In our study, we sought to systematically compare 3D digital and physical models for medical personnel and parent education compared to traditional methods. Parent and medical personnel understanding with 3D physical and digital models was significantly higher than traditional 2D schematics. Subjects also felt that physical models were overall more useful than digital ones. Physicians using models for parent education perceived the models to be useful without significantly impacting their clinical workflow.
Between the printed and digital modalities, printed models were perceived to be of greater benefit for parents. However, those participants who perceived themselves to be more comfortable with modern technology rated digital models more highly than printed models. Osakwe et el, who compared participant response to both printed models and digital representations included in a mobile app Heartpedia found a similar preference for digital models [6]. This preference is likely explained by familiarity with similar technology as well as additional visual exploration features that can be included in such a platform. Improved understanding from both 3D representations appeared to stem from more effective visualization of cardiac anatomy when presented in three dimensions consistent with previous findings that such anatomy is difficult to accurately extrapolate accurately from 2 dimensional representations. Interestingly, one participant in her commentary noted how her understanding of cardiac anatomy made it easier to see why there was a need to take precautions related to her condition. Such feedback is suggestive that there could be a link between improved understanding of CHD through 3D instruction and likelihood of taking appropriate precautionary steps and could form the basis of future study.
Medical personnel similarly reported greater benefit from 3D printed and digital models compared to traditional models. More accurate visualization of cardiac anatomy was felt to be contributory to improved understanding of underlying physiology and management by extension. These findings are consistent with previous studies including Loke at al. who compared the learner satisfaction and post-test scores between two groups, one exposed to 2D instruction and the other exposed to 3D instruction of Tetralogy of Fallot pathology and found higher learner satisfaction scores among the 3D participants compared to the 2D participants [1]. Post-test scores were, however, similar between the two groups. The authors note, however, that the multiple choice questions may not have adequately captured improvements in spatial conceptualization imparted by 3D instruction. Similarly, Jones et al. were able to demonstrate measurable gains in knowledge about vascular rings from post-test scores for pediatric residents exposed to lectures incorporating 3 D printed models compared to the control group [9]. The observed enhancement of the learning experience with 3D models seems to be broadly upheld in the literature by other studies including the roles of nurses and medical students [10, 11]. Our study demonstrated increased understanding for both relatively normal structure and complex palliations, consistent with the findings of Smerling et al. who demonstrated improvement in medical student understanding of CHD through the incorporation of 3D printed models across a spectrum of disease severity [10]. Consistent with the parent results, medical personnel with greater comfort with modern technology preferred digital models over printed models, though they found both preferable to traditional 2 dimensional models. As noted previously, this preference likely relates to perceived familiarity with the broader digital landscape and an appreciation of associated features.
To our knowledge, no previous study has examined the comparative use of 3D and digital models in comparison to traditional models as well as evaluated the feasibility of using such models in the daily workflow of a cardiology clinic. In this study, 3D models, both printed and digital, enhanced medical personnel and parental understanding of CHD. Concerning the feasibility of incorporating such instruction into the workflow of a clinic day, the physician feedback suggests that 3D instruction does not impose a significant burden. This finding is consistent with a previous study by Biglino et al which found that 3D instruction in clinic led to an average increase of 5 minutes per visit, not perceived to be problematic by responding clinicians [4]. In addition, even with such minor increases in immediate time spent, there may be significant time and anxiety sparing gains over a longer period with increased parental understanding and associated supportive actions. The feasibility of integration of 3D instruction into daily workflow has implications in the inpatient setting as well with Olivieri et al. demonstrating that 3D Heart models can be used to enhance congenital cardiac critical care following surgery via simulation training of multidisciplinary intensive care teams [12].
An important consideration for any future work in 3D instruction is the contribution to a growing virtual database of cardiac specimens. Kiraly et al. remind us that the international archives of cardiac specimens are not widely available due to data protection rules, reduced number of autopsies and improved survival rates of patients [13]. Therefore, the potential of 3D instruction lies not merely in the immediate pedagogical problems it can solve but in the broader body of visual knowledge it can create, readily available across the world.
The use of 3D models for education has found applications in multiple fields beyond medicine. Fonseca et al. compared two different learning methodologies for a group of first year architecture students [14]. One methodology consisted of traditional printing plans while the other included the use of 3 dimensional interactive models. The 3 D group found the instruction easier to follow and more satisfying. The authors note, however, that effective instruction in the use of the 3D models was important to their ultimate perceived effectiveness. Dadi et al examined the use of 3D printed models in engineering instruction [15]. In this case, the authors were interested in the relationship between 3D instruction and production efficiency. They found that instruction involving the use of 3D printed models led to outperformance of 2D instruction in productivity measures.
Given the potential in enhancing understanding demonstrated by 3D digital models and their associated benefits in regard to generation time and cost, future studies would benefit from a more extensive analysis of this modality, especially in interactive formats such as Virtual Reality (VR). Challenges remain in replicating the mechanical properties of cardiac tissue with 3D printed materials. The continued development of blended and layered materials should lead to more sophisticated models able to communicate nuanced information of cardiac structure and function [16]. The potential of 3D models may be further enhanced as the technology generating the models improves and integration of hybrid generative imaging data evolves [17]. Currently, the models are mostly generated from CT and MR data. A significant limitation of 3D printing, however, is that it produces a static model of an otherwise dynamic organ making it challenging to understand the hemodynamic functioning of the heart [18]. Integration of 3D Echocardiographic data will contribute to more accurate renderings. Anwar et al. note that there are currently highly accurate, non-invasive methods to assess cardiac function and blood flow over the cardiac cycle and that these methods could contribute to “4D” representation of function and flow [19]. Future work will expand to include modulating factors including degree of technology use in the learner, interaction time and ease of use. With these refinements, the full potential of 3D instruction to enhance understanding and communication around CHD may be progressively realized.