An ultrasonic aid for blind

Like everyone, a blind person has to meet his casual needs. The essential capability to meet these needs is mobility. When he meets his indispensable needs, at the same time he can be part of social life. The conventional way for a blind person to obtain mobility is by using a white cane. To move forward he can check the sidewalk by swinging the cane right and left. In this way he gets freedom to some degree. But this kind of freedom brings along some handicaps. While using the white cane with one hand the blind person has only one hand free for other activities. So the blind person has to do activities such as pushing, pulling, holding, catching with only one hand. With the stick in one hand for the blind person it is difficult to counteract immediately in situations such as tripping or falling. In addition to that, a blind person has to be warned of hot objects. A blind person usually has no equipment to avoid contact with objects such as a teapot, a glass of hot water or a hot saucepan. This can lead to serious injuries. With this project, it is intended to meet the everyday challenges of a blind person as mentioned above. Due to some special features the introduced product enables the blind person to use both hands for his activities. Today, ultrasonic applications are used in many areas, in particular in biomedical practice. Ultrasound technology is affordable and harmless for the environment and the user. In this project, an ultrasonic sensor (HC-SR04) is used to measure distance, a special feature to make life easier for blind people. The user moves forward while keeping his hands at a certain height and parallel to the ground. When he is getting closer to an object, the system gives a signal in increasing frequency. Furthermore the product has a temperature sensor. If the temperature perceived by a infrared thermometer reaches a certain level, the system alerts the user. It is possible to define the threshold value for the alert freely. The system presents a solution not only for blind but also for deaf people. The user is warned in a tactile way by a servo motor when he is getting to close to an object. The product is designed taking into consideration the ergonomic structure of the user's hand. The design has taken into consideration further factors such as user friendliness and costs.