In this lecture I'll discuss three loosely connected aspects of neuroengineering in our lab. The first relates to a method for the assessment of disability, the second describes an intervention to compensate for disability, and the third is a method for deciphering neural communication. I. Balance and maintenance of posture is particularly important for bipedal ambulation. Balance requires coordination of several sensory and motor systems in the body. When any of these is disrupted, it is necessary to understand what kind of medical intervention is appropriate. Conventional clinical evaluation of balance involves subjective assessment by a physician. The wide availability of multi-modal inertial motion sensors offers an objective way of assessing balance. The use of inertial motion sensors for determining displacement and attitude is prone to calculation errors that manifest as “drift”. Signal processing methods that use multiple sensors to correct these errors are reasonably effective for the present purpose. Using such inertial sensors, we were able to show that subtle age related changes alter balance in a number of standard tasks. II. Functional Electrical Stimulation has long been touted as a good way of obtaining artificial control of paralyzed muscle. However, multiple problems has restricted its use. One of the problems has been in controlling multiple muscles for complex functions. Using a multichannel stimulator and a multielectrode band worn on the forearm we were able to produce reproducible movement of fingers and the wrist. The stimulator has a single microcontroller and multiple high voltage outputs. Further work is in progress to develop control protocols. III. Neuronal communication uses frequency encoded pulses or “action potentials”. These action potential sequences often represent a continuous variation in a physical quantity like pressure or displacement. Therefore, it is of interest to demodulate the “firing rate” underlying the actional potential sequence to recover the original signal. A variety of demodulation methods can be used. For systems analysis of neural subsystems it is desirable to have a smooth demodulated signal with no phase shift. I'll discuss different demodulation and interpolation methods.