Originally Published EMDM November/December 2002
INDUSTRY NEWS
Rapid Prototyping Provides Clear 3-D Picture |
| Objet Geometries' QuadraTempo RP system, which uses the company's PolyJet process, produced this detailed prototype of a skull with criss-crossed blood vessels. The intricate 3-D model aided doctors in separating twins conjoined at the head. |
When 2-D images weren't an adequate solution to help separate conjoined twins in a Los Angeles hospital, medical professionals turned to the QuadraTempo rapid prototyping (RP) system by Objet Geometries (Rehovot, Israel). Joined at the head, the Guatemalan twins had blood vessels that were intertwined, making it almost impossible to use 2-D x-rays as a guide. Facing a challenging and delicate operation, doctors believed a 3-D RP system would work best to allow plastic surgeons to practice rerouting the blood supply and grafting skin to cover the separated brains.
Biomedical Modeling Inc. (Boston, MA, USA) combined data from multiple CT scans of the twins at different angles—since it wasn't possible to arrange them for just one scan. The company then created the appropriate STL files for rapid prototyping based on the composite information, and e-mailed the files to InterPRO (Deep River, CT, USA), which produced the actual prototypes.
An RP service bureau, InterPRO built the models with QuadraTempo. The system uses Objet Geometries' PolyJet process, which creates parts by jetting the company's proprietary photopolymer materials in 20-µm layers, curing each layer with ultraviolet light immediately after it is deposited. A second, gel-like photopolymer material is used for support, and is later easily removable by water jets.
"The QuadraTempo's ability to build delicate features without support structures allows us to clean the models much more easily after printing them," says InterPRO coowner Kevin Dyer. "The fine details in the skull models proved especially critical to achieving success, since the surgeons needed to examine the inside of the individual models and develop a plan for rerouting the intertwined blood vessels."
The PolyJet process's high resolution, 0.0008-in. layers, and features as small as 0.002 in. produce fine detail and smooth surface characteristics without labor-intensive sanding and finishing operations. The elimination of complicated postprocessing procedures, and fast build times, allow clients to deliver high-resolution prototypes faster and at a lower cost than competing technologies. "The design and product engineers who use such prototypes can analyze and evaluate different situations, which permits better planning, enables trial and error of real-life actions, and immediately improves the diagnostic process," says Hanan Yosefi, CEO of Objet Geometries. "The technology allows them to make all necessary adjustments before they move into the mass production process. Imagine how much more cost-effective it is to find a defect or error in the prototype stage, rather than finding it at the mass production stage," he adds.
The company's PolyJet process is now available on-line at www.atirapid.com. Powered by the RP service bureau Accelerated Technologies Inc. (Erlanger, KY, USA), the site provides instant quoting for 3-D printed rapid prototypes. Customers simply submit files for printing (or jetting) and receive price quotes and production-time information over the Internet. The ease of getting a quote through Accelerated Technologies' site is yet another example of how Objet Geometries makes rapid prototyping simple.
Copyright ©2002 European Medical Device Manufacturer
