【经济学人】医疗诊断 | 2017.01.14 | 总第782期

TAKE a cardboard disc and punch two holes in it, on either side of its centre. Thread a piece of string through each hole. Now, pull on each end of the strings and the disc will spin frenetically in one direction as the strings wind around each other, and then in the other, as they unwind.

取一张圆纸板，在其两侧的中心分别打两个孔，用多根线穿过每个孔。然后，拉动线的两端，随着多根线彼此缠绕在一起，纸盘将飞速向一个方向旋转，而当多根线彼此松开时，纸盘则将向另一个方向旋转。

• Disc：圆盘

• Frenetically：疯狂

Versions of this children’s whirligig have been found in archaeological digs across the world, from the Indus Valley to the Americas, with the oldest dating back to 3,300BC. Now Manu Prakash and his colleagues at Stanford University have, with a few nifty modifications, turned the toy into a cheap, lightweight medical centrifuge. They report their work this week in Nature Biomedical Engineering.

这个孩童时期的旋转玩具的变迁版本已经在世界各地的考古挖掘中找到，从印度河谷到美洲，最古老的可追溯到公元前3300年。如今，通过对其进行几处巧妙地修改，斯坦福大学的Manu Prakash和他的同事已将这种玩具改造成了廉价、轻便的医用离心机。他们在本周的自然生物医学工程杂志中对他们的工作进行了报告。

• Whirligig：旋转; 旋转玩具; 旋转木马; 循环

• Archaeological：考古学家

• Nifty：俏皮的，极好的;

What goes around...

离心机是什么样的

离心机

Centrifuges’ many uses include the separation of medical samples (of blood, urine, sputum and stool) for analysis. Tests to spot HIV, malaria and tuberculosis, in particular, require samples to be spun to clear them of cellular debris. Commercial centrifuges, however, are heavy and require power to run. That makes them impractical for general use by health-care workers in poor countries, who may need to carry out diagnostic tests in the field without access to electricity. They also cost hundreds—often thousands—of dollars.

离心机有许多用途，包括分离医疗样品（血液，尿液，痰液和粪便）用于医疗分析。尤其是检测艾滋病、疟疾和结核，这需要旋转样品以分离出细胞碎片。然而，商业离心机不但笨重，还需要电力驱动。因此对于贫穷国家的卫生保健工作者来说，离心机的普遍使用是不切实际的，他们进行诊断测试的地方也可能没有电。而且购买这些离心机需要花费数百美元（有时要数千美元）。

• Urine：尿; 小便; 下泉

• Sputum：痰

• Tuberculosis：肺结核

Dr Prakash’s device, which he calls a “paperfuge”, costs 20 cents and weighs just two grams. The standard version (pictured) consists of two cardboard discs, each 10cm across. One of the discs has two 4cm-long pieces of drinking straw glued to it, along opposing radii. These straws, which have had their outer ends sealed with glue, act as receptacles for small tubes that contain the blood to be centrifuged.

一种Prakash博士称为“纸质离心机”的仪器，重2克，成本只要20美分。标准版本（如图）包括两个纸板盘，每个直径10cm。有两个4厘米长的饮用吸管沿着相反的半径方向粘连在其中的一个圆盘上。这些吸管的外端用胶密封，用作容纳要离心血液的小管容器。

• Straw：吸管

• Glue：胶合; 紧附于;胶水; 胶粘物; 粘聚力;

Once the straws have been loaded, the two discs are attached face to face with Velcro, sandwiching the tubes between them. For string, Dr Prakash uses lengths of fishing line, tied at each end around wooden or plastic handles that the spinner holds.

当吸管装满液体后，两个圆盘被尼龙扣拉近贴合从而将他们之间的管子夹住。Prakash博士使用一定长度的钓鱼线将其末端连接到旋转者手握的木制或塑料手柄上。

The result, which spins at over 300 revolutions per second (rps) and generates a centrifugal force 10,000 times that of gravity, is able to separate blood into corpuscles and plasma in less than two minutes. This is a rate comparable to that of electrical centrifuges. Spinning samples for longer (about 15 minutes is ideal, though that is a lot of effort for a single spinner) can even separate red corpuscles, which may be infected by malarial parasites, from white ones, which cannot be so infected. The team is now trying the system out for real, to find out what works best, by conducting blood tests for malaria in Madagascar.

通过300多转/秒的转速所获得的离心力相当于其重力的10000倍，这足以保证在2分钟之内将血液分离成细胞和血浆。这个速度可以与电子离心机相媲美。将样本旋转更长时间（15分钟是最理想的，不过对单个旋转者而言，这要消耗许多精力）甚至能将可能被疟原虫感染的红细胞，和不会被感染的白细胞分离。该团队通过对马达加斯加岛的疟疾患者进行血液检查找出其最佳的工作模式，以便能将这一设备系统投入实际应用。

• corpuscle  n.[解剖]小体

Manu Prakash

Once samples have been separated, they still need to be analysed. Fortunately, the paperfuge is not the first cheap laboratory instrument Dr Prakash has invented. In 2014 he unveiled the “foldscope”, a microscope made from a sheet of paper and a small spherical lens. The foldscope goes on sale this year, but his laboratory has already distributed more than 50,000 of them to people in 135 countries, courtesy of a charitable donation that paid for them. He plans to ship a million more by the end of 2017. Putting this together with a paperfuge means it is now possible to separate biological samples and analyse them under a microscope using equipment that costs less than a couple of dollars.

当样本被分离后仍需进一步分析。厉害的是，纸质离心机并不是Prakash博士发明的第一个低价实验室仪器。2014年他向世人展现了“折叠镜”，这是由一片纸和一个小球面透镜构成的显微镜。“折叠镜”在今年上市，然而经由慈善捐助出资，他的实验室早已将其分销至135个国家超过5万人的手中。他计划到2017年底再生产100万台设备。折叠镜与纸质离心机的组合意味着使用只需几美元的显微镜设备分离并分析生物样本已成为现实。

• spherical lens：[光]球面透镜

• courtesy of：经由…提供；蒙…好意

翻译 ▍上善若水、hua外音

审核 ▍云图

编辑 ▍澜意

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