A helmet-mounted display (HMD)-based computer navigation system that partially mimics the U.S. Army's Land Warrior ensemble provided position information and map updates to soldiers navigating a three-kilometer course. Performance with the HMD system was compared to traditional navigation with paper map, compass, and a hand-held GPS receiver. New objective computer-based measures of navigational accuracy and situational awareness (SA) were developed. Traditional measures of navigational accuracy were not sensitive enough to detect differences between HMD and traditional navigational methods. The more sensitive new measure based on distance traveled found the HMD-based system to be superior. This method is easily adaptable to civilian applications such as orienteering. A supposed advantage of using HMDs is enhanced SA. A SA measure was developed which used probe questions generated by the computer. Although the probe questions found no significant differences between the conditions, the method seems promising for future applications.
The usefulness of wide excision assisted by a computer navigation system and reconstruction using a frozen bone autograft for malignant acetabular bone tumors: a report of two cases
