本文摘要:Medical implants.医用植入设备。
Medical implants.医用植入设备。A sweet idea.一个可爱的点子。Researchers are trying to harness glucose-the bodys own fuel-to power implantable gadgets 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 Americas Nuclear Regulatory Commission busy handing out citations to unsuspecting hospitals.和其他所有的电子设备一样,一个起搏器某种程度必须能源。
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大大尝试为其产品获取电能的各种方法。尝试了各种化学电池以及感应器电池计划,甚至是将放射线裂变的热能切换为电能的钚电源单元格。现在,钚电源起搏器还是偶尔的经常出现在停尸房和医院中,并且使得美国核管理委员无暇无暇惩处那些不善处置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,不能电池的锂电池更为广泛。
应用于在心脏病和神经源性疾病的重制设备中,一般需要获取7年到10年的用于时间。这么宽的用于时间变得绰绰有余:医学发展的速度意味著等到设备的电量用光就到了用一个更加先进设备的型号来更换整个设备的时候。
But that has not dissuaded 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.然而这并没制止研究人员之后找寻极致的,紧凑型的永久能源,从而使得这些重制设备仍然必须外部电池。现在,几个研究人员正在相似一个需要获取这样能源的方法,用于葡萄糖,即为人体所有细胞获取主要能源的一种糖。Many other ideas have been tried down the years. The kinetic 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 tuned device could capture background radio-frequency energy and rectify it into small amounts of usable power.这些年还有许多其他点子也被尝试。
比如,很久以前人体动能就用来为手表获取能量,这种动能也充足保持起搏器的运转。人体与外部环境的温差意味著热电偶需要产生一定数量能量。
一个必要回声装置需要捕捉北京射频能量并且将其转换成少量能用能源。Although all these ideas have been shown to work in theoretical tests on lab benches, they all suffer from the same handicap: intermittent 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.尽管这些点子在实验的理论测试中运转长时间,但是他们都有一个某种程度的缺失:间歇运营。
例如,正处于昏倒的患者产生的人体动能很少。正处于寒冷的房间中不会增加热电偶产生的能用能量。
另外射频很少见,但是也不是恣意可见。这些问题对于保持生命的可移植医疗设备来说都是十分相当严重的缺失。Power in the blood.血液中的能量。
A glucose-powered implant 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重制设备可以解决问题这些问题。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需要获得持续供给的能量并且完全可以在任何方位展开重制。
One approach, which has been employed by Sameer Singhal, a researcher at the CFD Research Corporation in Alabama, involves the same enzymes 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 molecule can be harnessed, but refinements to the technology should boost that number.就任于Alabama的CFD Research Corporation的研究人员Sameer Singhal所用于的方法牵涉到利用酶将活着细胞中的葡萄糖分解成。利用碳纳米管,他和他的同事在燃料电池的电子上寻找了2种有所不同的酶,在燃料电池中他们通过获释葡萄糖的电子来产生电能。现在,在一个葡萄糖分子中的24个能用电子中只有2个可以利用,但是对这项技术的先前完备应当不会使得可以利用的电子数量有所增加。Dr Singhal has implanted prototype devices into live beetles. Fitted with a fuel cell about the size of a penny, the bionic bugs were able to generate over 20 microwatts (20 millionths of a watt) during a two-week trial.Singhal博士将设备原型重制入了甲虫活体。
放进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 Singhals 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须要能量的15分之一,但是Singhal博士指出人类体积大小的细胞量需要产生充足的能量。
这里有个缺乏点:被称作生物污垢的过程,即被重制入人体的外来物不会映射蛋白质和的组织中。这不会使得Singhal博士的设备在重制后的几个月内之后无法用于。某种程度使人忧虑的是酶,这种物质随着时间的流逝不会被分解成。而遗失酶就意味著遗失能量。
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 platinum catalyst that does not degrade over time.一位MIT的电子工程师Rahul Sarpeshkar有个方法可以解决问题这两个问题。6月12号公开发表于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出的葡萄糖能量池,其效果会随着时间被巩固。The downside is that platinum is a less efficient catalyst than the enzymes used by Dr Singhal, and so Dr Sarpeshkars 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博士所用的酶比起效率不低,因此,Sarpeshkar博士的能量池运转效果很差。
但是它或许需要生产充足的电能来运转下一代超强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 foul 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问题方法:在大脑周围的脑脊液(CSF)中植入能量池。尽管脑脊液仅有所含体液中葡萄糖浓度的一半,但是这样做到完全可以使其免遭植入人体其他部位而被蛋白质和细胞围困的命运,因此使其使用寿命大大缩短。
Other approaches could yield more energy. Some soil-dwelling bacteria have evolved to deposit the electrons from glucose oxidation onto iron molecules, which allows researchers to trick them into living on the anode of a fuel cell. A colony of microbes like these, properly isolated from the hosts immune system, might be coerced into trading electrons for nutrients from the bloodstream. The bacteria can renew their own enzymes, so such a system should last indefinitely. But the idea of implanting a bacterial colony into a patient might be a tricky one to get past medical regulators-not to mention public opinion.其他一些方法则必须更好的能量。用一些土壤细菌将葡萄糖水解过程所产生的电子移往在铁分子上,这样研究人员就可以引诱这些细菌存活在能量池的阳极上。
像这样的克隆微生物,与宿主的免疫系统相分离,有可能不得不的用电子与体液互相交换营养成分。细菌可以新的转录他们自身的酶,因此这样的系统需要永久的持续下去。然而将细菌克隆体重制入病人的身体这种点子有可能无法通过医疗监管人员的监管,就更加不要说道公众舆论了。A better idea might be to retrain some of the bodys own cells to do the work. Just as an outdated procedure called a cardiomyoplasty involved severing 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 generator. Such a setup would be capable of producing enough electricity to drive even the most power-hungry of devices, like artificial hearts.一个更佳的点子有可能是将一些人体自身的细胞展开再行培训来已完成这个工作。
正如一个已过时的手术,叫作心肌成形术,将较较少中用的上背部肌肉截断并将它正弦再行心脏周围来帮助心脏运送血液,肌肉纤维或许可以经过在训练后来驱动机电发电机。这样的方法需要产生充足的电能来驱动哪怕是最花费能源的设备,比如人造心脏。
The energy density 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 refinement, 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获得了突飞猛进的发展,但是锂电池所倚赖的化学反应总有一天也无法产生与葡萄糖新陈代谢所产生的能量相匹敌的数量。一克葡萄糖所所含的化学能量相等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。
再行经过一点优化,糖就有可能为下一代可移植医疗设备的能源问题获取一个十分极致的解决办法。
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