Development of Computer Controlled Eyes for Patient Simulator

1. Development of Computer Controlled Eyes for Patient Simulator Silviu. C. Diaconu1, Emadaldine A. Elsamadicy1, Anas Othman1, Azreena A. Shukri1 Sponsors: Ray Booker2, Matthew Weinger, M.D.2 1 Vanderbilt University School of, Engineering, 2Center for Experiential Learning and Assessment CELA SIMULATION TECHNOLOGIES PROGRAM INTRODUCTION OUR EXPERIMENTAL SETUP Trauma care physicians rely heavily on human patient simulators (SimMan) to expose them to real-life medical scenarios. Realism is the most critical aspect of the learning process. However, an ongoing problem with SimMan is its fixed eyes. Physicians depend on various physiological responses of the eye to determine level of consciousness, degree of brain trauma, and responses to administered drugs. SimMan’s stationary eyes take away the realism and effectiveness from the simulation. Therefore, we have developed a cost-effective realistic eye simulator that has the ability to incorporate a range of physiological responses including movement, blinking, pupil dilation, and redness. 3D Studio Max is used to model the anatomical structures of the eye, while DX studio was used as the real-time rendering engine for controlling the animations. LCD SCREENS (LILIPUT 212GL-18NP) 3D Studio Max • The Lilliput screen: • Embedded video circuitry. • Size: 1.7”X2” . • Resolution: 116,160 (dots). • Cost: $60. 3D Real Time Animation Engine 1.8” LCD screen 3D Object • Limitations: • FFC cable – limits the separation between board and LCD. • Circuit board size – large due to integrated audio functions. • Backlight - generates heat. Renderer Control Symmetrical Video Feed OUR SOLUTION PROPOSAL We propose that by using micro-display technology we can implement 3D graphics integrated with a real-time rendering engine to model the detailed anatomical features and animate the physiological responses of the eye. ACCOMPLISHMENTS Hardware Software CURRENT EYE SIMULATORS • Mechanical eye simulators • Expensive ($600 ~ $2000). • Limited functions: movement and blinking. • High maintenance due to electrical and mechanical malfunctions. • Stand-alone eye simulators • Expensive ($2500). • Display anatomical eye features. • Too large for SimMan head. VGA Adapter Mapped Keyboard/Mouse Prototype: The anatomical and physiological responses of the eye were successfully modeled and animated such that they can be controlled by an external keyboard with the following controls: full range eye movement, blinking, pupil dilation /constriction, as well as varying degrees of eye redness. The two LCD screens were integrated within the limited space of the SimMan eye socket. The signal from the computer to the screens maintain a minimal time delay of (~0.5 sec). The screens properly displays the correct image in regards to both size and resolution. Developmental Costs: 3D EYE (3D STUDIO MAX) PERFORMANCE CRITERIA • Size – Has to fit into SimMan’s eye sockets (1’’ diameter) • Response Time – Externally controlled with minimal time delay. • Functionality– Speeds of functions must be controlled • Movement (Full Range) • Pupil dilation/constriction (1-10 mm) • Redness (varying intensity) • Blinking (Eyelids) Figure 1: Wire model of the eye using editable polygons to construct the eye ball and surrounding. Figure 2: Rendered image of the 3D eye model. Model includes eye lids, pupil, iris and sclera. 3D EYE (DX STUDIO) ACKNOWLEDGEMENTS Figure 3: The eye model controlled to look left after input from keyboard. Figure 4: Redness intensity changes after keyboard command. A special thanks to Mr. Ray Booker and Dr. Matthew Weinger for providing the original concepts, advice, and knowledge throughout the design process. Ronald Reiserer of VIBRE was an invaluable resource in the dissection of the SimMan head. GOALS • Create realistic eye features that can be computer controlled. • Integration of 3D computer graphics with micro-displays. • Create a cheaper alternative option for eye simulators. • Allows for simple adjustments of quality and basic eye functions.