Medical devices are instruments, devices, in vitro diagnostic reagents, materials and other related items that are used directly or indirectly in the human body, including the software systems that accompany it. Efficacy is mainly obtained by physical and other means, not by pharmacological, immunological or metabolic means. The world's first medical device was arguably the stethoscope, invented in 1816, and the industry has continued to evolve over the next 200 years.

Medical devices provide helpful information for medical or diagnostic purposes by examining samples from the human body and are used in a wide range of four main areas:

1. diagnosis, prevention, monitoring, treatment or mitigation of disease;

2. diagnosis, monitoring, treatment, mitigation, or functional compensation of injuries

3. the examination, replacement, regulation, or support of physiological structures or processes

4. support or maintenance of life.