Willem Einthoven found the beat and built a machine that could measure the electrical current a heart creates. It weighed 600 pounds.
An electrocardiogram — called informally an ECG or EKG — measures the small electric waves that a human heart creates. It’s been doing it for more than a century. And as heart disease remains a leading cause of death today, it continues to be one of the most commonly used tests in modern medicine.
Birth of the ECG
Dutch scientist Willem Einthoven, who won a Nobel Prize for crafting the medical tech masterwork, was building on a long history of tracking heartbeats that began in the late 1700s. A turning point came in 1872, when Gabriel Lippman came up with a gadget called a capillary electrometer, which could measure the voltage changes on the body’s surface produced by the pulses of the heart. A.D. Waller, using Lippman’s invention, captured the first actual measurement of a heart’s beating in 1887.
The things these worthy predecessors didn’t account for were inertia and friction inside the capillaries, so their recordings were imperfect at best. Willem Einthoven fixed that beginning in 1901. At first he used mathematical equations to hand-correct imprecisions in the now-familiar valleys and peaks made on photographic paper by the machine’s movements. Within a few years, he bettered the process by coming up with the string galvanometer (on table, at center), which automatically did the corrections for him.
Without Skipping a Beat
The electrical pulse that spurs a heart muscle’s contraction — or beat — starts at the top of the organ and spreads downward. Einthoven attached electrodes to both arms and the left leg, an arrangement later called Einthoven's triangle, to capture the path of the electric current from the upper right quadrant to the lower left. The first electrodes were vessels filled with saline that bathed each of the parts of the triangle, which meant, in short, patients had to dip their hands and foot into buckets (see above).
First used to study arrhythmias, by 1909, ECG’s had clinically diagnosed irregular heartbeats. A year later, they were being used to find the high rounded plateaus suggestive of a heart attack. Within two decades, ECG’s were the go-to test to distinguish if chest pain was originating in the heart or not, and exactly what was going on in the heart to cause that pain.
Cambridge Scientific Instrument Company of London — co-founded in 1881 by Charles Darwin’s youngest son, Horace — constructed the first table model of Einthoven’s electrocardiogram in 1911(above). It weighed a whopping 600 pounds and took five people to operate.
Over the intervening century the machine lost a considerable amount of weight, but not clinical heft. The modern ECG clocks in at just 8 pounds and remains the gold standard for never missing a beat.
“Life seems to go on without effort when I am filled with music.” – George Eliot
Instinctually, intuitively, we know that music makes life better.
For millennia, humans have used music to soothe to our souls and comfort pain. Parents worldwide sing lullabies to the young and mark special occasions such as birthdays, graduations, and weddings with song. We rely on music to help us power through workouts and tackle tasks we’d rather ignore, and we manipulate our moods with melodies.
Arctic creatures have a variety of adaptations for surviving subzero temperatures. Now, science is hoping to borrow a few of their techniques to extend the shelf life of human organs. Some creatures head south to survive the winter, but the North American wood frog stays put, enduring subzero temperatures by transforming into a frozen “frogsicle.” With no heartbeat or breathing for prolonged periods, the partially frozen amphibian gradually thaws and hops back to life as spring emerges.
Most people struggle with pain at some point in their life, and when it gets bad enough it can be a debilitating condition. However, while pain has its obvious and sometimes devastating downside, our ability to feel physical pain is also part of maintaining our health. For a time, physicians even referred to pain as “the fifth vital sign,” because it can be important to understanding the state of a person’s health and point to the presence of disease.