Those of you who have had an electrocardiogram, or ECG, probably remember the annoyance of what seems like dozens of sticky tabs all over your torso connected to equally as many leads outside—and inside—those too-small hospital gowns known as johnnys. Annoying as the procedure is, an ECG is still the most important test for the interpretation of cardiac rhythm. It can also be used to monitor the effect of drugs targeted at reducing cardiac disturbances like faulty rhythms and high blood pressure. But why does it have to be in a hospital? And what’s with all the sticky tabs and wires?
Those may become a thing of the past, thanks to a design by Ashraf Kodsy, which proposes an ECG box powered by Peltier cells, which deliver the thermoelectric effect, converting temperature gradient (body heat) to electricity. Constrained by the fact that the size of the ECG box was already decided pre-design, Kodsy nonetheless succeeded in creating a prototype Peltier cell casing and ECG box which, when sent to a manufacturer, could be printed via a 3D printer, one of the more amazing inventions of the 21st century.
The parts were then coated (presumably with a brush-on resin) and sanded to remove any surface irregularities. After a final coat of black finish, the models were deemed ready-to-go. Fastened to the outside front of a skin-tight T-shirt, and connected to those annoying leads all over the chest (designers couldn’t get rid of that, I guess), the final product sends the information to a USB drive, which can then display the needed information on a computer monitor. The concept is similar to the pants that can charge a cell phone that we reported on in February.
It’s an interesting way to take ECG readings, and would be extremely valuable in diagnosing supraventricular tachycardia, or SVT, a heart defect in which the heartbeat speeds up well past the normal range (i.e., 60-100 beats per minute). In its early stages, SVT can be difficult to diagnose because the episodes of arrhythmia are irregular and unpredictable, and require patients to stay in the hospital for 24 hours or more so the anomaly can be observed. In any case, it’s interesting to see the heat-to-energy conversion process being used outside the energy industry, and to such a potentially useful purpose.