Krzysztof Dobosz

OneHandBraille: An Alternative Virtual Keyboard for Blind People

This paper presents a new text entry method for visually impaired people called OneHandBraille. This gesture-based method uses only one user’s hand typing the Braille Code. Blind users do not have to learn a new code, some dots are simply replaced by swipes on the surface of a touch screen. The article describes the method, the evaluation of prototype implementation for mobile devices, and comparison to the most similar existing solution. The obtained results are encouraging and bring hope that the method can be useful in the real mobile application.

Mobile Gamebook for Visually Impaired People

The goal of the project was to create a mobile game application for Android OS platform that follows the rules of playing a gamebook. Developed application interacts with user using touch and speech interface, which is crucial in case of blind users. The paragraphs and general game data should be stored in external XML document. Game implementation introduced a form of entertainment for users with vision disabilities and established a speech and tactile interface implementation, which could be also used in implementation of other games, which target blind players.

Typing Braille Code in the Air with the Leap Motion Controller

The paper presents the new concept of typing the Braille Code. Developed method use a Leap Motion controller to recognize fingers responsible for typing proper Braille dots in the air. The recognition of input characters bases on the analysis of coordinates of the hands, fingers, phalanges and hand joints in three-dimensional space, which is observed by the controller. The arrangement of the hands doesn’t affect the accuracy of typed codes. Proposed method is implemented in the form of desktop application for personal computers. The evaluation shows the writing speed (7.4 WPM) and the MSD error rate (13.18%) comparable to Braille virtual keyboards using touchscreen.

Tablets in the Rehabilitation of Memory Impairment

The aim of this study was the analysis of existing sets of rehabilitation exercises for possible adapting them to mobile devices (tablets). We analyzed more than 300 different memory tasks presented on the pages of workbooks. Numerous tasks were classified to different categories because of the type of content and cognitive functions trained. For each type there was assigned a certain number of specific tasks. In each type the feasibility of adaptation for tablets (full, partial, impossible) and complexity of interaction (entering characters, indication, drag&drop) were evaluated. That is a big help for many older people (most of the patients in the Rehabilitation Center), because they have problems entering text with the virtual keyboard displayed on the screen.

One-Handed Braille in the Air

This paper presents a new concept the Braille typing by simple finger movements and swipe gesture in a 3D space. Braille codes are typed row by row. The content of the row is indicated by one or two fingers. At the end, a single swipe gesture must be performed to confirm a character. The best obtained results was 2.12 WPM. Although the value is low, the method has a significant advantage: it can be used for blind people with a paresis of one hand.

Continuous Writing the Braille Code

This paper describes a set of new methods of Braille character recognition with the use of mobile devices such as smartphones. In the frame of the studies, a set of four varying solutions was proposed, further called modes. They are: a simple mode, an acute angle mode, a minimum distance mode, and a scaled mode. Using them, the solutions are designed and implemented for the Android OS platform. The solutions were evaluated using a theoretical model called CLC (curve-line-corner). It was designed to deter-mine the speed of pen stroke gesture, although it is proven that there is no significant difference between pen and finger gestures, thus the results of the model appear to be valid. The model de-composes each stroke into simpler elements, allowing to calculate their production time using proper formulae. Once this is done the performance of the proposed solutions is compared with the existing ones. The results are satisfactory, as the average words per minute count was approximately 25. It is quite high result, although still on par with some of similar solutions.

Parallel Braille on Smartphones for Deaf-Blind People

The objective of this work is to develop an interaction method that uses the touch screen of smartphones and embedded vibration mechanisms. During the study, three methods of communication with deaf-blind were analyzed: Morse code, Braille code for one device, parallel Braille code for two devices. The new concept is the third one. The main device send one column of the Braille code to the second device, then both vibrate own columns of the current character. Analysis of methods was carried out by comparing the reading time and correctness of character recognition for different time units of vibration signals. Considering the fact that the efficiency and the correctness of the characters recognition of the parallel Braille are similar to Morse, this approach seems to be quite an interesting alternative for deaf-blind users.

Gamification of Cognitive Rehabilitation

Mobile applications have been introduced in the field of e-health for several years. The aim of this studies was the gamification of exercises used in the process of cognitive rehabilitation. Selected game elements have been incorporated to the mobile application. Then, three methods of evaluation was proposed: a questionnaire, the MMSE test, and a new universal factor independent on the exercise type. The factor allows the therapist to monitor and compare the progression in the rehabilitation. Pilot studies are finished, but the effect of gamification must be verified for a larger number of patients in longer time, because at present it cannot be unambiguously determined a positive influence of the gamification.

Touchless Virtual Keyboard Controlled by Eye Blinking and EEG Signals

The paper describes the idea of touchless virtual keyboard designed for disabled people with tetraparesis. Each key can be selected by three double eye blinks registered by EMG sensor. EEG signals are used as a support that allows the user to change the input mode of single characters to the mode of predicted words selection. The keyboard was implemented and evaluated during provided experiments. Obtained result (\(WPM=1.11\)) partially confirms the calculated typing speed (\(WPM=1.23\)). It is also found that the keyboard efficiency can be improved by using a list of predicted words, even the number of those words is low and they are short (\(WPM=1.27\)). Provided discuss presents that improved keyboard used by experienced users could achieve the typing efficiency even up to \(WPM=3.15\).

How to Control a Mobile Game

The aim of the study was the comparison of existing approaches of user interfaces for visually impaired people playing a mobile game. The mobile gamebook was taken into account as an example of the game. Seven different interfaces accessible for visually impaired people were studied analyzing the following aspects: interface reaction time, commands correctness, screen size influence, complexity of implementation, and number of available options. It was concluded, that perfectly accessible interface of a mobile game should consist of the lowest number of options as possible. When simple interfaces with limited number of options are designed, then swipes, multi-touch and sensors, due to the short reaction time and a high level of correctness of operations, are worth taking into account. The paper highlights, that the use of MVP design pattern allows developers to create mobile games with different methods of interaction, which can be changed in a runtime.