1. Technical Field
The present invention relates to a guiding tool for blind and visually impaired persons, and more particularly to such devices based on infra red directional light beams.
2. Discussion of the Related Art
Walking canes (also known as white canes or walking sticks) have been for many years the standard guiding tool for blind and visually impaired persons. Canes provide direct tactile information regarding obstacles in the blind's peri-personal space only, at a specified distance (of approximately 1.2 m), usually in a predetermined scan maneuver carried out by the person holding the cane.
Several attempts have been made throughout the years to replace the standard walking canes with electronic devices that provide similar or better indication regarding distances and the immediate environment. Known technologies used for distance sensing as a guiding tool for blind and visually impaired persons include: ultra sound, coherent light (laser), image processing, and parallax analysis.
One aspect of the invention provides a device for guiding a blind or visually impaired person by augmenting his or her ability to estimate the distance and shape of the objects within and outside the his or her peripersonal space. The device includes: one or more Infra Red (IR) emitter-sensor pairs, each pair having an emitter and a sensor pointing at a same spatial angle; a sensual signal generator; and an output unit. In operation, the emitter in each one of the pairs is configured to emit an IR light beam into a scene that contains objects, wherein each beam is associated with a unique direction and further creates an IR light spot on an object facing the emitter. Additionally, the sensor in each one of the pairs is configured to convert a direct IR reflections arriving from the spot associated with a respective emitter, into a respective electrical signal representative of a distance from the spot to the respective emitter. The sensual signal generator is configured to produce, for each IR reflection and based on the respective electrical signals and a respective conversion key, a sensual signal comprising an auditory signal and/or a vibratory signal, representative of the distance from the device to the one or more spots respectively. Additionally, the output unit is further configured to present a combination of the sensual signals to the blind or visually impaired person, such that each sensual signal associated with a unique direction is auditorily or vibratorily distinguishable from sensual signals associated with other directions.
Another aspect of the invention provides a method for guiding a blind or visually impaired person. The method may include the following stages: emitting one or more Infra Red (IR) light focused beams into a scene that contains objects, each beam is associated with a unique direction and further creates an IR light spot on an object facing the light beam; converting one or more direct IR reflections from the one or more spots, each associated with a unique direction, into respective electrical signals representative of a distance from the one or more spots respectively; producing, for each IR reflection and based on the respective electrical signals and a respective conversion key, a sensual signal comprising an auditory or vibratory signal, representative of the distance from the one or more spots respectively; and presenting a combination of the sensual signals, such that each sensual signal associated with a unique direction is auditorily or tactilely distinguishable.
These, additional, and/or other aspects and/or advantages of the embodiments of the present invention are set forth in the detailed description which follows; possibly inferable from the detailed description; and/or learnable by practice of the embodiments of the present invention.
For a better understanding of embodiments of the invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which like numerals designate corresponding elements or sections throughout.
In the accompanying drawings:
The drawings together with the following detailed description make apparent to those skilled in the art how the invention may be embodied in practice.
With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.
Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments and may be practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
When using two or more emitter-sensor pairs, as illustrated in further detail below, such that each pair is directed to a different predefined direction, person 100 may receive simultaneously the aforementioned spatial data associated with different directions that are distinguishable. Thus, in a top-middle-bottom partitioning of the space or center-left-right partitioning of directions that are distinguishable, person 10 may know which obstacles are associated with which height, a property currently lacking in standard walking canes.
Consistent with one embodiment of the invention, both emitter 240A and sensor 250A are coupled each with a scanning unit 280 and 290 respectively. scanning units 280 and 290 are configured to co-ordinately move the IR light beam 270A and respective detection cone 260A so that the scene is being scanned in a predefined pattern known or determined by the user so that device 100A may remain stationary.
According to another embodiment of the present invention, several pairs of IR emitter-sensors are provided as shown in
Consistent with one embodiment of the invention, the conversion key used for converting IR reflections into sensual signals indicative of distance may be unique for each pair and selected such that the vibratory signal exhibits, for example, higher values of at least one of: frequency and amplitude, for shorter distances, or activates actuators on different locations on the person's body. Similarly, the conversion key may be unique for each pair and selected such that the auditory signal exhibits higher values of at least one of: pitch and amplitude, for shorter distances.
Consistent with one embodiment of the invention, the conversion key is unique for each pair and selected such that it assigns a specified modulation for the auditory and vibratory signals respectively. These modulations may be, in the case of vibratory signal—different types of vibration waveforms. In the case of auditory signals—different types of audio waveforms that may be distinguishable, for example by representing different types of musical instruments.
Consistent with one embodiment of the invention, the one or more emitters are selected such that the respective IR light beams exhibit a beam angle equal to or smaller than 5° while aiming at a distance associated with a standard walking cane being 1.2 m, and in some applications, for distances above 4 m, a beam angle smaller than 1° would be preferred.
Consistent with one embodiment of the invention, the one or more emitters are selected such that the respective IR light beams exhibit a refresh rate equal to or greater than 50 Hz. The applicants have discovered that such a refresh rate is sufficient to maintain continuous indication of the distance over time, while scanning the scene using the device according to embodiments of the present invention. The continuous indication of distance is advantageous in providing an enhanced spatial perception of the scene as it enables a realistic study of the shapes, the orientation and relative location of the objects within the studied scene.
Consistent with one embodiment of the invention, the one or more sensors further comprise a colour detector configured to generate colour indicator signals based on specified wavelengths of colour light received by the colour detector, and wherein the sensual signal generator is further configured to generate at least one of: an auditory signal or a vibratory signal also based on the wavelength of the received colour light from each one of the one or more sensors. Additionally and alternatively, a specified modulation may also be applied to the signals thus conveying the information via the modulation parameters.
Consistent with one embodiment of the invention, wherein the sensual signal generator is further configured to assign a unique musical instrument for each auditory signal associated with an IR reflection arriving from a different direction.
Consistent with one embodiment of the invention, the light beams exhibit a refresh rate sufficiently high and wherein the conversion keys are calibrated such that pointing the one or more emitters continuously yields a distinguishable change in the auditory or vibratory signals. Alternatively, the light beams exhibit a refresh rate sufficiently high and wherein the conversion keys are calibrated such that a continuous change in the distance from the device to the one or more spots results in a continuous change in the respective auditory or vibratory signals.
Consistent with one embodiment of the invention, the device may be designed to weigh below 200 grams. Similarly and alternatively, the sensor and the emitter may be located within a compact housing so that the emitter-sensor pair is located within 7 cm from each other. Advantageously, these dimensions enable the use of the device according to embodiments of the present invention as a scanning tool usable for studying the spatial characteristics of the scene.
Consistent with one embodiment of the invention, the conversion key is unique for each pair and selected such that the vibratory signal exhibits higher values of at least one of: frequency and amplitude, for shorter distances. Additionally or alternatively, the conversion key is unique for each pair and selected such that the auditory signal exhibits higher values of at least one of: pitch and amplitude, for shorter distances. Additionally or alternatively, the conversion key is unique for each pair and selected such it assigns a specified modulation for the auditory and vibratory signals respectively.
Consistent with one embodiment of the invention, method 400 may further include the stage of sensing a colour wavelength of the object associated with each spot; producing an indicator signal based on sensed wavelengths of colour light; and generating at least one of: an auditory signal and/or a vibratory signal based on said wavelength of the received color light of the respective objects.
Consistent with one embodiment of the invention, method 400 may further include the stage of assigning a unique musical instrument for each auditory signal associated with an IR reflection arriving from a different direction, such that the respective auditory signal is presented in the assigned musical instrument.
Consistent with one embodiment of the invention, method 500 may further include the stage of refreshing the light beams in a rate sufficiently high and calibrating the conversion keys such that pointing the one or more light beams continuously, yields a distinguishable change in the auditory or vibratory signals.
Consistent with one embodiment of the invention, method 500 may further include the stage of refreshing the light beams in a rate sufficiently high and calibrating the conversion keys such that a continuous change in the distance from the person to the one or more spots results in a continuous change in the respective auditory or vibratory signals.
While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the preferred embodiments. Other possible variations, modifications, and applications are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB11/55774 | 12/19/2011 | WO | 00 | 11/12/2013 |
Number | Date | Country | |
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61427185 | Dec 2010 | US |