Current Research

Please see the publication section for an updated list of of our work or the table of student’s theses and dissertations below.

Haptic Simulator

In this research, we prodominately use a haptic minimally invasive surgical simulator previously developed by our lab and collaborating Electrical Engineering Lab. Accurate detection of mediated haptic information in minimally invasive surgery (MIS) is critical for applying appropriate force magnitudes onto soft tissue with the aim of minimizing tissue trauma.

Force perception in MIS is a dynamic process, with surgeons’ administration of force into tissue revealing information about the remote surgical site which further informs the surgeons’ haptic interactions. The relationship between applied force and material deformation rate provides biomechanical information specifying the deformation distance remaining until a tissue will fail: which is termed distance-to-break (DTB).

Our current research on this topic is continuing  to develop the theory of DTB and haptic simulators that can assist users to attune to the DTB invariant.


“Affordances” refer to the perceived functional significance of environmental features. Essentially affordances can be thought of as the things that can be done with the surfaces of the environment, such as whether a spot on the floor is “step-over-able” or whether the width of a doorway is “pass-through-able.” Affordances can also be thought of as what actions an actor is capable of completing in or with the environment, also known as action-capabilities.

All environments are filled with substances and surfaces, which can be directly perceived by organisms through detection of information rich optic arrays. In the case of the environment, the substances and surfaces present may change, just as the capabilities of an organism change due to factors such as physical growth and knowledge.

Our current research on this topic is examining tasks and constraints that can affect how humans perceive and act on the environment including:

  • Gap distances in stepping and leaping tasks that increase or decrease the perceptual and action margin of safety of actors
  • How the design of putter grips can constrain and affect the perception of hole size and performance in a putting task

Virtual Reality

Our work in Virtual Reality is another application of affordance research. Human beings are quite good at perceiving what we can or cannot do in the environment, meaning we are quite good at perceiving affordances. This ability of our perception-action system is no more apparent than at times when our capabilities change. The process by which perception of affordances is scaled to the (changing) relationship between environmental features and action capabilities is known as calibration.

However, does calibration occur in the exact same manner in virtual reality? For instance, virtual reality systems often represent the user as an avatar. With current technology virtual environments allow people to perform various tasks and actions that may not be possible or feasible in the real world, such as due to safety concerns or limited resources. The avatar is not always a direct reproduction of the user, meaning the represented avatar may possess different anthropometric dimensions than your body in the real world.

Our current research on this topic is to study calibration within virtual reality in terms of affordances and the Virtual Environments (VE).


Student’s Research


Year/ Status



Bliss Altenhoff 2015 Perceiving Soft Tissue Break Points in the Presence of Friction.
Lindsay Nebo (Long) 2013 Feeling for Failure: Haptic Force Perceptions of Soft Tissue Constraints in a Simulated Minimally Invasive Surgery Task.
Joshua Gomer 2010 Spatial Perception and Robot Operation.

Master Theses

Leah Hartman 2015 Investigation of Distance to Break using Compliant Nonlinear and Linear Materials in a Simulated Minimally Invasive Surgery Task.
Alan Campbell 2012 A Safety Based Analysis of Ladder Setup by Novice and Experienced Users.
Bliss Altenhoff 2012 Effects of Interaction with an Immersive Virtual Environment On Egocentric Distance Estimates.
Lindsay Nebo (Long) 2011 Steering Clear: The usability of a Vibrotactile Torso Display for Improving Simulated UGV Teleoperation Obstacle Avoidance.
Suzanne Butler 2007 Perceiving Aperture Widths During Teleoperation.
Joshua Gomer 2007 Radial Outflow In teleoperation: A Possible Solution for Improving Depth Perception in Degraded Conditions.
Kristen Moore 2006 Perceiving Affordances for Robots During Direct Line of Sight and Teleoperating Conditions.
Coleman Dash 2004 Self-produced motion as an effective depth cue for teleoperation.
Cynthia Rando 2004 The effects of handle orientation of a powered screwdriver and task position on muscle fatigue.
Marianne Liptak 2001 The effect of frequent rest breaks on worker productivity and perceived fatigue.
Joseph Chris Jenkins 1999 Weight perception via two-handed lifts.