described how a suffocating animal could be kept alive

十六世紀時，一位在法蘭德斯 名叫安德雷亞斯·維薩里的醫生

by inserting a tube into its trachea and blowing air to inflate its lungs.

描述過一種讓窒息動物不死的方式，

In 1555, this procedure didn't warrant much acclaim.

是透過將管子插進牠的氣管，

But today, Vesalius's treatise is recognized

然後灌入空氣讓牠的肺部膨脹。

as the first description of mechanical ventilation—

在 1555 年時， 這個醫療手段沒得到太多讚賞。

a crucial practice in modern medicine.

但如今維薩里的論文

To appreciate the value of ventilation,

被視為呼吸器的第一份記載，

we need to understand how the respiratory system works.

而呼吸器是現代醫學的重要醫療方式。

We breathe by contracting our diaphragms, which expands our chest cavities.

要懂得呼吸器的價值，

This allows air to be drawn in, inflating the alveoli—

我們必須先了解呼吸系統怎麼運作。

millions of small sacs inside our lungs.

我們透過收縮橫膈膜來呼吸，

Each of these tiny balloons is surrounded by a mesh of blood-filled capillaries.

橫膈膜會擴張我們的胸腔。

This blood absorbs oxygen from the inflated alveoli

這樣能讓空氣吸進來，讓肺泡充氣，

and leaves behind carbon dioxide.

肺泡是肺裡的上百萬顆小泡囊。

When the diaphragm is relaxed,

每個小氣球四周 都被充滿血液的微血管網包圍。

the CO2 is exhaled alongside a mix of oxygen and other gases.

血液從膨脹的肺泡吸進氧氣，

When our respiratory systems are working correctly,

留下二氧化碳。

this process happens automatically.

一旦橫隔膜放鬆，

But the respiratory system can be interrupted by a variety of conditions.

二氧化碳就會隨著 氧氣和其它氣體被吸入。

Sleep apnea stops diaphragm muscles from contracting.

我們的呼吸系統運作正常的話，

Asthma can lead to inflamed airways which obstruct oxygen.

這個過程就會自動發生。

And pneumonia, often triggered by bacterial or viral infections,

但是呼吸系統也可能 因為各種情況受阻。

attacks the alveoli themselves.

睡眠呼吸中止症 會讓橫隔膜的肌肉無法收縮。

Invading pathogens kill lung cells,

氣喘可能會造成氣道發炎， 進而阻隔氧氣。

triggering an immune response that can cause lethal inflammation

通常因細菌或病毒感染而引起的肺炎

and fluid buildup.

會攻擊肺泡。

All these situations render the lungs unable to function normally.

病原體侵入殺死肺細胞，

But mechanical ventilators take over the process,

引起的免疫反應可能造成嚴重發炎

getting oxygen into the body when the respiratory system cannot.

和肺部積水。

These machines can bypass constricted airways,

這些情況都讓肺無法正常運作。

and deliver highly oxygenated air to help damaged lungs diffuse more oxygen.

但呼吸器接管這個程序，

There are two main ways ventilators can work—

在呼吸系統失靈的時候， 將氧氣帶入身體。

pumping air into the patient's lungs through positive pressure ventilation,

這些機器可以繞過受阻的氣道，

or allowing air to be passively drawn in through negative pressure ventilation.

傳送含氧量高的空氣，

In the late 19th century,

協助散布更多氧氣到受損的肺中。

ventilation techniques largely focused on negative pressure,

呼吸器主要有兩種運作方式：

which closely approximates natural breathing

用正壓呼吸器把空氣打進病人肺部，

and provides an even distribution of air in the lungs.

或用負壓呼吸器讓空氣被動吸入。

To achieve this, doctors created a tight seal around the patient's body,

在 19 世紀末，

either by enclosing them in a wooden box or a specially sealed room.

呼吸器技術大部分都著重在負壓，

Air was then pumped out of the chamber,

因為這個方式較像自然呼吸，

decreasing air pressure, and allowing the patient's chest cavity

也讓空氣在肺部能分布得較為平均。

to expand more easily.

為了做到負壓，醫生 會用裝置密封病人身體，

In 1928, doctors developed a portable, metal device

可能是把病人放在 木盒或特製的密封室。

with pumps powered by an electric motor.

然後將空氣抽出，

This machine, known as the iron lung,

減少氣壓，讓病人的胸腔

became a fixture in hospitals through the mid-20th century.

能更輕易的擴張。

However, even the most compact negative pressure designs

1928 年，醫生製造了 可攜式金屬裝置，

heavily restricted a patient's movement

裡面有用電動馬達驅動的幫浦。

and obstructed access for caregivers.

這個機器也就是俗稱的鐵肺，

This led hospitals in the 1960's to shift towards positive pressure ventilation.

在 20 世紀中成為醫院的固定裝置。

For milder cases, this can be done non-invasively.

然而，即使最完善的負壓設計，

Often, a facemask is fitted over the mouth and nose,

都大大限制病人的行動，

and filled with pressurized air which moves into the patient's airway.

也妨礙醫護人員服務。

But more severe circumstances

這讓 1960 年代的醫院 轉而使用正壓呼吸器。

require a device that takes over the entire breathing process.

對病情較輕的患者而言， 不需侵入他們的身體就能做到。

A tube is inserted into the patient's trachea

一般會有面罩蓋住口鼻，

to pump air directly into the lungs,

加壓的空氣會送進病人的氣道。

with a series of valves and branching pipes

但較嚴重的病人

forming a circuit for inhalation and exhalation.

需要能完全代替病人呼吸的儀器。

In most modern ventilators,

插入病人氣管的管子

an embedded computer system

會把空氣直接打進他的肺部，

allows for monitoring the patient's breathing and adjusting the airflow.

一連串的氣閥和支管

These machines aren't used as a standard treatment,

形成吸氣和呼氣的迴路。

but rather, as a last resort.

大部分新型呼吸器會內建電腦系統，

Enduring this influx of pressurized air requires heavy sedation,

能夠監控病人呼吸、調整氣流。

and repeated ventilation can cause long-term lung damage.

這些機器不是用在一般標準治療上，

But in extreme situations,

而是不得已時的最後手段。

ventilators can be the difference between life and death.

要病人忍受這種加壓空氣， 需要施以高劑量鎮靜藥物，

And events like the COVID-19 pandemic

而且重覆換氣可能 造成肺部長期損傷。

have shown that they're even more essential than we thought.

但是在危急的情況下，

Because current models are bulky, expensive,

呼吸器能攸關生死。

and require extensive training to operate, most hospitals only have a few in supply.

像新型冠狀病毒肺炎大流行的情況，

This may be enough under normal circumstances,

可以看到呼吸器 比我們想像中還要不可或缺。

but during emergencies, this limited cache is stretched thin.

因為目前的樣式都很笨重、昂貴，

The world urgently needs more low-cost and portable ventilators,

而且需要大量訓練才能操作，

as well as a faster means of producing and distributing

大部分的醫院只有少數幾臺可用。

this life-saving technology.

也許在一般情況下還夠，