Remember those clear plastic models of human anatomy? Well, welcome to the ’90s when the plastic model has been replace with an image of two real human bodies, one male and one female, viewed in 3-D on your computer screen.

The newest models are realistic, interactive and don’t smell like formaldehyde. Called the Visible Human Project, the models are revolutionizing not only how healthcare professionals learn anatomy, but also how they learn basic procedures and how these skills are evaluated.

The Visible Human is a project of the National Library of Medicine (NLM). It is a data set made up of cross-section images of the human body obtained from computed tomography, magnetic resonance imaging, and cryosection scans of a male and a female cadaver. (Cryosection involves freezing the body and slicing it at wafer-thin intervals.)

Like cadavers, the models offer a look inside the body. But unlike cadavers, the models can be electronically dissected a number of times using different approaches, Ackerman said.

The full-body anatomical images take up about 15 gigabytes of computer memory for the male specimen, and about 40 gigabytes for the female. Images were obtained from the male specimen at 1-millimeter intervals, while images from the female specimen were taken at 0.33 mm intervals, yielding more data, according to Ackerman.

The project started in 1991, and it took 2 1/2 years just to find ideal specimens, he said. The male model was a 38-year-old prisoner who died by lethal injection in Texas. The female model was a 59-year-old Maryland resident who died of a blockage in the aorta caused by a small piece of calcium.

Thorax, including heart (with muscular left ventricle), lungs, spinal column, and major vessels.

The first nursing application was initiated by Virginia Barker, MSN, EdD, RN, dean of professional studies at State University of New York College at Plattsburgh. She has worked with engineers at HT Medical in Rockville, Md., for two years, developing a prototype device called CathSim, a simulator that will teach venipuncture to nursing students.

"I’d been reading for some time about the uses of virtual reality in medicine," Barber said. "And I wondered if there were a way to more effectively develop nursing skills without jeopardizing patients, while also increasing the learner’s satisfaction." Armed with a small amount of initial funding, she proposed the project to HT Medical.

Barker selected venipuncture because it is such a commonly performed invasive procedure. "Everyone you talk to has had blood drawn and has the horror tales that go along with it," Barker said.

CathSim, which hooks up to a Pentium PC, should hit the market this December. It is a device shaped like a forearm on which students can practice drawing blood while watching the results of their attempts on-screen. The device simulates the feel of different types of veins, including normal, sclerosed, and collapsed veins. It uses optical encoders to track the user’s movements and give on-screen feedback. "You see the skin dimpling and the canula filling with blood on-screen if you’re doing it correctly," said HT Medical spokesperson Monica Giffhorn. The realism of the simulation is due to the computerized anatomical images from the Visible Human Project.

"I can even tell you the degree of tremor in the student’s hand with this product," Barker said. The device allows instructors to evaluate students objectively in a way they couldn’t by simply watching students work and judging patients’ reactions. Students appreciate the confidence the device gives them, Barker said.

Barker said nursing schools are eager to test the prototype. She’s even been contacted by a veterinary school. Next, she hopes to work on simulation devices for different types of injections, the insertion of subclavian lines, and intertracheal aspiration. "It’s very different from when I started nursing in 1952," Barker said. "I don’t see many oranges around these days."