Abstract
In recent days, there has been major improvement on implantable biomedical systems that support most of the functionalities of implantable medical devices uses wires or wireless radiofrequency telemetry to communicate with circuitry outside the body. However, the wires are a common source of surgical complications, including breakage, infection and electrical noise. In addition, radiofrequency telemetry requires large amounts of power and results in low-efficiency transmission through biological tissue. Communication with implanted devices is usually accomplished with a wired connection or with wireless radiofrequency (RF) transmission. However, wires can break, become infected or introduce noise in the recording through movement artifacts or by antenna effects. Complications with wires are frequently reported with deep brain stimulation devices and with pacemakers and implantable cardioverter-defibrillators. Wireless RF telemetry has been used in several implantable medical devices to avoid the complications of wired implant. However, wireless RF telemetry requires significant power and suffers from poor transmission through biological tissue. RF telemetry also needs a relatively large antenna, which limits how small the implantable devices can be and prevents implantation in organs such as the brain, heart and spinal cord without causing significant damage.