Biomodeling By, Michael Lovrity

What is a Biomodel? The process of constructing, designing and analyzing complex 3D models of body parts through a computer imaging process. Allows almost perfectly shaped model be constructed to replace broken bones or other body parts i.e. artificial spinal discs. Helps surgeons to prepare prior to the actual surgery.

CT Image of a spine and 3D computerized model

Where Biomodeling is applied in: Spinal Surgery Surgical Oncology Thoracic and Cardiovascular Plastic and Reconstructive Craniofacial Maxillofacial Oral and Dental Orthopedic

How a Biomodel is made A CT scans the spine to produce a series of axial images then the scans are transferred to an image processing system that would produce a model to be manufactured by SLA (stereolithography). SLA involves a liquid-bed laser curing system, where a laser traces contours and polymerizes a photosensitive liquid plastic monomer. The SLA biomodels has been found to have an accuracy of within 1 mm of the scanned anatomy.

How a Biomodel is made (cont.) Artificial struts are built into the model, if needed, to position and hold separate structures in their anatomical positions. A typical model takes approximately 18 to 30 hours to build the SLA apparatus, depending on its geometry and volume. For cervical spine models or smaller spine segments can take between 12 and 16 hours to build the biomodel and the processing of CT data prior to building the model typically takes around 1 to 2 hours.

A stimulated spinal neurosurgery using a haptic device.

Results Based on the 5 cases of spinal biomodeling: An accurate physical model of the spine is an extremely effective tool. Increased patient education Increased patient’s consent Improved preoperative planning

Results (cont.) A study using biomodels in 45 complex cranio- maxillofacial surgeries found that: They had improved diagnosis Reduced operative time A later study of 6 patients using biomodels concluded that biomodels provided excellent understanding of the complex spinal pathology and helped surgical planning and performance.

Advantages Allows imaging data to be displayed in physical form. Allows accurate diagnosis and measurements to be made before surgery. Give researchers a better understanding of the biomechanics for example, the bracing of clubfoot.

Advantages (cont.) Gives the patient a better understanding of where the problem is and how it will be fixed. Error rates are as low as between 1% and 6$.

Disadvantages There’s a minimum 24 hours’ manufacturing time and the cost. The initial wax mold is fragile that branches smaller than 1 mm could not be displayed in the final model. Cost for custom-made models depend on size and are in the range of $1,800 - $2,200.

References iomechanics/ MC / /?i=6&from=/ /related df