Customized Surgical Implants

Models can also be used for pre-surgerical implant fabrication, where the model serves as a master from which the implant can be copied. This will allow for an accurate implant fit rather than the use of standard implant sizes. It is difficult to visualize and produce an CT images or x-rays. Using RP to make implants has proved to be an alternative to standard implants. Conventional methods for inserting an implant is to grind a standard implant before surgery, and during surgery to customize the implant for the individual.¹ A patient may be left on the operation table for hours and is put at risk for surgical complications. With the aid of RP, surgical implants have become more accurate and surgery time has been significantly reduced. Implants are automatically made to fit, thus less time is wasted trying to do this during surgery.

Prosthetics and Othotics

Rapid prototyping starts the design of a prosthetic or othotic device with the specific patient=s anatomy. A patient=s specific alignment characteristics are included in the prototype design, allowing a better customized fit. Through this process, the number of times that a prosthetic/othotic has to be refitted is decreased, thus cutting down on the overall cost. The creation of a leg prosthesis starts off with a plaster wrap to the residual limb to make a plaster casting. This casting is later filled with plaster to make a positive pattern for molding the prosthetic socket.¹ However, there are problems in using this standard method. Bony prominences must be accommodated by the prosthesis, and weight-bearing segments of the socket need structural reinforcement. With the aid of RP, the prosthesis uses an internally developed CAD system and a proprietary interactive CAD program to develop a biomechanically correct geometry that improves the fit, comfort, and stability.

MEMS

Microelectromechanical systems (MEMS) are micro-sized objects that are usually fabricated by the same techniques that are used to make integrated circuits. This techniques is additive or subtractive involving etching, spinning and micromachining silicon and other substrate. MEMS have several applications in the medical field for diagnostic systems, drug delivery and pumping systems, monitoring, electrical stimulation, prostheses and artificial organs, analysis systems, and minimally invasive surgery. In the area of diagnostics, MEMS have been used in catheters, ultrasound intravascular diagnostics, angioplasty and ECG=s.³ They can also be used to control drug delivery and pumping at the nanoliter level.³