Heart attacks are the number one killer in India. Many of these deaths could be prevented if people with heart disease underwent electrocardiograms (ECGs). But ECG machines are expensive (around US$10,000) and big, so they are usually found only in hospitals. The trouble is, some 70% of Indians live in rural areas where hospitals are scarce. General Electric has solved the problem by designing a handheld ECG machine that can be carried around. It is also cheaper to use than regular ECG machines, partly because the expensive paper they use has been replaced by the paper used by bus conductors to print tickets.