By Debbie Gregory.
Because IED explosions in Iraq and Afghanistan have maimed our soldiers’ bodies and faces, military medicine has made great advances in prosthetic development.
Now, military healthcare professionals at Walter Reed National Military Medical Center are working on rebuilding a wounded warrior’s face, using high-tech scanning and 3D visualization tools.
Rapid prototyping has several uses in the medical sector, including making models of actual bones so that surgeons can practice complicated procedures. Rapid prototyping also plays a role in leading edge stem cell research.
An example of this is taking place at Walter Reed. They had a patient who had a bony tumour that needed to be removed from the back of the knee. Unfortunately, this growth was dangerously close to a nerve and an artery, making the procedure tricky. The orthopaedic surgeon who was performing the operation was able to “practice” on the model of the knee, helping him avoid the dangerous areas during the actual surgery.
A 3D scanner is a device that analyzes a real-world object or environment to collect data on its shape, and possibly, its appearance (i.e. color). The collected data can then be used to construct digital, three dimensional models.
Many different technologies can be used to build these 3D scanning devices. Each technology comes with its own limitations, advantages and costs. One limitation is in the type of objects that can be digitized. For example, optical technologies encounter many difficulties with shiny, mirroring or transparent objects.
The purpose of a 3D scanner is usually to create a point cloud of geometric samples on the surface of the subject. These points can then be used to extrapolate the shape of the subject, in a process called reconstruction. If color information is collected at each point, then the colors on the surface of the subject can also be determined.
For purposes of medical diagnosis, it is most desirable to have as much detailed information on the anatomical and pathological features of the patient as possible. In clinical practice, examinations by the various scanning modalities (CT or MRI)) try to find the optimal trade-off between a high scanning resolution and the radiation harm or inconvenience for the patient.