Clinical practice is one of the most essential parts of medical education. Clinical practice plays a very important role in nurturing high-quality medical personnel by learning through practice how the theoretical contents of the medical education course are used in the actual clinical field [1,2]. For this reason, equipment for clinical practice is being developed and advanced. However, although various equipment and materials are used for clinical practice, there is a problem of using only a limited environment and model for clinical practice due to many limitations of the practice room and laboratory. Accordingly, many medical educational institutions perform only fragmentary clinical practice, and experience to understand the actual clinical field is not sufficiently provided. This situation in which the provision of experience is not sufficient makes it difficult for trainees to understand the anatomical features and may cause problems of clinical practice [1,3,4]. To solve the problem of clinical practice, medical educational institutions or trainees use various methods. Typically, mutual practice is performed between the patient and the trainee or between the trainee and the trainee, or a high-quality anatomical model is separately prepared and used for practice. However, the method of conducting mutual practice between the patient and the trainee or between the trainee and the trainee has disadvantages such as ethical or stability problems and difficulty in securing patients suitable for clinical practice, and the method of performing practice through a high-quality anatomical model requires a lot of time and money to search and purchase a high-quality model suitable for clinical practice, and it is difficult to respond to unexpected situations that occur in actual clinical practice. To solve these shortcomings, simulators using virtual reality (VR) or augmented reality (AR) technology are being used for clinical practice in many medical education fields [5,6]. In Northampton university, in order to improve nursing students' ability to respond to clinical situations, a virtual reality simulation product that integrates four HMD (Head mounted display) devices and a large screen was developed. Through this, nursing students can experience various clinical scenarios in a virtual environment, learn and verify clinical practice and communication skills [7]. Ox-ford University developed OMS (Oxford Medical Simulation) to improve the clinical practice of nurses, doctor and medical students working at John Radcliffe Hospital. through this simulation, clinical practice in nursing education, medical emergencies, pediatrics, internal medicine, mental health care, and physical examination can be learned and verified [7,8]. Falah et al. [9] developed a virtual reality-based cardiac anatomy education system using stereo 3D glasses to solve the problems of existing visualization-based anatomy education methods, and confirmed its usefulness through a group of medical experts. Schild et al. [10] developed an emergency response training simulation for anaphylactic shock, and improved training efficiency by adding a module so that two trainees and one educator can access the simulation at the same time. Pulijala et al. [11] developed a virtual reality education tool for loft type 1 fracture using HMD and Leap Motion(Ultraleap, Silicon Valley, US) [12], and verified the usefulness of the virtual reality education tool through a surgeon to confirm the potential of VR surgery for orthodontic surgery training. Ropelato et al. [13] produced an augmented reality-based microsurgery simulator that works with AR glasses for micromanipulation training in ophthalmic surgery, and verified the effectiveness of the simulator with 50 trainees. As a result of the verification, it was confirmed that the training method through the simulator improved the fine manipulation ability compared to the existing training method. Rhienmora et al. [14] developed a dental practice simulator using a haptic device and an augmented reality algorithm AR Toolkit [15], and several educators and experts identified the advantages and disadvantages of the technical practice simulator to confirm the potential of augmented reality technology in the field of dental practice. Si et al. [16] enhanced CT data-based brain 3D models to 3D printed skull models, developed an educational simulator that can train brain tumor resection through Hololens [17] and two haptic devices, and confirmed the usefulness and potential of augmented reality technology in neurosurgery training.

Many medical educational institutions and hospitals are developing and utilizing virtual reality or augmented reality-based clinical practice tools for training in various medical fields. However, studies on the development of simulators based on virtual reality or augmented reality related to vein blood sampling practice are still incomplete. Vein blood sampling is the most commonly used method of blood sampling, and as one of the methods of mass blood sampling, it is the act of extracting blood from veins. It is used to distinguish blood types, check various physiological indicators, and diagnose diseases. Then, a vein blood sampling interaction plan is implemented to perform vein blood sampling through 3D model manipulation using interactive equipment. Finally, the effectiveness of the simulator was evaluated by performing a usability test on the vein blood sampling simulator implemented for trainees in medical educational institutions. Therefore, this paper proposes a plan to develop a vein blood sampling simulator using virtual reality and interaction equipment. To this end, an environmental 3D model, an interactive 3D model and a blood vessel 3D model related to vein blood sampling tools are created to construct a virtual space similar to the actual space for vein blood sampling, and a virtual space is created using a virtual environment production tool. Then, a vein blood sampling interaction plan is implemented for performing vein blood sampling through 3D model manipulation using interactive equipment. Finally, we would like to evaluate the utility of the simulator by performing a usefulness test on the vein blood sampling simulator implemented for educators in medical education institutions.

This section may be divided by subheadings. It should provide a concise and precise description of the experimental results, their interpretation, as well as the experimental conclusions that can be drawn.

In this paper, a method for developing a vein blood sampling simulator based on a virtual environment was proposed, and the effectiveness of the developed vein blood sampling simulator was confirmed. The environmental model, interaction model, and blood sampling models used in the vein blood sampling simulator were created using 3D CAD software, and a patient 3D model including an anatomical 3D model was created and used to improve the realism of vein blood sampling, and information such as rigid body and collision was created for smooth interaction of each model using Unity. And, for interaction with virtual objects in the Unity environment, an interaction method using HMD controller-based ray-cast and an interaction method using haptic device-based collision were implemented and applied to the simulator. Then, in order to verify the effectiveness of the vein blood sampling simulator, usability evaluation was conducted on 40 dental students, and as a result, the validity of the vein blood sampling simulator was verified. As a result, it was confirmed that the practice of vein blood sampling is possible through the proposed vein blood sampling simulator.

However, it was confirmed that the proposed vein blood sampling simulator method was not suitable for application to the evaluation of vein blood sampling skills because it was difficult to evaluate the user's vein blood sampling practice process in real time and objectively. In the future, we will study the method for applying the proposed vein blood sampling simulator to the evaluation of vein blood sampling skills. To this end, we plan to develop a multi-access module that allows a large number of people to access the simulator so that the vein blood sampling practice process can be checked in real time, and we develop artificial intelligence model for evaluation of vein blood sampling techniques to objectively evaluate the user's vein blood sampling technique process.