Functional electrical stimulation to re-learn how to execute impaired functions, instead of making the consumer dependent on neuroprostheses for the rest of her/his life. Neurons are electrically active cells. In neurons, information is coded and transmitted as a series of electrical impulses called action potentials, which represent a brief change in cell electric potential of approximately 80–90 mV. Nerve signals are frequency modulated; i.e. the number of action potentials that occur in a unit of time is proportional to the intensity of the transmitted signal. Typical action potential frequency is between 4 and 12 Hz. An electrical stimulation can artificially elicit this action
Process tomography imaging methods are used in process tomography, e.g. ultrasonic imaging, positron emission tomography (PET), electrical resistance tomography (ERT) and electrical impedance tomography (EIT), electrical capacitance tomography (ECT), magnetic induction tomography (MIT). In all cases external sensors are used to detect signals from boundary of the object, and the three-dimensional material distribution or the velocity field is computed using the measured data. Process tomography is an area of rapid growth both in terms of research and applications. There are number of challenges remaining in this area including data processing an image reconstruction, and application of imaging modalities in a real applications.