Rick McKenzie, associate professor of electrical and computer engineering at ODU, demonstrates a mock- up of the virtual stethoscope.
NORFOLK—A Virtual Pathology Stethoscope invented by a team of researchers from Eastern Virginia Medical School (EVMS) and Old Dominion University’s Virginia Modeling, Analysis and Simulation Center (VMASC) has been licensed to a Texas-based company, Cardionics Inc., which manufactures medical diagnostic and teaching equipment.
The Virtual Pathology Stethoscope, or VPS, is a training device that can simulate the sounds of a human body’s circulatory and respiratory systems. It will be an important addition to the products offered by Cardionics, according to Keith Johnson, president of the company. Cardionics specializes in technologies related to auscultation, which is the art of listening for sounds made by the body's internal organs. Its current products include an E-Scope Electronic Stethoscope and a Pocket Monitor Analysis System that have helped to revolutionize bedside diagnoses.
The invention is the first licensed product to emerge from the National Center for Collaboration in Medical Modeling and Simulation, which is a joint venture of EVMS and Old Dominion University.
Thomas W. Hubbard, M.D., professor of pediatrics and director of the EVMS Office of Professional Development, leads the team of inventors. His top collaborator at VMASC is Frederic McKenzie, an ODU associate professor of electrical and computer engineering.
The Virtual Pathology Stethoscope will look much like this current product of Texas manufacturer Cardionics.
The VPS is designed to be used in tandem with a standardized patient (SP). Medical schools increasingly train doctors-to-be by using SPs, who are actors skilled at pretending to be sick. Working with SPs, medical students improve their interviewing skills and gain the medical judgment they need to diagnose ailments.
But when a medical student puts a conventional stethoscope to the body of the SP, the typically healthy sounds heard don't match the illness the SP is portraying. The VPS substitutes abnormal sounds for healthy sounds, so that when the student puts the augmented stethoscope to the SP’s body, the sounds provide evidence that can support the diagnosis. The sounds the teaching stethoscope plays are recorded from actual patients who have a variety of diseases.
Members of the VPS development team took the device and a veteran EVMS standardized patient, Patrick Walker, to the 4th annual Advanced Initiatives in Medical Simulations (AIMS) Conference and Congressional Exhibition in May in Washington, D.C. The invention drew the attention of numerous conference goers, including Virginia 4th District Rep. Randy Forbes and Rep. Patrick Kennedy of Rhode Island, the son of Massachusetts Sen. Edward Kennedy and a champion of health care issues in Congress.
Both Kennedy and Forbes took time to test the stethoscope on Walker. When they listened at his neck, they heard the whooshing sound of plaque-restricted blood flow through the carotid artery. When they listened to his chest, they heard crackling sounds in the lungs, a sign of pneumonia or congestive heart failure.
ODU and EVMS joined forces in 2001 to form the National Center for Collaboration in Medical Modeling and Simulation, which has attracted funding from several sources across the nation, including the Stemmler Medical Research Fund of the National Board of Medicine, as well as national media attention.
“The VPS is one example of the potential of medical simulation to improve the training of medical and health professionals and, ultimately, to improve patient safety,” said C. Donald Combs, Ph.D., who leads the medical modeling initiative at EVMS. Combs and Mark Scerbo, professor of human factors psychology at ODU, are co-directors of the National Center for Collaboration in Medical Modeling and Simulation.
An article late last year in Mechanical Engineering magazine focused on one of the products of the collaboration — a virtual operating room. This immensely complicated system, which can be used to train surgeons and other operating room personnel, utilizes ODU’s Cave Automatic Virtual Environment (CAVE). Combs said these simulations and others under development are the early returns on the investments that the federal and state governments have made in the region’s effort to expand simulation research and development beyond the military market into areas such as medical modeling and emergency response.
A primary mission of VMASC is to create modeling, simulation and visualization applications that are practical enough for commercial development. When representatives from the EVMS Theresa A. Thomas Center Professionals Skills Teaching and Assessment Center sought a way to enhance student training with SPs, they asked VMASC to create the VPS.
McKenzie, the VMASC researcher, said the team’s original VPS is very high-tech, but too expensive for broad use. This first system is called “tracked VPS” because it includes a sensing component that tracks on the body where the stethoscope’s head is placed so the appropriate sound recording can be cued. The team has a patent pending for the “tracked VPS,” but then moved on to improve the system’s practicality.
The more economical version, which is the one licensed to Cardionics, is “SP-triggered VPS,” for which another patent is pending. This is the system that was demonstrated at the AIMS conference, and for it the SP uses hidden controls to track the stethoscope’s head and to tell the system what sounds should be played. The second system is more economical because it does not have the automatic tracking component.
Preliminary tests with EVMS students have been promising. One series of tests reported in a paper written by McKenzie, Hubbard and other colleagues showed that the augmented standardized patient system is “a reliable and valid assessment tool.”
The project team also includes John Ullian, Gayle Gliva-McConvey and Robert Alpino of EVMS, and Hector Garcia, Reynel Castelino and Bo Sun from ODU/VMASC.
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