Virtual reality to help the diagnosis of back problems

Virtual reality conjures up images of video games - dizzying flights on simulated jets or auto races at death-defying speeds. But researchers at Ohio University have developed a kinder, gentler use for the technology: the diagnosis of back problems. Within the next two years, the team hopes to patent a software and equipment package that could be sold to schools that train osteopathic physicians, physical therapists and other medical practitioners.

Using the "Virtual Haptic Back," instructors can adjust the type and seriousness of back problems - such as an out-of-position vertebrae or vertebrae abnormally stiff to rotation - and track students' progress in making correct diagnoses as dysfunctions are made more difficult to find. The system works by giving users the sensation of touching a human back. Users see a three-dimensional image of a back on a computer screen. Through motor-driven finger cups suspended from mechanical arms, they can feel the texture and resistance of the skin and underlying bones. As users push, pull and slide their fingers through the air, the computer screen responds to their motions.

The key to the system is a sophisticated and highly sensitive "haptic" interface, which allows users to feel simulated computer objects, said Bob Williams, an associate professor of mechanical engineering in the Russ College of Engineering and Technology whose team has published results of early research on the system in recent issues of the Haptics-e Electronic Journal and the Virtual Reality Society Journal. The project is funded by a five-year, $1.1 million grant from the Osteopathic Heritage Foundation and received previous support from Ohio University's 1804 Fund.

Developers of the "Virtual Haptic Back" see their project as a way to make the training of osteopathic doctors and physical therapists more efficient and potentially more effective because it addresses two major challenges in the training process. First, it offers students the chance to practice their "palpation" skills on dysfunctional, albeit simulated, backs, said John Howell, an associate professor of biomedical sciences at the university's College of Osteopathic Medicine. This is particularly critical to osteopathic doctors, as a cornerstone of their methodology is manipulation of patients' muscles and bones for examination and treatment.

"In the laboratory, students learn by palpating each other, but they're mostly young, healthy adults who don't have major dysfunctions," he said, "so it's difficult at first for them to appreciate some of these dysfunctions."

The haptic back also introduces measurability to the practice and training of palpation, which has historically been "more of an art than a science," Williams said. "Right now, even the most experienced doctors can know it works, but there's no scientific basis for it."

Feedback from students and practicing osteopathic doctors has prompted the researchers to program increasing levels of realism into their virtual back program over the past two years. Users now give consistently higher ratings for usability and realism to each new version of the haptic back, according to the journal articles. Most recently, the researchers have been testing students on a "playback" mode, which stores experts' haptic back examinations. It can lead students through the motions of an expert by literally pulling them through an examination or can allow students to follow the expert's motions on their own via colored markers on the screen.

Future tests will compare medical students who used playback mode to those who didn't, to measure how effective the playback mode is in improving students' ability to identify dysfunctions, Howell said.

The researchers also will take their first hard look at the true effectiveness of the haptic back for training medical students. For almost two years, the team has been gathering data about the performance on the haptic back of medical students versus students with no medical training, said Bob Conatser Jr., lab research associate in the College of Osteopathic Medicine and the team's lead computer programmer. If the medical students have progressed more rapidly in their skills than the non-medical students, it will indicate that improvement in performance on the haptic back does, in fact, correlate to students' medical training and not just to increased ability on the haptic back itself, he said.

In the long run, Williams wants to develop the team's technology further so that medical students can train, diagnose and treat back problems through virtual manipulation. Another long-term goal could be the development of an entire virtual haptic body that could be used to train students to find everything from swollen lymph nodes to cervical cancer, Howell said.

In addition to Williams, Howell and Conatser, co-authors on the Virtual Reality Society Journal article were Kerry Holland and Dennis Cade of Ohio University's Department of Mechanical Engineering and School of Physical Therapy, respectively. Mayank Srivastava of the Department of Mechanical Engineering was a co-author on the Haptics-e Electronic Journal paper.