I have a tendency to assume the worst, and once in a while, this habit plays tricks on me.
我倾向于把事情往坏了想，而这种想法偶尔会把我弄糊涂。
For example, if I feel unexpected pain in my body that I have not experienced before and that I cannot attribute,
举例来说，如果我的身体突然感到疼痛，这种疼痛前所未有，并且我不清楚病因，
then all of a sudden, my mind might turn a tense back into heart disease or calf muscle pain into deep vein thrombosis.
那么我会突然认为背部剧痛是由心脏病所致，或者因为小腿肌肉疼痛而怀疑自己有了深部静脉血栓。
But so far, I haven't been diagnosed with any deadly or incurable disease. Sometimes things just hurt for no clear reason.
但至今为止，我还没被确诊患有任何致命或者难以治愈的疾病。有时这种事实会毫无缘由地使我伤心。
But not everyone is as lucky as me. Every year, more than 50 million people die worldwide.
但并不是所有人都像我这么幸运。每年，世界上都有超过五千万人死去。
Especially in high-income economies like ours, a large fraction of deaths is caused by slowly progressing diseases:
尤其像我们这种高收入经济体里，慢性病致死占了很大一部分：
heart disease, chronic lung disease, cancer, Alzheimer's, diabetes, just to name a few.
心脏病，慢性肺病，癌症，阿尔兹海默症，糖尿病，这些只是其中一小部分例子。
Now, humanity has made tremendous progress in diagnosing and treating many of these.
如今，人类已经在慢性病确诊和治疗上取得了显著进展。
But we are at a stage where further advancement in health cannot be achieved only by developing new treatments.
但就现阶段而言，医学上的进一步突破不能只依赖于研发新的治疗方法。
And this becomes evident when we look at one aspect that many of these diseases have in common:
而当我们观察所有这些疾病的一个共同点时，这一点就变得尤为明显：
the probability for successful treatment strongly depends on when treatment is started.
治疗的成功率很大程度上取决于何时开展治疗。
But a disease is typically only detected once symptoms occur.
但是一般来说，疾病只有在症状显现后才会被确诊。
The problem here is that, in fact, many diseases can remain asymptomatic, hence undetected, for a long period of time.
这里的问题在于，实际上，很多疾病一直没有临床症状，所以很长一段时间都不会被检测出来。
Because of this, there is a persisting need for new ways of detecting disease at early stage, way before any symptoms occur.
因此，在远早于症状显现出来前，便能检测出早期疾病的新治疗方法变得极为需要。
In health care, this is called screening.
在医疗保健上，这被称为筛检。
And as defined by the World Health Organization,
根据世界卫生组织（WHO）的定义，
screening is "the presumptive identification of unrecognized disease in an apparently healthy person, by means of tests ... that can be applied rapidly and easily ..."
筛检意为“在看似健康的人身上，通过快速简单的...多种检测手段...得出的未确诊疾病的假定诊断。”
That's a long definition, so let me repeat it:
这段定义非常长，所以我再重复一遍：
identification of unrecognized disease in an apparently healthy person by means of tests that can be applied both rapidly and easily.
在看似健康的人身上，通过多种快速简单的检测手段得出的未确诊疾病的假定诊断。
And I want to put special emphasis on the words "rapidly" and "easily" because many of the existing screening methods are exactly the opposite.
我想着重强调“快速”和“简单”这两个词，因为现阶段的很多筛检方法并没做到这两点。
And those of you who have undergone colonoscopy as part of a screening program for colorectal cancer will know what I mean.
而在座的观众中做过直肠癌筛检程序之一，即结肠镜检查的人将会明白我的话中之意。
Obviously, there's a variety of medical tools available to perform screening tests.
显而易见，目前有许许多多可应用于筛检的医学手段。
This ranges from imaging techniques such as radiography or magnetic resonance imaging to the analysis of blood or tissue.
其中包括X射线放射成像、磁共振成像、还有血液和组织分析。
We have all had such tests. But there's one medium that for long has been overlooked:
我们一直都拥有这些技术。但有一个长期被忽视的媒介：
a medium that is easily accessible, basically nondepletable,
一个可轻易接触到的，基本无损耗的，
and it holds tremendous promise for medical analysis. And that is our breath.
拥有巨大前景的医学分析媒介。这便是我们的呼气。
Human breath is essentially composed of five components: nitrogen, oxygen, carbon dioxide, water and argon.
人类呼出的气体基本由五个部分组成：氮、氧、二氧化碳、水和氩。
But besides these five, there are hundreds of other components that are present in very low quantity.
除此之外，还有其它上百种含量极低的成分。
These are called volatile organic compounds, and we release hundreds, even thousands of them every time we exhale.
它们是挥发性有机物质，而我们每次呼气都会释放成百甚至上千种有机物质。
The analysis of these volatile organic compounds in our breath is called breath analysis.
以这些挥发性有机物为对象的分析被称为呼气分析。
In fact, I believe that many of you have already experienced breath analysis.
事实上，我相信在座的许多人都已经做过呼气分析。
Imagine: you're driving home late at night,
试想一下：你在深夜开车回家，
when suddenly, there's a friendly police officer who asks you kindly but firmly to pull over and blow into a device like this one.
突然这时，有位亲切的警官，和善却态度坚决地要求你靠边停车，并朝这个仪器里呼气。
This is an alcohol breath tester that is used to measure the ethanol concentration in your breath
这是酒精呼气检测仪，用于测量呼出气体中的酒精含量
and determine whether driving in your condition is a clever idea.
以评估你此时的身体条件是否允许开车。
Now, I'd say my driving was pretty good, but let me check.
我觉得我的驾驶水平很不错，但让我现在检测一下。
0.0, so nothing to worry about, all fine.
0.0，所以没什么好担心的，一切正常。
Now imagine a device like this one, that does not only measure alcohol levels in your breath,
现在试想这样一台仪器，它不仅可以检测呼气中的酒精含量，
but that detects diseases like the ones I've shown you and potentially many more.
还可以检测出像我刚刚介绍过的那样的疾病，甚至可能检测出更多种。
The concept of correlating the smell of a person's breath with certain medical conditions, in fact, dates back to Ancient Greece.
这种将人类呼气中的气味和他的某种健康状况所联系起来的概念，实际上起源于古希腊。
But only recently, research efforts on breath analysis have skyrocketed, and what once was a dream is now becoming reality.
但直到最近，关于呼气分析的研究成果才有了飞跃性的进展，曾经只存在于想象中的事物如今变成了事实。
And let me pull up this list again that I showed you earlier.
我现在再展示一下刚才的那张单子。
For the majority of diseases listed here,
有大量证据表明，
there's substantial scientific evidence suggesting that the disease could be detected by breath analysis.
这张单子中的大部分疾病，可以通过呼气分析检测到。
But how does it work, exactly? The essential part is a sensor device that detects the volatile organic compounds in our breath.
但呼气分析到底是如何检测的？分析仪器里必不可缺的部分是可以检测呼气中挥发性有机物的感应器。
Simply put: when exposed to a breath sample,
简单地说，当把此装置置于呼气样本中，
the sensor outputs a complex signature that results from the mixture of volatile organic compounds that we exhale.
它便会输出复杂的信号，这些信号便是来源于我们呼气中的挥发性有机物。
Now, this signature represents a fingerprint of your metabolism, your microbiome and the biochemical processes that occur in your body.
而这些信号就好比你体内的新陈代谢，微生物菌群，以及生化过程的“指纹”。
If you have a disease, your organism will change, and so will the composition of your exhaled breath.
如果你患有某种疾病，你的机体会产生变化，这也包括了呼出气体的成分。
And then the only thing that is left to do is to correlate a certain signature with the presence or absence of certain medical conditions.
接下来该做的，便是把某个信号与某项身体状况的存在与否给联系起来。
The technology promises several undeniable benefits.
这项技术具备一些不可忽视的优点。
Firstly, the sensor can be miniaturized and integrated into small, handheld devices like this alcohol breath tester.
首先，感应器可以微型化，并被整合进小型便携设备，比如酒精呼气检测仪。
This would allow the test to be used in many different settings and even at home,
这使得测试可在很多不同情境下，甚至在家里完成，
so that a visit at the doctor's office is not needed each time a test shall be performed.
如此一来，每次检测便没必要去医生办公室才能完成了。
Secondly, breath analysis is noninvasive and can be as simple as blowing into an alcohol breath tester.
其次，呼气分析是无创的，就像朝酒精检测仪里吹气那样简单。
Such simplicity and ease of use would reduce patient burden and provide an incentive for broad adoption of the technology.
此种简单且易操作的特点可以减轻病人的负担，还可以促进这项技术的推广。
And thirdly, the technology is so flexible that the same device could be used to detect a broad range of medical conditions.
另外，这项技术的灵活性使得仪器能被应用于检测很多方面的身体状况。
Breath analysis could be used to screen for multiple diseases at the same time.
呼气检测可以同时筛检多种疾病。
Nowadays, each disease typically requires a different medical tool to perform a screening test.
如今，每种疾病的筛检需要用到不同医疗仪器。
But this means you can only find what you're looking for.
但这意味这你只能有目的的进行疾病监测。
With all of these features, breath analysis is predestined to deliver what many traditional screening tests are lacking.
有了这些特点，呼气分析就可以弥补传统筛检里的不足。

And most importantly, all of these features
而最重要的是，所有这些特点
should eventually provide us with a platform for medical analysis that can operate at attractively low cost per test.
最终可提供一个平均花费相当低的医疗分析平台。
On the contrary, existing medical tools often lead to rather high cost per test.
相较之下，现在的医疗仪器常常意味着高昂的成本。
Then, in order to keep costs down, the number of tests needs to be restricted,
为了降低成本，检测的数量便被限制，
and this means (a) that the tests can only be performed on a narrow part of the population, for example, the high-risk population;
这说明：(a)检测只能提供给一小部分人，比如高危人群；
and (b) that the number of tests per person needs to be kept at a minimum.
(b)每人的检测数要被控制在最少。
But wouldn't it actually be beneficial if the test was performed on a larger group of people,
但如果这些检测被提供给更多的人，
and more often and over a longer period of time for each individual?
甚至长此以往提供给每一个人，这样岂不是更有益？
Especially the latter would give access to something very valuable that is called longitudinal data.
尤其是后一种情况，将会在最后提供一种名为“纵向数据”的宝贵数据。
Longitudinal data is a data set that tracks the same patient over the course of many months or years.
纵向数据是一种跟踪记录同一个病人在数月或数年内情况的数据组。
Nowadays, medical decisions are often based on a limited data set,
如今，医疗上的决策常受有限数据组限制，
where only a glimpse of a patient's medical history is available for decision-making.
仅仅只有病人的一部分病史对决策有帮助。
In such a case, abnormalities are typically detected by comparing a patient's health profile to the average health profile of a reference population.
在这种情况下，病人身体的异常一般是通过将病人的健康概貌和参考组的平均健康概貌作比较。
Longitudinal data would open up a new dimension and allow abnormalities to be detected based on a patient's own medical history.
纵向数据将会开拓出新的维度，并以病人自己的病史为依据检测出身体异常。
This will pave the way for personalized treatment.
这将会为个性化治疗开辟道路。
Sounds pretty great, right? Now you will certainly have a question that is something like,
这听起来很棒，对吧？现在，你肯定会冒出一个问题：
"If the technology is as great as he says, then why aren't we using it today?"
“如果这项技术真的有他说得那么好，为什么现在还没被应用呢？”
And the only answer I can give you is: not everything is as easy as it sounds.
我能给出的唯一答复是：并不是所有事情都像听起来那么简单。
There are technical challenges, for example.
比如，现阶段还存在着技术上的难关。
There's the need for extremely reliable sensors that can detect mixtures of volatile organic compounds with sufficient reproducibility.
我们需要非常可靠的感应器，可靠到以足够的再现性检测到挥发性有机混合气体。
And another technical challenge is this:
另一个技术难关是这个：
How do you sample a person's breath in a very defined manner so that the sampling process itself does not alter the result of the analysis?
要如何明确清楚地抽样调查一个人呼出的气体，以保证抽样过程本身不会改变分析结果呢？
And there's the need for data. Breath analysis needs to be validated in clinical trials,
另外，我们还需要数据。呼气分析需在医疗测试中进行验证，
and enough data needs to be collected so that individual conditions can be measured against baselines.
同时需要收集足够的数据，以保证个体的身体状况可通过对比基准线来检测。
Breath analysis can only succeed if a large enough data set can be generated and made available for broad use.
呼气分析只有在能生成大量的数据组并广泛应用的情况下才能成功。
If breath analysis holds up to its promises, this is a technology that could truly aid us to transform our health care system
如果呼气分析有望成功，这将会成为能真正帮助我们改革医疗系统的技术，
transform it from a reactive system where treatment is triggered by symptoms of disease to a proactive system,
从一个只有在病症显现时才能给出治疗的应激系统，转变成主动出击的系统，
where disease detection, diagnosis and treatment can happen at early stage, way before any symptoms occur.
而在这个系统里，疾病的检测、诊断和治疗可在疾病早期就被应用，远早于病症显现之时。
Now this brings me to my last point, and it's a fundamental one. What exactly is a disease?
这便让我将演讲引向最后一点，也是最基础的一点。疾病到底是什么？
Imagine that breath analysis can be commercialized as I describe it, and early detection becomes routine.
想象一下，呼吸分析就像我描述的那样被商业化，早期检测成为常规流程。
A problem that remains is, in fact, a problem that any screening activity has to face because, for many diseases,
还留有的一个问题，实际上，是任何筛检手段都需要面对的问题，因为，对于大多数疾病而言，
it is often impossible to predict with sufficient certainty whether the disease would ever cause any symptoms or put a person's life at risk.
想要以足够的肯定性来检测此种疾病是否会显现症状，或使病人命悬一线，通常是不可能的。
This is called overdiagnosis, and it leads to a dilemma.
这被称为“过度诊断”，而它会将我们置于困境。
If a disease is identified, you could decide not to treat it because there's a certain probability that you would never suffer from it.
如果某种疾病被检测出来，你可以决定不去治疗它，因为有可能病人从不会因这疾病而受煎熬。
But how much would you suffer just from knowing that you have a potentially deadly disease?
但如果你只知道可能得了绝症，这又会让你受到何种程度的煎熬呢？
And wouldn't you actually regret that the disease was detected in the first place?
你会不会因为疾病从一开始就被检测出来而感到后悔呢？
Your second option is to undergo early treatment with the hope for curing it.
你的第二种选择是抱着能够被治好的希望去接受早期治疗。
But often, this would not come without side effects.
但是，这经常会带来副作用。
To be precise: the bigger problem is not overdiagnosis, it's overtreatment,
准确地来说：更大的问题并不是过度诊断，而是过度治疗，
because not every disease has to be treated immediately just because a treatment is available.
因为并不是仅因为这种疾病有治疗方法就要去马上接受治疗。
The increasing adoption of routine screening will raise the question:
频繁进行常规筛检会引发一个问题：
What do we call a disease that can rationalize treatment, and what is just an abnormality that should not be a source of concern?
我们该如何判断某种疾病是需要治疗，还是视它为不需要担心的身体异常？
My hopes are that routine screening using breath analysis can provide enough data and insight
我希望应用呼气分析的常规筛检可以提供充足的数据和见解，
so that at some point, we'll be able to break this dilemma and predict with sufficient certainty whether and when to treat at early stage.
能让我们以后打破僵局，有充分的把握来预测、此疾病是否需要在早期进行治疗。
Our breath and the mixture of volatile organic compounds that we exhale hold tremendous amounts of information on our physiological condition.
我们的呼气和其中包含的挥发性有机物蕴含着透露我们身体状况的丰富信息。
With what we know today, we have only scratched the surface.
我们目前的认识只是九牛一毛。
As we collect more and more data and breath profiles across the population,
随着我们在人群中收集到越来越多的数据和呼吸信息，
including all varieties of gender, age, origin and lifestyle, the power of breath analysis should increase.
包括各种性别、年龄、种族和生活方式，呼气分析的权威性将会增强。
And eventually, breath analysis should provide us with a powerful tool
最终，呼气分析将成为强有力的工具，
not only to proactively detect specific diseases but to predict and ultimately prevent them.
它不仅能尽早检测出某种疾病，还可以预测和最终预防疾病。
And this should be enough motivation to embrace the opportunities and challenges that breath analysis can provide,
这应该能敦促我们接受呼气分析所带来的机遇和挑战，
even for people that are not part-time hypochondriacs like me. Thank you.
甚至包括不同于我这种偶发疑病症患者的人。谢谢。