What is disclosed is a system and method for determining the time it takes for an arterial pulse pressure wave to transit between a proximal and a distal point of a patients body. In one embodiment, a signal is received from each of a first and second device worn circumferentially around a proximal and a distal region, respectively. The devices are worn on an area of exposed skin. Each of the devices comprises at least one emitter/detector pair fixed to an inner side of each device and has at least one detector paired to at least one illuminator. Each detector has at least one sensor that is sensitive to a wavelength band of light emitted by its illuminator. Each device generates signals that are proportional to an intensity of light emitted by an illuminator. The signals are analyzed to determine arterial pulse wave transit time between the proximal and distal regions.
