scholarly journals Assessing Variability in Segmentation Algorithms for 3D Printing at the Point of Care

2021 ◽  
Author(s):  
Magdalene Fogarasi ◽  
James Coburn ◽  
Beth Ripley
Keyword(s):  
3D Printing ◽  
Point Of Care ◽  
Clinical Intervention ◽  
Critical Parameters ◽  
Patient Specific ◽  
Anatomical Location ◽  
3D Print ◽  
Software Applications ◽  
Global And Local ◽  
Geometric Variation

Abstract 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 their principal features. We also identify critical parameters and steps in the workflow where geometric variation may be introduced. We then provide suggested methods to measure or reduce the variation and mitigate these risks.Methods: Using a clinical head CT scan of a mandible containing a tumor, we performed segmentations in four separate programs using workflows optimized for each. Differences in segmentation were calculated using several techniques.Results: Visual inspection of print-ready models showed distinct differences in the thickness of the medial wall of the mandible adjacent to the tumor. Residual volumes were calculated to generate pairwise agreement and disagreement percentages between each as the program’s model. For the relevant ROIs, statistically significant differences were found globally in the volume and surface area comparisons between final bone and tumor models, as well locally between nerve centroid measurements – major variance introduced due to workflow is highlighted in difference heat maps. 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 can be introduced to patient-specific models from differences in software applications. The global and local variations should be evaluated for a full understanding of geometric variations. The clinical implications of these variations vary by anatomical location and should be evaluated on a case-by-case basis by certified clinicians. Understanding the basic functions of segmentation and 3D print preparation software is essential for users intending to adopt the use of patient-specific models for clinical intervention or decision making.

scholarly journals Assessing Variability in Segmentation Algorithms for 3D Printing at the Point of Care

2021 ◽  
Author(s):  
Magdalene Fogarasi ◽  
James C Coburn ◽  
Beth Ripley
Keyword(s):  
3D Printing ◽  
Point Of Care ◽  
Clinical Intervention ◽  
Critical Parameters ◽  
Patient Specific ◽  
Anatomical Location ◽  
3D Print ◽  
Software Applications ◽  
Global And Local ◽  
Geometric Variation

Abstract 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 model. 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 their principal features. We also identify critical parameters and steps in the workflow where geometric variation may be introduced. We then provide suggested methods to measure or reduce the variation and mitigate these risks. Methods: Using a clinical head CT scan of a mandible containing a tumor, we performed segmentations in four separate programs using workflows optimized for each. Differences in segmentation were calculated using several techniques.Results: Visual inspection of print-ready models showed distinct differences in the thickness of the medial wall of the mandible adjacent to the tumor. Residual volumes were calculated to generate pairwise agreement and disagreement percentages between each as program’s model. For the relevant ROIs, statistically significant differences were found globally in the volume and surface area comparisons between final bone and tumor models, as well locally between nerve centroid measurements – major variance introduced due to workflow is highlighted in difference heat maps. 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 can be introduced to patient specific models from differences in software applications. The global and local variations should be evaluated for a full understanding of geometric variations. The clinical implications of these variations vary by anatomical location and should be evaluated on a case-by-case basis by certified clinicians. Understanding the basic functions of segmentation and 3D print preparation software is essential for users intending to adopt the use of patient specific models for clinical intervention or decision making.

scholarly journals On-Demand Intraoperative 3-Dimensional Printing of Custom Cranioplastic Prostheses

2018 ◽  
Vol 15 (3) ◽  
pp. 341-349 ◽  
Author(s):  
Alexander I Evins ◽  
John Dutton ◽  
Sayem S Imam ◽  
Amal O Dadi ◽  
Tao Xu ◽  
...  
Keyword(s):  
3D Printing ◽  
Perioperative Complications ◽  
Ease Of Use ◽  
Patient Specific ◽  
Production Time ◽  
3 Dimensional ◽  
3D Print ◽  
Fused Deposition ◽  
On Demand ◽  
Dimensional Printing

Abstract BACKGROUND Currently, implantation of patient-specific cranial prostheses requires reoperation after a period for design and formulation by a third-party manufacturer. Recently, 3-dimensional (3D) printing via fused deposition modeling has demonstrated increased ease of use, rapid production time, and significantly reduced costs, enabling expanded potential for surgical application. Three-dimensional printing may allow neurosurgeons to remove bone, perform a rapid intraoperative scan of the opening, and 3D print custom cranioplastic prostheses during the remainder of the procedure. OBJECTIVE To evaluate the feasibility of using a commercially available 3D printer to develop and produce on-demand intraoperative patient-specific cranioplastic prostheses in real time and assess the associated costs, fabrication time, and technical difficulty. METHODS Five different craniectomies were each fashioned on 3 cadaveric specimens (6 sides) to sample regions with varying topography, size, thickness, curvature, and complexity. Computed tomography-based cranioplastic implants were designed, formulated, and implanted. Accuracy of development and fabrication, as well as implantation ability and fit, integration with exiting fixation devices, and incorporation of integrated seamless fixation plates were qualitatively evaluated. RESULTS All cranioprostheses were successfully designed and printed. Average time for design, from importation of scan data to initiation of printing, was 14.6 min and average print time for all cranioprostheses was 108.6 min. CONCLUSION On-demand 3D printing of cranial prostheses is a simple, feasible, inexpensive, and rapid solution that may help improve cosmetic outcomes; significantly reduce production time and cost—expanding availability; eliminate the need for reoperation in select cases, reducing morbidity; and has the potential to decrease perioperative complications including infection and resorption.

scholarly journals From print to patient: 3D-printed personalized nerve regeneration

2016 ◽  
Vol 38 (4) ◽  
pp. 28-31 ◽  
Author(s):  
Blake N. Johnson ◽  
Michael C. McAlpine
Keyword(s):  
3D Printing ◽  
Point Of Care ◽  
Implantable Devices ◽  
Patient Specific ◽  
Biological Design ◽  
Surgical Methods ◽  
Biological Discovery ◽  
3D Printed ◽  
Multiple Materials ◽  
Scientific Standards

3D printing is revolutionizing regenerative medicine and accelerating the pace of biological discovery via its ability to interweave materials and components of disparate properties, guided by anatomical digital templates. These capabilities have led to a breakthrough in the customization and personalization of complex biological systems and devices ranging from platform technologies such as organs-on-a-chip, to implantable devices, such as patient-specific scaffolds. Yet, understanding and regenerating the nervous system has historically provided a challenging benchmark for drug therapy, surgical methods and bioengineering strategies. The question we pose is can: 3D printing be utilized to address these scientific standards? In principle, extrusion-based 3D printing should offer the ability to flexibly interweave multiple materials, over various length scales, while incorporating diverse functionalities. This may allow the ability to expand biological design paradigms and develop them into novel personalized device architectures. Indeed, 3D printing appears poised to offer an exciting future in the realization of personalized anatomical nerve pathways and platforms for point-of-care opportunities from print to patient.

scholarly journals The quest to 3D print body parts

2016 ◽  
Vol 38 (4) ◽  
pp. 24-27 ◽  
Author(s):  
Anthony Atala ◽  
Karen Richardson
Keyword(s):  
3D Printing ◽  
Reconstructive Surgery ◽  
Patient Specific ◽  
Body Parts ◽  
3D Print ◽  
Prosthetic Limbs ◽  
3D Printed

From engineering and manufacturing to art and education, 3D printing is helping to drive innovation in many different fields. Medicine is no exception. The technology is being used to print prosthetic limbs and to fabricate patient-specific models of body parts for surgeons to use as guides during reconstructive surgery. A 3D printed titanium jawbone has been implanted in a patient, as has a tailormade, bioresorbable tracheal splint that saved a baby's life.

scholarly journals In-Hospital 3D Printed Scaphoid Prosthesis Using Medical-Grade Polyetheretherketone (PEEK) Biomaterial

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Philipp Honigmann ◽  
Neha Sharma ◽  
Ralf Schumacher ◽  
Jasmine Rueegg ◽  
Mathias Haefeli ◽  
...  
Keyword(s):  
3D Printing ◽  
Point Of Care ◽  
Low Cost ◽  
Three Dimensional ◽  
Patient Specific ◽  
Fused Filament Fabrication ◽  
Patient Specific Implants ◽  
Surgical Guides ◽  
3D Printed ◽  
Medical Grade

Recently, three-dimensional (3D) printing has become increasingly popular in the medical sector for the production of anatomical biomodels, surgical guides, and prosthetics. With the availability of low-cost desktop 3D printers and affordable materials, the in-house or point-of-care manufacturing of biomodels and Class II medical devices has gained considerable attention in personalized medicine. Another projected development in medical 3D printing for personalized treatment is the in-house production of patient-specific implants (PSIs) for partial and total bone replacements made of medical-grade material such as polyetheretherketone (PEEK). We present the first in-hospital 3D printed scaphoid prosthesis using medical-grade PEEK with fused filament fabrication (FFF) 3D printing technology.

scholarly journals Point-of-Care 3D Printing: a Low-Cost Approach to Teaching Carotid Artery Stenting

2021 ◽  
Author(s):  
Pieter De Backer ◽  
Charlotte Allaeys ◽  
Charlotte Debbaut ◽  
Roel Beelen
Keyword(s):  
3D Printing ◽  
Carotid Artery ◽  
Carotid Artery Stenting ◽  
3D Model ◽  
Point Of Care ◽  
Low Cost ◽  
Patient Specific ◽  
Stent Deployment ◽  
Invasive Approach ◽  
Minimal Invasive Approach

Abstract Background Carotid Artery Stenting (CAS) is increasingly being used in selected patients as a minimal invasive approach to carotid endarterectomy. Despite the abundance of performed endovascular treatments, the concept of stent-placement is still unclear to many patients. Furthermore, visual feedback on stent-deployment is difficult to obtain as it is always performed under radiographic feedback. Three-Dimensional (3D) printing might tackle both challenges. A particular use case of Point-of-Care 3D Printing is the pretreatment printing of vascular anatomy in support of endovascular procedures. Purpose This study reports the first use of a low-cost patient-specific 3D printed model for CAS education to both experienced surgeons and patients. Methodology An angio computed tomography (CT) scan was segmented and converted to STL format using Mimics inPrint™ software. The carotid arteries were bilaterally truncated to fit the whole model on a Formlabs 2 printer without omitting the internal vessel diameter. Next, this model was offset using a 1 mm margin. A ridge was modelled on the original vessel anatomy which was subsequently subtracted from the offset model in order to obtain a deroofed 3D model. All vessels were truncated as to facilitate flow on the inside. Results Date-expired carotid artery stents were successfully deployed inside the vessel. The deroofing allows for clear visualization of the bottlenecks and characteristics of CAS deployment and positioning, including foreshortening and tapering of the stent. This low-cost 3D model provides insights in stent deployment and positioning, and allows for patient-specific procedure planning. Conclusion Printing patient-specific 3D models preoperatively could assist in accurate patient selection, a better preoperative planning and case-specific training. Furthermore, this 3D model also allows for better patient education and informed consent. However, more research is warranted to evaluate the added value of these models.

Design of a Patient Specific, 3D printed Arm Cast

2017 ◽  
Vol 2 (2) ◽  
pp. 135 ◽  
Author(s):  
Angus P Fitzpatrick
Keyword(s):  
3D Printing ◽  
Critical Parameters ◽  
Patient Specific ◽  
Water Repellent ◽  
Layer By Layer ◽  
Imaging Data ◽  
Manufacturing Technique ◽  
3D Printed ◽  
User Centric ◽  
Product Realization

<p>3D printing is a manufacturing technique by which the material is added layer by layer to create a physical three-dimensional object. This manufacturing technique had primarily found uses in academic and commercial sectors for prototyping and product realization purposes. However, more recently the home consumer market has seen a surge in low cost printers bringing this capability to the masses. More recently 3D printing has seen considerable interest from the clinical sector, where alongside the synergistic use with medical imaging data, a whole generation of patient specific implantable technologies, splints/casts and resection guides can be created. Predominantly, clinical applications have focused on the use of 3D printing for bone replacement, however with the advent of more sophisticated multi-material printers, interest has now begun to move to applications in orthotics and orthopedic casting.</p><p>This study is to review and evaluate the feasibility of designing and realizing a more patient specific orthopedic cast to surpass current limitation with traditional fiberglass/plaster casts, through the use of advanced 3D modelling and printing techniques. To directly compare the efficacy of the traditional and 3D printed casts, we shall investigate critical parameters such as the time for manufacture, the overall weight of the final product, the accuracy off the cast relative to the patient’s unique anatomy and additional user-centric metrics (comfort, aesthetics, etc.). The design examined made use of advanced mesh structures throughout the bulk of the cast, such that the device would require less material (by weight) during fabrication, could allow for tunable weight and mechanical properties and allow for air penetration to the person skin, thereby reducing discomfort due to prolonged moisture exposure (chaffing, bad smells, etc.). As the primary focus of this study is the design and product realization phases and we shall not assess metrics relating to patient recover time or experience.</p><p>Overall it was found that the 3D printed cast was significantly lighter, with improved water repellent and air circulation properties, as compared to a traditional cast. Through the use of high precision design/manufacturing techniques, the final device could be accurately reproduced to match the test patient’s unique anatomy, thereby optimizing the orientation of the patient’s bones during post fracture recovery. It was however found that the manufacturing time for the 3D printed cast was slower than traditional casting methods owing to the additional time during the design phase. In future work we aim to address this limitation and to devise a streamlined methodology such that a generic cast design can be adapted to patient specific anatomical data through parametric design algorithms.</p><p>Ultimately, it was found that through the use of advanced design techniques, patient specific data and 3D printing, a custom orthopedic cast could be realized and with significant potential to augment current use of this technology for surgical intervention and improve patient outcomes. The use of advanced manufacturing in the medical field will likely enable more patient specific/user-centric treatment in the near future.</p>

scholarly journals Quantitative Assessment of Point-of-Care 3D-Printed Patient-Specific Polyetheretherketone (PEEK) Cranial Implants

2021 ◽  
Vol 22 (16) ◽  
pp. 8521
Author(s):  
Neha Sharma ◽  
Soheila Aghlmandi ◽  
Federico Dalcanale ◽  
Daniel Seiler ◽  
Hans-Florian Zeilhofer ◽  
...  
Keyword(s):  
3D Printing ◽  
Quantitative Assessment ◽  
Point Of Care ◽  
Peak Load ◽  
Dimensional Accuracy ◽  
Patient Specific ◽  
Study Results ◽  
3D Printed ◽  
Cranial Implants ◽  
Accuracy And Repeatability

Recent advancements in medical imaging, virtual surgical planning (VSP), and three-dimensional (3D) printing have potentially changed how today’s craniomaxillofacial surgeons use patient information for customized treatments. Over the years, polyetheretherketone (PEEK) has emerged as the biomaterial of choice to reconstruct craniofacial defects. With advancements in additive manufacturing (AM) systems, prospects for the point-of-care (POC) 3D printing of PEEK patient-specific implants (PSIs) have emerged. Consequently, investigating the clinical reliability of POC-manufactured PEEK implants has become a necessary endeavor. Therefore, this paper aims to provide a quantitative assessment of POC-manufactured, 3D-printed PEEK PSIs for cranial reconstruction through characterization of the geometrical, morphological, and biomechanical aspects of the in-hospital 3D-printed PEEK cranial implants. The study results revealed that the printed customized cranial implants had high dimensional accuracy and repeatability, displaying clinically acceptable morphologic similarity concerning fit and contours continuity. From a biomechanical standpoint, it was noticed that the tested implants had variable peak load values with discrete fracture patterns and failed at a mean (SD) peak load of 798.38 ± 211.45 N. In conclusion, the results of this preclinical study are in line with cranial implant expectations; however, specific attributes have scope for further improvements.

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