Problem

Microsurgery is a surgical discipline that combines magnification with advanced diploscopes, specialized precision tools and various operating techniques.
Training in this discipline is usually performed on living rats. This form of living simulator, has the advantage of being very realistic. However, it also has disadvantages, such as there is no room for trial and error, it has low availability for training outside the classroom, high operating costs, and few objective measures to analyze progress.

Process

• Understand and specify the user to identify pain points and potential improvements
• Specify the user requirements to define learning objectives and performance metrics
• Iteratively prototype and test different solutions with participants
• Analyze the data and conclude

User Research

Originally, microsurgery students were seen as the main users of the future simulator. However, if one digs deeper, it becomes clear that in addition to the students, the teachers must also be included, as well as the institute at which microsurgery is taught. Teachers should include the simulator in their teaching, and in return the simulator can provide data from which the teacher can better assess the students' skills. Institutes need to see value in the simulator as they provide the budget for such a simulator.

Here are the main techniques used for the User Research.

• Observations inside the operating theater and microsurgery school
• Semi structured Interviews with people involved in education
• Online Survey with 21 microsurgery students participating
• Map common Microsurgical procedures in a Flowchart

Specify User Requirements

3 training modules were created, each with its own learning objectives, instructions, difficulty levels, and performance metrics. To address key pain points identified during user research, we decided to use virtual reality because it offers benefits not covered by current simulators. Most important to us was the repeatability of the tasks and the ability to measure all movements, allowing for an objective evaluation of each student.

Prototyping

Prototyping in virtual reality is still uncharted territory and therefore requires creativity and sometimes unconventional solutions to arrive at a good Minimum Viable Product. One of the finished prototypes can be seen in the following video.

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Testing and Data Analysis

After several iterations of improvements and testing on the fly, we conducted a pilot study. We standardized the testing procedure that each participant went through to eliminate confounding variables. Depending on the experience our participants had with working manually under a microscope, we categorized them as experts, advanced, and novices.

During testing, we recorded the time taken to complete the task and the x-y-z coordinates of the right and left hands.  After finishing the experiment, we handed out a User Experience Questionnaire (UEQ) and the System Usability Scale (SUS).

It could be observed that the expert finished the task twice as fast as the two other control groups. A visual difference between the fine movements of our expert and the movements of the control groups could also be observed when recording the movements of the participants. The User Experience Questionnaire and the System Usability Scale revealed no significant problems in the handling of the prototype.

Conclusion

With our study we could show that it will be possible to build a microsurgical training simulator with a head mounted display and two haptic arms. Initial doubts about the feasibility due to technical problems could be dispelled. This work can be taken as a basis for future work to create a novel high fidelity simulator for microsurgery students.