Radiography Virtual Reality Simulator

Jarek Stelmark, Assistant Professor
Allied Health Sciences

 

E-learning, virtual learning and mixed reality techniques are now a global integral part of the academic and educational systems. Simulation is a technique for practice and learning that can be applied to many different disciplines and trainees. It is a technique to replace and augment real experiences allowing immersion in a dimension that reproduces substantial aspects of the real world in a fully interactive fashion. Virtual reality simulations help to attenuate errors and preserve a culture of safety, especially in radiation imaging field where there is very low tolerance for any deviation from set radiation protection standards.

 

In this interdisciplinary project Prof. Stelmark, Dr. Czarnocha and Dr. Biao joined forces to evaluate if the virtual reality laboratory simulations help radiologic technology students master the radiographic technique computation problem solving skills in digital computed radiography cassette and direct radiography cassette-less radiography environment. Simulations of different clinical situations and exposure indicator standards may allow students to develop computational fluency when formulating radiographic techniques and gained self-confidence and deeper interest in the more challenging material. Furthermore, these students become technologists and their confusion with the nuances of exposure computation may continue throughout their career and may result in continuous application of unnecessary radiation to patients.

 

Radiography program faculty will incorporate the virtual reality laboratory simulations into his Radiologic Science I course during the Spring 2018 semester. Virtual reality simulation will give the perception of a real clinical environment. Imaging procedures will be conducted from behind a lead impregnated glass window just above the x-ray machine console. Trainees will have to initiate all exposure from behind the console unit and he or she will have an option to use either computed radiography unit or direct radiography unit. The console unit will allow, just like the real clinical unit, the trainee to manipulate various technical factors like: kVp, mA, exposure time, focal spot size, image receptor speed class, SID, OID, and SOD. In addition, the trainee will be able to change radiographic grids ratios when exposing thick and dense body parts. Furthermore, radiation dose delivered to the image receptor (cassette) could be expressed with various descriptors (indicators) like lgm, EI, or S number. The trainee will also have ability to turn off the brightness correcting algorithm to observe how radiation dose affects the image brightness. The lab manual will have techniques deliberately set too high or too low. The trainee will expose the virtual patient with these technical factors outside of the optimal diagnostic range. He or she will process the image receptor, analyze exposure index (dose descriptor to the image receptor), analyze signal to noise ratio, and the radiation dose delivered to a virtual patient. It will be then up to the trainee to determine which technical factor or factors will have to be adjusted during the repeat exam to generate new image with an optimal radiographic quality and minimum radiation dose.

 

The Radiography Simulation Module is hosted by the simulation server as a Web service and is designed and maintained by the Natural Sciences department faculty. The student user is required to sign in with his/her user name and password to access the simulation tool. The simulation server will record the visit information, such as login time and length of visit, of each user to facilitate pedagogical research at the end of the term. The student user can practice using most personal digital devices such as a smart phone, laptop and desktop since the simulation system is programed as a Java applet which is allowed to be embedded in a webpage.

 

Simulation module is the core of this project, and it consists of three components: control panel, scanned image and animation of electron flow. The control panel is designed to have the same user interface as that of the real radiography system in the radiology lab. A student is able to adjust several parameters using buttons on the panel. Ideally, if a student logs in with a device enabled touch screen, he/she could have the same experience in operating the equipment as if he/she were in the lab. Without the need to share a limited number of expensive equipment with peer students, a student is free to explore the function of the equipment so as to avoid operating radiography system mistakenly in the lab. When a student finishes adjusting all parameters and is ready to start the scan, all input will be collected and used to generate the resultant image.

 

Image area has the function of editing the preselected image based on the choice of parameters, which allows a student to identify the change of image based on his/her operation. Meanwhile, a simulation module will play animation of electron flow differently according to the user input. Motion of invisible particles is presented in an intuitive way, and could better illustrate physics principle behind the real-life application.

 Virtual Reality Component

To enhance the user experience of 2D animation, virtual reality technology is introduced to provide the user with an immersive environment of learning. Once a user sets the parameter in a simulation module and starts the scan, a 3D virtual reality environment will be constructed to display the motion of electrons as well as the parameter setting. VR component allows the user to get close to an X-ray in a safe way.

 

 

 

 

 

 

 

                                                                                               

                                                                                       

 

 

 

 

                                                                                                       

 

Mathematics Pedagogy of the VR Prototype.

The physics and mathematics of every “radiology situation” is short. The collection of problems and conceptual questions, which address every variable in the relevant formula is followed by the general proportion problem involving them has been developed.

 

Example: Electromagnetic Radiation. Tube Current and Exposure Time. mAs reciprocity.

  • What mA station was used to generate 40 mAs, when 0.05 sec time was used?
  • What time was used to generate 100 mAs when 100 mA station was used?
  • The original image was generated using 0.8 sec and 200 mA. Due to the motion the image must be repeated with 0.4 sec and _______mA to generate the same mAs like the original image.
  • A general problem

 

The problems will be calculated and checked against relevant simulation. The computer simulation will serve both as the generator of problems grounded in “simulate/virtual” reality and as a check for students’ mathematical computation. Special simulation will be designed which will coordinate the computation, visual experience and graphs of proportional quantities.

 

Research Questions:

  1. Did the students find the virtual reality lab simulations helpful?

It will be answered by administering a survey to students at the beginning and the end of the semester.

  1. Did the virtual reality fully-interactive lab assignments improve students’ ability to compute radiographic technique?

It will be answered from regression analysis on the relationship between the final grade (dependent variable) in the course and the average of grades obtained on the weekly post-virtual laboratory assessment quizzes (independent variable).

  1. Which technique factors computation was improved the most?

It will be answered from the analysis of students’ performance on the weekly post-virtual laboratory assessment quizzes.

  1. How did the frequency and length of interactions with the virtual reality lab simulations affect student learning?

It will be answered from regression analysis on the relationship between the frequency and length of interaction with the virtual reality lab simulations and the final grade in the course.

  1. Which group of students’ benefited the most from interactions with the virtual reality labs?

It will be answered from the analysis of students’ group performance on the weekly post-virtual laboratory assessment quizzes.

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