Clinical Simulation in 3D
Victor Spitzer, PhD
University of Colorado Center for Human Simulation
Aurora, Colorado
May 19, 2010
Anatomy is the foundation for all health care careers. It is essential training for a competent workforce. With the rapid expansion of supporting medical knowledge from genetics and immunology to pharmacology and cell and molecular biology, anatomical training is often minimized. In addition, it is frequently taught as a collection of structures for memorization instead of the intricate multi-dimensional functional systems that keep us alive and productive. A 3D perception of the structure of the human body, we feel, will promote understanding over memorization and enable more critical thinking for just-in-time and on-the-job education required by this rapidly evolving information overload situation.
Why Anatomy with Simulation?
Mannequin-based simulation concentrates on physiology and pathophysiology with little or no emphasis on relevant anatomy. The WELLS Center ( accentuates a thorough understanding of the anatomy as a precursor to mannequin-based simulation scenarios in order to deliver a deeper understanding of the medical issues and procedures involved. Anatomy is provided by the WELLS Center through a program called the VH Dissector (Touch of Life Technologies, Inc. ( The VH Dissector is based on the anatomy of the Visible Human, funded by the National Library of Medicine in the early 1990s. The VH Dissector is available for conventional computer monitors – and also for display in 3D stereo by the most popular methods.
Why virtual anatomy?
We are all built the same – yet fingerprints and DNA argue the opposite. We teach anecdotal anatomy and accentuate consistency of the human form but constantly highlight variations from “normal” anatomy. Health care also require knowledge of pathologic and traumatic variations form “normal” anatomy. Virtual anatomy provides a mechanism for presenting “normal”, pathologic and traumatic variations to the user in rapid sequence (rapid compared to encountering these variations on the job) as a basis for the development of critical thinking and problem solving skills to deal with perturbations that have not specifically been taught. This advantage of virtual reality will be realized as we develop techniques for rapidly and realistically producing the look and feel of human body variation.
Why 3D stereoscopic anatomy?
One of the most difficult parts of understanding clinical anatomy is appreciating the spatial relationships of anatomical structures to their neighbors. Three-dimensional models provide this understanding but they are generally lacking in detail and often of limited availability. The National Library of Medicine’s Visible Human has all the detail of photography and this three-dimensional collection of photographs forms a basis for modeling the entire body in a virtual world. That body (and any of its parts) can then be displayed in stereo 3D to provide, for example, a real world appreciation for the path of a neurovascular structure such as the radial nerve spiraling around the humerus or the proximity of the distal esophagus to the heart and that relationship’s utility in cardiac monitoring with ultrasound.
Which 3D stereoscopic display?
With the current groundswell of interest in stereoscopic display for the consumer market the price is decreasing and the options expanding for displaying high quality stereoscopic information. The WELLS Center utilizes single-user 3D stereo displays (using active stereo) for learner-centered activities and a large, back-projection system for teacher centered or small group activities. The large display utilizes passive stereo and is large enough to display the Visible Human Male – “life size”, (6’1” from the tips of his toes to the top of his head). The large screen format is housed in a room that comfortably seats 12 people. Stereoscopic displays provide viewers with two views of the same three-dimensional scene but from different viewing angles. The most natural presentation of the two viewing angles mimics the angle of separation of our eyes. Some methods for presenting the two views include
Displaying L and R eye images simultaneously on separate sources for a direct and isolated view by each eye. This method can provide no image cross-talk and can be inexpensive for static images
(ViewMaster, ToLTech dual LED displays)
Displaying L and R eye images sequentially to the field of view of both eyes while simultaneously blocking the view of the R and L eye respectively with shuttered glasses. The electronic blocking is often not 100% and therefore allows image cross-talk. This method has been expensive but could become relatively inexpensive with consumer adoption
(Electronic shuttering or Active stereo)
Displaying L and R eye images simultaneously on separate sources polarized in opposite directions while simultaneously blocking the view of the R and L eye respectively. This method relies on polarization of light to completely block one image from the view of one of the eyes. Image cross-talk is a problem. This method is the most popular form for large audiences as the viewing glasses can be inexpensive.
(Polarized or Passive stereo)
Other methods that provide a perception of depth include projection onto objects of familiarity – such as the human body (real or plastic). Projecting organs or other anatomical structures (landmarks) onto the surface of a live human or the plastic form of simulation mannequins presents the anatomy of interest in its natural context – a mixture of Reality and Virtual Reality – referred to as Augmented Reality.
What anatomical data?
The Visible Human was created at the Center for Human Simulation at the University of Colorado in the early 1990s. The 3D image dataset is composed of nearly 2,000, 1mm spaced images of transverse cross-sections through an adult human male cadaver and over 5,000 images through a female. The images are available under license from the National Library of Medicine but the key to their use is the identification and full extent of the anatomical components in each of the pictures. With this information each system and structure can be displayed in 3D stereo and even felt through the use of haptic interface.
Procedure simulation for workforce training at maximum efficiency with zero risk!
This combination of whole-body 3D, photorealistic anatomy coupled with our ability to see and feel the body as we would a patient provides an opportunity for procedure simulation without patient risk. A simulator is currently available for diagnostic knee arthroscopy and R&D is near completion on needle simulations for joint injection/aspiration, regional anesthesia, pressure measurement and neuromuscular injections and biopsy.