Electronic and Tissue Interactions

Integration of medical devices into the patients is a must-pass step for the devices to function as intended. Obviously, it can be easier for devices that are intended to work for hours or days than those intended to function for years. Mechanical forms, fit and placement, electrical, chemical, and/or optical communications, and biological interactions are among the factors that need be considered. For certain devices and applications, the changes of devices over time are parts of the intended designs such as those with resorbable devices. More factors need be considered for them.<br/>This talk is focused on how the tissues of the patients may impact the devices’ placement and their functions. Specific examples would include how the patient tissues mechanically and biologically affect the electric and /or electronic devices, causing the functions to be different than observed in vitro. One example is electrodes of electrical stimulation devices such as cardiac pacemakers. The electrodes inserted in the tissues must have certain electric and chemical properties in order for them to deliver the electric signals to the tissues. Another example is implanted electronic devices that must be protected from being damaged by the body fluids of the patients. Water diffused into electronics can easily lead to loss of functions. This is one of the most critical questions that need be answered to make devices for long term implantable applications for the patients. Biocompatibility of devices will also be discussed briefly.