Multi-material three dimensional printed models for simulation of bronchoscopy.

BACKGROUND: Bronchoscopy involves exploration of a three-dimensional (3D) bronchial tree environment using just two-dimensional (2D) images, visual cues and haptic feedback. Sound knowledge and understanding of tracheobronchial anatomy as well as ample training experience is mandatory for technical mastery. Although simulated modalities facilitate safe training for inexperienced operators, current commercial training models are expensive or deficient in anatomical accuracy, clinical fidelity and patient representation. The advent of Three-dimensional (3D) printing technology may resolve the current limitations with commercial simulators. The purpose of this report is to develop and test the novel multi-material three-dimensional (3D) printed airway models for bronchoscopy simulation. METHODS: Using material jetting 3D printing and polymer amalgamation, human airway models were created from anonymized human thoracic computed tomography images from three patients: one normal, a second with a tumour obstructing the right main bronchus and third with a goitre causing external tracheal compression. We validated their efficacy as airway trainers by expert bronchoscopists. Recruited study participants performed bronchoscopy on the 3D printed airway models and then completed a standardized evaluation questionnaire. RESULTS: The models are flexible, life size, anatomically accurate and patient specific. Five expert respiratory physicians participated in validation of the airway models. All the participants agreed that the models were suitable for training bronchoscopic anatomy and access. Participants suggested further refinement of colour and texture of the internal surface of the airways. Most respondents felt that the models are suitable simulators for tracheal pathology, have a learning value and recommend it to others for use in training. CONCLUSION: Using material jetting 3D printing to create patient-specific anatomical models is a promising modality of simulation training. Our results support further evaluation of the printed airway model as a bronchoscopic trainer, and suggest that pathological airways may be simulated using this technique.

Implementation of team-based learning on a large scale: Three factors to keep in mind.

Team-based learning (TBL) is a structured form of small group learning that can be scaled up for delivery in large classes. The principles of successful TBL implementation are well established. TBL has become widely practiced in medical schools, but its use is typically limited to certain courses or parts of courses. Implementing TBL on a large scale, across different courses and disciplines, is the next logical step. The Lee Kong Chian School of Medicine (LKCMedicine), a partnership between Nanyang Technological University, Singapore and Imperial College London, admitted its first students in 2013. This new undergraduate medical program, developed collaboratively by faculty at both institutions, uses TBL as its main learning and teaching strategy, replacing all face-to-face lectures. TBL accounts for over 60% of the curriculum in the first two years, and there is continued learning through TBL during campus teaching in the remaining years. This paper describes our experience of rolling out TBL across all years of the medical curriculum, focusing on three success factors: (1) "team-centric" learning spaces, to foster active, collaborative learning; (2) an e-learning ecosystem, seamlessly integrated to support all phases of the TBL process and (3) teaching teams in which experts in pedagogical process (TBL Facilitators) co-teach with experts in subject matter (Content Experts).

Summative and Formative Style Anatomy Practical Examinations: Do They Have Impact on Students' Performance and Drive for Learning?

Anatomical knowledge is commonly assessed by practical examinations that are often administered in summative format. The format of anatomy practical examination was changed at the Lee Kong Chian School of Medicine in Singapore from summative (graded; must pass) to formative (ungraded; no pass/fail) in academic year (AY) 2017-2018. Both assessment formats were undertaken online, but the formative mode used a team-based learning activity comprising individual and team assessments. This gave an unique opportunity to investigate: (1) the impact of two different online assessment formats on student performance in practical examination; (2) the impact of new formative practical examination on students' performance in summative examinations; and (3) students' opinions of these two practical examination formats. The class of 2021 perceptions was obtained as they experienced both formats. A retrospective cohort study was also conducted to analyze the Year 2 students' performance in anatomy practical and year-end summative examinations of cohorts AY 2015-2016, AY 2016-2017 (summative format), and AY 2017-2018 (formative format). There were no significant differences in students' performance between two practical examination formats. The cohort who experienced the formative format, performed significantly better in summative examinations (mean ± SD: 82.32 ± 10.22%) compared with the cohort who experienced the summative format (73.77 ± 11.09%) (P < 0.001). Students highlighted positive features of the formative practical examination, including team reinforcement of learning, instant feedback, and enhanced learning. These findings indicate that students continue to study for anatomy practical examination without the need for external drivers. The team-based learning style practical examination enhances students' performance in summative examinations.

Development of a three-dimensional printed heart from computed tomography images of a plastinated specimen for learning anatomy.

Learning anatomy is commonly facilitated by use of cadavers, plastic models and more recently three-dimensional printed (3DP) anatomical models as they allow students to physically touch and hold the body segments. However, most existing models are limited to surface features of the specimen, with little opportunity to manipulate the structures. There is much interest in developing better 3DP models suitable for anatomy education. This study aims to determine the feasibility of developing a multi-material 3DP heart model, and to evaluate students' perceptions of the model. Semi-automated segmentation was performed on computed tomgoraphy plastinated heart images to develop its 3D digital heart model. Material jetting was used as part of the 3D printing process so that various colors and textures could be assigned to the individual segments of the model. Morphometric analysis was conducted to quantify the differences between the printed model and the plastinated heart. Medical students' opinions were sought using a 5-point Likert scale. The 3DP full heart was anatomically accurate, pliable and compressible to touch. The major vessels of the heart were color-coded for easy recognition. Morphometric analysis of the printed model was comparable with the plastinated heart. Students were positive about the quality of the model and the majority of them reported that the model was useful for their learning and that they would recommend their use for anatomical education. The successful feasibility study and students' positive views suggest that the development of multi-material 3DP models is promising for medical education.

Collaborative Regulation of LRG1 by TGF-ß1 and PPAR-ß/δ Modulates Chronic Pressure Overload-Induced Cardiac Fibrosis.

BACKGROUND: Despite its established significance in fibrotic cardiac remodeling, clinical benefits of global inhibition of TGF (transforming growth factor)-ß1 signaling remain controversial. LRG1 (leucine-rich-α2 glycoprotein 1) is known to regulate endothelial TGFß signaling. This study evaluated the role of LRG1 in cardiac fibrosis and its transcriptional regulatory network in cardiac fibroblasts. METHODS: Pressure overload-induced heart failure was established by transverse aortic constriction. Western blot, quantitative reverse transcription polymerase chain reaction, immunofluorescence, and immunohistochemistry were used to evaluate the expression level and pattern of interested targets or pathology during fibrotic cardiac remodeling. Cardiac function was assessed by pressure-volume loop analysis. RESULTS: LRG1 expression was significantly suppressed in left ventricle of mice with transverse aortic constriction-induced fibrotic cardiac remodeling (mean difference, -0.00085 [95% CI, -0.0013 to -0.00043]; P=0.005) and of patients with end-stage ischemic-dilated cardiomyopathy (mean difference, 0.13 [95% CI, 0.012-0.25]; P=0.032). More profound cardiac fibrosis (mean difference, -0.014% [95% CI, -0.029% to -0.00012%]; P=0.048 for interstitial fibrosis; mean difference, -1.3 [95% CI, -2.5 to -0.2]; P=0.016 for perivascular fibrosis), worse cardiac dysfunction (mean difference, -2.5 ms [95% CI, -4.5 to -0.4 ms]; P=0.016 for Tau-g; mean difference, 13% [95% CI, 2%-24%]; P=0.016 for ejection fraction), and hyperactive TGFß signaling in transverse aortic constriction-operated Lrg1-deficient mice (mean difference, -0.27 [95% CI, -0.47 to -0.07]; P<0.001), which could be reversed by cardiac-specific Lrg1 delivery mediated by adeno-associated virus 9. Mechanistically, LRG1 inhibits cardiac fibroblast activation by competing with TGFß1 for receptor binding, while PPAR (peroxisome proliferator-activated receptor)-ß/δ and TGFß1 collaboratively regulate LRG1 expression via SMRT (silencing mediator for retinoid and thyroid hormone receptor). We further demonstrated functional interactions between LRG1 and PPARß/δ in cardiac fibroblast activation. CONCLUSIONS: Our results established a highly complex molecular network involving LRG1, TGFß1, PPARß/δ, and SMRT in regulating cardiac fibroblast activation and cardiac fibrosis. Targeting LRG1 or PPARß/δ represents a promising strategy to control pathological cardiac remodeling in response to chronic pressure overload.

Evaluation by medical students of the educational value of multi-material and multi-colored three-dimensional printed models of the upper limb for anatomical education.

For centuries, cadaveric material has been the cornerstone of anatomical education. For reasons of changes in curriculum emphasis, cost, availability, expertise, and ethical concerns, several medical schools have replaced wet cadaveric specimens with plastinated prosections, plastic models, imaging, and digital models. Discussions about the qualities and limitations of these alternative teaching resources are on-going. We hypothesize that three-dimensional printed (3DP) models can replace or indeed enhance existing resources for anatomical education. A novel multi-colored and multi-material 3DP model of the upper limb was developed based on a plastinated upper limb prosection, capturing muscles, nerves, arteries and bones with a spatial resolution of ∼1 mm. This study aims to examine the educational value of the 3DP model from the learner's point of view. Students (n = 15) compared the developed 3DP models with the plastinated prosections, and provided their views on their learning experience using 3DP models using a survey and focus group discussion. Anatomical features in 3DP models were rated as accurate by all students. Several positive aspects of 3DP models were highlighted, such as the color coding by tissue type, flexibility and that less care was needed in the handling and examination of the specimen than plastinated specimens which facilitated the appreciation of relations between the anatomical structures. However, students reported that anatomical features in 3DP models are less realistic compared to the plastinated specimens. Multi-colored, multi-material 3DP models are a valuable resource for anatomical education and an excellent adjunct to wet cadaveric or plastinated prosections. Anat Sci Educ 11: 54-64. © 2017 American Association of Anatomists.