丁黎明

為方便缺失手臂的殘疾人的生活，上海交大研究人員研發(fā)出了一款技術先進的義肢。

Gu Guoying and his colleagues at Shanghai Jiao Tong University， in China， have just come up with what looks to be a significant advance—an affordable prosthetic hand that not only responds like a real one to signals from the wearer's brain， but is also able to signal back to the brain what it is touching and doing.

The whole hand is covered with a flexible elastomer （彈性體） layer to imitate skin and is attached to the user's residual limb. In contrast to current models， which are electrically powered， the new prosthetic hand is powered by a compressed air pump. This reduces its weight below 300 grams—half that of some current models.

The hand uses similar signal processing algorithms （算法） to other prosthetics on the market. The big advance is that it does not require invasive surgery or electronic implants into the residual limb to communicate with the user's brain. Sensors on the skin record electrical signals from the remaining arm muscles. The signals then are interpreted by pattern recognition software that sends appropriate commands to the pump to move the artificial hand. Meanwhile， other signals travel in the opposite direction from sensors in the hand's fingertips to nerves in the arm， from which they are relayed to the brain and provide a sense of touch. The result is something which responds like a hand and feels like one to the user.

Dr Gu and his colleagues compared the efficacy of their invention with that of existing models using tests borrowed from research into strokes and spinal cord injuries. These included writing， grasping and lifting objects， and lifting food to the mouth. Normally， they found it worked bet-ter—particularly for delicate tasks like handling fragile objects， petting a cat and shaking hands.

The other advantage of Dr Gu and his colleagues invention is that it is cheap. The components it is made from cost about $500. Existing models may sell for $10，000 or more. If it goes into production， that will permit the transformation of many more of the lives of the people who have lost a hand， or were born without one.

Reading check

1. What makes the prosthetic hand an advance？

A. Its shape. B. Its functions.

C. Its structure. D. Its skin.

2. What's the advantage of the power system of the new hand？

A. It weighs less.

B. It's more powerful.

C. It costs less.

D. It's more energy-efficient.

3. What does the underlined word “resi-dual” in paragraph 2 probably mean？

A. Injured. B. Remaining.

C. Missing. D. Artificial.

4. What can we infer from the last para-graph？

A. We can buy the new prosthetic hand for about $500.

B. The new prosthetic hand is not available on the market at present.

C. Disabled people have benefited a lot from the new product.

D. The new invention is not expensive.

Language Study

Difficult sentence in the text

Meanwhile， other signals travel in the opposite direction from sensors in the hand's fingertips to nerves in the arm， from which they are relayed to the brain and provide a sense of touch. 與此同時，其他信號則以相反的方向從指尖上的傳感器傳到手臂的神經中，再從那里傳到大腦，從而產生觸覺。