Wander into the HIT Lab any Thursday afternoon and you will likely find yourself engaged in a lively discussion of the future of medical interface technology. These days you are also likely to find our medical advisors (representing a broad spectrum of medical specialties from a number of area hospitals) gathered in the sim lab, taking turns at "putting their heads inside" a virtual emergency room.

This replica of the Harborview trauma center was created from still images photographed by Peter Oppenheimer and mapped as a continuous texture map onto a cylindrical geometry, in a manner similar to Quicktime VR. This approach provides a strong sense of presence within the simulated environment, and is suitable for situations in which the user's virtual position remains relatively stable. A second environment will soon be completed based on stills Oppenheimer acquired of the 18th MASH unit while it was deployed at Ft. Lewis earlier this year.

Inside the virtual ER, doctors and other medical personnel can grab data objects (such as radiology images, simulated teleconsultant video, EKG recordings, heart rhythm strips, and vital signs data) and place them anywhere in the space. Each object can also be stabilized relative to a number of different reference points, such as the room, the virtual patient, the user's head, and the user's body. Objects can also be made visible or invisible at the user's command. The objective of all this activity is to explore the design space for medical interfaces of the future, to determine how immersive augmented space might best be utilized.

Several recent innovations have enhanced the research capabilities of the HITLab's clinical simulation environment: the LIMIT (Laboratory for Integrated Medical Interface Technology), also known as the "Virtual ER."

During the autumn 1996 term, Dr. Stan Kaufman, HITL medical advisor and an experienced cardiologist and medical informatics fellow at Seattle's VA Hospital, led a team of programmers including Edward Miller and Ivan Poupyrev in the development of several novel spatial representations of electrocardiogram (ECG) data. Using the concepts of primary and secondary task loading developed for aviation display research, the team also implemented methods for immersively testing the effectiveness of new display objects and presentation styles. Results of Kaufman's studies were presented at the Medicine Meets Virtual Reality conference in January '97 and at the American College of Cardiology meeting in March.

With waveform data stream capability represented by the ECG, the LIMIT team is now focusing on immersive simulation of advanced interfaces for radiology tasks, incorporating the Lab's tablet-based "working surfaces"

Stretching the LIMIT approach for image selection, processing and annotation. Dr. David Haynor, UW radiologist and a long-time HITLab medical advisor, is providing domain guidance and appropriate image data for this activity.

In addition to cardiology and radiology, data elements relevant to general surgery will also be incorporated into the LIMIT over the next six months, under a DARPA-sponsored project with Prof. Blake Hannaford (director of the UW Biorobotics Lab) and Dr. Mika Sinanan (director of the UW Center for Videoendoscopic Surgery).

The LIMIT testbed was featured in Olympia, WA at a legislative reception sponsored by the Washington Technology Center and the Association of Washington Business. Using Poupyrev's nonlinear "go-go" reaching metaphor, participants were able to grab and relocate clinical data objects, such as x-rays and Kaufman's spatial ECG model, in an immersive version of the Harborview Medical Center emergency room. The demonstration effectively conveyed the potential of VR as a medical interface prototyping environment.