Next-generation biomedical implants using additive manufacturing of complex, cellular and functional mesh arrays

2010 ◽  
Vol 368 (1917) ◽  
pp. 1999-2032 ◽  
Author(s):  
L. E. Murr ◽  
S. M. Gaytan ◽  
F. Medina ◽  
H. Lopez ◽  
E. Martinez ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Bone Ingrowth ◽  
Solidification Rate ◽  
Functionally Graded ◽  
Patient Specific ◽  
Biomedical Implants ◽  
Design Elements ◽  
Software Models ◽  
Hip Stems

In this paper, we examine prospects for the manufacture of patient-specific biomedical implants replacing hard tissues (bone), particularly knee and hip stems and large bone (femoral) intramedullary rods, using additive manufacturing (AM) by electron beam melting (EBM). Of particular interest is the fabrication of complex functional (biocompatible) mesh arrays. Mesh elements or unit cells can be divided into different regions in order to use different cell designs in different areas of the component to produce various or continually varying (functionally graded) mesh densities. Numerous design elements have been used to fabricate prototypes by AM using EBM of Ti-6Al-4V powders, where the densities have been compared with the elastic (Young) moduli determined by resonant frequency and damping analysis. Density optimization at the bone–implant interface can allow for bone ingrowth and cementless implant components. Computerized tomography (CT) scans of metal (aluminium alloy) foam have also allowed for the building of Ti-6Al-4V foams by embedding the digital-layered scans in computer-aided design or software models for EBM. Variations in mesh complexity and especially strut (or truss) dimensions alter the cooling and solidification rate, which alters the α -phase (hexagonal close-packed) microstructure by creating mixtures of α / α ′ (martensite) observed by optical and electron metallography. Microindentation hardness measurements are characteristic of these microstructures and microstructure mixtures ( α / α ′) and sizes.

scholarly journals Main Clinical Use of Additive Manufacturing (Three-Dimensional Printing) in Finland Restricted to the Head and Neck Area in 2016–2017

2019 ◽  
Vol 109 (2) ◽  
pp. 166-173 ◽  
Author(s):  
A.B.V. Pettersson ◽  
M. Salmi ◽  
P. Vallittu ◽  
W. Serlo ◽  
J. Tuomi ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Patient Specific ◽  
Future Research ◽  
Imaging Data ◽  
University Hospitals ◽  
Three Dimensional Printing ◽  
Dimensional Printing ◽  
Head Area

Background and Aims: Additive manufacturing or three-dimensional printing is a novel production methodology for producing patient-specific models, medical aids, tools, and implants. However, the clinical impact of this technology is unknown. In this study, we sought to characterize the clinical adoption of medical additive manufacturing in Finland in 2016–2017. We focused on non-dental usage at university hospitals. Materials and Methods: A questionnaire containing five questions was sent by email to all operative, radiologic, and oncologic departments of all university hospitals in Finland. Respondents who reported extensive use of medical additive manufacturing were contacted with additional, personalized questions. Results: Of the 115 questionnaires sent, 58 received answers. Of the responders, 41% identified as non-users, including all general/gastrointestinal (GI) and vascular surgeons, urologists, and gynecologists; 23% identified as experimenters or previous users; and 36% identified as heavy users. Usage was concentrated around the head area by various specialties (neurosurgical, craniomaxillofacial, ear, nose and throat diseases (ENT), plastic surgery). Applications included repair of cranial vault defects and malformations, surgical oncology, trauma, and cleft palate reconstruction. Some routine usage was also reported in orthopedics. In addition to these patient-specific uses, we identified several off-the-shelf medical components that were produced by additive manufacturing, while some important patient-specific components were produced by traditional methodologies such as milling. Conclusion: During 2016–2017, medical additive manufacturing in Finland was routinely used at university hospitals for several applications in the head area. Outside of this area, usage was much less common. Future research should include all patient-specific products created by a computer-aided design/manufacture workflow from imaging data, instead of concentrating on the production methodology.

Shape Accuracy and Surface Quality of Additively Manufactured, Optimized, Patient-Specific Bone Plates

2020 ◽  
Vol 15 (2) ◽  
Author(s):  
Michael Seebach ◽  
Christian Fritz ◽  
Johanna Kerschreiter ◽  
Michael Friedrich Zaeh
Keyword(s):  
Additive Manufacturing ◽  
Surface Quality ◽  
Bone Ingrowth ◽  
Medical Application ◽  
Bone Plates ◽  
Patient Specific ◽  
Shape Accuracy ◽  
Quality Requirements ◽  
Medical Quality ◽  
Manufacturing Technologies

Abstract Powder-based additive manufacturing technologies such as powder bed fusion (PBF) using a laser beam (PBF-LB) and PBF using an electron beam (PBF-EB) allow the manufacturing of complex, patient-specific implants from titanium alloys at appropriate manufacturing expenses and thus production cost. To meet medical quality requirements, mechanical post-treatment (e.g., grinding and polishing) is often required. However, different medical applications require specific quality characteristics. It is therefore necessary to assess the fulfillment of the requirements for each case individually with regard to the manufacturing technologies. This study investigated the potential of the two mentioned additive manufacturing technologies for manufacturing patient-specific, topology-optimized bone plates that are used for osteosynthesis (the joining of bone segments) in the reconstruction of the mandible (lower jaw). Identical individualized implants were manufactured and subsequently treated with established industrial processes and examined according to medical quality requirements. Crucial quality requirements for this medical application are the shape accuracy (for exact bone positioning and even load transmission) as well as the surface quality (to enhance fatigue strength and prevent bone ingrowth in view of the subsequent easy removal of the plates). The machining of the implants is shown in comparison to distinguish the two manufacturing processes from established procedures.

scholarly journals Evolution of design considerations in complex craniofacial reconstruction using patient-specific implants

2016 ◽  
Vol 231 (6) ◽  
pp. 509-524 ◽  
Author(s):  
Sean Peel ◽  
Satyajeet Bhatia ◽  
Dominic Eggbeer ◽  
Daniel S Morris ◽  
Caroline Hayhurst
Keyword(s):  
Additive Manufacturing ◽  
Case Studies ◽  
Computer Aided Design ◽  
Titanium Implants ◽  
Patient Specific ◽  
Patient Case ◽  
Computer Aided Manufacturing ◽  
Design Considerations ◽  
Computer Aided ◽  
Aided Design

Previously published evidence has established major clinical benefits from using computer-aided design, computer-aided manufacturing, and additive manufacturing to produce patient-specific devices. These include cutting guides, drilling guides, positioning guides, and implants. However, custom devices produced using these methods are still not in routine use, particularly by the UK National Health Service. Oft-cited reasons for this slow uptake include the following: a higher up-front cost than conventionally fabricated devices, material-choice uncertainty, and a lack of long-term follow-up due to their relatively recent introduction. This article identifies a further gap in current knowledge – that of design rules, or key specification considerations for complex computer-aided design/computer-aided manufacturing/additive manufacturing devices. This research begins to address the gap by combining a detailed review of the literature with first-hand experience of interdisciplinary collaboration on five craniofacial patient case studies. In each patient case, bony lesions in the orbito-temporal region were segmented, excised, and reconstructed in the virtual environment. Three cases translated these digital plans into theatre via polymer surgical guides. Four cases utilised additive manufacturing to fabricate titanium implants. One implant was machined from polyether ether ketone. From the literature, articles with relevant abstracts were analysed to extract design considerations. In all, 19 frequently recurring design considerations were extracted from previous publications. Nine new design considerations were extracted from the case studies – on the basis of subjective clinical evaluation. These were synthesised to produce a design considerations framework to assist clinicians with prescribing and design engineers with modelling. Promising avenues for further research are proposed.

scholarly journals Additively manufactured versus conventionally pressed cranioplasty implants: An accuracy comparison

2018 ◽  
Vol 232 (9) ◽  
pp. 949-961 ◽  
Author(s):  
Sean Peel ◽  
Dominic Eggbeer ◽  
Hanna Burton ◽  
Hayley Hanson ◽  
Peter L Evans
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Best Practice ◽  
Patient Specific ◽  
Computer Aided ◽  
Design Software ◽  
Uk National Health Service ◽  
Similar Accuracy ◽  
The Uk ◽  
Aided Design

This article compared the accuracy of producing patient-specific cranioplasty implants using four different approaches. Benchmark geometry was designed to represent a cranium and a defect added simulating a craniectomy. An ‘ideal’ contour reconstruction was calculated and compared against reconstructions resulting from the four approaches –‘conventional’, ‘semi-digital’, ‘digital – non-automated’ and ‘digital – semi-automated’. The ‘conventional’ approach relied on hand carving a reconstruction, turning this into a press tool, and pressing titanium sheet. This approach is common in the UK National Health Service. The ‘semi-digital’ approach removed the hand-carving element. Both of the ‘digital’ approaches utilised additive manufacturing to produce the end-use implant. The geometries were designed using a non-specialised computer-aided design software and a semi-automated cranioplasty implant-specific computer-aided design software. It was found that all plates were clinically acceptable and that the digitally designed and additive manufacturing plates were as accurate as the conventional implants. There were no significant differences between the additive manufacturing plates designed using non-specialised computer-aided design software and those designed using the semi-automated tool. The semi-automated software and additive manufacturing production process were capable of producing cranioplasty implants of similar accuracy to multi-purpose software and additive manufacturing, and both were more accurate than handmade implants. The difference was not of clinical significance, demonstrating that the accuracy of additive manufacturing cranioplasty implants meets current best practice.

An Investigation Into the Challenges of Using Metal Additive Manufacturing for the Production of Patient-Specific Aneurysm Clips

2019 ◽  
Vol 13 (3) ◽  
Author(s):  
Brandon J. Walker ◽  
Benjamin L. Cox ◽  
Ulas Cikla ◽  
Gabriel Meric de Bellefon ◽  
Behzad Rankouhi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Surgical Complication ◽  
Vascular Anatomy ◽  
Patient Specific ◽  
Biomedical Implants ◽  
Metal Additive Manufacturing ◽  
316 L Stainless Steel ◽  
Material Choice ◽  
Metal Additive

Cerebral aneurysm clips are biomedical implants applied by neurosurgeons to re-approximate arterial vessel walls and prevent catastrophic aneurysmal hemorrhages in patients. Current methods of aneurysm clip production are labor intensive and time-consuming, leading to high costs per implant and limited variability in clip morphology. Metal additive manufacturing is investigated as an alternative to traditional manufacturing methods that may enable production of patient-specific aneurysm clips to account for variations in individual vascular anatomy and possibly reduce surgical complication risks. Relevant challenges to metal additive manufacturing are investigated for biomedical implants, including material choice, design limitations, postprocessing, printed material properties, and combined production methods. Initial experiments with additive manufacturing of 316 L stainless steel aneurysm clips are carried out on a selective laser melting (SLM) system. The dimensions of the printed clips were found to be within 0.5% of the dimensions of the designed clips. Hardness and density of the printed clips (213 ± 7 HV1 and 7.9 g/cc, respectively) were very close to reported values for 316 L stainless steel, as expected. No ferrite and minimal porosity is observed in a cross section of a printed clip, with some anisotropy in the grain orientation. A clamping force of approximately 1 N is measured with a clip separation of 1.5 mm. Metal additive manufacturing shows promise for use in the creation of custom aneurysm clips, but some of the challenges discussed will need to be addressed before clinical use is possible.

Laser Metal Deposition Process

3D Printing ◽  
2017 ◽  
pp. 172-182 ◽  
Author(s):  
Rasheedat M. Mahamood
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Experimental Studies ◽  
Deposition Process ◽  
Metal Deposition ◽  
Functionally Graded ◽  
Laser Metal Deposition ◽  
Graded Material ◽  
Directed Energy

Laser metal deposition process belongs to the directed energy deposition class of additive manufacturing process that is capable of producing highly complex part directly from the three dimensional (3D) computer aided design file of the component by adding materials layer after layers. Laser metal deposition process is a very important additive manufacturing process and it is the only class of additive manufacturing process that can be used to repair valued component parts which were not repairable in the past. Also because this additive manufacturing process can handle multiple materials simultaneously, it is used to produce part with functionally graded material. Some of the features of the laser metal deposition process are described in this chapter. Some experimental studies on the laser metal deposition of Titanium alloy- composite are also presented.

Laser Metal Deposition Process

2016 ◽  
pp. 46-59 ◽  
Author(s):  
Rasheedat M. Mahamood
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Experimental Studies ◽  
Deposition Process ◽  
Metal Deposition ◽  
Functionally Graded ◽  
Laser Metal Deposition ◽  
Graded Material ◽  
Directed Energy

Laser metal deposition process belongs to the directed energy deposition class of additive manufacturing process that is capable of producing highly complex part directly from the three dimensional (3D) computer aided design file of the component by adding materials layer after layers. Laser metal deposition process is a very important additive manufacturing process and it is the only class of additive manufacturing process that can be used to repair valued component parts which were not repairable in the past. Also because this additive manufacturing process can handle multiple materials simultaneously, it is used to produce part with functionally graded material. Some of the features of the laser metal deposition process are described in this chapter. Some experimental studies on the laser metal deposition of Titanium alloy- composite are also presented.

scholarly journals A comparative assessment of two designs of hip stem using rule-based simulation of combined osseointegration and remodelling

2019 ◽  
Vol 234 (1) ◽  
pp. 118-128 ◽  
Author(s):  
Souptick Chanda ◽  
Kaushik Mukherjee ◽  
Sanjay Gupta ◽  
Dilip Kumar Pratihar
Keyword(s):  
Bone Remodelling ◽  
Bone Ingrowth ◽  
Stress Shielding ◽  
Patient Specific ◽  
Rule Based ◽  
Trade Off ◽  
Adaptive Process ◽  
Optimization Study ◽  
Hip Stems

The stem–bone interface of cementless total hip arthroplasty undergoes an adaptive process of bone ingrowth until the two parts become osseointegrated. Another important phenomenon associated with aseptic loosening of hip stem is stress-shielding induced adverse bone remodelling. The objective of this study was to preclinically assess the relative performances of two distinct designs of hip stems by addressing the combined effect of bone remodelling and osseointegration, based on certain rule-based criteria obtained from the literature. Premised upon non-linear finite element analyses of patient-specific implanted femur models, the study attempts to ascertain in silico outcome of the hip stem designs based on an evolutionary interfacial condition, and to further comment on the efficacy of the rule-based technique on the prediction of peri-prosthetic osseointegration. One of the two hip stem models was a trade-off design obtained from an earlier shape optimization study, and the other was based on TriLock stem (DePuy). Both designs predicted similar long-term osseointegration (∼89% surface), although trade-off stem predicted higher post-operative osseointegration. Proximal bone resorption was found higher for TriLock (by ∼110%) as compared to trade-off model. The rule-based technique predicted clinically coherent osseointegration around both stems and appears to be an alternative to expensive mechanobiology-based schemes.

Indirect Additive Manufacturing (AM) of Apatite-Wollastonite (A-W) Glass-Ceramic for Medical Implants

2015 ◽  
Vol 786 ◽  
pp. 354-360 ◽  
Author(s):  
S.F. Khan ◽  
Kenneth W. Dalgarno ◽  
Rakhmad Arief Siregar
Keyword(s):  
Additive Manufacturing ◽  
Glass Ceramic ◽  
Computer Aided Design ◽  
Initial Study ◽  
Patient Specific ◽  
Congenital Defects ◽  
Geometrical Shape ◽  
Medical Implants ◽  
Stl File ◽  
Patient Specific Implants

Bone replacements for congenital defects, cancer resections, and traumas are typically performed using bone grafting. However, due to scarcity of the source material, synthetic materials for bone replacements are sometimes used instead. Unfortunately, the ability to engineer anatomically correct pieces of viable and functional human bone are difficult and time-consuming through conventional manufacturing methods. This paper proposes an alternative route which incorporates the use of AM technology for fabricating patient-specific implants. The implants were computer-aided design (CAD) from a stereolithography (STL) file of a mandible. AM method was combined with lost wax casting (LWC) technology to produce the customised A-W glass-ceramic implants. An initial study of sintered A-W was performed on cylindrical samples show on average 19.8% porous with on average 75% of the porosity being open and an average flexural strength of 82.6 MPa. The A-W scaffolds display a degree of macro-and micro porosity. The geometrical shape of the A-W implants shows a close resemblance to the required implant. Additive manufacturing assisted fabrication of A-W glass-ceramic provides a promising method for manufacturing customised medical implants.

Numerical Analysis of the VAD Outflow Cannula Positioning on the Blood Flow in the Patient–Specific Brain Supplying Arteries

2020 ◽  
Vol 22 (2) ◽  
pp. 619-636 ◽  
Author(s):  
Zbigniew Tyfa ◽  
Damian Obidowski ◽  
Krzysztof Jóźwik
Keyword(s):  
Blood Flow ◽  
Computer Aided Design ◽  
Volume Flow Rate ◽  
Flow Distribution ◽  
Primary Objective ◽  
Patient Specific ◽  
Blood Flow Distribution ◽  
Reconstruction Process ◽  
Outflow Cannula ◽  
The Brain

AbstractThe primary objective of this research can be divided into two separate aspects. The first one was to verify whether own software can be treated as a viable source of data for the Computer Aided Design (CAD) modelling and Computational Fluid Dynamics CFD analysis. The second aspect was to analyze the influence of the Ventricle Assist Device (VAD) outflow cannula positioning on the blood flow distribution in the brain-supplying arteries. Patient-specific model was reconstructed basing on the DICOM image sets obtained with the angiographic Computed Tomography. The reconstruction process was performed in the custom-created software, whereas the outflow cannulas were added in the SolidWorks software. Volumetric meshes were generated in the Ansys Mesher module. The transient boundary conditions enabled simulating several full cardiac cycles. Performed investigations focused mainly on volume flow rate, shear stress and velocity distribution. It was proven that custom-created software enhances the processes of the anatomical objects reconstruction. Developed geometrical files are compatible with CAD and CFD software – they can be easily manipulated and modified. Concerning the numerical simulations, several cases with varied positioning of the VAD outflow cannula were analyzed. Obtained results revealed that the location of the VAD outflow cannula has a slight impact on the blood flow distribution among the brain supplying arteries.

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