How We Help the Body Breathe

science & techNLM Circulating Now1928–1951 · Copenhagen, Denmark

How We Help the Body Breathe

the gist

Artificial breathing is far older than modern medicine, but its machines split into two families. Positive-pressure devices push air into the lungs, while negative-pressure devices lower the pressure around the chest so the lungs inflate, as they do naturally. The iron lung, developed by Philip Drinker and Louis Agassiz Shaw at Harvard in 1928–1929, was the best-known negative-pressure machine and kept polio patients alive. A 1951 polio outbreak in Copenhagen exposed its limits, and Bjorn Ibsen's team showed that forcing air in through a tracheostomy saved more lives, marking the shift toward positive pressure that underlies modern intensive care.

how it works

Lungs expand when the pressure around them falls below the air pressure outside the body. Negative-pressure machines copy this by sealing the body in a chamber and lowering the pressure around the chest. Positive-pressure machines do the reverse, pushing air into the airways, which is simpler and more controllable but can damage lungs if pressure is too high.

so what

Every modern ventilator and ICU traces back to this switch. The history shows why breathing support is so hard to get right: too much pressure can injure lungs as badly as no treatment at all.

the bigger pattern

Medicine often swings between competing approaches; here, the preference for negative pressure lasted until a crisis forced a change. Similar shifts happened when the polio epidemics showed that large, costly machines could not meet demand.

fun fact

The iron lung was a sealed metal tank in which the patient's head stuck out through a collar, while the rest of the body sat inside.

U.S. National Library of Medicine

Illustrative photo · Photo Credit: Content Providers(s): CDC/GHO/Mary Hilpertsha…, Public domain, via Wikimedia Commons

source: NLM Circulating Now ↗

historyWikipediaclassic1336–1565 · Karnataka, India

Hampi was once one of the world's largest cities, until its Vijayanagara capital was destroyed in 1565

the gist

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.

how it works

The city was built around a fortified core with temples, markets and water structures along the river, supplied by an extensive network of roads and waterworks. When the empire fell, the city was not rebuilt, so its stone monuments were left standing.

so what

Hampi shows how quickly a great city can vanish after a military defeat, and how a ruined capital can remain sacred. Its ruins give historians a view of medieval South Asia that few other sites can match.

fun fact

The name Hampi comes from Pampa, an old name for the Tungabhadra River.

From Wikipedia, the free encyclopedia · text CC BY-SA 4.0

Image: Wikimedia Commons

source: Wikipedia ↗

2 min

politicsshortCNA2:01

False allegations about Singapore’s hand in Indonesia’s markets and a made-up meeting

from CNA

CNA Verify has found close to 400 posts pushing falsehoods tying Singapore to Indonesia’s stock market rout and to a secret meeting that never took place. Together, they drew nearly 12 million views, and some were circulated by accounts that appeared to be working in concert, across multiple social media platforms.

Here’s how the disinformation campaign targeting Singapore was uncovered.

on YouTube: CNA ↗