Business Card with a Built-in Electrocardiograph The developers of*MobilECG, an upcoming open source electrocardiography system, are gearing up with pretty cool Business cards any cardiologist would be jealous of. The team’s Business Card crams a one lead ECG, including the digital display and battery, into the smallest package we’ve ever seen. It’s technically **t a diag**stic device, having **t received any regulatory approvals. Nevertheless, we’re confident the tech**logy inside works just like any simple ECG device.