The heart beats, and on a paper ECG strip, each beat looks like a sharp spike with two humps: a quick rise, then a smaller wave, then a descent. A doctor looks at such a strip and sees the rhythm, but the shape of each spike, how exactly the muscle contracted, is hard to discern, especially if the recording lasts a full day.
This new method turns that strip into a colorful carpet. Each beat is cut into pieces and laid out one below the other, like rows of tiles. Color shows the signal's height: dark blue is low, bright yellow is high. The result is an image where you can immediately see: if the rhythm speeds up, the rows compress; if the beat's shape changes, the pattern on the carpet distorts. Previously, such changes were looked for separately, but now they are visible together, like cracks on a single tile.
This carpet is not just about the heart. Any repeating pattern, from breathing to oscillations in machinery, can be decomposed the same way. But for doctors, the key point is: now a long recording can be taken in at a single glance, like a carpet on the floor, and you can immediately see where the pattern has gone wrong.
The longest continuous heart monitoring lasted 14 years: a patient wore an implanted recorder that captured every beat.