Wired connection of implantable devices:A circulatory assist system isdisclosed, the system including an implantable electrical device having anelectric motor, an implantable controller connected to the implantableelectrical device, and an implantable power source connected to the controllerfor supplying power to the controller. Advantages:The controller is attachable to afirst side of a percutaneous connector.
A second side of the percutaneousconnector, opposite to the first side, allows external connectivity to thementioned controller.Disadvantages:- wires can break, so the patients must havesome sort of surgery, which makes it harder, more expensive, and less feasible. – wires may become infected or introduce noisein the recording through movement artifacts or by antenna effects. -Complications with wires are frequentlyreported with deep brain stimulation devices and with pacemakers andimplantable cardioverter-defibrillators. Wireless medical telemetry:Wireless medical telemetry is generally used to recordthe physiological information of the patient (e.g., cardiac signals) over adistance through radio-frequency communication between a transmitter and acentral monitoring station.Other wireless communication systemshave been investigated to connect with implants such as ultrasound and optics.
Advantages:Allow the patient to move to the bedcontrol system with the eavesdropper with a hard-wired connection.Disadvantages:-However, wireless RF telemetry requires significant power.-It suffers from poor transmission through biological tissue.-RFtelemetry also needs a relatively large antenna, which limits how small theimplantable devices can be and prevents implantation in organs such as thebrain, heart and spinal cord without causing significant damage.-Thesemethods also have low-efficiency transmission through the body and would bedifficult to miniaturize. it is hard to find an appropriate commercial battery.Up to now, finding the battery has been a bottleneck in arterial blood pressuremeasurement system development. For example, Frounhofer’s blood pressuremeasurement system is assembled with an inner-arterial pressure sensor and anouter-arterial battery.
Implant-to-surface communication:Where asmall signal (~50 pA) was transmitted through the body and detected at areceiving electrode. In this system, a single transmitting and a singlereceiving electrode were placed near the skin without touching it, capacitivelycoupled to the body. Another set of electrodes at the transmitter and receiverwere also oriented away from the body and were capacitively coupled to theenvironmental ground, serving as the signal’s return path.Advantages:- This type of telemetry is calledcapacitive sensor communication and has been used first in surfacecommunications with both transmitting and receiving electrodes placed near oron the skin.-This allows for easy precipitation andposture of the skin electrodes to develop the quality of reception signals. Disadvantages:-The majorlimitation of this transmission method is its reliance on capacitiveconnections to both the body and ground and thus has not been used forcommunicating with implanted devices. -Severalapplications of capacitive intrabody communication have been developed fortransmitting data to consumer electronic devices.
-Because the signal has to travel through theskin, which is less conductive than many of the tissues inside the body, moresignal attenuation occurs.