Digitizer is a device that enables the recording of the object surface and its reconstruction on a computer as a cloud of dots.
Three-dimensional digitization of objects is the process of registering and processing of dots from the object surface and reconstruction of their spatial coordinates in the computer in order to obtain true computer representation of the object surface. The device that conducts the process of digitization is called digitizer. Digitizers can be contact and contactless. For non-contact digitizers most common principle is to use the digitizing camera and structured light. Structured light is obtained using a laser line module or by projecting a structured light pattern on the object surface. By knowing all parameters of the camera, the computer reconstruction of the surface is performed, which results with a cloud of points representing the geometric patterns of the observed surface. Dots are then mathematical processed using triangulation by which points are connected in a triangles which results with a surface composed of a great number of triangular surfaces. Such surface is suitable for visualization and further processing.
The limiting factor for wider use of digitizing technology is still their price. Although the price of digitizers varies significantly between manufacturers and models, it is still very high even for a simple implementations, making them inaccessible to a wider applications. That this was the main encouragement for creating digitizing assembly from commercially available components whose primary purpose would be the recording of the surface of human body for the needs of medical diagnostics of static disorder of the spine, although with modifications the device could be used for other purposes. Leading directoin in development of this system was the problem of static deformities of the spine in the school population, which is of utmost importance to establish an early presence of a change for the earlier approach to treatment, because only such an approach can be expected to be successful. By this method, under certain conditions it is possible to implement a three-dimensional recording of spine surface. By using computer and obtained surface measurements and analysis is conducted in order to determine the asymmetry, size and shape of individual anatomic and topographic features of the spain, and generally to determine pathological changes from the referent norms for particular age and sex of examinee. It is important to emphasize that this method of digitizing is completely safe and easy to use, and as such can be quickly implemented in the health system, while the cost is considerably more affordable than other available methods. System for digitizing is made of an linear axis which is fixed to the portal with the digital camera and laser line module. Generator of laser beam illuminates the object, creating a curve on the surface of the object, which is being recorded by a digital camera. Upon completion of recording of one section, portal linearly moves to the next known position from which the whole process repeats. As a result, a cloud of dots composed of a series of curve segments is generated, which are being processed, visualized and analyzed. The accuracy of this system is 0.25 mm which makes it appropriate for the mentioned purpose.
As a continuation of this project, the Motion Capture Systemwas developed. It is a device for dynamic testing of the spine functions which enables functional measurement of intervertebral joint movements. The ultimate goal is to develop a complete system for conducting spine examinations and to connect to relevant orthopedic and neurological institutions.