Three-Dimensional Printing of Archived Human Fetal Material for Teaching Purposes

3D printing as a pedagogical tool for teaching normal human anatomy: a systematic review

BACKGROUND

Three-dimensional-printed anatomical models (3DPAMs) appear to be a relevant tool due to their educational value and their feasibility. The objectives of this review were to describe and analyse the methods utilised for creating 3DPAMs used in teaching human anatomy and for evaluating its pedagogical contribution.

METHODS

An electronic search was conducted on PubMed using the following terms: education, school, learning, teaching, learn, teach, educational, three-dimensional, 3D, 3-dimensional, printing, printed, print, anatomy, anatomical, anatomically, and anatomic. Data retrieved included study characteristics, model design, morphological evaluation, educational performance, advantages, and disadvantages.

RESULTS

Of the 68 articles selected, the cephalic region was the most studied (33 articles); 51 articles mentioned bone printing. In 47 articles, the 3DPAM was designed from CT scans. Five printing processes were listed. Plastic and its derivatives were used in 48 studies. The cost per design ranged from 1.25 USD to 2800 USD. Thirty-seven studies compared 3DPAM to a reference model. Thirty-three articles investigated educational performance. The main advantages were visual and haptic qualities, effectiveness for teaching, reproducibility, customizability and manipulability, time savings, integration of functional anatomy, better mental rotation ability, knowledge retention, and educator/student satisfaction. The main disadvantages were related to the design: consistency, lack of detail or transparency, overly bright colours, long printing time, and high cost.

CONCLUSION

This systematic review demonstrates that 3DPAMs are feasible at a low cost and effective for teaching anatomy. More realistic models require access to more expensive 3D printing technologies and substantially longer design time, which would greatly increase the overall cost. Choosing an appropriate image acquisition modality is key. From a pedagogical viewpoint, 3DPAMs are effective tools for teaching anatomy, positively impacting the learning outcomes and satisfaction level. The pedagogical effectiveness of 3DPAMs seems to be best when they reproduce complex anatomical areas, and they are used by students early in their medical studies.

In jars: The integration of historical anatomical and pathological potted specimens in undergraduate education

INTRODUCTION

Across the UK, many anatomy departments possess historical potted wet cadaveric specimen collections, such as organs preserved in fluid-filled jars. Although considered obsolete by some for anatomical education, there is immense potential for their utilisation in teaching, particularly in institutes that have limited access to cadavers or have had body donation rates impacted by the Covid-19 pandemic. Another benefit of historical potted cadaveric specimens is that severe pathology, often not seen today, can be observed by the student.

MATERIAL AND METHODS

The aim of this study was to understand students' opinions and attitudes towards the use of historical anatomical and pathological potted wet specimen collections in undergraduate science teaching. Following their integration into the anatomy program of a Clinical Sciences degree, seventy-seven undergraduate students completed a five-point Likert questionnaire on their perspective for the integration of the historical potted specimens in anatomical education. This study was approved by the Research Ethics committee at the University of Bradford RESULTS: The study demonstrated that 90 % of students found the collection useful in teaching, 92 % would like to see the collection used more in teaching, and 76 % of students found that the collection encouraged them to consider medical ethics and the donor.

CONCLUSIONS

In conclusion, the survey findings suggest that further utilisation of historical potted wet specimen collections would be useful in the teaching of anatomy and that these collections could potentially encourage conversations on post-mortem bodily integrity, ethics, and organ donation.

The Third Dimension: 3D Printed Replicas and Other Alternatives to Cadaver-Based Learning

Capturing the 'third dimension' of complex human form or anatomy has been an objective of artists and anatomists from the renaissance in the fifteenth and sixteenth centuries onwards. Many of these drawings, paintings, and sculptures have had a profound influence on medical teaching and the learning resources we took for granted until around 40 years ago. Since then, the teaching of human anatomy has undergone significant change, especially in respect of the technologies available to augment or replace traditional cadaver-based dissection instruction. Whilst resources such as atlases, wall charts, plastic models, and images from the Internet have been around for many decades, institutions looking to reduce the reliance on dissection-based teaching in medical or health professional training programmes have in more recent times increasingly had access to a range of other options for classroom-based instruction. These include digital resources and software programmes and plastinated specimens, although the latter come with a range of ethical and cost considerations. However, the urge to recapitulate the 'third dimension' of anatomy has seen the recent advent of novel resources in the form of 3D printed replicas. These 3D printed replicas of normal human anatomy dissections are based on a combination of radiographic imaging and surface scanning that captures critical 3D anatomical information. The final 3D files can either be augmented with false colour or made to closely resemble traditional prosections prior to printing. This chapter details the journey we and others have taken in the search for the 'third dimension'. The future of a haptically identical, anatomically accurate replica of human cadaver specimens for surgical and medical training is nearly upon us. Indeed, the need for hard copy replicas may eventually be superseded by the opportunities afforded by virtual reality (VR) and augmented reality (AR).

Toward Emulating Human Movement: Adopting a Data-Driven Bitmap-Based "Voxel" Multimaterial Workflow to Create a Flexible 3D Printed Neonatal Lower Limb

It is increasingly common to produce physical anatomical medical models using high-fidelity multiproperty 3D printing to assist doctor-patient communication, presurgical planning, and surgical simulation. Currently, most medical models are created using image thresholding and traditional mesh-based segmentation techniques to produce mono-material boundaries (STL file formats) of anatomical features. Existing medical modeling manufacturing methods restrict shape specification to one material or density, which result in anatomically simple 3D printed medical models with no gradated material qualities. Currently, available high-resolution functionally graded multimaterial 3D printed medical models are rigid and do not represent biomechanical movement. To bypass the identified limitations of current 3D printing medical modeling workflows, we present a bitmap-based "voxel" multimaterial additive manufacturing workflow for the production of highly realistic and flexible anatomical models of the neonatal lower limb using computed tomographic ("CT") data. By interpolating and re-slicing a biomedical volumetric data set at the native 3D printer z resolution of 27 μm and using CT scan attenuation properties (Hounsfield units) to guide material mixing ratios, producing highly realistic models of the neonatal lower limb at a significantly faster rate than other manufacturing methods. The presented medical modeling workflow has considerable potential to improve medical modeling manufacturing methods by translating medical data directly into 3D printing files aiding in anatomical education and surgical simulation practices, especially in neonatal research and clinical training.

Feasibility Analysis of 3D Printing With Prenatal Ultrasound for the Diagnosis of Fetal Abnormalities

OBJECTIVE

To assess the feasibility and accuracy of 3D printing with prenatal three-dimensional ultrasound (3DUS) in the diagnosis of fetal abnormalities.

METHODS

Fetuses initially diagnosed with various abnormalities were included in this retrospective study. The fetuses were examined by 3DUS, modeled, and 3D printed, and the dimensional accuracy of the 3D prints was analyzed. The effectiveness, demand, necessity of 3D printing, and the diagnostic accuracy of different methods were analyzed based on questionnaire responses from 40 senior ultrasound doctors and 40 postgraduate students.

RESULTS

A total of 12 fetuses with cleft lip and palate, spinal, heart, or brain abnormalities were included for detailed assessment. All deviations (mean deviation: 0.1 mm) between the original images and the final 3D prints lay within the consistency boundary (-1.12, 1.31 mm) (P > .05). In the subsequent analyses, 90.8% of the doctors and 94.2% of the students strongly agreed that 3D printing could precisely represent and depict fetal abnormalities. The average misdiagnosis rate of the doctors decreased from 5% to 0.4% after the application of 3D printing combined with 3DUS in comparison with 3DUS alone, and the corresponding value for the students dropped from 17.9% to 5.2%.

CONCLUSIONS

The errors in modeling and 3D printing based on 3DUS were within acceptable limits, and 3D printing improved the diagnosis of various fetal abnormalities.

E-Learning Three-Dimensional Anatomy of the Brainstem: Impact of Different Microscopy Techniques and Spatial Ability

Polarized light imaging (PLI) is a new method which quantifies and visualizes nerve fiber direction. In this study, the educational value of PLI sections of the human brainstem were compared to histological sections stained with Luxol fast blue (LFB) using e-learning modules. Mental Rotations Test (MRT) was used to assess the spatial ability. Pre-intervention, post-intervention, and long-term (1 week) anatomical tests were provided to assess the baseline knowledge and retention. One-on-one electronic interviews after the last test were carried out to understand the students' perceptions of the intervention. Thirty-eight medical students, (19 female and 19 males, mean age 21.5 ± SD 2.4; median age: 21.0 years) participated with a mean MRT score of 13.2 ± 5.2 points and a mean pre-intervention knowledge test score of 49.9 ± 11.8%. A significant improvement in both, post-intervention and long-term test scores occurred after learning with either PLI or LFB e-learning module on brainstem anatomy (both P < 0.001). No difference was observed between groups in post-intervention test scores and long-term test scores (P = 0.913 and P = 0.403, respectively). A higher MRT-score was significantly correlated with a higher post-intervention test score (r_k  = 0.321; P < 0.05, respectively), but there was not a significant association between the MRT- and the long-term scores (r_k = -0.078; P = 0.509). Interviews (n = 10) revealed three major topics: Learning (brainstem) anatomy by use of e-learning modules; The "need" of technological background information when studying brainstem sections; and Mnemonics when studying brainstem anatomy. Future studies should assess the cognitive burden of cross-sectional learning methods with PLI and/or LFB sections and their effects on knowledge retention.

Development of a 3D Printed Lung Model Made of Synthetic Materials for Simulation

BACKGROUND

 Considering the complexity of lung structures and the difficulty of thoracoscopic surgery, simulation-based training is of paramount importance for junior surgeons. Here, we aim to design a high-fidelity lung model through utilizing the three-dimensional (3D) printing technology combined with synthetic materials to mimic the real human lung.

METHODS

 The 3D printed lung model was manufactured based on the computed tomography images of a randomly selected male patient. Synthetic materials were used for the construction of lung parenchyma, blood vessels, and bronchi. Then, the model was assessed in terms of its visual, tactile, and operational features by participants (the senior surgeons, junior surgeons, and medical students), who were asked to complete the specially designed survey-questionnaires.

RESULTS

 A 3D printed model of the right lung made of synthetic materials was successfully fabricated. Thirty subjects participated in our study (10 senior surgeons, 10 junior surgeons, and 10 medical students). The average visual evaluation scores for senior surgeons, junior surgeons, and medical students were 3.97 ± 0.61, 4.56 ± 0.58, 4.76 ± 0.49, respectively. The average tactile evaluation scores were 3.40 ± 0.50, 4.13 ± 0.68, 4.00 ± 0.64, respectively. The average operation evaluation scores were 3.33 ± 0.83, 3.93 ± 0.66, 4.03 ± 0.66, respectively. Significant lower scores were obtained in the group of the senior surgeons compared with the other two groups.

CONCLUSION

 A high level of fidelity was exhibited in our 3D printed lung model and it could be applied as a promising simulator for the surgical training in the future.

External surface anatomy of the postfolding human embryo: Computer-aided, three-dimensional reconstruction of printable digital specimens

Opportunities for clinicians, researchers, and medical students to become acquainted with the three‐dimensional (3D) anatomy of the human embryo have historically been limited. This work was aimed at creating a collection of digital, printable 3D surface models demonstrating major morphogenetic changes in the embryo's external anatomy, including typical features used for external staging. Twelve models were digitally reconstructed based on optical projection tomography, high‐resolution episcopic microscopy and magnetic resonance imaging datasets of formalin‐fixed specimens of embryos of developmental stages 12 through 23, that is, stages following longitudinal and transverse embryo folding. The reconstructed replica reproduced the external anatomy of the actual specimens in great detail, and the progress of development over stages was recognizable in a variety of external anatomical features and bodily structures, including the general layout and curvature of the body, the pharyngeal arches and cervical sinus, the physiological gut herniation, and external genitalia. In addition, surface anatomy features commonly used for embryo staging, such as distinct steps in the morphogenesis of facial primordia and limb buds, were also apparent. These digital replica, which are all provided for 3D visualization and printing, can serve as a novel resource for teaching and learning embryology and may contribute to a better appreciation of the human embryonic development.

Applications of 3D printed bone tissue engineering scaffolds in the stem cell field

Due to traffic accidents, injuries, burns, congenital malformations and other reasons, a large number of patients with tissue or organ defects need urgent treatment every year. The shortage of donors, graft rejection and other problems cause a deficient supply for organ and tissue replacement, repair and regeneration of patients, so regenerative medicine came into being. Stem cell therapy plays an important role in the field of regenerative medicine, but it is difficult to fill large tissue defects by injection alone. The scientists combine three-dimensional (3D) printed bone tissue engineering scaffolds with stem cells to achieve the desired effect. These scaffolds can mimic the extracellular matrix (ECM), bone and cartilage, and eventually form functional tissues or organs by providing structural support and promoting attachment, proliferation and differentiation. This paper mainly discussed the applications of 3D printed bone tissue engineering scaffolds in stem cell regenerative medicine. The application examples of different 3D printing technologies and different raw materials are introduced and compared. Then we discuss the superiority of 3D printing technology over traditional methods, put forward some problems and limitations, and look forward to the future.

The reproduction of human pathology specimens using three-dimensional (3D) printing technology for teaching purposes

The teaching of medical pathology has undergone significant change in the last 30-40 years, especially in the context of employing bottled specimens or 'pots' in classroom settings. The reduction in post-mortem based teaching in medical training programs has resulted in less focus being placed on the ability of students to describe the gross anatomical pathology of specimens. Financial considerations involved in employing staff to maintain bottled specimens, space constraints and concerns with health and safety of staff and student laboratories have meant that many institutions have decommissioned their pathology collections. This report details how full-colour surface scanning coupled with CT scanning and 3 D printing allows the digital archiving of gross pathological specimens and the production of reproductions or replicas of preserved human anatomical pathology specimens that obviates many of the above issues. With modern UV curable resin printing technology, it is possible to achieve photographic quality accurate replicas comparable to the original specimens in many aspects except haptic quality. Accurate 3 D reproductions of human pathology specimens offer many advantages over traditional bottled specimens including the capacity to generate multiple copies and their use in any educational setting giving access to a broader range of potential learners and users.

3D Printed Biomimetic Rabbit Airway Simulation Model for Nasotracheal Intubation Training

Rabbit inhalation anesthesia by endotracheal intubation involves a higher risk among small animals owing to several anatomical and physiological features, which is pathognomonic to this species of lagomorphs. Rabbit-specific airway devices have been designed to prevent misguided intubation attempts. However, it is believed that expert anesthetic training could be a boon in limiting the aftermaths of this procedure. Our research is aimed to develop a novel biomimetic 3D printed rabbit airway model with representative biomechanical material behavior and radiodensity. Imaging data were collected for two sacrificed rabbit heads using micro-computed tomography (μCT) and micro-magnetic resonance imaging for the first head and cone beam computed tomography (CBCT) for the second head. Imaging-based life-size musculoskeletal airway models were printed using polyjet technology with a combination of hard and soft materials in replicates of three. The models were evaluated quantitatively for dimensional accuracy and radiodensity and qualitatively using digital microscopy and endoscopy for technical, tactic, and visual realism. The results displayed that simulation models printed with polyjet technology have an overall surface representation of 93% for μCT-based images and 97% for CBCT-based images within a range of 0.0-2.5 mm, with μCT showing a more detailed reproduction of the nasotracheal anatomy. Dimensional discrepancies can be caused due to inadequate support material removal and due to the limited reconstruction of microstructures from the imaging on the 3D printed model. The model showed a significant difference in radiodensities in hard and soft tissue regions. Endoscopic evaluation provided good visual and tactile feedback, comparable to the real animal. Overall, the model, being a practical low-cost simulator, comprehensively accelerates the learning curve of veterinary nasotracheal intubation and paves the way for 3D simulation-based image-guided interventional procedures.

What Is the Role of 3D Printing in Undergraduate Anatomy Education? A Scoping Review of Current Literature and Recommendations

INTRODUCTION

Three-dimensional (3D)-printed models have become increasingly popular as an alternative to the traditional method of cadaveric dissection in teaching anatomy. It has the advantage of lower cost and higher reproducibility. It has been widely used in the postgraduate setting, but its efficacy in undergraduate education has not been studied extensively.

OBJECTIVES

A scoping review of the literature was undertaken systematically to investigate the role of 3D printing in the anatomy education of undergraduate medical students.

METHODS

A systematic literature search of databases (EMBASE, Pubmed, Educational Resources Information Center, British Education Index and Australian Education Index) was undertaken using relevant keywords.

RESULTS

The search yielded 83 results, which were narrowed down to 13 articles after application of exclusion criteria. The literature supported that 3D printing was a useful tool for studying normal, uncommon and pathological anatomy. However, limitations include low fidelity in replicating the colour and textural physical properties of soft tissues and the trade-off between cost and fidelity.

CONCLUSIONS

It is believed that 3D printing would increasingly be integrated into undergraduate anatomy education, and it might also potentially be used in the assessment of anatomical knowledge and clinical skills training. The establishment of an online 3D model database may facilitate educators to easily manufacture models for specific educational purposes.

Tutorials for Integrating 3D Printing in Engineering Curricula

Three-dimensional (3D) printing can revolutionize the way products have been designed and manufactured. This necessitates engineering graduates equipped with the knowledge and skills of 3D printing. As a result, the educational aspects of 3D printing have earned a great deal of attention. Nevertheless, to teach 3D printing in an undergraduate engineering degree program, an outcomes-oriented approach integrating engineering design, object visualization/digitization, and 3D printing domains can be used. Accordingly, this study presents a tutorial development method to teach undergraduate engineering students the knowledge and skills of 3D printing. The method integrates the abovementioned domains maintaining a hierarchy among the seven ABET-prescribed outcomes. The hierarchy organizes the outcomes into three levels (primary, secondary, and tertiary). The presented method is implemented by introducing a tutorial where a spur gear-pinion pair is designed, visualized, digitized, and 3D printed systematically. E-learning tools can be developed to deliver the tutorial online.

Ethical Rationales and Guidelines for the Continued Use of Archival Collections of Embryonic and Fetal Specimens

Benefits from the use of cadavers in anatomical education are well described. Historically, human embryos and fetal cadavers were used in anatomy education to understand development and congenital malformations. Recently, three-dimensional printed models produced from archival fetal specimens, and online repositories of images from archival collections of embryos and fetuses, have been used as an educational tool in human development courses. Given that the archival specimens were likely obtained prior to the era of informed consent, this raises questions about their appropriate and ethical use. Because some institutions in the United States retain archival collections of embryonic and fetal specimens that were once used as educational tools, their existence and utility require frequent reexamination against contemporary ethical frameworks to guide appropriate use or utilization. Four ethical rationales for uses of these collections are examined, including destruction, indefinite storage, use in research, and use in health professions education. Guidelines for the use of archival collections of human embryos and fetuses are presented. Indefinite storage and use in health professions education are supported, while use in research is also permitted, however, such use is limited and dependent on circumstance and purpose. The development of current digital repositories and three-dimensionally printed models based on archival collections that were collected without informed consent, or those promoting commercial opportunity, are not supported. New embryonic and fetal donations obtained with informed consent should include reference to potential uses with new technology and virtual, genetic, or imaging applications.

Three-dimensional Printing in Anatomy Education: Assessing Potential Ethical Dimensions

New technological developments have frequently had major consequences for anatomy education, and have raised ethical queries for anatomy educators. The advent of three-dimensional (3D) printing of human material is showing considerable promise as an educational tool that fits alongside cadaveric dissection, plastination, computer simulation, and anatomical models and images. At first glance its ethical implications appear minimal, and yet the more extensive ethical implications around clinical bioprinting suggest that a cautious approach to 3D printing in the dissecting room is in order. Following an overview of early groundbreaking studies into 3D printing of prosections, organs, and archived fetal material, it has become clear that their origin, using donated bodies or 3D files available on the Internet, has ethical overtones. The dynamic presented by digital technology raises questions about the nature of the consent provided by the body donor, reasons for 3D printing, the extent to which it will be commercialized, and its comparative advantages over other available teaching resources. In exploring questions like these, the place of 3D printing within a hierarchical sequence of value is outlined. Discussion centers on the significance of local usage of prints, the challenges created by regarding 3D prints as disposable property, the importance of retaining the human side to anatomy, and the unacceptability of obtaining 3D-printed material from unclaimed bodies. It is concluded that the scientific tenor of 3D processes represents a move away from the human person, so that efforts are required to prevent them accentuating depersonalization and commodification.

Three-Dimensional Printing of Fetal Models of Congenital Heart Disease Derived From Microfocus Computed Tomography: A Case Series

This article presents a case series of n = 21 models of fetal cardiovascular anatomies obtained from post mortem microfocus computed tomography (micro-CT) data. The case series includes a broad range of diagnoses (e.g., tetralogy of Fallot, hypoplastic left heart syndrome, dextrocardia, double outlet right ventricle, atrio-ventricular septal defect) and cases also had a range of associated extra-cardiac malformations (e.g., VACTERL syndrome, central nervous system anomalies, renal anomalies). All cases were successfully reconstructed from the microfocus computed tomography data, demonstrating the feasibility of the technique and of the protocols, including in-house printing with a desktop 3D printer (Form2, Formlabs). All models were printed in 1:1 scale as well as with the 5-fold magnification, to provide insight into the intra-cardiac structures. Possible uses of the models include education and training.

Using Electronic Tools and Resources to Meet the Challenges of Anatomy Education in Sub-Saharan Africa

Anatomy education forms the foundation of a successful medical education. This has necessitated the development of innovative ideas to meet up with current realities. Despite these innovative ideas, there are challenges facing anatomy education, especially in sub-Saharan Africa. Problems such as inadequate teaching experts and outdated curricula have made anatomy education in sub-Saharan Africa uninviting and disinteresting. Several interventions have been suggested, such as the procurement of teaching tools and upgrading of teaching infrastructure. However, in this age of information technology; anatomy education, especially in sub-Saharan Africa could benefit from the integration of electronic tools and resources. This article explores the electronic tools and resources such as three-dimensional printing, educational games, and short videos that are readily available for the teaching of anatomy in sub-Saharan Africa. The author concludes by discussing how these electronic tools and resources can be used to address many of the challenges facing anatomy education in sub-Saharan Africa.

A composite 3D printed model of the midcarpal joint

Three-dimensional (3D) printing has recently been developed as a resource for teaching human anatomy through the accurate reproduction of anatomical specimens. Using a composite 3D printed model with the incorporation of metal and magnets, we were able to demonstrate and analyse movements at the midcarpal joint during the 'dart thrower's motion', which is an important motion in daily activities involving the use of the hand. The hand component with the distal row of carpal bones was subjected to flexion and extension at the midcarpal joint and observed for simultaneous abduction/adduction. Notable adduction was observed in the flexed position as compared to the extended position. Moreover, while the primary movements at the midcarpal joint were taking place in the medial part of the joint, the lateral part of the joint (which is ellipsoid) served to accommodate the arc of movement. We suggest that such composite 3D printed models are useful teaching tools for enhancing the understanding of complex joint movements.