Craniosynostosis, a congenital premature fusion of cranial sutures, causes abnormal skull growth and potential neurodevelopmental complications. Surgical correction aims to restore cranial shape and allow normal brain growth. Three-dimensional printed patient-specific models are increasingly used for preoperative planning, surgical rehearsal, and training, particularly in complex cases. However, while anatomically accurate, these models often fail to replicate the mechanical behavior of pediatric cranial bone. This study evaluated six fused deposition modeling (FDM) materials—PLA, ASA, PET-G, Simu Bone, polypropylene (PP), and TPU—against pediatric calvarial bone specimens using three-point bending tests and finite element simulations. Native bone showed a mean Young’s modulus of 375 ± 204 MPa. Simu Bone was overly stiff (3380 ± 14 MPa), TPU too compliant (61 ± 11 MPa), and PP most closely approximated bone mechanics, though with printing challenges. Infill reduction modestly decreased stiffness. Finite element analysis indicated that replicating global elasticity alone is insufficient, as regional deformation patterns are critical for realistic simulation. These findings emphasize the need to balance mechanical fidelity and printability in 3D-printed cranial models, with PP providing the closest match for pediatric surgical training.
Three-dimensional (3D) visualization, modeling, and printing can enhance planning for septal myectomy in hypertrophic obstructive cardiomyopathy; however, their role in postoperative decision-making is less well defined. A 49-year-old man underwent extended septal myectomy planned using cardiac computed tomography angiography (CTA)–based 3D modeling and virtual myectomy; patient-specific 3D-printed models processed using hydrogen peroxide plasma were used intraoperatively to guide resection. Intraoperative echocardiography confirmed relief of obstruction with resolution of systolic anterior motion (SAM) and a low residual left ventricular outflow tract (LVOT) gradient (6 mmHg). On postoperative day 3, dyspnea recurred with severe LVOT obstruction (peak gradient of 73 mmHg) and SAM. Repeat CTA and 3D modeling showed no residual anatomic septal substrate (maximal basal septal thickness of 15 mm), supporting a dynamic mechanism consistent with relative intravascular hypovolemia, tachycardia, and a hyperdynamic left ventricle. Hemodynamically targeted conservative management—preload augmentation, discontinuation of vasodilatory therapy, and intensified heart-rate control—normalized LVOT gradients (12 mmHg by postoperative day 7) and improved functional capacity. This case report illustrates how repeated 3D assessment and printing can support effective surgical treatment in a patient with complex cardiac pathology and help avoid premature reintervention by excluding structural causes of early postoperative obstruction and guiding reversible, physiology-based management.
Unicompartmental knee arthroplasty (UKA) is an effective treatment for medial compartment knee osteoarthritis, with its outcomes highly dependent on the accuracy of prosthesis positioning. Conventional UKA, performed using traditional instrumentation, often relies heavily on surgical experience and may lead to variability in alignment. The emergence of 3D-printed patient-specific instrumentation (PSI) offers a promising approach to improve prosthesis placement accuracy and operational reproducibility. This study aims to evaluate the postoperative prosthesis position and short-term clinical outcomes of UKA assisted by 3D-printed PSI. A retrospective analysis was conducted on 22 patients (25 knees) who underwent PSI-guided UKA between May 2023 and May 2024. These were compared with 25 patients (31 knees) undergoing conventional UKA during the same period. Postoperative radiographic assessments included prosthesis position, limb alignment, and range of motion (ROM) in the sagittal plane. Clinical outcomes were evaluated using functional scores. Both groups showed significant improvement in limb alignment and knee function postoperatively (p < 0.05), with no significant difference in preoperative and postoperative FTA within or between groups. The PSI group demonstrated superior outcomes in AKS-K score (91.7 ± 8.2 vs. 85.5 ± 6.9) and ROM (128.6° ± 9.4° vs. 120.3° ± 7.4°) compared to the control group (p < 0.05). Prosthesis positioning was significantly more accurate in the PSI group regarding coronal and sagittal alignment of both tibial and femoral components (p < 0.05). No significant difference was found in joint line height restoration. 3D-printed PSI significantly enhances the accuracy of prosthesis positioning in UKA, reduces operative time, and lowers the learning curve for less-experienced surgeons. Its core value lies in translating complex biomechanical requirements into standardized, executable surgical plans, thereby minimizing outliers in key alignment parameters.
To use digital technologies, including high-resolution imaging, computer-aided design (CAD), and three-dimensional (3D) printing, to introduce a streamlined process by enabling rapid, reproducible, and cost-effective digital fabrication of orbital prostheses, thereby addressing the limitations of conventional manual prostheses, which remain labor-intensive, poorly reproducible, and often fail to achieve optimal marginal adaptation. This study presented a digital workflow for silicone orbital prostheses fabrication, combining CT-derived 3D reconstruction, reverse engineering, and stereolithography to produce customized silicone prostheses with 3D-printed photocurable resin negative molds. Mimics 10.01 software was used for 3D reconstruction, and defect margin delineation and prosthesis design were performed using Geomagic Studio 2013 software. The resulting prostheses demonstrated favorable facial symmetry, accurate skin color matching, excellent fit, and high wearing comfort, representing a promising approach to enhance the quality of life of our patients. This approach minimized reliance on extensive manual labor, facilitated archiving and reproduction, and offers satisfactory efficiency and esthetic outcomes, thereby providing a practical alternative for orbital rehabilitation. The digital workflow described herein established an efficient and systematic procedure for the fabrication of silicone orbital prostheses.
Surgical planning in complex congenital heart disease (CHD) often involves challenging decisions between univentricular and biventricular repair. Traditional imaging modalities such as echocardiography, CT, MRI, and angiography provide detailed data but lack intuitive three-dimensional spatial visualization. This study aimed to establish a low-cost, scalable 3D modeling and surgical simulation approach for broader access to this technology in mid-sized or resource-limited pediatric cardiology centers. We retrospectively studied 25 patients with complex CHD who underwent 3D modeling to assess suitability for biventricular repair. Patient-specific cardiac models were generated using open-source segmentation and post-processing software and fabricated using a desktop stereolithography (SLA) Formlabs 3D printer. Surgical baffles were simulated digitally and incorporated into the models to assess the feasibility of biventricular repair. Models were reviewed in multidisciplinary team meetings and shared online via a 3D viewing platform (Sketchfab) to allow remote consultation. Of the 25 patients evaluated, 14 (56
Introduction Dental rehabilitation has a significant impact on health-related quality of life (HRQOL) for patients undergoing microvascular reconstruction of the jaw. Virtual surgical planning (VSP) and computer-aided design and computer-aided manufacturing (CAD/CAM) technology allows for precise and timely delivery of an implant-retained dental prosthesis. This study characterizes the cost to produce a point of care (in-house) 3D-printed resin dental prostheses for patients undergoing osseous free flap reconstruction. Methodology Implant-retained dental prostheses for patients undergoing osseous free flap reconstruction of the maxilla or mandible produced by the Integrated Prosthetics and Reconstruction (IPR) laboratory at Chris O’Brien Lifehouse Hospital between July 2023 and June 2024 were analysed. The costs of producing the prostheses were calculated using a “bottom up” approach where all activities associated with start-up, planning and fabrication were accounted for and unit costs for each activity quantified. Prostheses with incomplete data were excluded. All costs are reported in 2024 as USD. Results Twenty-one patients met the study inclusion criteria of which the majority (n = 19) underwent mandibular reconstruction. Twelve patients underwent reconstruction for benign disease and 17 patients had the prosthesis placed at the primary reconstruction. The mean cost of producing the dental prosthesis was $861.72 (range: $702.78 - $1032.34). Start-up costs were the highest contributor (mean cost $333.71) per prosthesis, followed by the design/planning phase (mean cost $260.37), and fabrication phase (mean cost $267.64). The overall cost increased with increasing number of implant fixtures and the number of prosthetic units placed. Conclusion VSP and CAD/CAM technology allows for rapid and accessible dental rehabilitation following osseous free flap reconstruction. However, the significant startup costs of these technologies are likely to be a barrier to institutions wanting to introduce point-of-care manufacturing of dental prosthetics.
The Latarjet procedure is effective for treating recurrent anterior shoulder instability, but graft-related complications may occur. Accurate preoperative planning is essential to minimize these complications. Three-dimensional (3D) printed models may support surgical planning; however, their role in Latarjet surgery remains unclear. This study aimed to evaluate whether coracoid dimensions measured on 3D-printed models differ from intraoperative measurements and whether their use influences surgical decision-making. In this cross-sectional study, 25 patients underwent computed tomography based 3D printing of the scapula. Coracoid length, width, and thickness were measured on the 3D-printed models and compared with intraoperative pre- and post-osteotomy measurements using precision calipers. Surgeons also subjectively rated the usefulness of the 3D models for surgical planning. No significant differences were observed in coracoid thickness among the three measurement time points (p = 0.6956). Significant differences were found for coracoid length (p = 0.0005) and width (p = 0.02) between the 3D model and pre-osteotomy measurements, while no differences were observed between pre- and post-osteotomy measurements. The models were rated as “very helpful” in 28
Abstract Background Native polyetheretherketone (PEEK) exhibits limitations in mechanical strength, radiographic visibility, and bioactivity for craniomaxillofacial (CMF) applications. This proof-of-concept study establishes the feasibility of point-of-care (POC) manufacturing for three functionalized PEEK composites for patient-specific CMF implants using a high-temperature material extrusion (MEX) system, with application-specific material selection to overcome these limitations. Methods Carbon fiber-reinforced PEEK (CFR-PEEK), barium sulfate-filled PEEK (BaSO₄-PEEK), and biphasic calcium phosphate-filled PEEK (BCP-PEEK) were fabricated into patient-specific mandibular reconstruction plates, orbital floor implants, and chin augmentation implants, respectively. Manufacturing success rates, dimensional accuracy via root mean square (RMS) deviation analysis, post-sterilization dimensional stability, and layer adhesion quality were evaluated. Results Fabrication success rates of 100% (CFR-PEEK), 100% (BaSO₄-PEEK), and 85.7% (BCP-PEEK) were achieved. Dimensional accuracy analysis revealed RMS deviations of 0.16–0.29 mm between 3D-printed implants and original designs, within clinically acceptable ranges. Post-sterilization dimensional changes were minimal (RMS 0.05–0.07 mm). Complete layer adhesion was demonstrated across all materials, with no delamination or cracking observed. Conclusion These findings establish the manufacturing viability of POC fabrication of application-matched PEEK composites for patient-specific CMF implants, enhancing mechanical, radiographic, and bioactive properties whilst maintaining geometric customization.
Abstract Background Cartilage repair is challenging due to the tissue’s limited regenerative capacity. Synthetic 3D-printed scaffolds provide essential structural support, but typically lack the bioactivity needed for cell integration. A promising approach combines 3D-printed porous scaffolds filled with self-assembling peptide hydrogels, which serve as nanofiber scaffolds inside the macropores of the structural scaffold, creating a hybrid structure. Methods The selection strategy for the 3D printing of the synthetic scaffolds was driven by two distinct cross-linking processes: a vinyl-ester based thiol-ene photopolymer crosslinked via free radical polymerization and printed with digital light processing, resulting in a stiff mechanical network and polydimethylsiloxane, namely AMSil™ 20503-50 from the AMSil™ 20,503 series, printed via liquid deposition modeling and crosslinked through polyaddition, which yields flexible scaffolds capable of adapting to dynamic mechanical environments. These properties make them suitable for load-bearing applications where structural integrity is paramount. Both 3D-printed scaffold types, characterized by interconnected macropores ranging from 0.8 to 1.2 mm, were augmented with a peptide hydrogel scaffold, such as RADA16 and IEIK13, that self-assembles inside the macropores to create a nanofiber network mimicking the extracellular matrix and enhancing bioactivity. Results The hybrid structure, combining the macropores of a structural 3D-printed scaffold and the nanofiber network of the peptide hydrogel scaffold improved cell adhesion, proliferation, and differentiation. Comparative analysis showed that, while both RADA16 and IEIK13 hydrogels enhanced cell integration within the macropores, RADA16 was especially effective in supporting cartilage-like ECM formation. Conclusions The creation of a hybrid scaffold with hierarchical porosity—integrating the structural macropores of a synthetic 3D-printed scaffold with the bioactive nanofiber network of a peptide hydrogel—addresses the limitations of purely structural scaffolds. The hybrid approach not only enhances fast and accessible scaffold fabrication but also accelerates the development of functional scaffolds.
Abstract Background The retrosigmoid approach is a standard surgical route used for the treatment of various tumors and vascular lesions in the cerebellopontine angle. However, postoperative reconstruction of the surgical defect could remain challenging, particularly in cases requiring intraoperative extension. For this reason, a novel concept was developed to define the surgical approach and enable precise defect coverage using a patient-specific implant. This concept was designed to be patient-specific and realized through 3D printing. Methods The developed 3D printed template-implant concept was designed to facilitate precise craniotomy. The template is used as a stencil and a surgical marker is applied to delineate the implant contours directly on the patient’s skull. This outline subsequently serves as a guide for where to perform the craniotomy and defines its boundaries. The custom-fit implant replicates the template design and ensures complete coverage of the craniotomy defect, while allowing intraoperative adjustment if required. Preclinical testing was conducted on a 3D printed simulation model representing the posterior cranial fossa (surgical area). The novel concept was tested by nine senior and attending neurosurgeons from the University Hospital Leipzig. Bilateral craniotomies were performed using the template and subsequently closed with the implant. The fit of the implant was evaluated using CT scans. The time required for preparation, including craniotomy, as well as for post-procedure handling, including implant placement, was recorded. Results The average gap of the new concept was 2.11 mm, which was significantly smaller than that of the current standard approach (5.52 mm) and showed lower variability. The entire procedure, including craniotomy and implant placement, took an average of 13 min and 20 s. Conclusion The novel template-implant concept for retrosigmoid approaches improves defect coverage and reduces gap sizes. Furthermore, it demonstrates the potential of 3D printed patient-specific implants for more precise and predictable surgical procedures, although further studies are required to validate efficiency and clinical safety.
The aim of the article is to present the development and application of a 3D-printed skull base model, which includes the internal carotid arteries, tumour and the optic nerve, to train neurosurgeons and ear, nose and throat (ENT) in performing the endonasal endoscopic approach (EEA). This procedure is challenging due to the proximity of critical structures such as nerves, blood vessels and brain. The 3D model was generated using magnetic resonance imaging (MRI) and computed tomography (CT) scans, which provided detailed anatomical data. These scans were processed with 3D reconstruction software to accurately replicate the key areas, including the tumour and surrounding structures. Neurosurgery and ENT consultants and residents, practised the EEA using these printed models. After completing the procedures, participants filled out a questionnaire to evaluate the realism and reliability of the model by applying a statistical analysis appropriate to the study. The participants reported that the 3D-printed models provided a highly realistic simulation of the anatomical structures involved in the EEA. The model was deemed effective in replicating the key areas of interest, allowing them to safely practise the procedure in a controlled environment. Our results show that in two days approximately and for less than 10€, the surgeon may have the opportunity to train the surgery after establishing the printing parameters. A strong positive correlation was found among these variables (p < 0.01), suggesting that those who found the model useful also perceived a greater clinical applicability and believed that the 3D-printed model could help improve their surgical skills. The study demonstrates that 3D-printed models based on MRI and CT scans offer a reliable and realistic method for surgical training. These models provide an essential tool for practising complex procedures, such as the EEA, improving the safety and effectiveness of surgical training and potentially enhancing patient outcomes.
Point-of-care (POC) three-dimensional (3D) printing of medical devices presents a paradigm shift in personalized medicine, yet clinical implementation of polyetheretherketone (PEEK) implants remains limited by regulatory, technical, and quality assurance challenges. Traditional external manufacturing timelines of 2–6 weeks constrain immediate reconstruction capabilities, particularly in trauma and oncologic cases requiring rapid intervention. Structured frameworks enabling MDR-compliant hospital-based production of implantable devices remain limited in the literature. We implemented a comprehensive European Union Medical Device Regulation (EU MDR) 2017/745 Article 5(5)-compliant POC manufacturing framework incorporating an electronic quality management system aligned with ISO 13,485, a manufacturing execution system enabling end-to-end device traceability, risk management, process validation, biocompatibility evaluation, and integrated post-market surveillance. Medical-grade PEEK was processed using validated high-temperature specialised material extrusion 3D printers. Representative clinical applications of the EU MDR-compliant point-of-care manufacturing framework are illustrated in two anatomical contexts: (1) a POC 3D-printed PEEK cranial implant and (2) a POC 3D-printed PEEK facial implant. Manufacturing turnaround from image acquisition to sterile delivery was operationally achievable within 3–5 days. The patient-matched implants demonstrated accurate anatomical fit without intraoperative modification, with no major device-related complications observed. The framework has supported the production of over 40 + POC 3D-printed PEEK implants at the index institution and has since been adopted at multiple European centres, demonstrating transferability beyond the index case series. This work describes a validated EU MDR Article 5(5)-compliant framework for hospital-based production of patient-matched 3D-printed PEEK implants, demonstrated across cranial and facial reconstruction. Early clinical results support safety and feasibility, with end-to-end manufacturing achievable within a week, enabling flexible surgical planning. The framework provides a replicable pathway for regulated POC implant production, with multi-centre adoption and long-term outcome surveillance as critical next steps.
Traditional methods for producing custom-made orthoses are often time-consuming, labor-intensive, and reliant on manual processes, which limit both scalability and the degree of individualization. The development of 3D scanning technologies, computer-aided design (CAD), and additive manufacturing offers a promising alternative enabling patient-specific solutions with greater precision, speed, and efficiency. This study aimed to create an algorithm for automating the design process of personalized knee orthoses based on 3D scanning and intended for 3D printing production. A parametric modeling workflow was developed in the Rhino environment using the Grasshopper plug-in to streamline personalized knee orthoses creation. The process began with acquiring high-quality 3D scans using Structure Sensor Mark II scanner mounted on an iPad with 3DsizeMe software. The parametric algorithm was transformed into an autonomous Rhino plug-in using C# language and RhinoCommon API. As part of Post-Market Clinical Follow-up (PMCF), three participants with knee joint disorders used orthoses for one month. Assessment used a 5-point scale (1 = poor, 5 = excellent). Personalized orthoses were manufactured using powder-bed fusion technology with PA11 CF nylon powder reinforced with carbon fibers. Design time was reduced from approximately 8 h to 10,3 ± 1,4 min. In Grasshopper prototype phase, average design time was 26,7 ± 4,5 min. Following the implementation of the Rhino plug-in, the design time was further reduced to approximately 10 min. The tool was shown to meet user requirements and fulfill its intended purpose. All three PMCF participants rated orthoses positively, reporting high comfort, effective stabilization, increased physical activity, and overall satisfaction with functionality and appearance. Participants P1 and P2 noted a large increase in physical activity, with P1 indicating pain reduction that increased mobility. This study demonstrates that the combined use of Rhino and Grasshopper provides an effective platform for parametric design of personalized knee orthoses based on patient-specific 3D scans. The workflow reduced design time to approximately 10,3 ± 1,4 min, highlighting potential for routine clinical applications. This reduction is economically significant, lowering labor costs and implementation thresholds for personalized orthotic solutions in clinical practice.
Abstract Background This study investigates a 3D printed, noninvasive headrest that was designed for use in orbital and skull base surgeries and compares the stability of this innovative headrest to conventional head immobilization devices using accelerometer-based measurements. Methods A 3D model of a headrest was developed using two plastic materials: polyethylene terephthalate glycol (PETG) and thermoplastic polyurethane (TPU). Stability, in g-force, was measured for these headrests, Gel Head Donut Adult Blue Diamond®, and a no headrest condition. A non-embalmed cadaver’s head was placed in each headrest condition and subjected to controlled oscillations using Bellco Glass’ Orbital Shaker. Acceleration data were recorded over a 3-second interval. Results The average acceleration, measured in g-force (g), over 3 s for each headrest configuration was: (1) no headrest: 0.068116 g ± 0.058498, (2) Gel Donut head immobilizer: 0.064223 g ± 0.027463, (3) PETG headrest: 0.053331 g ± 0.037782, and (4) TPU headrest: 0.056254 g ± 0.032200. The PETG headrest showed a 21.71% improvement over no headrest and a 16.96% improvement over the gel donut headrest in maintaining head stability. And the TPU headrest showed a 17.41% improvement over no headrest and a 12.41% improvement over the gel donut headrest in maintaining head stability. Conclusions The PETG and TPU headrest provided greater stability compared to the commonly used Gel Head Donut headrest and in the absence of a headrest. This study suggests that the design of this headrest offers a potential noninvasive head stability device, regardless of material composition, that may improve the safety and efficacy of orbital and skull base surgery.
This study assessed two different 3D-printed endovascular simulation models and a digital simulator for training of endovascular interventions. Thirty-two vascular surgeons and radiologists completed interventions using two transparent 3D-printed models—a flexible model, printed with Stereolithography (SLA), and a stiff model using Fused Deposition Modelling (FDM) technology —as well as a digital simulator. A standardized questionnaire assessed the models’ perceived face and construct validity as well as their concurrent validity. Additionally, the impact of model material (flexible vs. stiff) on perceived fidelity and utility were evaluated. All participants completed the three interventions successfully. There was an even distribution of sex (16 males and females) and experience among the participants. The flexible 3D-printed model demonstrated significantly higher face and construct validity scores compared to the stiff model and the digital simulator (p < 0.001). No significant differences were observed between the digital and stiff models for face and construct validity (p = 1.0, p = 0.38). Regarding concurrent validity, there was a significant preference for the 3D-printed models (72
Veterinary anatomy education increasingly demands innovative strategies to enhance spatial understanding and student engagement. Mixed augmented reality (MAR) has emerged as a promising tool, integrating virtual anatomical models into real environments. This study aimed to describe the pratical implemention and evaluate the pedagogical benefits of a MAR-based holographic platform for teaching selected osteological structures in veterinary anatomy. A Veterinary Anatomy Holographic Platform (VAHP) was developed using 3D digitized bone models integrated into a mixed reality display. Anatomical models of equine skull, scapula, femur, and the canine axis were processed using photogrammetry and 3D Slicer, then rendered with Unreal Engine 4.27. The platform was implemented during regular classrom session with 80 veterinary students. Learners interacted with the holographic models and subsequently completed a four-question proficiency test. Results were compared to a control activity using real anatomical specimens and analyzed using Z-tests for two proportions. Significant improvements in permfomance were observed in three of the four test questions after using the VAHP (p < 0.05), particularly for structure requiring complex spatial reasoning. No statistical improvement was found for one question (p = 0.058). The holographic session were well accepted by students and promoted engagement in the classroom. This proof-of-concept study showed that the VAHP, delivered through a mixed reality headset, can enhance anatomical learning and engagement in osteology. Broader and longer-term studies are needed to confirm its impact and guide curriculum integration.
BackgroundTechnological advancements have made 3D printing more accessible and affordable for both individuals and institutions. Despite significant efforts by the International Medical Device Regulators Forum to standardize 3D printing regulations for medical use, challenges remain. We conducted a survey to gather insights from physician end-users on their opinions regarding the regulation of 3D printing in medicine. Additionally, since FDA guidance is often adopted internationally, this survey aimed to capture the demographics of physician end-users globally and provide a snapshot of the current use of 3D printing in clinical practice and research.MethodsAfter developing and validating a 26-question survey, we emailed it to the corresponding authors of all PubMed-indexed publications on 3D printing in medicine. Participants received an introductory email explaining the survey's purpose and an invitation to participate. Only responses from participants who declared themselves to be physicians were accepted. The survey was open for responses from April 5th to May 3rd, 2022, with weekly reminders sent until the response period closed. Responses with at least 80% survey completion were accepted for analysis.ResultsOut of 951 surveys sent, we received 114 responses (11.9%) with an average completion rate of 89%. Most respondents were from Europe (35.5%) and North America (30.9%), followed by Australia and New Zealand (9.1%). The majority were affiliated with academic institutions (83.9%) and were primarily surgeons (49.1%). The most common application of 3D printing was surgical planning (74.1%), followed by medical education (61.6%). Nearly 50% of respondents used open-source segmentation software without FDA approval. Most had access to an onsite printer (82.2%) and specially trained staff to assist with segmentation (53.4%).ConclusionsThe integration of 3D printing technologies into clinical practice will continue to grow. This paper presents the largest survey of physicians practicing 3D printing to date. Given the underrepresentation of this key demographic within regulatory bodies, the opinions and positions of physician respondents reported here should be considered in the development and application of new guidelines and regulations in the field.
Three-dimensional (3D) ultrasound provides more intuitive, detailed, and comprehensive diagnostic information. The primary objective of this study was to develop affordable, lightweight, and wide-field 3D ultrasound probes which is a critical challenge for expanding the accessibility and utility of this technology. We describe an affordable freehand scanning 3D ultrasound reconstruction system. The system utilizes a QR code film attached to the skin surface for positioning. During each ultrasound scan, a lightweight camera fixed on the probe records the QR codes within the scanning area. Based on QR code features, a skin map is constructed, and ultrasound images and film image information are preprocessed. The calibration relationship between the ultrasound probe and camera field of view is determined. Finally, comprehensive algorithms such as ORB-SLAM positioning are used for three-dimensional image reconstruction. Through hand-scanning tests, the results show that the scanning speed is 15 mm/s, and when the image acquisition frame rates are 10 Fps/s, 20 Fps/s, and 30 Fps/s, the maximum cumulative error of ORB-SLAM algorithm positioning does not exceed 2
In the 2019/2020 winter semester, the University of Augsburg’s Faculty of Medicine introduced a competence-oriented model degree program with a spiral curriculum integrating theory and practice. A key feature, the clinical longitudinal course, emphasizes practical skills such as skin examination. Existing training materials for punch biopsies, e.g., foam models and fruit, have proven insufficient. This project aimed to create a realistic, cost-effective, reusable three-dimensional (3D) skin model to improve the teaching of punch biopsy and suturing techniques. The 3D skin model was developed in a multistage process. It began with a 3D scan created via a handheld 3D scanner and refined in 3D modeling software. A fused deposition modeling (FDM) printer produced negative molds that were filled with silicone, resulting in a realistic model. After several iterations, a design was achieved that successfully simulated the tactile and functional aspects of punch biopsy and skin suturing. Student feedback was collected through an anonymous online questionnaire assessing perceived realism, usefulness for practicing punch biopsies and suturing, and impact on their confidence. The silicone-based skin simulator debuted in the 2023–2024 winter semester’s ‘examination of the skin’ course. A total of 82 students participated in the course, of whom 58 completed the evaluation questionnaire. The students used the model to perform punch biopsies and suturing, reporting that its material properties allowed these procedures to be practiced under course conditions. With a low production cost (of 0.62 € per model) compared to commercial models, it is a cost-efficient alternative to previous materials. The students provided positive feedback, reporting increased confidence in performing these procedures on humans for the first time. The 3D training model is an important advancement in introducing 3D technologies in practical training, providing realistic, cost-effective practice for punch biopsy and suturing. Its successful integration into the curriculum highlights its potential for broader applications in medical education. The evaluation indicated that the model provided realistic skin properties and proved effective for practicing punch biopsies and suturing, thus addressing the limitations of traditional training materials.
