INTRODUCTION This abstract describes a passive unobtrusive gait-monitoring device, based on a highly sensitive optic fiber floor vibration sensor. Long-term in-home gait monitoring provides a measure of a person's functional ability and activity levels, which can help 'evaluate' a person's health over a long period of time. Such a passive gait-monitoring device can be useful for assessing healing/deterioration following therapeutic interventions. It can also contribute to the detection of general health problems early. The ability to distinguish between normal walking and limping or shuffling, which may be precursors to a fall, as well as detecting falls, is of utmost value to elder populations. Elders, who represent 12% of the population, account for 7 5% of deaths from falls [1]. The considerable cost involved in the treatment and hospitalization of fall injuries and even death due to falls could be greatly reduced if falls could be predicted and avoided through appropriate intervention. BACKGROUND Current gait analysis techniques broadly fall under three categories depending upon the type of device used: wearable devices, walk on devices and visual gait analysis tools and techniques. These gait laboratory equipment and analysis techniques yield excellent and detailed gait characteristics and enable clinicians to prescribe an appropriate intervention. However, the equipment required is extremely expensive, in the range of tens of thousands to a few hundred thousand dollars. The computational power required for the image based analysis make longitudinal in-home gait monitoring using these technologies impractical.