Application of 3D Printing in the Construction of Burr Hole Ring for Deep Brain Stimulation Implants

3D printing make possible to develop individualized burr hole rings for patients. Our protocol provide the detailed procedures for using 3D model program to construct these implants. 3D printing objects have a high product efficiency, a low cost and are customizable.

With the help of 3D printing, patients can obtain implants that are highly specific to their individual needs. To draw a 2D image of a burr hole ring, open a new graphical document in the 2D CAD software program. Click Draw and Line and draw a reference point with a solid line on the drawing.

Then click Modify and Offset and type the specific offset distance in the command line. To select the area to be trimmed, click Modify and Trim and click the extra line. To draw the top view, click Draw and Line to construct the reference point and click Daw, Circle and Center Diameter to input the quantitative value of the specific radius of the circle or diameter in the command window.

Then click the center of the reference point to form a circle. Next, draw the left view of the inner burr hole ring using the same approach as that for the front view. Click Dimension and Diameter and click on the circumference to mark the diameter of the circle.

Click on Dimension and Linear to mark the length and thickness of all of the associated structures. Then click Dimension and Radius to mark the angle of the chamber. Using the same protocol, construct 2D drawings of the outer burr hole ring and mark the actual size and the labeling.

Then click Save to save the 2D image of the burr hole ring. To draw a 3D image of the burr hole ring, open the 3D drawing software program and select the front plane as the sketch plane. Click Default under Sket view and select the dotted line tool to draw the top section of the part in the two-dimensional sketch.

Click Conform and Done and click the datum plane icon. In the menu manager, select Create, Solid, Add Sheet, Rotate and Done. Then click Bilateral in the Properties menu and click Done.

To construct the cross-section of the hook of the outer burr hole ring, click Front, Forward, Default, Datum Plane and Dotted Line. Click Confirm and Done and enter 50 in angle and indicated direction 45 and click Done in the protrusion. Then click the coloring button.

Next select Redefine in the part feature and click the line structure of the hook. Select Section, Define and Sketch. Click the dotted line icon.

Create two square embossments on the hook section, click OK, Done and Coloring. Click the datum access icon and click Insert a Datum and Cross. Click the center axis of the line structure.

Click angle in the datum plane and click the front plane in the line structure view. Then click Input Value in the Offset menu and enter minus 45 in angle and indicated direction 45. Click Features, Copy and Mirror.

Click the hook as the object and click Done Select and Done. Click the datum plane to complete the copy and copy the remaining two hooks in the same manner. Then click Create Concentric Circle to construct a circle with a radius of 7.23 millimeters and click the segmentation of primitives at selected points icon to remove the unnecessary lines of the circle.

To create a complete outer wall section, click the solid line button and click OK and Done. Enter four as the enter depth and click Coloring. Click Mirror and Done.

Click the object and Done. Then click the datum plane to complete the copy. To confirm, click Copy, Mirror and Done and select two outer walls in different directions.

Then click Done and click the datum plane to complete the copy. To enhance the graphic details, click View, Model Settings, Color and Appearance, Add and adjust the RGB color slider to brown. Then click Close, Settings and OK.Click the Eliminating Hidden Lines button and click the Create Concentric Circle.

Continue to create an outer edge on the outer wall and click the Segmentation of Primitives at Selected Points button to remove excess lines. Click the Solid Line button to connect the newly added outer edge into a complete section and click OK.Enter 0.8 as the enter depth and click OK in the protrusion window. In the menu manager, click Copy, Mirror, Done, click the object and click Done.

Click Generate Benchmark and Offset and click the input value in Offset. Then enter 0.4 as the isometric of the specified direction and click Done. Click Copy, Mirror and Done and click the outer wall.

To complete the mirror operation of the outer wall and the square embossing, click Done Select and Done and click the datum of the image to complete the copy. Select File and Copy and save the file in stl format. Enter the part number and click OK.Then in the output STL dialogue box, adjust the cord height to 006 and the angle control to 0.00001, click Apply and OK.To print the rings, open the project files in the model detecting software.

Confirm that the outer ring is complete and click Part, Export Part as STL and Save. Following model detection, open the slicing software and click File and Load Model File and open one stl file. Click the left mouse button to select the moving track of the part and adjust the position of parts.

Set the print speed to 30 millimeters per second, the printing temperature to 210 degrees Celsius and the bed temperature to 80 degrees Celsius. Then click Tool Path to SD to save the file in G-code format and to generate the printed path. When the temperature rises to the preset value, click Print and select the target file and Confirm to start printing.

After the bottom supporting grid has been constructed, the printing nozzle will begin to construct the outer ring vertically, layer by layer. After the outer ring is formed, the printer nozzle will print the inner ring on the right side. After both rings have cooled, remove the models from the platform.

Here, the absolute error and error range were calculated for five groups of parts that were produced as demonstrated. The results indicate that in the outer ring, the maximum absolute error and minimum absolute error were found in the outside diameter of the waist and in the thickness of the top respectively. In the inner ring, the maximum absolute error and the minimum absolute error were found in the inside diameter and in the thickness of the top respectively.

The total error range was 0.00, 0.59.3D and MR data has a potential to be used to build the actual imaging of the burr hole rings if the thick can be extract from images. Our protocol provides a rapid and accurate method for constructing deep brain stimulation implants through the integration of clinical imaging data and 3D printing.