## 3 Results
### Summary of the Selected Articles
#### 3.1.4 Medicine
The first study gave unfavorable experiences because the model was left out of the field of vision, generating disgust and complexity for users. On the other hand, the second examination seemed to be promising since it allowed greater control in these aspects even though the problem persisted [53]. Evaluating the accuracy based on points with AR in laparoscopic liver resection surgery was another study presented to determine the points of operation or need forattention with signaling through digital images. Although the research could be achieved, it is still necessary to improve the precision, since it is difficult to observe the exact point of the damage and variations in the movement. In any case, it can be functional to measure the dimension of the lesion site [54]. AR is also used to improve surgeons' understanding of anatomy and pathology, where it improves planning, intraoperative guidance, and better patient care. This study explains how 3D anatomical models are created and deployed in AR for Microsoft HoloLens devices in urologic oncology to guide the surgery. Obtaining the result of successful implementation, allowing the specific cancer models to be seen determining the dominant tumors with the key anatomic structures, preparing the surgeon for complex surgical cases, and describing, to the patient, their state. AR is making great progress in the medical field, and it is expected that these uses can be implemented in the future since it allows visual support to be obtained as a guide and feedback in real time [55]. Another similar AR implementation was made in research about the context of kidney cancer, showing the impact of the use of AR and 3D printed models for patients' instruction in their medical status, medical treatments, surgery procedures, and advances in their conditions. AR allows detection as well as the visualization of tumor size, enabling the doctor to make identifications with greater agility, which is important for decision making [56]. Moreover, an AR system was analyzed which was created to support surgeons and a test was carried out for craniomaxillofacial surgeries using a lightweight and portable device potentially useful for keeping the natural view of the operating room. For the examination, the researchers used a pair of stereo-rig cameras and a mini projector; these items helped to make a comparison between a custom-made VST HMD (Video see-through, head-mounted device) and a normal AR projection. The correct calibration was the key to the accuracy of the device and lighting was not a variable, but it was important to consider in future studies because it might vary in a common operating room. Unfortunately, both AR methods had a certain lack of accuracy; however, they are still in the range of acceptance to be used [57]. One of the articles showed AR implementation for the teaching of physiology and anatomy, key to the brain and mechanisms underlying dementia, where the feasibility of its implementation was evaluated. Comparisons were made with 24 students divided into two groups (12 in each group), one that used AR and the other with traditional models based on brochures with the same information. With AR it was possible to view the data with a cube facing the camera of a tablet, representing a 3D model of the brain, and receiving narrated information. The results were obtained through a 15-item multiple-choice questionnaire (MCQ) with similar information in both cases and nonsignificant variation; however, AR was perceived as highly useful for learning and understanding dementia [58]. The last article was based on the use of AR during the period of the COVID-19 pandemic to find places contaminated with COVID and thus be able to prevent the spread. Likewise, through AR, the graphical representation of the type of virus was achieved and how it can be treated. This study emphasizes that in medicine, AR has supported physiotherapy, psychotherapy, anxiety, stress, and pain management treatments, in addition to supporting surgical operations [11].