Medical device means an instrument, apparatus, appliance, material or other article, including the required software, used alone or in combination in the human body; whose use on the surface of the human body and in the body is not obtained by pharmacological, immunological, or metabolic means, but which may be involved in these means and play a certain auxiliary role; and whose use is intended to achieve the following intended purposes: (1) prevention of disease, diagnosis, treatment, monitoring, and mitigation of disease; (2) diagnosis, treatment, monitoring, mitigation, and compensation for injury or disability; (3) study, substitution, and regulation of anatomical or physiological processes; and (4) pregnancy control.