Additive manufacturing, more colloquially known as 3D printing, describes any fabrication process that creates an object by adding together portions of a base material, often in a layer-by-layer fashion. 3D printing provides a number of unique benefits, such as acceleration of the prototyping process and the ability to generate complex internal geometries. The IEM 3DP Core makes use of three additive manufacturing technologies:
- Fused Deposition Modeling (FDM): Also known as fused filament fabrication (FFF), this 3D printing technique creates parts by heating and depositing threads of thermoplastic. FDM/FFF is economical and produces strong parts, although the surface finish can be rough.
- Stereolithography (SLA): This 3D printing process builds parts by selectively curing layers of a liquid photopolymer with a laser. SLA is costlier than FDM/FFF but produces parts with a finer surface finish.
- Polyjet: This proprietary Stratasys additive manufacturing technique uses multiple photopolymer materials simultaneously to create functionally graded parts. The rigidity, opacity, and color of the finished product can all be selectivly tuned by adjusting how much of each material is used in a given region of the part.
The 3DP Core is able to print parts using a wide variety of different polymer materials, both rigid and flexible. Multiple-material prints are also possible using both the FFF and Polyjet printers, which allows for models with visually differentiated areas to indicate pathologies or regions of interest.
Raw radiological scans (such as MRI and CT scans) are simply collections of pixels, with no intrinsic identifying information to distinguish between anatomical features. Segmentation involves assigning a label to each region of a given image to identify that region as a part of a particular organ. Interpolation is then performed between each of the two-dimensional regions in the image stack to produce a three-dimensional model of the organ. This digital 3D organ model can then be printed to provide the clinician with a physical replica of the patient's organ for pre-procedural strategizing. This classification process is generally peformed manually by a skilled technician or radiologist, due to the signal-to-noise ratio of the images and the high variabilty intrinsic to many pathologies.