# A Review of Training and Guidance Systems in Medical Surgery
## 1 Introduction  
Learning is difficult in life-critical areas (e.g., medicine), where the required level of expertise is high, and students need to spend a considerable amount of time in operation rooms or using training stations. Training methods have been evolving thanks to the advances in technology, and the current trends focus on e-learning courses and technology-enhanced learning methodologies to improve the education processes. Previous works in the area state that users are using virtual environments to understand concepts or acquire skills. However, these virtual environments often do not provide feedback or help during task execution. One of the current goals of technology applied in education is to assess the skills and knowledge obtained in simulators.  
Educational models have been characterized as approaches where an expert teaches a user how to complete a task correctly. This has been considered as an effective technique to acquire new knowledge [1]. Nevertheless, training methods are affected by technological progress. Human-computer interaction (HCI) is a multidisciplinary field that focuses on studying the interactionbetween humans (the users) and computers. HCI has been a research topic since the creation of computers and learning environments, or computer-assisted instruction (CAI) systems. Current approaches in learning environments, such as E-learning courses and Technology-Enhanced Learning (TEL) methodologies, have been gaining focus of higher education institutions as feasible ways to enhance and reinforce the knowledge acquired in classes. These can be used as auxiliary elements for courses or as abundant educational resources on specific concepts. Additionally, artificial intelligence (AI) in education has been a current topic over the past two decades [2; 3; 4], where a wide range of methods have been used to assist users [5].  
One of the main areas where these technology-oriented practices have been used is the medical field. Surgical procedures need a high level of skill and mastery due to their complex nature. The dissection of human corpses has been a traditional method to study anatomy and practice different surgical interventions since ancient times [6]. Among the difficulties found in this method are the legal problems in acquiring the cadavers and their subsequent preservation in appropriate containers with adequate solutions to maintain organoleptic characteristics. Moreover, the use of live animals for dissection and surgery training is a practice that faces increasing ethical concerns, and it has been discouraged [7]. Nevertheless, they often only resemble the real characteristics of human anatomy, and their use is limited to specific procedures, and they cannot be reused. Therefore, TEL approaches, such as Interactive Learning Environment (ILE), can provide students new ways to practice their skills before they can perform real surgeries.  
Virtual environments are used to simulate a wide range of situations that doctors could face during surgeries. They can be easily reconfigured to reflect different scenarios or vary the difficulty of the performed tasks. Moreover, former virtual environments only exploited the senses of sight and hearing; however, haptic devices have gained terrain in the developing process of these environments. This technology enables users to manipulate objects in a virtual scene and feel the force feedback. Haptics solutions offer tangible interfaces with a high level of usability. This has led several companies and authors to create e-learning environments for medical education (Figure 1).