第二节 阅读理解

　　Robotic surgery is one thing, but sending a robot inside the body to carry out an operation quite another, which has long been a goal of some researchers to produce tiny robotic devices being capable of traveling through the body to deliver drugs or to make repairs without the need for a single cut, the possibility of which has just got a bit closer.

　　However, unlike the plot of one film-which featured a microscopic crew and submarine traveling through a scientist's bloodstream-this device could not be inserted into blood vessels(管)because it is too big. While other types of miniature swallowable robots have been developed in the past, their role has mostly been limited to capturing images inside the body. In a presentation this week to the International Conference, Daniela Rus and Shuhei Miyashita of the Massachusetts Institute of Technology described a robot they have developed that can be swallowed and used to collect dangerous objects accidentally taken in.

To test their latest version, Dr Rus and Dr Miyashita designed a robot as a battery hunter, which might seem to be an odd task, but more than 3,500 people in America alone, most of them children, swallow the tiny button cells used in small electronic devices by accident every year. To start with, the researchers created an artificial esophagus(食道)and stomach made out of silicone(硅胶). It was closely modeled on that found in a pig and filled with medical liquid; the robot itself is made from several layers of different materials, including pig intestine(肠), and contains a little magnet. This is folded up and encased in a 10mm×27mm capsule of ice. Once this reaches the stomach the ice melts and the robot unfolds which is moved and guided with the use of a magnetic field outside the body. In their tests, the robot was able to touch a button battery and draw it with its own magnet, and during dragging it along, the robot could then be directed towards the intestines where it would eventually be gotten rid of through the anus(肛门). After it, the researchers sent in another robot loaded with medication to deliver it to the site of the battery burn to speed up healing.