Invention by KTU scientists: “white cane” used by blind people will be replaced by piezoelectric probe

Pjezoelektrinis liestukas KTU

The only tool that helps blind people to navigate in space is the “white cane”. However, the latter not only does not meet the needs of the ever-changing modern society but hardly helps not to get lost in urban environment. When using the “white cane” blind people experience considerable inconveniences when trying to get from point A to point B, overcome obstacles, or identify the objects on the road.

After taking into consideration the evolving technologies and their application possibilities, the team of KTU scientists in cooperation with “Informacinių technologijų organizacija” has developed a system for blind people that enables the blind to work with 2D graphics and helps them to orient in space. A person with visual impairment only needs to have a tablet or a smart phone, and a special probe designed by scientists. With a smartphone hanging on a chest and a piezoelectric probe scanning its screen, it is possible to identify the obstacle and overcome it. The new system is also able to define the colour. How this device could facilitate life for the blind and replace the “white cane”, – this you will discover after reading our conversation with the project manager professor Ramutis Bansevičius.

Obstacle signalled by sound signal or an impulse

The probe scans the screen crossing certain lines and contours specific for a certain scenery, and the software turns them into electrical signals of certain frequency. The frequency of these signals depends on the lines, contours, or the colour of the background. After determining that a certain frequency corresponds to a certain colour, the blind person is able to understand not only the obstacle itself but also what colour it is. “Lens of a tablet or a smart phone located on a touch screen records the scenery that is filtered with the help of a software leaving only essential features of the object, for example, doors, stairs, pedestrian crossing, etc.” – Bansevičius R. described the principle of operation.

Electrical signals may be perceived in 2 ways: converting them into sound signals of audible range, or by transmitting them to Braille needles that are located in the probe and are in contact with the finger. According to the professor, blind people have extremely-well developed and sensitive hearing, therefore, the majority of them prefer impulse-based warning rather than sound signals. However, everyone has the right of choice.

Differences between the “white cane” and piezoelectric probe

To understand how a blind man feels among the objects that are obvious to us, professor suggest imagining being in a forest: “How a person with visual impairment can go through a forest without hitting against the trees? He only needs to hang a smart phone on his neck for the lens to record the scenery in front of him. The software filters out unnecessary details leaving only tree trunks. By scanning the screen with a finger (acoustic signal) or a probe (the effect of Braille needles to the finger), the blind person perceives the location of the obstacle and is able to overcome it”, – assured Bansevičius R. Thus, contrary to using the “white cane”, there is no need to touch the obstacle: the person is informed about the obstacle in advance. Moreover, this system also helps to recognize colours. Taking into account the technical capabilities and the price of the “white cane” and the piezoelectric probe, this is not an expensive invention. “Only piezoelectric probe needs to be manufactured, and the special application that may be constantly updated and improved is installed separately to the phone or a tablet. The cost of the probe is approximately LTL 50”, – said the professor.

Invention that awaits for recognition

This new system for blind people was presented at Vilnius Innovation Forum among the most advanced inventions. Since this is a new invention, mass production of piezoelectric probes has not been started – investors are sought. For the near future, further tests are planned to improve this device.

The invention “Probe intended for blind or partially sighted people to work with tablets and smartphones” (authors R. Bansevičius, M. Gudauskis, A. Žvironas, V. Jūrėnas, applicant – Kaunas University of Technology) has already been registered at the State Patent Bureau of the Republic of Lithuania. In 2014, the team of scientists is planning to obtain European patent.


Photo: Jonas Klėmanas, KTU