What are the implantable medical devices?

There are many kinds of implantable medical devices, which are generally divided into two categories. One is passive implantable devices, including bone and joint substitutes, cardiovascular implants, artificial heart valves, breast implants, intraocular lens implants, vascular stents, artificial organs and so on. The other is an active implant device. Include implantable cardiac pacemakers, cochlear implants, implantable nerve stimulators, implantable electromechanical cardiac circulatory systems, etc.