United Kingdom Medical Device Regulations

Medical Device: means an instrument, apparatus, appliance, material or other article, whether used alone or in combination, together with any software necessary for its proper application, which-

(a) is intended by the manufacturer to be used for human beings for the purpose of-
   (i) diagnosis, prevention, monitoring, treatment or alleviation of disease,
   (ii) diagnosis, monitoring, treatment, alleviation of or compensation for an injury or handicap,
   (iii) investigation, replacement or modification of the anatomy or of a physiological process, or
   (iv) control of conception; and
(b) does not achieve its principal intended action in or on the human body by pharmacological, immunological or metabolic means, even if it is assisted in its function by such means, and includes devices intended to administer a medicinal product or which incorporate as an integral part a substance which, if used separately, would be a medicinal product and which is liable to act upon the body with action ancillary to that of the device;

Active implantable medical device means a medical device which-

-relies for its functioning on a source of electrical energy or a source of power other than that generated directly by the human body or by gravity; and

-is intended to be totally or partially introduced into the human body (whether surgically or medically, including being introduced into a natural orifice) and which is intended to remain in the human body after completion of the surgical or medical procedure during which it is introduced, even if it is intended to administer a medicinal product or incorporates as an integral part a substance which, if used separately, would be a medicinal product.