Microfabricated implantable wireless microsystems: Permanent and biodegradable implementations

The tremendous technological convergence of microfabrication technology, wireless communication technology, and low-power circuitry has opened the possibility of widespread use of microfabricated implantable wireless microsystems. A typical operational mode for these microsystems is to transduce a physiological parameter relevant to a disease state of interest, and wirelessly communicate this parameter external to the body to guide therapy. For chronic disease states, long-term, permanent sensors are of interest; while for acute disease states, biodegradable wireless microsystems may be of interest. Two microsystem examples, permanent pressure sensors for chronic monitoring of patients with congestive heart failure, and biodegradable pressure sensors for acute monitoring of patients with transient conditions, are given.