A medical<unk> is an<unk> used in medicine. The first uses of<unk>  were in radiopharmaceuticals, and this is still the most common use. However more recently, separated stable<unk>  have also come into use. Examples of non-radioactive medical<unk>  are: * Deuterium in deuterated drugs * Carbon-13 used in liver function and metabolic tests
Isotopes in medicine
Carbon nanotubes in medicine
Cancer research
Clinical engineering
Drug development
Drug discovery
Assistive technology
Wireless device radiation and health