VOA慢速英语2015 新型可穿戴附加设备有效减轻腿部肌肉的负荷

Motor-Free Device Reduces Stress from Walking 新型可穿戴附加设备有效减轻腿部肌肉的负荷

Devices that help people walk were once thought to be difficult, if not impossible, to design. Until recently, such a device required electricity from an external power supply. Now, American scientists have built a small, wearable addition to normal shoes. Their new invention eases the load on muscles in the leg and makes walking easier.

Steven Collins and Greg Sawicki are biomedical engineers. They both studied how human beings walk. They found that our ankles and calves¹ perform motions similar to a spring joined to a clutch. In an automobile², a clutch is used to connect and disconnect a driving or driven part of an engine or other piece of equipment. The researchers found that the human body parts are able to both store and release energy, just like a spring.

Steven Collins works with Carnegie Mellon University in Pennsylvania. Greg Sawicki is with North Carolina State University. He spoke³ to VOA on Skype.

"We found in basic science experiments that that system, your calf⁴ and Achilles tendon, works a lot like a catapult. So, the muscle holds on to the tendon and your body actually stretches your Achilles tendon quite a bit and then stores the energy in the tissue and then it's given back to propel you forward in the world."

Mr. Sawicki says he and Mr. Collins designed a mechanical device that performs the same kind of energy ‘give-and-take’ outside the body. Their new ankle exoskeleton is made of carbon fiber⁵ and metal. It connects to ordinary shoes and takes over part of the work of walking. Mr. Sawicki says the device reduces the amount of energy required for walking by as much as seven percent.

The unpowered ankle exoskeleton can help people walk farther with the same amount of energy. It also can restore normal movement for individuals who have trouble walking.

Mr. Sawicki says it takes only a few minutes for someone to get used to the ankle exoskeleton. He says the wearer quickly learns to use less muscle energy, letting the device do much of the work.

"You really don't notice it until when you take it off. And when you take it off you realize that it was there and giving you the boost."

Mr. Sawicki says the device is mainly meant for people recovering from a surgery operation or a stroke. He adds that anyone who spends a lot of time walking, like hospital workers and policemen, could use the device.

There are no plans to make the ankle exoskeleton available to the general public. But the inventors say some manufacturers have expressed interest in the device.

Words in this Story

boost – n. help or encouragement; a push upward

exoskeleton – n. an artificial external supporting structure

restore – v. to give back someone or something that was lost or taken : to return someone or something

spring – n. a twisted or coiled piece of metal that returns to its original shape when it is pressed down or stretched

1 calves   

n.(calf的复数)笨拙的男子，腓；腿肚子( calf的名词复数 )；牛犊；腓；小腿肚v.生小牛( calve的第三人称单数 )；（冰川）崩解；生（小牛等），产（犊）；使（冰川）崩解

参考例句：

• a cow suckling her calves 给小牛吃奶的母牛
• The calves are grazed intensively during their first season. 小牛在生长的第一季里集中喂养。 来自《简明英汉词典》

2 automobile   

n.汽车，机动车

参考例句：

• He is repairing the brake lever of an automobile.他正在修理汽车的刹车杆。
• The automobile slowed down to go around the curves in the road.汽车在路上转弯时放慢了速度。

3 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

4 calf   

n.小牛，犊，幼仔，小牛皮

参考例句：

• The cow slinked its calf.那头母牛早产了一头小牛犊。
• The calf blared for its mother.牛犊哞哞地高声叫喊找妈妈。

5 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。