Application of mixed augmented reality with holographic platform for interactive teaching of veterinary osteology

Abstract

Background

Veterinary anatomy education increasingly demands innovative strategies to enhance spatial understanding and student engagement. Mixed augmented reality (MAR) has emerged as a promising tool, integrating virtual anatomical models into real environments. This study aimed to describe the pratical implemention and evaluate the pedagogical benefits of a MAR-based holographic platform for teaching selected osteological structures in veterinary anatomy.

Methods

A Veterinary Anatomy Holographic Platform (VAHP) was developed using 3D digitized bone models integrated into a mixed reality display. Anatomical models of equine skull, scapula, femur, and the canine axis were processed using photogrammetry and 3D Slicer, then rendered with Unreal Engine 4.27. The platform was implemented during regular classrom session with 80 veterinary students. Learners interacted with the holographic models and subsequently completed a four-question proficiency test. Results were compared to a control activity using real anatomical specimens and analyzed using Z-tests for two proportions.

Results

Significant improvements in permfomance were observed in three of the four test questions after using the VAHP (p < 0.05), particularly for structure requiring complex spatial reasoning. No statistical improvement was found for one question (p = 0.058). The holographic session were well accepted by students and promoted engagement in the classroom.

Conclusions

This proof-of-concept study showed that the VAHP, delivered through a mixed reality headset, can enhance anatomical learning and engagement in osteology. Broader and longer-term studies are needed to confirm its impact and guide curriculum integration.

Introduction

Traditional veterinary anatomy teaching faces ongoing challenges, including logistical limitations and difficulties in understanding complex spatial relationships of anatomical structures. Emerging technologies, such as 3D printing and augmented reality (AR), have been proposed as effective alternatives to overcome these challenges [1–5]. In this context, mixed augmented reality stands out by integrating digital elements into the real environment, allowing students to directly interact with three-dimensional holographically projected anatomical models [6, 7].

Previous studies have demonstrated the pedagogical effectiveness of these technologies, particularly in improving the acquisition of spatial and conceptual knowledge in complex anatomy, such as cardiac structures [6] and craniofacial anatomy [7–9]. Recently, the integration of AR with advanced devices using mixed reality headmounted display has shown great potential in improving precision in complex medical procedures, including craniofacial reconstructions, providing real-time feedback and enhanced safety during interventions [7, 10, 11].

Although anatomical specimen dissection remains the gold standard for applied learning, limitations related to preservation, cost, and environmental impact are significant [12, 13]. Furthermore, recent studies suggest that using holographic models can reduce cognitive load and increase student engagement, facilitating deeper and longer-lasting comprehension of anatomical relationships [14].

Based on these premises, the objective of this study is to describe the practical implementation and pedagogical benefits of the Veterinary Anatomy Holographic Platform (VAHP), specifically designed for interactive teaching of equine skull, scapula, and femur bones, as well as the canine axis bone anatomy.

Materials and methods

Acquisition of anatomical models

Anatomical models of equine skull, scapula, and femur bones were obtained from STL files stored in the digital library of the School of Veterinary Medicine and Animal Science, University of São Paulo (FMVZ-USP)‘s 3D Digitization and Printing Laboratory [15]. An adult equine skull was digitized through photogrammetry using a Canon REBELS T5I camera equipped with a Canon EFS 18-55 mm lens. Technical parameters included ISO ranging from 500 to 800, white balance set at 5500K, and exposure times between 1/30 and 1/70 seconds, with illumination provided by two 100-watt reflectors. Approximately 400 images with 4K resolution (3840 ×2160 pixels) were captured in CR2 format, processed in Adobe Lightroom, and exported as JPEG for 3D model creation using Metashape software (Agisoft). The canine cervical axis bone was segmented using 3D Slicer software from axial images. Initially, an automatic thresholding segmentation was applied, followed by manual refinements to ensure anatomical accuracy. Smoothing techniques were also applied to enhance the model’s definition.

Development of the holographic platform

The VAHP was developed using Unity® (Unity Technologies) and Unreal Engine 4.27.2 (Epic Games, 2019) graphic engines integrated using a mixed reality headmounted display (Microsoft HoloLens). The application was built in C language and extensively tested for stability prior to classroom use.

Study design

This study followed a within-subjects experimental pedagogical design to evaluate the effectiveness of a mixed augmented reality (MAR) holographic platform for teaching veterinary osteology. The same group of students participated in both a control condition (traditional teaching with real bone specimens) and na experimental condition(MAR-based holographic teaching), allowing direct comparison of learning outcomes while controlling for inter-individual variability in prior anatomical knowledge.

Participants

Eight firts-semester students, all enrolled in the “Descritive Anatomy of Domestic Animals I course, at the School of Veterinary Medicine and Animal Science, University of São Paulo, during the first semester of 2024. All participants attended the same lectures and practical classes as part of the regular curriculum. No additional inclusion or exclusion criteria were applied.

Instructional conditions and procedures

The learning intervention consisted of two sequential phases: (1) Control condition: Traditional osteology practical classes: Students participated in two consecutive weeks of face-to-face practical sessions using preserved real anatomical bone specimens of equine skull, scapula, and femur, and the canine axis vertebra. (2) Experimental condition: Mixed augmented reality sessions: In the third week, the same students were organized into groups of five and interacted with digitized holographic bone models using the VAHP on Microsoft HoloLens 2 devices. The holographic models were derived from 3D digitization (photogrammetry and segmentation) and were fully manipulable in the virtual space, allowing zoom, rotation, and spatial exploration.

The order of exposure was fixed: all students first attended the control condition, followed by the experimental condition one week later. This sequential arrangement was necessary due to logistical constraints and to ensure all students had access to both modalities.

Measurement instrument

They explored anatomical models of the equine skull, scapula, and femur and canine axis. Subsequently, students completed a proficiency test with 4 Questions (Question 1: equine lacrimal boné; Question 2: canine axis tooth, Question 3: canine scapular spine, and Question 4: equine femoral trochlea) compared to prior practical activity with real anatomical specimens.

Immediately after each learning activity, the same four-question osteology proficiency test was administered. A within subjects design allowed direct comparison of learning outcomes between the tho teaching approaches, controlling for interindividual diferences.

Data analysis

The proportion of correct answers for each question was calculated separately for the control and experimental conditions. Statistical analysis was performed using a Z-test for two proportions to compare the percentage of correct answers between the two modalities for each question. A significance threshold of p < 0.05 was adopted.

Ethics approval

The Ethics and Animal Experimentation Committee of School of Veterinary Medicne and Animal Scince (CEUAVET) of the University of São Paulo approved the study (Protocol no. 6,323,261,119) and Ethical Appreciation Presentation Certificate/CAAE (Protocol no: 23,418,019.00000.0065). All procedures involving human participants were conducted in accordance with the ethical standards of the institutional and national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. ‘Clinical trial number: not applicable.’

Results

Initially, the Unity® graphic engine was tested due to its user-friendly interface. However, during development for HoloLens, Unreal Engine demonstrated superior performance, particularly in ease of compilation and compatibility with the device’s configuration. Unreal Engine also facilitated development without traditional programming through its visual scripting technology (Blueprints). The final software, VAHP, built using Unreal Engine version 4.27.2, provided greater stability and compatibility with the HoloLens simulator compared to version 5.0.3, which showed reduced performance and increased device heating (Fig. 1).

Fig. 1.

Practical classroom application of the veterinary anatomy holographic Platform) using the Microsoft HoloLens 2. (left) students interacting with equine osteological holograms during immersive anatomy practice. (right) guided immersive session where veterinary students examine and discuss 3D holographic models while wearing mixed reality headsets. Both sessions took place during practical activities of the “descriptive anatomy of domestic Animals” course at the School of veterinary Medicine and Animal Science – University of São Paulo

During practical classes (Fig. 2), significant improvements in students’ performance were observed after using VAHP. For Question 1 (equine lacrimal bone), no significant statistical difference was found (Z = 1.89; p = 0.058). However, significant differences were detected for Questions 2 (canine axis tooth, Z = 3.78; p = 0.00016), 3 (canine scapular spine, Z = 2.19; p = 0.028), and 4 (equine femoral trochlea, Z = 3.78; p = 0.00016) (Fig. 3).

Fig. 2.

Instructors and teaching assistants providing guidance on the use of HoloLens devices during practical osteology sessions of the VCI1101 course (descriptive anatomy of domestic Animals I) at the School of veterinary Medicine and Animal Science, University of São Paulo (FMVZ-USP), during the first semester of 2024

Fig. 3.

Performance results from the osteology proficiency assessment following the use of the veterinary anatomy holographic Platform (VAHP). The questions addressed the identification of specific anatomical landmarks on equine and canine bones: question 1 – lacrimal bone of the equine skull; question 2 – dens of the canine axis; question 3 – spine of the canine scapula; question 4 – trochlea of the equine femur

Discussion

Mixed augmented reality applications, particularly with advanced devices like Microsoft HoloLens 2, demonstrate significant potential for enhancing medical education, reflecting a growing trend in recent literature. The improvement in anatomical comprehension observed aligns with prior studies reporting enhanced spatial perception, motivation, and engagement when using holographic models compared to traditional methods [7, 14].

The significant improvement observed in three of four evaluated questions highlights the efficacy of visual and interactive learning. This supports previous findings that immersive holographic technology improves spatial understanding and reduces cognitive load [6]. However, the lack of significant improvement in Question 1 suggests variability in the effectiveness of holographic methods across different anatomical structures, possibly requiring varied exposure or instructional approaches.

The application of mixed augmented reality (MAR), particularly through advanced devices such as the Microsoft HoloLens 2, has shown considerable promise in medical and anatomical education. In our study, the use of the Veterinary Anatomy Holographic Platform (VAHP) significantly enhanced students’ spatial understanding and engagement, especially in questions that required recognition of complex three-dimensional relationships. These findings align with previous studies that emphasize how MAR improves visualization and conceptualization of intricate anatomical structures [16, 17]. In addition, recent studies by Di Mitri et al. [4, 5] have explored the intersection between immersive technologies and embodied learning in health education. These authors propose theoretical frameworks and instructional design models that integrate multiple modes of interaction: visual, auditory, and haptic, supported by multimodal data and learning analytics, offering support for both deliberate practice and personalized teaching. Such an approach provides a conceptual basis for understanding and enhancing the impact of mixed reality in anatomy teaching, directly aligning with the findings of this study.

It is important to emphasize that this investigation was intentionally designed as a pilot classroom study. The decision to digitize four osteological specimens (equine skull, scapula, femur, and the canine axis vertebra) and to use a four-question proficiency test was made to ensure alignment with the syllabus of the Descriptive Anatomy of Domestic Animals I course and to maintain feasibility within the available teaching time. This focused scope allowed the assessment of VAHP in real classroom conditions without disrupting the scheduled curriculum.

While this limited number of specimens and test questions does not capture the full breadth of students’ anatomical knowledge, the significant learning gains observed in three of the four targeted concepts suggest that even within a narrow content set, MAR can enhance spatial comprehension. These findings provide an encouraging foundation for future studies.

For subsequent research, we plan to: expand the variety and number of anatomical specimens digitized for holographic visualization; increase the number of assessment items to capture a broader range of anatomical competencies, incorporate validated perception questionnaires to measure student motivation, usability perception, and perceived cognitive load in addition to objective knowledge assessments.

By framing the present work as a proof-of-concept pedagogical study, we acknowledge its limitations while underscoring its contribution as an initial step toward the systematic integration of MAR into veterinary anatomy curricula.

Another limitation of the present study is the absence of a structured questionnaire or validated instrument to directly assess students’ perceptions of the MAR tool. Although our observations during classroom activities and informal feedback from students indicated high levels of engagement and interactivity, these impressions were not quantified through standardized measures.Therefore, any claims regarding increased motivation or interactivity must be interpreted cautiously, as they are based on observational evidence rather than empirical perception data. Future studies will address this gap by incorporating validated perception questionnaires to evaluate dimensions such as motivation, usability, and perceived cognitive load alongside objective learning outcomes. This will allow for a more comprehensive and evidence-based assessment of the pedagogical impact of the VAHP.

It is also important to note that this study incorporated a direct comparison with traditional anatomy teaching methods. The same cohort of students first attended conventional osteology practical sessions using real anatomical bone specimens, followed by mixed augmented reality sessions with the VAHP. The same four-question proficiency test was applied after each condition, enabling a within-subject comparison. Statistical analysis revealed significant performance improvement in three of the four assessed questions when using VAHP, suggesting that mixed augmented reality can complemente, and in certain aspects enhance, the learning outcomes achieved through traditional approaches. This comparative design strengthens the validity of our findings and reinforces the potential value of integrating MAR into veterinary anatomy curricula.

One of the primary benefits observed was the increase in student motivation and interactivity. As reported by Gnanasegaram et al. [18], MAR models offer a multisensory learning experience, which supports deeper cognitive processing and retention. Students not only engage more readily with holographic simulations but also demonstrate greater confidence when applying their knowledge in physical specimens, suggesting effective knowledge transfer. Another advantage is the reduction of cognitive load. Studies such as Nicholson et al. [19] have shown that MAR applications help students process spatial information more efficiently by reducing the abstract reasoning typically required when interpreting two-dimensional resources. This benefit was reflected in our results, where the majority of students performed significantly better after the MAR-based intervention.

However, the technology also presents limitations. The lack of significant improvement in one of the test questions may indicate variability in learning efficacy depending on the anatomical structure or the student’s familiarity with digital tools. This is consistent with the findings of Gao et al. [20], who emphasized the importance of instructional design and structure-specific customization in the deployment of AR applications. Additional limitations include access to infrastructure and financial constraints. As highlighted by Milgram et al. [21], MAR systems require substantial investment in hardware, software, and instructor training, which may restrict widespread adoption in resource-limited academic settings. Furthermore, while most students adapt quickly to the use of wearable MAR devices, a subset may encounter usability or comfort issues, particularly with extended exposure [22].

Overall, our findings confirm that MAR, when thoughtfully integrated into the veterinary anatomy curriculum, can serve as a highly effective supplementary method. It enhances anatomical understanding, sustains engagement, and complements conventional dissection methods. Future studies should explore the impact of extended exposure time, adaptive learning interfaces, and the integration of MAR with other digital and physical teaching resources [23].

Conclusions

This study demonstrated the potential of mixed augmented reality, specifically the Veterinary Anatomy Holographic Platform (VAHP) using a mixed reality headmounted display, as an effective supplementary tool for interactive learning of veterinary anatomy. Significant improvements were noted in student comprehension in 75% of the evaluated questions after using the device, particularly for anatomical concepts involving spatial relations. However, these findings should be interpreted in light of the pilot and proofofconcept nature of this work. The scope of the present study was intentionally limited to four digitized osteological specimens and a small set of assessment items, evaluated within a single course offering. While the results are promissing, they primarily serve as preliminar evidence supporting tge feasibility and pedagocical potencial of MRA in veterinary anatomy teaching. Future research should focus on largerscale and longitudinal investigations, encompassing a wider range of anatomical structures, more comprehensive assessment tools, and standardized perception questionnaires. Such studies will help determine the longterm impact, scalability, and integration pathways for MARbased tools within veterinary and other health sciences curricula.

Abbreviations

VAHP

Veterinary Anatomy Holographic Platform

AR

Augmented Reality

MAR

Mixed Augmented Reality

STL

Standard Tessellation Language

Author contributions

C.L.R., A.C.A.N. conception and design of the work; C.LR., A.C.A.N. acquisition, analysis, and interpretation of data; C.LR., A.C.A.N, C.LR. writing - original draft preparation. C.LR., A.C.A.N. writing – review and editing. All authors have read and agreed to the published version of the manuscript. They all have also agreed to be personally accountable for their contributions and to ensure that questions related to the accuracy or integrity of any part of the work are appropriately investigated, resolved, and the resolution documented in the literature.

Funding

This research received technical support from the 3D Digitization and Printing Laboratory at FMVZ-USP and partial funding from CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) and by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 88887.180817/2025-00.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.