World’s Smallest Pacemaker is Made for Newborns, Activated by Light, and Requires No Surgery

World’s smallest pacemaker next to a grain of rice – Credit: John Rogers / Northwestern University press releaseNorthwestern University engineers have developed a pacemaker so small that it can fit inside the tip of a syringe and be non-invasively injected into the body, according to a new study published in Nature.Although it can work with hearts of all sizes, the pacemaker is particularly well-suited to the tiny, fragile hearts of newborn babies with congenital heart defects.A pacemaker is an implantable device that helps maintain an even heart rate, either because the heart’s natural cardiac pacemaker provides an inadequate or irregular heartbeat, or because there is a block in the heart’s electrical conduction system.Smaller than a single grain of rice, the pacemaker is paired with a small, soft, flexible, wireless, wearable device that mounts onto a patient’s chest to control pacing. When the wearable device detects an irregular heartbeat, it automatically shines a light to activate the pacemaker.These short light pulses, which penetrate through the patient’s skin, breastbone, and muscles, control the pacing.Designed for patients who only need temporary pacing, the pacemaker simply dissolves after it’s no longer needed. All the pacemaker’s components are biocompatible, so they naturally dissolve into the body’s biofluids, bypassing...
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First major chunk breaks off world's biggest iceberg

PARIS - An enormous chunk has broken off the world's largest iceberg, in a possible first sign the behemoth from Antarctica could be crumbling.The colossal iceberg -- which is more than twice the size of Greater London and weighs nearly one trillion tonnes -- had largely stayed intact since it started slowly moving north in 2020.It has been drifting toward the remote island of South Georgia in the South Atlantic, raising the prospect it could run aground in shallower water and disrupt feeding for baby penguins and seals.But a chunk about 19 kilometres (12 miles) long has cleaved off, said Andrew Meijers from the British Antarctic Survey, who encountered the iceberg in late 2023 and has tracked its fate via satellite ever since."This is definitely the first significant clear slice of the iceberg that's appeared," the physical oceanographer told AFP.Soledad Tiranti, a glaciologist currently on an Argentinian exploration voyage in the Antarctic, also told AFP that a section had "broken" away.The jagged piece has an area of roughly 80 square kilometres (31 square miles) -- huge in its own right, but just a fraction of the approximately 3360 square kilometres that remained.Meijers said icebergs were full of deep fractures, and although this monumental specimen had shrunk over time and lost a much smaller piece, it had "held together...
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