Case Study 11—Implanted Medical Devices
This chapter is an amalgamation of several different medical devices that I have encountered. It will focus on devices that surgeons implant in patients to provide years of therapy (e.g. pacemakers, stimulators, and drug pumps). They are Class III devices that require premarket approval, or PMA. They are either life-sustaining or safety-critical devices and must be proved to be so through clinical trials to be both safe and effective. Figure 14.1 illustrates just one of these types of implantable medical devices. Implanted devices that stimulate tissue electrically often are preferable to
drug therapies or surgery because they have far fewer side effects and are reversible-they can be removed or turned off if they cause problems. Implantable drug pumps provide better, closed-loop control of drug delivery. Surgeries to implant these devices occur every day in hospitals around the
world. Some might be simple outpatient surgeries, such as stimulator implants. Others might require a week-long hospital stay.