The starting point of the development was to make measurable and long-term traceable mental and physical abilities limited by traditional testing tools. How can we perform effective and accurate aptitude tests, mental health assessments on people even in their homes, without the stressful situation associated with clinical trials? The answer was the development of an exciting, challenging, yet fun measuring tool, GraviTab. The process of play, as a spontaneous, self-forgetful activity, provides an excellent opportunity to examine concentration, sensorimotor abilities, and other hard-to-measure areas. Mobile phones and broadband internet access have made it possible to transmit measurement data quickly, allowing the expert to evaluate the results without physical contact.

The hardware

The hardware part of the GraviTab game is a 40-centimeter-diameter, circular, hand-held skill game in which the user tilts a metal ball in a track system according to the selected task type by tilting the board. An LED was placed in each node of the hexagonal grid-shaped path system to illuminate the selected task in red, green, and orange. For example, in “Collect and Avoid in Game”, the goal is to “collect” all the green dots bypassing the red light nodes. In addition to the multicolor LEDs, an induction coil was placed in the nodes to sense the passage of the metal ball. Passes through the node are timestamped in the web server database, so the entire process of the game being played can be reproduced later, which is the basis of the evaluation process. In addition to passing through the nodes, the fine movements performed by the device - the tilting of the board - are measured with a gyroscope built into the device. The data of this is also stored in the online database, on the basis of which the analysis of the player's movements can be realized. Did you consciously, firmly, move the ball with subtle movements, or did you try to solve the task with possible, high-swinging tilts? The process of problem solving and the related - continuously recorded - movements are the two layers of information, which can be combined to reveal interesting correlations about reaction times, memory, about eye-hand coordination, problem-solving ability.

The software

Gravitab, as a physical device, has been treated as a hardware peripheral since the beginning of development. We wanted to put as little logic as possible into the device itself. The entire program logic was installed in the mobile application and the server-side application for easier development. On a hardware device connected via Bluetooth, similarly to an interactive screen, we only wanted to display the task issued by the mobile application, as well as detect the user's movement, the progress of the task solution with sensors, and send the sensor data to the mobile application.

The application

The Android application that can be installed on a mobile phone (we plan to develop an iOS application later) provides the following features:

• User registration: by entering age, gender, health status
• Login (the subject logs in on their own or their doctor logs in on behalf of the patient)
• Game management: we have developed different games for different test areas (reflex, memory, concentration, etc.), from which the user can choose which one he wants to play with.
• During the game, the Android application controls the Gravitab hardware device, the application turns the LEDs on and off according to the selected task, and detects the goals achieved during the game.
• After the game is over, you can see a quick statistic of the results, which includes:
• Playing time, playing time corrected for error points
• Number of steps (passing through a node with the ball), its ratio to the minimum number of steps
• Average ball speed
• Number of errors
• Amplitude of the tilt of the board - plotted on a graph, percentage of fine, medium and large movements

The application transmits all information related to the games to the web server database, assigned to the given user, which can be used for comparative tests and analyzes later.

To compare the user's game results, the Comparison function must be selected in the application, where the user can compare his performance with his own previous game results or with the results of his reference group. By reference group we mean people of the same age, gender and health status as the user. However, in order to carry out such a comparison effectively, it is necessary to test a large number of people, only in this way can we collect a representative amount of data. Our long-term goal is to have standardized results for the most popular game types. This can be a good starting point for assessing the condition of any patient.

Web server

As mentioned earlier, after the completion of a game, the mobile application sends all game data to the web server, where it is stored in an online database assigned to the user's identity. These can be retrieved at any time, from anywhere, and are suitable for analyzes and long-term follow-up studies.

The following data is stored in the database:

• User information
• Game type, ID
• Date of game
• Playing time
• Achieved game goals
• Errors
• Time-stamped passages through nodes
• Recording movements with the board based on gyroscope data (50 data / second)

Summary

The ability to play and play ideally accompanies a person throughout his life. In the case of children, it is an important element of mental and physical development, in adulthood it provides the opportunity for active recreation and regeneration. It helps to preserve the mental state in old age.

The GraviTab sensor motor development game combines the benefits of manual action that requires in-depth concentration with a digital world that connects multiple users. The hardware part of the GraviTab game is a real, tangible skill game in which the user tilts a metal ball in a level system according to the selected task type by tilting the board. The issuance of tasks and the evaluation at the end of the game is already done by a smartphone app. This allows for measurability in the skill development game, a comparison of the user's performance in the same task type with their previous performance and their peers playing with GraviTab. The GraviTab tool is also excellent for suitability tests, with targeted task types appropriate to the field.