EMBRIO – a 3D Software for Learning Embryology

Leandro G. Garcia 1+, Danilo A. Pacheco2, Ronnayb L. de Sousa3, Ronielson S. Santos3 and Fabio

H. R. Brune 3

UFT – Federal University of Tocantins, Brazil 1 Department of Medicine, 2 Department of Architecture, 3 Department of Computer Science

Abstract. This paper presents an embryology teaching system called EMBRIO, developed to improve the learning of embryology based on learning objects. In this sense, the changes observed in the development of the conceptus, which would otherwise be hardly understood from two-dimensional figures as printed in textbooks, may be more easily visualized upon complete comprehension, using three-dimensional models. The learning objects present in EMBRIO were developed based on the analysis of hundreds of two-dimensional images of the conceptus, obtained from different sources. The result was the creation of a system containing tens of three-dimensional images of the conceptus, at distinct development stages. The aim is to increase the students’ understanding of embryology, improving chances of producing correct diagnoses by health professionals in the future concerning inborn malformations. This correct diagnosis may also, in many cases, mean a better quality of life for the subject carrying a malformation.

Keywords: Embryology, Learning Objects, Computer Education.

1. Introduction This paper presents a new teaching model to teach human embryology that uses learning object built as

three-dimensional models. A learning object is defined as any digital, reusable resource that may break the educational content down to smaller chunks, in an object-oriented programming mindset [1]. This type of approach has the potential to improve the teaching of embryology, since the two-dimensional visualization of the conceptus, as observed in textbooks, is a limiting factor against learning. In embryology, the object of study is called conceptus and, in the present case, it represents the being formed as of fertilization. The teaching model in human embryology we propose herein presents two dimensions. It should be noted that the use of learning objects currently practised and also described in this paper, represents only one of these dimensions, as shown at the end of this article.

In order to gain access and to interact with learning objects, we developed a system called EMBRIO. EMBRIO is a system designed as a tool to provide computer education for a particular group which, in the present study, is formed by students of health-related courses. This system contains several learning objects (in the present case, three-dimensional models of the conceptus, in a specific area of study) that afford students to visualize anatomy aspects and their interconnections, in a three-dimensional environment and interactively, during the most complex stages of intrauterine development. With that in mind, tens of three-dimensional models representing development stages of conceptus at several different days during intrauterine life. Apart from facilitating the comprehension of embryology, our system also allows the student to concomitantly observe more accurate images of the maturation stages of each of the human body’s systems, at a given intrauterine life date. This image is essential in the teaching of this course, since it allows the direct application of knowledge in clinical practice.

Human embryology is the science that addresses human organs development, from fertilization to birth [2]. The innovation presented in the present paper lies in the fact that we aimed primarily at mimicking the sequences of events the conceptus undergoes towards reaching a relatively stable form in its development, based on the coordinated creation of learning objects. In this sense, our teaching model attempts to place the student inside the uterus of a pregnant woman, affording to observe, in an active way, the main changes in intrauterine development, with time.

+ Corresponding author. Tel.: + 55 63 323280; fax: + 55 63 323280. E-mail address: lggarcia@uft.edu.br

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The teaching of embryology has evolved considerably in the recent decades. Anatomical structures that in the past were not well characterized or represented in textbooks may today be visualized as colour drawings, together with the interconnections they have with one another. This improved representation of anatomic structures and of the genetic and biochemical processes involved in the development of the conceptus make a vast amount of new information available, increasing the complexity of this course.

Currently, by far most embryology textbooks divide the conceptus in its several constituent systems, and show the development of each of these systems in separate, throughout pregnancy [2], [3], [4], [5]. [6]. In these textbooks, many times the transformations that take place in a given system are not appropriately linked to the respective uterine age. We believe that, due to this kind of approach, a small part of students taking courses in health-related areas cannot connect the sequences of events that take place during conceptus development as a whole. We observed that, considering a determined development stage of the digestive system, at a given pregnancy phase, a small number of students at times is unable to clearly identify the development stage of the cardiovascular, nervous or urogenital systems. In these cases, these students in particular do not acquire a global view of conceptus development at a specific moment during intrauterine life. On the contrary, these students have but a view of each system in separate, unconnected to uterine life as a whole. These students may have to face severe problems in their professional practice, given that when a three-month pregnant woman is referred to an obstetrician, the doctor will have to know the normal development status of all of the human body’s systems at the same time, at this date in particular.

Yet another important problem that may emerge associated to the current teaching model adopted in embryology is linked to the fact that most anatomical structures are represented as two-dimensional images in textbooks [2], [3], [4], [5], [6], [7], and that students do not have physical contact, as it were, with the conceptus. Often these images are difficult to understand, and a considerable number of these students simply attend an embryology course without ever gaining any precise insight on some intrauterine life stages. Even the dummies nowadays used in the teaching of embryology do not come up to scratch, both in terms of anatomy and of comprehension, towards shedding light on the inner changes the conceptus undergoes.

In this scenario, the potential advantages brought about by EMBRIO are numerous. Increased understanding of embryology by students taking health-related courses leads to better chances of reaching correct diagnosis of inborn malformations. These malformations are defined as changes in embryo and foetus development [3]. In these cases, correct diagnosis may imply the difference between gaining or not the access to better quality of life for the individual carrying these malformations. A better comprehension of how human body systems develop with time also helps form a health professional more appropriately trained to instruct the pregnant woman about substances and microorganisms that may lead to these dysfunctions at a given moment during pregnancy. In this sense, pregnant women could refrain from forming certain habits that could lead to these malformations.

The authors organized this paper in accordance to the IMRAD structure: introduction, methods, results and discussion; which is adopted as part of the Uniform Requirements for Manuscripts Submitted to Biomedical Journals of the International Committee of Medical Journals Editors, 2008 update. The authors believe that adopting this structure would help search engines in international databases to store and to retrieve information within research papers in order to facilitate meta-analyses and systematic reviews.

2. Methods This study was conducted using three computers and a scanner. The computer used to compile and run

the system is equipped with a 1-Gbyte dedicated video card. The BLENDER software [8] was installed in all computers used. According to the BLENDER website [8], “BLENDER is a free open source 3D content creation suite, available for all major operating systems under the GNU General Public License”.

BLENDER affords to create simple three-dimensional objects, computer animations, and games. In the present case, tens of three-dimensional objects were created containing all human body systems. After, we used a “game engine” of BLENDER to generate an executable three-dimensional object that could be freely manipulated by the user. Each three-dimensional model linked to a given intrauterine phase represents a

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learning object. These objects were generated according to a chronological order in terms of embryo development. In this sense, these objects gained complexity as the present study evolved with time.

The content used to carry out this study belongs to the databank of our University Library [1] – [7], [9], though some material was also obtained in the internet [10], [11] or through the use of a computational system called HUMAN EMBRYOLOGY AND TERATOLOGY 3-1 [12].

3. Results In the present paper, we present a very intuitive graphic interface system, which allowed managing the

call and the use of learning objects. After compiling the system using BLENDER, we could access the first screen of the graphic interface for the user (figure 1a).

Fig. 1: EMBRIO system’s interface (a) first screen; (b) access menu after pressing the button “EMBRIO”; (c) second menu accessed after pressing “Terceira Semana” (third week); (d) 21 days old 3D-model, accessed after pressing “21 DIAS” (21 days). View of the neural plate and the “ectoderma” (ectoderm) limited by the boundaries of the “âmnio”

(amnion).

Clicking on EMBRIO on the first screen of the system allows accessing the models created in this study through a general panel that opens a menu where one can choose to visualize the models developed each week during this study (figure 1b). By choosing the week one wishes to investigate, we are given access to a second menu, where we can select visualizing a given model related to a particular day in the same week previously chosen (figure 1c). It should be observed that models were not generated for all weekly phases of embryo development and that daily models are not available for one same week. In our example, we chose the three-dimensional model representing the 21st day of embryo development, when we can see the neural plate and ectoderm limited by amnion boundaries (figure 1d). Figure 1d also shows the basic commands associated to the system. The buttons on the top right side of the screen afford to exclude or insert parts of the object studied. The textbox below the top right side buttons allow visualizing the part names of the

(a) (b)

(c) (d)

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conceptus by placing the cursor on each. For some learning objects, buttons may be exhibited on the left side of the screen, which allow carrying out transversal and longitudinal sections of the models studied. Below that, also on the left, three spheres associated to arrows are shown. Clicking on these affords the user to move the object across different planes.

For all learning objects generated, the user may dismantle and reassemble chunks of the conceptus and visualize parts and names. This is made clear in figure 2, which shows the three-dimensional model of a 21-day-old conceptus with a partially sectioned amnion.

Fig. 2: 21-day-old 3D-models with partial section of the “amnion” (a) view of “mesoderma intra-embrionário” (intraembryonic mesoderm) with intraembryonic coelom, vessels, somites and notochord; (b) “endoderma”

(endoderm’s view); (c) transversal cut for viewing the three layers (ectoderm with neural plate, intraembryonic mesoderm, endoderm) simultaneously beyond intraembryonic coelom, somites and notochord; (d) longitudinal cut for viewing the ectoderm with neural plate, notochord, endoderm, cardiogenic mesoderm, oropharyngeal membrane and

cloaca membrane simultaneously.

Figure 2 shows the intraembryonic mesoderm, the location of the oropharyngeal and cloacal plates, somites, notochord, intraembryonic coelom, blood vessels and endocardial tubes. All these structures are found below the neural plate and the ectoderm, as shown in figure 1d. Figure 2b shows the endoderm, immediately below the intraembryonic mesoderm. Figure 2c shows a transversal cut of the conceptus to allow visualization of the three layers (ectoderm with neural plate, intraembryonic mesoderm, endoderm), at the same time. Note the presence of intraembryonic coelom (white), somites (purple), and notochord (brown) in the intraembryonic mesoderm. Figure 2d shows a longitudinal section of the conceptus showing the same layers as above, as well as the oropharyngeal and cloacal membranes and the region the heart forms (cardiogenic mesoderm).

We start generating some models associated to several days of the third week of intrauterine life. Several models associated to this same week allow the user to run all actions described above (figures 1d and 2).

(a) (b)

(d) (c)

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Later, we generated some models associated to several days of the fourth week of intrauterine life. After that, only one model associated to the fifth, sixth, seventh and eight weeks each were generated. In order to show the degree of complexity associated to the changes in the conceptus, we also added figures of the conceptus at the sixth week of development (figure 3). Figure 3a shows an outer view of conceptus, without the amnion. When the skin, bones, and pericardiac, pleural and peritoneal membranes are removed, we visualize the inner structures already formed and the degree of development (figure 3b). Removing the neural tube reveals the parts of the concept already formed and the respective development stage (figure 3c). We may proceed, removing parts of the conceptus so as to visualize only the digestive tube and the urogenital tract (figure 3d).

Fig. 3: Partially sectioned 3D-models of the sixth week (a) external surface; (b) under skin view without bones and pericardiac, pleural and peritoneal membranes; (c) boneless model without neural tube and pericardiac, pleural and

peritoneal membranes; (d) digestive tube and the primitive urogenital tract view.

4. Discussion The choice of models that are part of the system is carried out considering the degree of difficulty

students face when taking a embryology course concerning the understanding of given embryo development stages. The fact that most organs in the human body are formed upon the eight week of intrauterine life was also considered. For this reason, almost all models generated cover the first weeks of intrauterine life.

Considering the fact that important changes take place in the conceptus after the eighth week, in the months to come our research group intends to generate learning objects representing the conceptus at ages of 11th, 12th and 24th week of intrauterine life. After, a few considerable structural changes are observed in structures of the conceptus’ systems and therefore students do not face significant difficulties to understand them based solely on existing teaching materials. Due to this, we do not see the need for models associated to development stages beyond the 24th week of intrauterine life.

(d)

(a) (b)

(c)

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The second dimension of our study is linked to the fact that we also intend to generate written material that fits perfectly the use of the learning objects developed. In this written material, we intend to explore the development of the conceptus considering intrauterine life stages as the main focus. In this sense, we aim at analyzing all systems constituting the conceptus, at the same time, for a given stage of intrauterine life, from fertilization to birth. This approach allows redefining the way embryology is taught, by stimulating a change in paradigms, where focus is placed not on the study of body systems in separate with time, but on given periods of intrauterine life. Therefore, we aim at establishing a more close connection between theory of embryology and the events that take place in the life of the embryo.

A classical example of the good use of a computational tool perfectly adjusted to the teaching of a theory is the softwares Maple and Mathematica [13], used in the teaching of differential calculus. Our aim is to obtain the same kind of results, so that everything the student reads in the written material can be directly visualized in three-dimensional models.

Currently, several computer systems are in use to teach anatomy and physiology [14] [15], [16]; however, none of these systems is used in association with written material, like a textbook for undergraduate students, in such a manner that allows them to perfectly adjust the use of the computer system to the theory presented in the textbook. We believe that our teaching approach, which includes written material closely related to learning objects, will afford students to more easily understand such a complex topic as embryology. This approach will subsequently be tested in classroom to probe the teaching model of human embryology proposed by our research group, verifying its validity in comparison to the current teaching model of embryology courses.

5. References [1] R.J. Beck. Learning Objects: What? Center for International Education. University of Winsconsin. Milwaukee.

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[2] J. Hib. Embriologia Médica. Rio de Janeiro: Guanabara Koogan, 2007.

[3] K.L. Moore. Embriologia Médica. 8th edition. Elsevier, 2008.

[4] T.W. Sadler. Langman’s Medical Embryology. 12th editon. Lippincott Wiliams & Wilkins, 2011.

[5] L.R. Cochard. Atlas de Embriologia Humana de Netter. 1st edition. Artmed, 2003.

[6] G.C. Schoenwolf, et al. Larsen Embriologia Humana. 4th edition. Elsevier, 2009.

[7] J.W. Rohen. Embriologia Funcional. 2nd edition. Guanabara Koogan, 2005.

[8] http://www.blender.org/

[9] C.L. Prata and A.C.A.A. Nascimento. Objetos de Aprendizagem – Uma proposta de recurso pedagógico. MEC, SEED, 2007.

[10] http://www.theodora.com/anatomy/development_of_the_vascular_system.html

[11] T. A. Marino. Embryology and disorders of sexual development. Perspect Biol Med. 2010 Autumn;53(4):481-90.

[12] G. Rager et al. Human Embryology and Teratology - A concise course. 2008. CD-ROM.

[13] I. Shingareva. Maple and Mathematica:A Problem Solving Approach for Mathematics. 2nd edition. Springer, 2009.

[14] http://www.adameducation.com/

[15] http://www.primalpictures.com/

[16] http://www.visiblebody.com/

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