经济学人449:医用植入设备 一个甜美的想法

 　　Science and technology.

　　科技。

　　Medical implants².

　　医用植入设备。

　　A sweet idea.

　　一个甜美的想法。

　　Researchers are trying to harness glucose³-the body's own fuel-to power implantable gadgets⁴ such as pacemakers.

　　研究人员正试图利用葡萄糖-人体自身的燃料-作为像起搏器这样的可植入设备的能源

　　LIKE any other electrical device, a pacemaker needs a power source. Since the first permanent pacemaker was installed in 1958, manufacturers of implantable medical devices (IMDs) have tinkered with many different ways of supplying electricity to their products. A variety of chemical batteries have been tried, as well as inductive recharging schemes and even plutonium power cells that convert the heat from radioactive decay into electricity. Plutonium-powered pacemakers still turn up from time to time in mortuaries and hospitals, and a failure to dispose of them properly keeps America's Nuclear Regulatory Commission busy handing out citations⁵ to unsuspecting hospitals.

　　和其他所有的电子设备一样，一个起搏器同样需要能源。自从1958年第一个永久起搏器被植入后，可植入医疗设备的制造商就在不断尝试为其产品提供电能的各种方法。尝试了各种化学电池以及感应充电计划，甚至是将放射衰变的热能转换为电能的钚电源单元格。现在，钚电源起搏器还是时不时的出现在停尸房和医院中，并且使得美国核管理委员忙于忙于处罚那些疏于妥善处理钚电源起搏器的医院。

　　Today, non-rechargeable lithium-based batteries are common. Used in many cardiological and neurological implants, they provide between seven and ten years of life. That is more than enough: the speed of medical progress is such that by the time the battery has run down it is generally time to replace the whole device with a newer model in any case.

　　如今，不可充电的锂电池较为普遍。应用在心脏病和神经源性疾病的移植设备中，一般能够提供7年到10年的使用时间。这么长的使用时间显得绰绰有余：医学发展的速度意味着等到设备的电量用光就到了用一个更先进的型号来替换整个设备的时候。

　　But that has not dissuaded⁶ researchers from continuing to seek perfection, in the form of a compact, perpetual energy source which does not require external recharging. Now, several researchers are closing in on just such a solution using glucose, a type of sugar that is the main energy source for all cells in the body.

　　然而这并没有阻止研究人员继续寻找完美的，紧凑型的永久能源，从而使得这些移植设备不再需要外部充电。现在，几个研究人员正在接近一个能够提供这样能源的方法，使用葡萄糖，即为人体所有细胞提供主要能源的一种糖。

　　Many other ideas have been tried down the years. The kinetic⁷ energy of the human body, for example, has long been harnessed to power watches, and should also be enough to keep a pacemaker ticking. Temperature differences between the body and the ambient air mean that thermoelectric couples can generate useful quantities of juice. A properly tuned⁸ device could capture background radio-frequency energy and rectify⁹ it into small amounts of usable power.

　　这些年还有许多其他想法也被尝试。比如，很久以前人体动能就用来为手表提供能量，这种动能也足够维持起搏器的运转。人体与外部环境的温差意味着热电偶能够产生一定数量能量。一个适当调谐装置能够捕获北京射频能量并且将其转换成少量可用能源。

　　Although all these ideas have been shown to work in theoretical tests on lab benches, they all suffer from the same handicap: intermittent¹⁰ operation. Unconscious patients, for instance, generate little kinetic energy. Sitting in a warm room reduces the power available from thermocouples. And radio waves are common but not ubiquitous. These are serious drawbacks for an IMD that may be responsible for keeping someone alive.

　　尽管这些想法在实验的理论测试中运转正常，但是他们都有一个同样的缺陷：间歇运行。例如，处于昏迷的患者产生的人体动能很少。处于温暖的房间中会减少热电偶产生的可用能量。另外射频很常见，但是也不是处处可见。这些问题对于维持生命的可移植医疗设备来说都是十分严重的缺陷。

　　Power in the blood.

　　血液中的能量。

　　A glucose-powered implant¹ would solve such problems. Glucose is continuously delivered throughout the body by its circulatory systems. A sugar-powered device would therefore have access to a constant supply of fuel, and could be implanted almost anywhere.

　　而一个葡萄糖供能的移植设备可以解决这些问题。葡萄糖由人体的循环系统被源源不断的输送到人体各处。一个糖分供能的设备因此能够取得持续供给的能量并且几乎可以在任何位置进行移植。

　　One approach, which has been employed by Sameer Singhal, a researcher at the CFD Research Corporation in Alabama, involves the same enzymes¹¹ that break down glucose within a living cell. Using carbon nanotubes, he and his colleagues immobilised two different enzymes on the electrodes of a fuel cell, where they generated electricity by freeing electrons from glucose. At present, only two of the 24 available electrons in a single glucose molecule¹² can be harnessed, but refinements¹⁴ to the technology should boost that number.

　　就职于Alabama的CFD Research Corporation的研究人员Sameer Singhal所使用的方法涉及利用酶将活细胞中的葡萄糖分解。利用碳纳米管，他和他的同事在燃料电池的电子上找到了2种不同的酶，在燃料电池中他们通过释放葡萄糖的电子来产生电能。现在，在一个葡萄糖分子中的24个可用电子中只有2个可以利用，但是对这项技术的后续完善应该会使得可以利用的电子数量有所增加。

　　Dr Singhal has implanted prototype devices into live beetles¹⁵. Fitted with a fuel cell about the size of a penny, the bionic bugs¹⁶ were able to generate over 20 microwatts (20 millionths of a watt) during a two-week trial.

　　Singhal博士将设备原型移植进了甲虫活体。放入了一个一便士大小的能量池，这些甲虫在2周实验期内产生了20微瓦（一瓦特的百万分之二十）。

　　That is only around a fifth of the power that a pacemaker requires, but Dr Singhal reckons that a human-sized version of his cell would be able to deliver enough juice. There is a catch, though: a process called biofouling, in which foreign objects implanted in the body become encrusted with proteins and tissue. That could render Dr Singhal's device inoperable after only a few months. Equally worrying are the enzymes, which tend to break down over time. Losing enzymes means losing power.

　　这只是一个起搏器所需能量的15分之一，但是Singhal博士认为人类体积大小的细胞量能够产生足够的能量。这里有个欠缺点：被称做生物污垢的过程，即被移植进人体的外来物会嵌入蛋白质和组织中。这会使得Singhal博士的设备在移植后的几个月内便无法使用。同样使人担忧的是酶，这种物质随着时间的推移会被分解。而丢失酶就意味着丢失能量。

　　Rahul Sarpeshkar, an electrical engineer at the Massachusetts Institute of Technology, has a solution to both these problems. In a paper published on June 12th in Public Library of Science, Dr Sarpeshkar and his colleagues describe building a glucose fuel cell which uses a platinum¹⁸ catalyst¹⁹ that does not degrade over time.

　　一位MIT的电子工程师Rahul Sarpeshkar有个方法可以解决这两个问题。6月12号发表于Public Library of Science的一篇论文中，Sarpeshkar博士和他的同事证实用铂催化剂打造的葡萄糖能量池，其效果不会随着时间被削弱。

　　The downside is that platinum is a less efficient catalyst than the enzymes used by Dr Singhal, and so Dr Sarpeshkar's cell works less well. But it might be able to generate enough electricity to run the next generation of ultra-low-power IMDs.

　　该方法的缺点是铂催化剂与Singhal博士所用的酶相比效率不高，因此，Sarpeshkar博士的能量池运转效果不好。但是它也许能够生产足够的电能来运转下一代超低功耗的可移植医疗设备。

　　Dr Sarpeshkar also has a novel solution to the biofouling problem: implant the fuel cell in the cerebrospinal fluid (CSF) surrounding the brain. Although the CSF has only half the glucose concentration of the bloodstream, it is virtually free of the proteins and cells which would foul¹⁷ a device implanted in other areas of the body, and thus its life would be greatly extended.

　　另外，Sarpeshkar博士还有一个针对于生物燃料问题的新型解决方法：在大脑周围的脑脊液（CSF）中植入能量池。尽管脑脊液仅含有体液中葡萄糖浓度的一半，但是这样做几乎可以使其免于植入人体其他部位而被蛋白质和细胞包围的命运，因此使其使用寿命大大延长。

　　Other approaches could yield more energy. Some soil-dwelling bacteria have evolved to deposit the electrons from glucose oxidation onto iron molecules²⁰, which allows researchers to trick them into living on the anode of a fuel cell. A colony of microbes like these, properly isolated²¹ from the host's immune system, might be coerced²² into trading electrons for nutrients²³ from the bloodstream. The bacteria can renew their own enzymes, so such a system should last indefinitely. But the idea of implanting a bacterial²⁴ colony into a patient might be a tricky²⁵ one to get past medical regulators-not to mention public opinion.

　　其他一些方法则需要更多的能量。用一些土壤细菌将葡萄糖氧化过程所产生的电子安置在铁分子上，这样研究人员就可以诱使这些细菌存活在能量池的阳极上。像这样的克隆微生物，与寄主的免疫系统相分离，可能被迫的用电子与体液交换营养成分。细菌可以重新激活他们自身的酶，因此这样的系统能够永久的持续下去。然而将细菌克隆体移植进病人的身体这种想法可能无法通过医疗监管人员的监管，就更不要说公众舆论了。

　　A better idea might be to retrain some of the body's own cells to do the work. Just as an outdated²⁶ procedure called a cardiomyoplasty involved severing²⁷ a seldom-used upper-back muscle and wrapping it around the heart to assist in pumping blood, muscle fibres might be retrained to crank an electromechanical generator²⁸. Such a setup would be capable of producing enough electricity to drive even the most power-hungry of devices, like artificial hearts.

　　一个更好的想法可能是将一些人体自身的细胞进行再培训来完成这个工作。正如一个已过时的手术，叫做心肌成形术，将较少用到的上背部肌肉切断并将它包络再心脏周围来协助心脏输送血液，肌肉纤维也许可以经过在训练后来驱动机电发电机。这样的方法能够产生足够的电能来驱动哪怕是最耗费能源的设备，比如人造心脏。

　　The energy density²⁹ of lithium batteries has come a long way in the past few decades, but the chemical reaction on which they rely will never be able to match the energy available from the metabolisation of glucose. The chemical energy in a gram of glucose is nearly half the amount available from petrol, a famously energy-dense fuel. With a bit of refinement¹³, sugar could prove a very sweet solution for powering the next generation of IMDs.

　　在过去的几十年间，锂电池的能量密集度取得了长足的发展，但是锂电池所依赖的化学反应永远也无法产生与葡萄糖代谢所产生的能量相匹敌的数量。一克葡萄糖所含有的化学能量相当于半克汽油能产生的能量，原油是众所周知的能源密集型燃料。再经过一点优化，糖就有可能为下一代可移植医疗设备的能源问题提供一个十分完美的解决办法。

1 implant   

vt.注入，植入，灌输

参考例句：

• A good teacher should implant high ideals in children.好教师应该把高尚理想灌输给孩子们。
• The operation to implant the artificial heart took two hours.人工心脏植入手术花费了两小时。

2 implants   

n.（植入身体中的）移植物( implant的名词复数 )

参考例句：

• Hormone implants are used as growth boosters. 激素植入物被用作生长辅助剂。 来自《简明英汉词典》
• Perhaps the most far-reaching project is an initiative called Living Implants From Engineering (LIFE). 也许最具深远意义的项目，是刚刚启动的建造活体移植工程 (LIFE)。 来自英汉非文学 - 生命科学 - 医学的第四次革命

3 glucose   

n.葡萄糖

参考例句：

• I gave him an extra dose of glucose to pep him up.我给他多注射了一剂葡萄糖以增强他的活力。
• The doctor injected glucose into his patient's veins.医生将葡萄糖注入病人的静脉。

4 gadgets   

n.小机械，小器具（ gadget的名词复数 ）

参考例句：

• Certainly. The idea is not to have a house full of gadgets. 当然。设想是房屋不再充满小配件。 来自超越目标英语 第4册
• This meant more gadgets and more experiments. 这意味着要设计出更多的装置，做更多的实验。 来自英汉非文学 - 科学史

5 citations   

n.引用( citation的名词复数 )；引证；引文；表扬

参考例句：

• The apt citations and poetic gems have adorned his speeches. 贴切的引语和珠玑般的诗句为他的演说词增添文采。 来自《现代汉英综合大词典》
• Some dictionary writers use citations to show what words mean. 有些辞典的编纂者用引文作例证以解释词义。 来自辞典例句

6 dissuaded   

劝（某人）勿做某事，劝阻( dissuade的过去式和过去分词 )

参考例句：

• He was easily dissuaded from going. 他很容易就接受劝告不走了。
• Ulysses was not to be dissuaded from his attempt. 尤利西斯想前去解救的决心不为所动。

7 kinetic   

adj.运动的；动力学的

参考例句：

• There exist many sources of energy both potential and kinetic.存在着许多势能和动能的能源。
• The kinetic theory of gases is the best known example.气体动力学理论就是最有名的例子。

8 tuned   

adj.调谐的，已调谐的v.调音( tune的过去式和过去分词 )；调整；（给收音机、电视等）调谐；使协调

参考例句：

• The resort is tuned in to the tastes of young and old alike. 这个度假胜地适合各种口味，老少皆宜。
• The instruments should be tuned up before each performance. 每次演出开始前都应将乐器调好音。 来自《简明英汉词典》

9 rectify   

v.订正，矫正，改正

参考例句：

• The matter will rectify itself in a few days.那件事过几天就会变好。
• You can rectify this fault if you insert a slash.插人一条斜线便可以纠正此错误。

10 intermittent   

adj.间歇的，断断续续的

参考例句：

• Did you hear the intermittent sound outside?你听见外面时断时续的声音了吗？
• In the daytime intermittent rains freshened all the earth.白天里，时断时续地下着雨，使整个大地都生气勃勃了。

11 enzymes   

n. 酶，酵素

参考例句：

• It was said that washing powders containing enzymes remove stains more efficiently. 据说加酶洗衣粉除污更有效。
• Among the enzymes which are particularly effective are pepsin, papain. 在酶当中特别有效的是胃朊酶、木瓜酶。

12 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

13 refinement   

n.文雅；高尚；精美；精制；精炼

参考例句：

• Sally is a woman of great refinement and beauty. 莎莉是个温文尔雅又很漂亮的女士。
• Good manners and correct speech are marks of refinement.彬彬有礼和谈吐得体是文雅的标志。

14 refinements   

n.（生活）风雅；精炼( refinement的名词复数 )；改良品；细微的改良；优雅或高贵的动作

参考例句：

• The new model has electric windows and other refinements. 新型号有电动窗和其他改良装置。 来自《简明英汉词典》
• It is possible to add a few useful refinements to the basic system. 对基本系统进行一些有益的改良是可能的。 来自《简明英汉词典》

15 beetles   

n.甲虫( beetle的名词复数 )

参考例句：

• Beetles bury pellets of dung and lay their eggs within them. 甲壳虫把粪粒埋起来，然后在里面产卵。 来自《简明英汉词典》
• This kind of beetles have hard shell. 这类甲虫有坚硬的外壳。 来自《现代汉英综合大词典》

16 bugs   

adj.疯狂的，发疯的n.窃听器( bug的名词复数 )；病菌；虫子；[计算机]（制作软件程序所产生的意料不到的）错误

参考例句：

• All programs have bugs and need endless refinement. 所有的程序都有漏洞，都需要不断改进。 来自《简明英汉词典》
• The sacks of rice were swarming with bugs. 一袋袋的米里长满了虫子。 来自《简明英汉词典》

17 foul   

adj.污秽的；邪恶的；v.弄脏；妨害；犯规；n.犯规

参考例句：

• Take off those foul clothes and let me wash them.脱下那些脏衣服让我洗一洗。
• What a foul day it is!多么恶劣的天气！

18 platinum   

n.白金

参考例句：

• I'll give her a platinum ring.我打算送给她一枚白金戒指。
• Platinum exceeds gold in value.白金的价值高于黄金。

19 catalyst   

n.催化剂，造成变化的人或事

参考例句：

• A catalyst is a substance which speeds up a chemical reaction.催化剂是一种能加速化学反应的物质。
• The workers'demand for better conditions was a catalyst for social change.工人们要求改善工作条件促进了社会变革。

20 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

21 isolated   

adj.与世隔绝的

参考例句：

• His bad behaviour was just an isolated incident. 他的不良行为只是个别事件。
• Patients with the disease should be isolated. 这种病的患者应予以隔离。

22 coerced   

v.迫使做( coerce的过去式和过去分词 )；强迫；（以武力、惩罚、威胁等手段）控制；支配

参考例句：

• They were coerced into negotiating a settlement. 他们被迫通过谈判解决。
• He was coerced into making a confession. 他被迫招供。 来自《简明英汉词典》

23 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

24 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。

25 tricky   

adj.狡猾的，奸诈的；(工作等)棘手的，微妙的

参考例句：

• I'm in a rather tricky position.Can you help me out?我的处境很棘手，你能帮我吗？
• He avoided this tricky question and talked in generalities.他回避了这个非常微妙的问题，只做了个笼统的表述。

26 outdated   

adj.旧式的，落伍的，过时的；v.使过时

参考例句：

• That list of addresses is outdated,many have changed.那个通讯录已经没用了，许多地址已经改了。
• Many of us conform to the outdated customs laid down by our forebears.我们许多人都遵循祖先立下的过时习俗。

27 severing   

v.切断，断绝( sever的现在分词 )；断，裂

参考例句：

• The death of a second parent is like severing an umbilical cord to our past. 父母当中第二个人去世，就象斩断了把我们同过去联在一起的纽带。 来自辞典例句
• The severing theory and severing method for brittle block are studied. 研究裂纹技术应用于分离脆性块体的分离理论和分离方法。 来自互联网

28 generator   

n.发电机，发生器

参考例句：

• All the while the giant generator poured out its power.巨大的发电机一刻不停地发出电力。
• This is an alternating current generator.这是一台交流发电机。

29 density   

n.密集，密度，浓度

参考例句：

• The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
• The region has a very high population density.该地区的人口密度很高。