Before revision:  In this paper, we propose using the time it takes a person to move between rooms in their home - referred to as 'transition times' - estimated from passive infrared motion sensors installed in a patients own home to predict gait velocity.
After revision:  In this paper, we propose using the time it takes a person to move between rooms in their home - referred to as 'transition times' - estimated from passive infrared motion sensors installed in the consecutively visited room pair carry rich latent information about a person's gait velocity. We name this time gap transition time and show that despite a six second refractory period of the PIR sensors, transition time can be used to obtain an accurate representation of gait velocity.