When you get a cut, you cover it with a bandage. How do you know when to change it? Maybe you just wait until it's wet or dirty. But when people have long-term or chronic (慢性的)wounds that take months to get better, changing bandages too early or to late could make healing take even longer. Changing the dressing on a wound too often can provide an opportunity for infections to get in. But if a bandage gets very wet very quickly from the inside, it might be filling with pus (脓)--a sign an infection has begun. Judging just when to change is important.
Chronic wounds are common in people who are older or who have certain health conditions. Chronic wounds affect around 6.5 million people per year in the United States. When Anushka Naiknaware, 13, learned about chronic wounds, she decided to make a device that could alert a person when it's time to change their bandages.
After a lot of trials and errors, the teen settled on a design that used an “ink” filled with carbon nanoparticles(纳米粒子). The teen loaded her ink into a printer cartridge (墨盒) to print onto her special paper, which was to be made into bandage. Well, actually, Anushka loaded her ink into many, many printer cartridges. Just changing a printer cartridge isn't easy, and filling one is even harder.
The small printed papers cost only 5 to 10 cents, Anushka estimates. The Bluetooth sensor is more expensive, but the teen notes that it could be used over and over again. She also knows there is a long way to go before her design can help patients. It hasn't been tested on a real person yet. “You have to make sure everything works perfectly,” she says.
