# Gesture-Based User Interface for Vehicle On-Board System: A Questionnaire and Research Approach
## 4 Evaluations
### Characteristic of Research Group  
Research study was conducted of two stages: (1) a NUI topic e-survey and (2) a set of gesture recognition experiments. A total of 40 voluntary participants took part in the first stage, including 23 fully physically fit people and 17 with mobility disabilities, regardless of gender. The survey results are presented in the Appendix A, Figure A1. The prepared survey included both questions about the determination of physical characteristics (e.g., degree of disability, type of disability) and determining knowledge about NUI. Most of the respondents (84%) were active vehicle drivers and 69% of all participants think that technology can significantly help decreasing the disability barrier during vehicle using. 74% of our respondents were severe disabled and 22% of them had a moderate disability. The remaining 4%, They were participants with a light disability. All of our respondents have any of steering aid tools in their cars, which means that their cars had to be specially adapted. Half of respondents knew what NUI means and They could identify popular NUI types (e.g., gesture-based recognition interface or voice-based interface). But, very important is, that most of them (52%) did not use NUI technology before. Thanks to this, these people could be invited for further research on GRI experiments. Thus, a total of 13 voluntary participants took part in the second stage, including 4 fully physically fit people and 9 with mobility disabilities, regardless of gender (Table 2). It must be noticed that all disabled participants were physically independent and all of them had all upper and lower limbs. The age distribution of 13 people who took part in the research experiment is as follows: under 30 (u_01, u_02, u_03, u_08, u_11), 31-40 (u_04, u_09, u_10, u_12) and over 41 (u_05, u_06, u_07, u_13). Below, there is a brief description of people with disabilities. U_02 suffers from cerebral palsy, four-limb paresis with a predominance of the left side. The left hand of the subject is spastic. Three weeks before testing, this hand was operated on for wrist flexor tenotomy. The user is not able to activate by this hand any of car switches in a conventional way. Right hand is functional, and the strength in both limbs according to the Lovet scale is 4/5. Research for the right hand did not show any differences from the test scenarios. The results are different for the  
Figure 4: The sensor location: in the center dashboard (**top**), near the armrest and gear shift (**bottom**). left hand. Some gestures are not recognized immediately and They need to be repeated several times. They also require additional focus of user to the movements performed. The left hand during the tests tried quickly, increased spasticity was observed. This could be due to the patient's illness, as well as the surgery three weeks before the test. U_03 suffers from a (lat. myelomeningcoele) in the lumbosacral segment, between the L5 and S1 vertebrae. He has paresis of lower limbs, so he uses the manual mechanism of gas and brake. He has a problem with reaching for the side window opening buttons and controlling the multimedia system and air conditioning (he controls them only when the vehicle is not moving). This is due to the location of the buttons. For this person, a more convenient location of the depth camera turned out to be place near the gear shift lever, due to having in his car a specialized equipment that requires constant use of the hand to control the gas and brake. The same condition occurs in u_04,..., u_08. U_09 suffers from a rare disease-type 4 of mucopolysaccharides, and because of this she moves with crutches every day. The biggest problem for this participant is getting in and out of the vehicle due to degeneration of the hip joints. She quickly got used to the gestures of the gesture-based system and it became intuitive for her. She preferred the location of the camera near the gear shift lever.