The Perception of Visual and Haptic Feedback

Understanding how people process visual and haptic feedback is an active area of research. With better insight, simulators can be optimized to provide the degree of visual and haptic fidelity necessary for learning. This project is an attempt to answer two questions regarding visual and haptic perception: How consistently can individuals recall a specific haptic experience, and the ability of individuals to perceive latency between haptic and visual feedback.

We developed a needle-insertion simulator depicting an idealized needle-stick scenario. Test subjects see a needle poised over a skin patch. Using the CathSim™ AccuTouch™ device, subjects can insert and remove the needle from the skin. As the needle is inserted, the skin deform, then "pops" back upward as the needle penetrates. At the same time, The AccuTouch™ provides haptic feedback by increasing resistance to needle penetration, then pressure is suddenly released as the needle enters the skin.

In the first experiment, 27 volunteers attempted to reproduce the correct amount of needle resistance, based on their experience with IV-needle insertion. The group's experience with IV insertion varied widely, ranging from none to more than 3,000 procedures performed. In the second experiment, 28 volunteers interacted with the simulator while the delay between the visual and haptic feedback of needle penetration was varied.

Our experiments showed that an individual's ability to consistently recall a specific haptic experience (in this case, the appropriate amount of force experienced during IV insertion) varied widely. Moreover, it had no correlation with the individual's experience. We were also able to show that 99% of those tested were unable to perceive haptic/visual latencies of at least 54 milliseconds. While intriguing, further experiments are necessary to fully explore the implications suggested by our initial results.

Acknowledgements

This work is supported by the U.S. Army Medical Research and Materiel Command under Contract No. DAMD17-03-C-0102. The views, opinions and/or findings contained in this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation.