Implantable Systems

Abstract

Nowadays, with the rapid development of bioengineering, implantable medical devices are being widely employed in treating human ailments These devices, which are implantable in the human body, include pacemakers, smart prostheses, drug pumps, cochlear implants, implantable defibrillators, neurostimulators, bladder stimulators, nerve stimulators, and diaphragm stimulators They perform a real-time control and/or monitoring of several physiological parameters Over 6 million heart patients worldwide have implanted pacemakers and about 150,000 pacemakers are being surgically implanted every year in the United States alone (Wang, 2003) These pacemakers, and defibrillators, help in treating several heart conditions including fibrillation, atrial and ventricular tachyarrhythmia, and bradycardia (Soykan, 2002) These monitoring systems can communicate wirelessly with an external readout unit By means of this architecture, the use of transcutaneous wires and the risk of infection can be avoided and necessary data can be collected easily Wireless communication allows regular monitoring of several physiological parameters like the blood pressure, heart rate, and body temperature of patients during their daily activities at home (Tamura et al , 2011; Valdastri et al , 2004) These data can be collected and sent to a remote medical unit via Internet for the medical staff to access and assess and then assist the patient accordingly (Halperin et al , 2008) As shown in Troyk et al (2007), myoelectric sensors are another example of an implantable medical device They are composed of several myoelectric electrodes implanted in the residual limb of patients with a prosthetic arm These electrodes detect intramuscular myoelectric activity and provide signals that are elaborated to control the prosthesis Typically, implantable medical devices are powered by batteries, which is a severe limitation In most cases, because of battery discharge, an implantable system will need battery replacement through a surgical operation For example, although an implanted defibrillator lasts about 10 years, its battery 2