In health care, the single most obvious environment needing these capabilities is in the operating room. This capability can also be used in the intensive care unit, the emergency department or within ambulatory clinics. The User's Interface Is Paramount Because wearable computers place a premium on a portable, interactive user paradigm where the computing system has minimal intrusion on the user's environment, an innovative interface is essential. This is reinforced by constraints on the size, weight and power consumption of components. One of the most distinguishing aspects of wearables is their choice of display technology.
Systems tend to use a head-mounted video display.
One of the user's eyes views the display and the other surveys the ambient environment. This arrangement has worked well for mobile workers such as repair technicians who need both hands free while simultaneously requiring them to access technical documentation such as maintenance and repair manuals. By switching their attention from one eye to another the user can switch between computer and environmental contexts as needed. This approach, while feasible, has several drawbacks that make consideration of alternate displays worthwhile. The display unit, while continuing to shrink in size, is still large enough to be clumsy and it must be mounted in front of the user's face.