A Step Toward Identifying Sources of Medical Errors: Modeling Standards of Care Deviations for Different Disease States.

Objective: To examine the feasibility of utilizing electronic health records (EHR) to determine a metric for identifying physician diagnostic and treatment deviations in standards of care for different disease states. Methods: A Boolean-rule-based model compared deviations in standards of care across four disease states: diabetes, cardiovascular disease, asthma, and rheumatoid arthritis. This metric was used to identify the relationship between physician deviations in standards of care procedures, before and after diagnosis, for 76 internal medicine physicians. Results: The Boolean-rule-based model identified patterns of standards of care deviation for the physicians before diagnosis and during treatment. The deviations identified for each of the four disease states were then related to Continuing Medical Education courses that could support further training. The rule-based model was extended and improved by including system and process aspects of medical care that are not specifically related to the physician, yet potentially have an impact on the physician's decision to deviate from the standards of care. Conclusion: The Boolean-rule-based approach provided a means to systematically mine EHRs and use these data to assess deviations in standards of care that could identify quality of care issues stemming from system processes or the need for specific CME for a physician.

Recovery from virtual environment exposure: expected time course of symptoms and potential readaptation strategies.

OBJECTIVE: This study investigated potential means of facilitating a return to normal functioning following virtual environment (VE) exposure using a peg-in-hole exercise in recalibrating hand-eye coordination, a targeted gait movement (rail walking) in recalibrating vestibular (i.e., postural) aftereffects, and natural decay. BACKGROUND: Despite technology advances and considerable efforts focused on the identification and quantification of VE aftereffects, few have addressed means for recuperation, the focus of the current study. METHOD: After 15 min-60 min of VE exposure and recalibratory exercises, hand-eye coordination and postural stability were assessed electronically, the former via a 3-D measure capturing pointing errors, and the latter by head and body oscillations while standing in the tandem Romberg position. Both measurements were collected immediately after VE exposure and every 15 min up to 1 hr thereafter. RESULTS: Participants (more than 900 college students) who experienced the peg-in-hole readaptation strategy had a significant decrease (p < 0.000 in pointing errors following the exercise; the other two methods (i.e., rail walking, natural decay) showed no significant change. For posture, all groups showed significant improvement during the 15 minutes after VE exposure, yet none returned to baseline by 1 hr postexposure. CONCLUSION: Although hand-eye coordination readaptation strategies showed noticeable effects immediately after they were performed, aftereffects were not completely eliminated after 1 hr; hence further research on readaptation strategies is essential to achieve more substantial recalibratory gains in hand-eye coordination and posture. Additionally, hand-eye coordination and vestibular aftereffects may require a period exceeding the VE immersion time in order to recover. APPLICATION: These findings may serve as a guide in the development of monitoring policies following VE exposure.

Effects of low stereo acuity on performance, presence and sickness within a virtual environment.

To examine the effect of stereo vision on performance, presence and oculomotor disturbances within a virtual environment (VE), two groups of 23 participants (good stereo acuity/low stereo acuity) were evaluated. Groups were matched in terms of gender, age and VE design factors (the latter were accounted for to ensure a similar VE experience between groups). Participants were immersed in a VE maze for up to 1h during which time they interacted with the environment while performing a number of stationary and movement-based tasks. Individuals with low stereo acuity traveled further to complete two tasks in the VE, yet performance time on these tasks was comparable to participants with good stereo acuity. Although participants with impaired stereo vision likely did not fully benefit from a stereoscopic view of the scene, they may have received sufficient depth information from movement-based cues to efficiently accomplish these tasks in a comparable amount of time. Overall performance, based on both the number of tasks completed and the total translational distance moved (based on input device movement) within the VE was not hindered for those with low stereo acuity. In addition, the expected increase in oculomotor disturbances for this group was not evident in this study, and both groups reported comparable amounts of presence from VE exposure. These results suggest that when head tracking is included as part of the VE experience (i.e., motion parallax cues exist), participants with low stereo acuity can be expected to perform comparable to normal sighted individuals, experience a comparable sense of presence, and report no increase in adverse effects when viewing scenes via stereoscopic displays. Thus, motion parallax cues may adequately provide a sense of depth within a VE, and alleviate theorized performance decrements for individuals with low stereo acuity. The results of this study have implications for those designing entertainment simulations or other such applications open to the general public, where people with low stereo acuity may routinely participate.

Identification of metaphors for virtual environment training systems.

The objective of this effort was to develop potential metaphors for assisting wayfinding and navigation in current virtual environment (VE) training systems. Although VE purports a number of advantages over traditional, full-scale simulator training devices (deployability, footprint, cost, maintainability, scalability, networking), little design guidance exists beyond individual instantiations with specific platforms. A review of metaphors commonly incorporated into human-computer interactive systems indicated that existing metaphors have largely been used as orientation aids, mainly in the form of guided navigational assistance, with some position guidance. Advanced metaphor design concepts were identified that would not only provide trainees with a useful orienting framework but also enhance visual access and help differentiate an environment. The effectiveness of these concepts to aid navigation and wayfinding in VEs must be empirically validated.

What to expect from immersive virtual environment exposure: influences of gender, body mass index, and past experience.

For those interested in using head-coupled PC-based immersive virtual environment (VE) technology to train, entertain, or inform, it is essential to understand the effects this technology has on its users. This study investigated potential adverse effects, including the sickness associated with exposure and extreme responses (emesis, flashbacks). Participants were exposed to a VE for 15 to 60 min, with either complete or streamlined navigational control and simple or complex scenes, after which time measures of sickness were obtained. More than 80% of participants experienced nausea, oculomotor disturbances, and/or disorientation, with disorientation potentially lasting > 24 hr. Of the participants, 12.9% prematurely ended their exposure because of adverse effects; of these, 9.2% experienced an emetic response, whereas only 1.2% of all participants experienced emesis. The results indicate that designers may be able to reduce these rates by limiting exposure duration and reducing the degrees of freedom of the user's navigational control. Results from gender, body mass, and past experience comparisons indicated it may be possible to identify those who will experience adverse effects attributable to exposure and warn such individuals. Applications for this research include military, entertainment, and any other interactive systems for which designers seek to avoid adverse effects associated with exposure.