been infected with malaria. [00:44.76]Trained workers, equipment and time [00:47.71]are not always available in poor parts of the world. [00:52.11]The newly developed device only needs a person [00:56.04]to place a finger on a laser device. [00:59.60]Doctor Dmitri Lopotko is a researcher [01:03.51]at the department of biochemistry and cell biology [01:07.51]at Rice University in Houston, Texas. [01:10.50]"We shine a very short light pulse through the skin. [01:15.09]And this light pulse is absorbed only by malaria parasites [01:21.42]because of the wavelength we use. [01:25.16]And in response to this short light pulse, [01:30.16]the parasite literally explodes," he said. [01:33.48]The light pulse comes from a low-powered laser. [01:37.80]It has less power than a laser point. [01:41.17]It shines on a very tiny particle called the hemozoin [01:46.43] [01:49.61]once it has infected red blood cells. [01:52.87]Hemozoin crystals are not found in red cells [01:56.72]that are not infected with malaria. [01:59.86]As the crystals are heated by the laser, [02:03.15]they create small bubbles inside infected cells. [02:07.25]Doctor Lopotko says the bubbles exploded, [02:10.93]and then make a sound that scientists can hear and count. [02:17.15]"You can detect just a few infected cells [02:21.39]in a million normal cells," he said. [02:24.92]Doctor Lopotko says when researchers tested the device, [02:29.17]it was never wrong. [02:30.96]And it was able to find malaria infection early [02:35.20]when treatment is very important. [02:37.13]The device can be carried and uses its batteries. [02:41.64]It costs about 10,000 to 20,000 dollars to make. [02:46.64]But Doctor Lopotko says [02:48.91]considering the number of people it can test, [02:51.67]that is not a lot of money. [02:54.51]"Each device will be capable to screen more than 200,000 people per year. [03:01.18]So the cost of analysis for each patient [03:06.65]will be less than 50 cents," he said. [03:08.83]People without medical training can use the device [03:12.73]to discover whether people are infected with malaria. [03:16.29]Doctor Lopotko says the light beam used by the device is safe. [03:21.85]Researchers will now test the device at a hospital in Houston [03:27.20]that cares for patients infected with malaria. [03:30.69]If those tests are successful, [03:33.31]researchers will test the device throughout the world this year. [03:38.17]An article describing the malaria detection device [03:42.48]was published in the journal [03:44.40]Proceedings of the National Academy of Sciences. [03:47.84]And that's the VOA Learning English Health Report. [03:52.40]I'm Christopher Cruise.