Implantable microsystems

A microsystem is a collection of electromechanical and electronic elements that have been reduced in size using advanced lithographic and machining techniques. Many types of medical devices rely on microsystem architecture to improve the health and well-being of millions of people. These systems are found in devices which are used for short and long periods of time, in diagnostic and therapeutic applications, and in devices which have limited contact with the patient and devices that are permanently implantable. Many types of implantable devices rely on microelectromechanical systems (MEMS) to achieve their functionality. Integrated circuit technology has extended beyond the fabrication of electronic elements to millimeter-scale mechanical structures with subelements in the nanometer to micrometer range. These MEMS devices often possess a high level of integration and provide numerous functions in one monolithic package. In addition, these devices allow the creation of sensors and actuators with enhanced stability and low power consumption. However the MEMS device on its own is not able to function in the body without the requisite power source, physiologic interface, and packaging that allow it to perform its intended function over the intended lifetime. This chapter describes different implantable microsystems and there use in clinical application