Why your blood should flow like ketchup - Sean Farrington

You're listening to TED Talks Daily where we bring you new ideas to spark your curiosity every day. I'm your host, Elise. Rheology is the branch of physics that studies the deformation and flow of materials, both solids and liquids. And while this may be one of the lesser known scientific fields of study, according to chemical engineer Sean Farrington, it has the potential to completely transform how we understand and diagnose cardiovascular disease. In his talk, Sean sheds light on why this field is so powerful and why it's time for engineers and medical professionals to work together to integrate this emerging science into routine care.

您正在收听的是《TED每日演讲》，我们每天为您带来激发好奇心的新观点。我是主持人Elise。流变学是物理学的一个分支，研究固体和液体材料的变形和流动。化学工程师肖恩·法林顿认为，尽管这可能是较为冷门的科学领域之一，但它有潜力彻底改变我们理解和诊断心血管疾病的方式。在他的演讲中，肖恩阐明了这一领域为何如此强大，以及为何当下正是工程师和医疗专业人员携手合作，将这门新兴科学融入常规诊疗的时候。

When I was a kid, my uncle would tell me these great stories about his aerospace engineering career. He used to tell me all about the machinery and the designs that he built throughout his life and always said he picked the perfect career for himself because of all the cool stuff he was able to build. Once he told me about working in the nose cone of an Apollo rocket, fixing some sensitive piece of equipment just a few days before its launch.

小时候，叔叔常给我讲他航天工程职业生涯的精彩故事。他总和我分享他一生中建造的机器和设计，并常说，正因为能造出所有这些酷炫的东西，他为自己选择了完美的职业。有一次他告诉我，在阿波罗火箭发射前几天，他曾在火箭的鼻锥里修理一些精密的设备。

I was enamored by this. Listening to his stories had me daydreaming about all the innovative technology that I could build. And it's what inspired me to become an engineer, too.

我为此着迷。听着他的故事，我幻想着自己能够创造的各种创新技术。这也激励我成为了一名工程师。

Since going down this path, I've learned there's more to engineering than just the amazing stuff we build. There's also a vital responsibility in the work and sometimes with the ability to save human life. Put simply, when engineers mess up, people die. And this is what my PhD advisor warned me about when I started working with him four years ago.

踏上这条路后，我逐渐明白，工程学不仅仅是建造奇妙的事物。这份工作还承载着至关重要的责任，有时甚至关乎拯救生命。简而言之，工程师若犯错，便可能致人死亡。这正是四年前我开始与我的博士生导师共事时，他警告过我的。

When I decided to follow the path of chemical engineering, I could have never imagined I'd be doing my PhD in a field of study called rheology. But rheology was interesting to me enough, so I spend a few years of my life understanding it. Rheology is the study of flow and deformation of materials. It's mainly a method to measure the viscosity, or thickness of a material so that it works for its intended function.

当初决定走上化学工程这条路时，我从未想过自己会在一个名为“流变学”的领域攻读博士学位。但流变学令我深感兴味，因此我花费数年时间去理解它。流变学是研究材料流动与变形的学科。它主要是一种测量材料粘度（或稠度）的方法，以确保材料能实现其预期功能。

Rheology is best used for materials that are neither liquid nor solid, but some combination of both. The concepts of rheology are easiest to understand when we compare across different products because it is essential to almost every consumer product on the market, whether that's a lotion that evenly coats your hands, or a motor oil that lubricates at all operating temperatures or cement that won't harden before making it to the job site. And there's so many other examples across many industries.

流变学最适用于那些既非纯液体也非纯固体，而是介于两者之间的材料。当我们比较不同产品时，流变学的概念最易理解，因为它对市面上几乎每一种消费品都至关重要——无论是能均匀涂抹在手上的乳液、在所有工作温度下都能润滑的机油，还是运抵工地前不会凝固的水泥。各行各业中还有无数类似的例子。

So why don't I take you over to the rheology lab where I can demonstrate this for you? Okay, first off. Everybody has their favorite peanut butter. Unless you're allergic, and maybe you prefer the one that will stick to the bread. Or you prefer the one that can't support itself and just slides right off. But how about shampoo? So the purpose of shampoo is to squeeze from the bottle and sit on your hand so that you can sufficiently measure out a drop that cleans your hair. But how about when that shampoo gets a little low, right? And now you fill it up with water so that you can save that last little drop. And now it no longer stays in the palm of your hand, completely ruining one of its core functions.

那么，让我带您去流变学实验室，为您做个演示吧？好的，首先。每个人都有自己的心头好花生酱。除非你过敏，可能你喜欢粘在面包上的那种，或者你喜欢那种稀得挂不住、直接滑落的那种。但洗发水呢？洗发水的目的是能从瓶中挤出并停留在手上，以便你适量取出用于清洁头发。但当洗发水快用完时呢？你加水进去想用完最后一滴，结果它却无法再停留在手掌中，完全破坏了其核心功能之一。

Okay, now for my favorite example will be the last one, that's ketchup, because ketchup, there's such a huge difference in the texture between those popular brands. And for this one, we'll do a little bit of an experiment. We have one ketchup in each beaker, and when I flip them, we're going to watch closely to see which one drains faster. Okay, we can see there's clearly one ketchup that's much thicker than the other. And that happens to be the one that's my preference. So all of these materials are a part of a class of materials called non-Newtonian fluids. Rheology is used to measure the different flow properties of each of these materials so that they can be made reproducibly and with the most desired texture for their application.

好，现在举我最喜欢的例子，也是最后一个——番茄酱。因为不同流行品牌的番茄酱在质地口感上差异巨大。为此，我们做个小实验。两个烧杯各有一种番茄酱，当我翻转它们时，请仔细观察哪一种流得更快。好了，我们清楚地看到一种番茄酱比另一种稠得多。而那恰好是我偏爱的那款。所有这些材料都属于一类叫做“非牛顿流体”的材料。流变学用于测量这些材料各自不同的流动特性，从而能可重复地生产它们，并使其具备应用中最理想的质地。

Maybe by now you see the value of rheology for product manufacturing. But why should your blood flow like ketchup? Well, one application of rheology that I'm most interested in is in medical diagnostics. You see our blood, it doesn't flow like water, how you might imagine. Rather, it flows a bit close to ketchup and that's because blood is a non-Newtonian fluid, just like all the materials in my demonstration. Specifically, it's a shear thinning fluid. And it does this because it's necessary for healthy blood flow. If your blood's viscosity is too high, there's a higher chance of developing something like a clot or potentially an aneurysm. So measuring this information would allow physicians another method to detect for cardiovascular disease. Yet it's not being used because rheology is this niche, technical engineering field largely unknown to the public.

或许现在您看到了流变学在产品制造中的价值。但为何你的血液应该像番茄酱一样流动呢？其实，我最感兴趣的流变学应用之一是在医疗诊断领域。你看，我们的血液并不像你想象中那样像水一样流动。相反，它流动起来有点接近番茄酱，这是因为血液也是一种非牛顿流体，就像我演示中的所有材料一样。具体来说，它是一种“剪切稀化”流体。这种特性对健康的血流是必需的。如果你的血液粘度过高，形成血栓或动脉瘤的风险就会增加。因此，测量这些信息能为医生提供另一种检测心血管疾病的方法。然而，它尚未被使用，因为流变学是一个小众的、技术性的工程领域，公众知之甚少。

But I bet everyone here can think of at least one person in their lives who has or had a heart condition. Some studies show that up to 46% of people over the age of 40 have some form of coronary atherosclerosis, which is a chronic condition where plaque builds up in your arteries and narrows them, reducing the flow. One quarter of deaths in the United States are caused by heart disease. One major challenge within these diseases is to detect them early so that medication and treatment have enough time to take effect.

但我敢打赌，在座各位都能想起生活中至少有一位患有或曾患有心脏病的人。一些研究表明，高达46%的40岁以上人群患有某种形式的冠状动脉粥样硬化，这是一种慢性病，斑块在动脉内堆积使其变窄，减少血流。在美国，四分之一的死亡是由心脏病引起的。应对这些疾病的一大挑战是及早发现，以便药物和治疗有足够时间生效。

Blood pressure is a metric commonly used by physicians to inform their decisions for medications and treatment of cardiovascular disease and blood pressure monitoring has been going on for over 300 years. Now imagine the past 300 years if physicians didn't know about blood pressure monitoring. There would be countless unnecessary suffering. This is the stage that blood rheology is at, though blood's viscosity has been studied for over 100 years and blood rheology has shown significant evidence correlating it to cardiovascular disease. It's still not widely used as a diagnostic tool. Spreading awareness about rheology is necessary so that it becomes known as commonly as blood pressure monitoring.

血压是医生常用的决策指标，用于指导心血管疾病的用药和治疗，血压监测已有超过300年的历史。试想一下，如果过去300年医生不知道血压监测，将会有多少不必要的痛苦。这正是血液流变学目前所处的阶段——尽管对血液粘度的研究已逾百年，且血液流变学已显示出其与心血管疾病相关的有力证据，但它仍未作为诊断工具被广泛使用。传播对流变学的认知是必要的，以便它能像血压监测一样为人所熟知。

Blood rheology is one of those areas where physicians can work together with the engineers so that we can proactively create solutions that put this knowledge into practice. Some of my work as a PhD student is to help simplify the rheological measurement. While I'm studying the rheology of blood and it's used for cardiovascular disease diagnosis, I'm also building a small microfluidic chip. My goal in this work is to measure the same rheological information in a small, cheap, portable device that we are able to do in a bulky stationary half a million dollar machine.

血液流变学正是医生可以与工程师协作的领域之一，以便我们能够主动创建解决方案，将这一知识付诸实践。我作为博士生的一部分工作就是帮助简化流变学测量。在研究生血液流变学及其用于心血管疾病诊断的同时，我也在构建一个微型微流控芯片。我这项工作的目标，是能用一个小型、廉价、便携的设备，测量出目前需要一台庞大、固定、价值五十万美元的机器才能获取的相同流变学信息。

This could simplify the rheological measurement, making it more accessible for many doctors. And some physicians have begun to use blood rheology to augment their patient care. And they've seen positive results so far, but just like the blood pressure monitor, we'll all be better off when the public has a greater awareness of this technology so that we can help improve cardiovascular disease. And so that's why I'm asking you to just have a conversation with someone in your life about this science. And if you're in the medical community, I want you to take a closer look at blood rheology, dive into this science and see how you might be able to use it in your field.

这将能简化流变学测量，让更多医生易于使用。一些医生已开始利用血液流变学来加强患者护理，且目前已看到积极成效。但正如血压计一样，当公众对这项技术有更深入的了解时，我们所有人都会受益，从而帮助我们改善心血管疾病防治。这就是我请求您与生活中的某人谈谈这门科学的原因。如果您身处医学界，我希望您仔细研究血液流变学，深入这门科学，看看如何在您的领域应用它。

There's so much valuable information in blood rheology that tells us about our health. If we can just get over its obscurity. We might be able to help solve some of our most pressing modern medical issues if we just spread a little awareness. We could save lots.

血液流变学中蕴含了大量关于我们健康状态的宝贵信息。只要我们能够拨开其冷门的面纱。如果我们能稍微传播一点这方面的认知，我们或许就能帮助解决一些最紧迫的现代医学问题。我们可以拯救许多生命。

That was Sean Farrington at TEDx Wilmington in Delaware, USA, in 2025.

以上是肖恩·法林顿于2025年在美国特拉华州威尔明顿市TEDx大会上的演讲。