A medical device is an instrument, apparatus, implant, in vitro reagent, or similar or related article that is used to diagnose, prevent, or treat disease or other conditions, and does not achieve its purposes through chemical action within or on the body (which would make it a drug). Whereas medicinal products (also called pharmaceuticals) achieve their principal action by pharmacological, metabolic or immunological means, medical devices act by other means like physical, mechanical, or thermal means.
Medical devices vary greatly in complexity and application. Examples range from simple devices such as tongue depressors, medical thermometers, and disposable gloves to advanced devices such as computers which assist in the conduct of medical testing, implants, and prostheses. The design of medical devices constitutes a major segment of the field of biomedical engineering.
Biomedical device product manufacturing is a long process requiring robust SOPs and guidelines for production. These days, with the aid of CAD or modelling platforms, the work is now much faster, and this can act also as a tool for strategic design generation as well as a marketing tool (Wong et al., 2013). 
Failure to meet cost targets will lead to substantial losses for an organisation. In addition, with global competition, the R&D of new biomedical devices is not just a necessity, it is an imperative for biomedical device manufacturing companies. The realisation of a new design can be very costly, especially with the shorter product life cycle. As technology advances, there is typically a level of quality, safety and reliability that increases exponentially with time (ibid.).
Example: Initial models of the artificial cardiac pacemaker was an external support device that transmits pulses of electricity to the heart muscles via electrode leads on the chest. The electrodes contact the heart directly through the chest, allowing stimulation pulses to pass through the body. Recipients of this typically suffered infection at the entrance of the electrodes, which led to the subsequent trial of the first internal pacemaker, with electrodes attached to the myocardium by thoracotomy. Future developments led to the isotope-power source that would last for the lifespan of the patient.
The global medical device market reached roughly 209 billion US Dollar in 2006.