With the BodyExplorer, 'You won't feel a thing...'
December 2, 2013 12:00 AM
The internal sensors of the BodyExplorer.
Doug Nelson, a bio-engineering graduate student at the University of Pittsburgh, demonstrates the Body Explorer simulator, which is designed to help medical personnel get immediate feedback on medical procedures in a more realistic learning experience.
By Kathryn Sterling / Pittsburgh Post-Gazette
Douglas Nelson, a Ph.D. student in bioengineering at the University of Pittsburgh, handed me a syringe he had prepared. His adviser, Joseph Samosky, assistant professor of anesthesiology and bioengineering, encouraged me to inject the drug as fast as possible into the patient on the gurney in front of us. So I did. "Owww!" the patient screamed.
Luckily, the patient in this case was only a simulator -- a mannequin enhanced with augmented reality -- and the scream came from a computer at the foot of the gurney. The drug I injected into an IV line was really a saltwater solution. The simulator detected the rate of injection and, because it was too fast, emitted the scream.
I was in the University of Pittsburgh Simulation and Medical Technology Research and Development Center, and the researchers were having me try out the BodyExplorer simulator firsthand.
BodyExplorer is a system designed to help train medical professionals. Using the simulator, they can observe internal anatomy, practice skills such as administering medication and inserting an endotracheal tube, and receive immediate feedback on their actions.
The simulator's components include a standard projector, the mannequin body, a Wii remote, and a wireless mouse pen. The projector projects images of internal anatomy down onto the mannequin's chest. The Wii remote is attached to the projector and tracks the location of an infrared LED at the tip of the mouse pen, communicating the data to a computer via a Bluetooth connection. This allows the learner to use the pen like a virtual scalpel, opening windows that reveal different layers of internal anatomy, as if cutting deeper and deeper into the body.
"We developed and modified the IR pen input device from the 'Wiimote Whiteboard' system created by Johnny Chung Lee, a former student at CMU who is now at Google," Mr. Samosky explains. "It's a nice example of how open source software developed for one purpose (a low-cost electronic whiteboard) can be creatively applied to benefit a completely different application."
With the wireless mouse pen, the learner can open, move, and resize windows, viewing the musculature of the torso and the underlying bones and organs. Removing the ribs and sternum reveals an animated heart. The heart animation is a series of 30 images that together make up one contraction cycle; when played rapidly in a continuous loop, the heart appears to be beating.
"A very fundamental limitation of medical training that we're trying to address in some of our work is the simple fact that bodies are mainly visually opaque," said Mr. Samosky, director of the R&D center.
In addition to viewing the internal anatomy of the torso, the student can display physiological data on it, such as an electrocardiogram, and hear audio of a heartbeat. These elements of augmented reality may give learners an advantage over training in a clinical setting, Mr. Samosky said. Viewing the ECG directly on the chest, for instance, forces students to focus on the patient rather than on a machine. And the 3-D computer graphics and audio let students see and hear the internal consequences of their external actions.
For example, injecting the mannequin with simulated epinephrine causes the heart to visibly beat faster, and the sound of the heartbeat to increase in concert with the motion. Administering metoprolol, a beta-blocker used to treat high blood pressure, slows the heart rate. And a user who injects a simulated drug too rapidly will hear the "Wilhelm scream," a male-voice sound effect that has been so overused in movies that directors like Peter Jackson and Quentin Tarantino use it in all their films as an inside joke.
The developers of BodyExplorer used the Wilhelm scream as a bit of tongue-in-cheek humor, but also to get students emotionally engaged with the technology. Since injecting certain drugs too rapidly can lead to adverse effects such as low blood pressure, trainees need to learn how to control the rate of injection. The scream provides the kind of immediate feedback that may be missing in training scenarios where there is a delay between the time a trainee makes a mistake and then recognizes it as such. The developers hope that receiving immediate feedback will help students remember their mistakes and avoid repeating them with real patients.
Like all the projects the center develops, BodyExplorer is intended to improve patient safety. Mr. Samosky likens simulation-based training for health care to flight simulation.
"As a pilot, you can enter a simulated cockpit and be exposed to nearly anything that could go wrong with the plane and learn how to handle that before you encounter it in real life," he said. "We feel that we can bring some of those advantages to health care training, so that presumably, perhaps in the early stages of training, you can get a little bit higher on your learning curve before you touch an actual, living, breathing, pain-feeling patient."
Patient safety is a significant issue in the United States; the Institute of Medicine estimates that about 100,000 Americans die every year from preventable medical errors. (By comparison, annually there are about 34,000 deaths from motor vehicle accidents.) Better training is one way to reduce medical errors, Mr. Samosky said.
His own motivation for improving patient care comes in part from personal experience. He said, "I have witnessed medical errors that occurred to both of my parents and at least in one case caused them harm." He noted that many of the people who have worked in the lab have had a similar motivation.
In addition to BodyExplorer, researchers in the lab are working on other novel technologies. One is a simulated arm used to train students on peripheral nerve block, or knocking out the sensation in a particular part of the body. The arm looks and feels as though it is covered in flesh, and provides trainees with immediate feedback on whether they have correctly injected the local anesthetic. The researchers hope to begin clinical trials on the device next year.
The researchers have also been working on a CAVE, or Computer-Augmented Virtual Environment. In a CAVE, several projectors display images onto four walls surrounding a space to create the illusion of a certain environment. The technology could be used, for example, to train students on how to care for patients in a medical evacuation helicopter.
The lab's work is multidisciplinary, drawing on varied fields such as design, electrical engineering, computer science and materials science.
"That's one thing I really like about it," said the director, who came to the University of Pittsburgh from Harvard. Noting that the lab has worked with students from the University of Pittsburgh, Carnegie Mellon University and the Art Institute of Pittsburgh, he said, "One of the attractions of Pittsburgh for doing this kind of work is that within just a mile of where you're standing right now we have amazing resources."
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