This book presents new systems and circuits for implantable biomedical applications, using a non-conventional way to transmit energy and data via ultrasound. The authors discuses the main constrains (e.g. implant size, battery recharge time, data rate, accuracy of the acoustic models) from the definition of the ultrasound system specification to the in-vitro validation.The system described meets the safety requirements for ultrasound exposure limits in diagnostic ultrasound applications, according to FDA regulations. Readers will see how the novel design of power management architecture will meet the constraints set by FDA regulations for maximum energy exposure in the human body. Coverage also includes the choice of the acoustic transducer, driven by optimum positioning and size of the implanted medical device. Throughout the book, links between physics, electronics and medical aspects are covered to give a complete view of the ultrasound system described. Provides a complete, system-level perspective on the use of ultrasound as energy source for medical implants; Discusses system design concerns regarding wireless power transmission and wireless data communication, particularly for a system in which both are performed on the same channel/frequency; Describes an experimental study on implantable battery powered biomedical systems; Presents a fully-integrated, implantable system and hermetically sealed packaging.