3D printing in medicine最新文献

Background: Simulation in the field of gynecological pelvic examination with educational purposes holds great potential. In the current manuscript we evaluate a 3D printed model of the female pelvis, which improves practical teaching of the gynecological pelvic examination for medical staff.

Methods: We evaluated the benefit of a 3D printed model of the female pelvis (Pelvisio®) as part of a seminar ("skills training") for teaching gynecological examination to medical students. Each student was randomly assigned to Group A or B by picking a ticket from a box. Group A underwent the skills training without the 3D printed model. Group B experienced the same seminar with integration of the model. Both groups evaluated the seminar by answering five questions on Likert scales (1-10, 1 = "very little" or "very poor", 10 equals "very much" or "very good"). Additionally, both groups answered three multiple-choice questions concerning pelvic anatomy (Question 6 to 8). Finally, Group B evaluated the 3D printed model with ten questions (Question 9 to 18, Likert scales, 1-10).

Results: Two of five questions concerning the students' satisfaction with the seminar and their gained knowledge showed statistically significant better ratings in Group B (6.7 vs. 8.2 points and 8.1 vs. 8.9 points (p < 0.001 and p < 0.009). The other three questions showed no statistically significant differences between the traditional teaching setting vs. the 3D printed model (p < 0.411, p < 0.344 and p < 0.215, respectively). The overall mean score of Question 1 to 5 showed 8.4 points for Group B and 7.8 points for Group A (p < 0.001). All three multiple-choice questions, asking about female pelvic anatomy, were answered more often correctly by Group B (p < 0.001, p < 0.008 and p < 0.001, respectively). The mean score from the answers to Questions 9 to 18, only answered by Group B, showed a mean of 8.6 points, indicating, that the students approved of the model.

Conclusion: The presented 3D printed model Pelvisio® improves the education of female pelvic anatomy and examination for medical students. Hence, training this pivotal examination can be supported by a custom designed anatomical model tailored for interactive and explorative learning.

Background: The goal of stabilization of the femoral neck is to limit morbidity and mortality from fracture. Of three potential methods of fixation, (three percutaneous screws, the Synthes Femoral Neck System, and a dynamic hip screw), each requires guide wire positioning of the implant(s) in the femoral neck and head. Consistent and accurate positioning of these systems is paramount to reduce surgical times, stabilize fractures effectively, and reduce complications. To help expedite surgery and achieve ideal implant positioning in the geriatric population, we have developed and validated a surgical planning methodology using 3D modelling and printing technology.

Methods: Using image processing software, 3D surgical models were generated placing guide wires in a virtual model of an osteoporotic proximal femur sawbone. Three unique drill guides were created to achieve the optimal position for implant placement for each of the three different implant systems, and the guides were 3D printed. Subsequently, a trauma fellowship trained orthopedic surgeon used the 3D printed guides to position 2.8 mm diameter drill bit tipped guide wires into five osteoporotic sawbones for each of the three systems (fifteen sawbones total). Computed Tomography (CT) scans were then taken of each of the sawbones with the implants in place. 3D model renderings of the CT scans were created using image processing techniques and the displacement and angular deviations at guide wire entry to the optimal sawbone model were measured.

Results: Across all three percutaneous screw guide wires, the average displacement was 3.19 ± 0.12 mm and the average angular deviation was 4.10 ± 0.17^o. The Femoral Neck System guide wires had an average displacement of 1.59 ± 0.18 mm and average angular deviation of 2.81 ± 0.64^o. The Dynamic Hip Screw had an average displacement of 1.03 ± 0.19 mm and average angular deviation of 2.59 ± 0.39^o.

Conclusion: The use of custom 3D printed drill guides to assist with the positioning of guide wires proved to be accurate for each of the three types of surgical strategies. Guides which are used to place more than 1 guide wire may have lower positional accuracy, as the guide may shift during multiple wire insertions. We believe that personalized point of care drill guides provide an accurate intraoperative method for positioning implants into the femoral neck.

Background: 3D printing (3DP) has enabled medical professionals to create patient-specific medical devices to assist in surgical planning. Anatomical models can be generated from patient scans using a wide array of software, but there are limited studies on the geometric variance that is introduced during the digital conversion of images to models. The final accuracy of the 3D printed model is a function of manufacturing hardware quality control and the variability introduced during the multiple digital steps that convert patient scans to a printable format. This study provides a brief summary of common algorithms used for segmentation and refinement. Parameters for each that can introduce geometric variability are also identified. Several metrics for measuring variability between models and validating processes are explored and assessed.

Methods: Using a clinical maxillofacial CT scan of a patient with a tumor of the mandible, four segmentation and refinement workflows were processed using four software packages. Differences in segmentation were calculated using several techniques including volumetric, surface, linear, global, and local measurements.

Results: Visual inspection of print-ready models showed distinct differences in the thickness of the medial wall of the mandible adjacent to the tumor. Volumetric intersections and heatmaps provided useful local metrics of mismatch or variance between models made by different workflows. They also allowed calculations of aggregate percentage agreement and disagreement which provided a global benchmark metric. For the relevant regions of interest (ROIs), statistically significant differences were found in the volume and surface area comparisons for the final mandible and tumor models, as well as between measurements of the nerve central path. As with all clinical use cases, statistically significant results must be weighed against the clinical significance of any deviations found.

Conclusions: Statistically significant geometric variations from differences in segmentation and refinement algorithms can be introduced into patient-specific models. No single metric was able to capture the true accuracy of the final models. However, a combination of global and local measurements provided an understanding of important geometric variations. The clinical implications of each geometric variation is different for each anatomical location and should be evaluated on a case-by-case basis by clinicians familiar with the process. Understanding the basic segmentation and refinement functions of software is essential for sites to create a baseline from which to evaluate their standard workflows, user training, and inter-user variability when using patient-specific models for clinical interventions or decisions.

We present a digital workflow for the production of custom facial orthosis used for burn scar management using smartphone three-dimensional (3D) scanner and desktop 3D printing. 3D facial scan of a 48-year-old lady with facial burn scars was obtained. 3D modeling with open-source programs were used to create facemask then 3D printed using rigid polylactic acid (PLA) filament and semi-rigid thermoplastic polyurethane (TPU). Conventional facemask was used as a control. Each mask was worn for 7 days. Primary outcomes were level of comfort, and adherence to treatment. The conventional facemask was the most convenient followed by the TPU-facemask (mean comfort score of 9/10 and 8.7/10, respectively). Patient's compliance was high for both TPU and conventional masks, each was worn for at least 21 hours/day for 7 days. On the contrary, PLA-facemask was not well tolerated. The proposed digital workflow is simple, patient-friendly and can be adopted for resource-intensive healthcare.