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WO1998014149A1 - Method and device for facilitating the movements of the visually handicapped - Google Patents

Method and device for facilitating the movements of the visually handicapped

Info

Publication number
WO1998014149A1
WO1998014149A1 PCT/FI1997/000491 FI9700491W WO9814149A1 WO 1998014149 A1 WO1998014149 A1 WO 1998014149A1 FI 9700491 W FI9700491 W FI 9700491W WO 9814149 A1 WO9814149 A1 WO 9814149A1
Authority
WO
WIPO (PCT)
Prior art keywords
frequency
reflected light
amount
signal
strength
Prior art date
Application number
PCT/FI1997/000491
Other languages
French (fr)
Inventor
Onni Ilmari HYTÖNEN
Original Assignee
Hytoenen Onni Ilmari
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hytoenen Onni Ilmari filed Critical Hytoenen Onni Ilmari
Priority to AU40161/97A priority Critical patent/AU4016197A/en
Publication of WO1998014149A1 publication Critical patent/WO1998014149A1/en

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61H—PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY
    • A61H3/00—Appliances for aiding patients or disabled persons to walk about
    • A61H3/06—Walking aids for blind persons
    • A61H3/061—Walking aids for blind persons with electronic detecting or guiding means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
    • G01C3/00—Measuring distances in line of sight; Optical rangefinders
    • G01C3/02—Details
    • G01C3/06—Use of electric means to obtain final indication
    • G01C3/08—Use of electric radiation detectors
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61H—PHYSICAL THERAPY APPARATUS, e.g. DEVICES FOR LOCATING OR STIMULATING REFLEX POINTS IN THE BODY; ARTIFICIAL RESPIRATION; MASSAGE; BATHING DEVICES FOR SPECIAL THERAPEUTIC OR HYGIENIC PURPOSES OR SPECIFIC PARTS OF THE BODY
    • A61H3/00—Appliances for aiding patients or disabled persons to walk about
    • A61H3/06—Walking aids for blind persons
    • A61H3/061—Walking aids for blind persons with electronic detecting or guiding means
    • A61H2003/063—Walking aids for blind persons with electronic detecting or guiding means with tactile perception

Definitions

  • This invention concerns a method and device intended for visually handicapped persons, or, more precisely, a method and device by means of which visually handicapped persons can easily follow the white line at the side of a road, for example.
  • One device in use is an ultrasound radar, which provides a visually handicapped person with an audible warning of a possible collision.
  • This device does not, however, precisely indicate the direction of an obstacle, because the ultrasound beam it transmits is about 10 degrees wide. The beam cannot be narrowed, because narrrow beam radar will create too weak an echo from soft material.
  • One proposed device processes the video signal from a CCD camera to give an electrical stimulus to the optic nerves in the fundus of the eye, or to a separate sensor plate.
  • the device is impractical, as the image it provides is too vague.
  • this invention is intended to create a method and device by which a visually handicapped person can easily and safely follow the line at the side of a road, for example, or differently coloured lines drawn in the corridors of a hospital and which guide patients to desired places.
  • the method and device according to the invention can also be used, for example, to read bar codes located on adhesive labels at suitable places in a town, and which provide information that can be read by a device according to the invention.
  • An additional purpose is to create a method and device by which the desired information can be received as an audible signal or, for example, as a vibration or similar movement related to the device.
  • the drawing shows a diagram of the basic construction of a device developed to implement the method according to the invention.
  • the basic components are an oscillator 7, the frequency of which can be adjusted within set limits by using a suitable control.
  • the oscillator 7 controls an amplifier 3, which provides voltage for a laser 1.
  • the light emitted by the laser 1 is controlled by optics 9.
  • Optics 2, on the other hand, controls phototransistors 4 and 5. But there may be three transistors, for example, instead of the two shown.
  • Phototransistor 5 controls the audible channel amplifier 10, which feeds audible frequencies to earphones. The sound volume can be controlled conventionally by a suitable control.
  • Phototransistor 4 controls amplifier 8.
  • the luminous point of the laser 1 moves to transistor 4, whence amplifier 8 drives oscillator 7, for example, altering the frequency from an original 400 Hz to 500 Hz.
  • the frequency can be altered in several steps, if the object continues to approach, as a separate phototransistor and amplifier are provided for this purpose.
  • the frequencies can be selected freely and those given are only examples.
  • the device now invented differs essentially in its operation from previously known devices. It has no deflection of the laser ray or field of vision. Instead, the ray of light of laser 1 is modulated to a certain frequency which is received directly through a photosensitive element, particularly a phototransistor 5, and an amplifier 10. Besides the actual reception channel, there is thus at least one other channel for altering the modulation frequency of the laser at a set distance from the device.
  • the operating principle relies on the fact that a change in the illuminance of a point in the path of the laser ray causes a change in the sound volume, making it easy to follow an object that is lighter and therefore more reflective.
  • the device can be very small - the size of a flashlight, for example - with the transmission optics 9 and reception optics 2 located in the front of the case surrounding the device, and the other components located suitably.
  • the visually handicapped generally have sensitive fingertips, because they read Braille with their fingers.
  • Advantage can be taken of this, in a device according to the invention, by equipping it with a raised dot 11 , for example, to which a received signal can be fed as vibration in addition to, or instead of, an audible signal.
  • the figure shows how raised dot 11 can be connected externally to a device according to the invention by means of a flexible ring 14, for example, on the finger of the user.
  • the raised dot can also be suitably connected to the case of the device itself. If required, it is possible to use a switch, not described here, to select the indicator device, earphones or raised dot.
  • Converter 6 can convert the frequency of the vibration to a relatively low level that is easy to detect.
  • Switch 15 which alters the angle of the laser can also be connected to the invention, thus allowing the device to identify contrasts only from an area within a certain, predetermined distance. This characteristic can focus measurement and prevent points farther away from interfering with the signals given by the device.
  • the construction described above is very simple and cheap to build. Thanks to the small number of components, it is also highly reliable. A particular advantage is that it can be used to read variations in contrast, which no previously known device has been capable of. As stated above, this permits the user to follow, for instance, a line beside a road or other objects by simply moving the laser ray transversely to the line, and to obtain precise information on the direction of the lighter area.
  • a device according to the invention can also be used to read bar codes in which dark and light areas alternate in a known manner.
  • a device for processing the information contained in a bar code can be included in the device or can form a separate unit, as illustrated by reference number 12 in the figure. In this way, guide signs for the visually handicapped can be easily arranged by sticking bar code labels conveying certain information onto traffic-light posts at the corners of streets.
  • the device can be easily developed to express certain standard codes in the form of speech read by the device.
  • the invention can be adapted in many ways without deviating from the inventive idea and scope of protection of the accompanying Claims.
  • the case of a device according to the invention can be small and can be shaped as desired.

Landscapes

  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Pain & Pain Management (AREA)
  • Physical Education & Sports Medicine (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Engineering & Computer Science (AREA)
  • Epidemiology (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Rehabilitation Therapy (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Optical Radar Systems And Details Thereof (AREA)
  • Rehabilitation Tools (AREA)

Abstract

The object of the invention is a method and device for facilitating the movements of the visually handicapped. According to the invention, a laser is modulated to a certain frequency and the reflected light of the aforementioned frequency is received by a photosensitive element (5) and converted to audible or mechanical vibration signals in proportion to the amount of reflected light.

Description

Method and device for facilitating the movements of the visually handicapped
This invention concerns a method and device intended for visually handicapped persons, or, more precisely, a method and device by means of which visually handicapped persons can easily follow the white line at the side of a road, for example.
When visually handicapped persons move about out-of-doors, they usually rely on a white stick and possibly a guide dog. Although a wide range of devices exploiting senses other than the sense of vision have been theoretically developed to aid the visually handicapped, only a few of them have been actually put to practical usage.
One device in use is an ultrasound radar, which provides a visually handicapped person with an audible warning of a possible collision. This device does not, however, precisely indicate the direction of an obstacle, because the ultrasound beam it transmits is about 10 degrees wide. The beam cannot be narrowed, because narrrow beam radar will create too weak an echo from soft material.
Numerous other applications are known, few of which have gone further than trial operation. One proposed device processes the video signal from a CCD camera to give an electrical stimulus to the optic nerves in the fundus of the eye, or to a separate sensor plate. The device is impractical, as the image it provides is too vague.
Other known devices proposed for use by the visually handicapped - those described in US patents 5307137, 3654477 and 5487669, for example - are used to measure distance and operate mainly on the radar principle. They are both expensive and complex in their construction. The use of a variable-frequency audible signal to continuously indicate the distances measured, as proposed in the last of the publications listed above, causes an annoying cacophony of sound because the device varies the frequency the whole time - even in response to small unintentional hand movements. Thus, instead of a precise estimation of distance, the device creates an unbearable noise of varying frequency. Another drawback with all the solutions described above is that none of them can indicate differences of contrast.
Thus, this invention is intended to create a method and device by which a visually handicapped person can easily and safely follow the line at the side of a road, for example, or differently coloured lines drawn in the corridors of a hospital and which guide patients to desired places. The method and device according to the invention can also be used, for example, to read bar codes located on adhesive labels at suitable places in a town, and which provide information that can be read by a device according to the invention.
An additional purpose is to create a method and device by which the desired information can be received as an audible signal or, for example, as a vibration or similar movement related to the device.
The above and other advantages and benefits of this invention have been achieved in the characteristic manner described in the accompanying Claims.
In the following, the invention is described in greater detail by reference to the accompanying drawing, which shows a diagram of the basic features of a device developed to implement the method according to the invention.
Thus, the drawing shows a diagram of the basic construction of a device developed to implement the method according to the invention. The basic components are an oscillator 7, the frequency of which can be adjusted within set limits by using a suitable control. The oscillator 7 controls an amplifier 3, which provides voltage for a laser 1. The light emitted by the laser 1 is controlled by optics 9. Optics 2, on the other hand, controls phototransistors 4 and 5. But there may be three transistors, for example, instead of the two shown. Phototransistor 5 controls the audible channel amplifier 10, which feeds audible frequencies to earphones. The sound volume can be controlled conventionally by a suitable control. Phototransistor 4 controls amplifier 8. When an obstacle (such as the upper part of an image drawn on a horizontal line) approaches the device, the luminous point of the laser 1 moves to transistor 4, whence amplifier 8 drives oscillator 7, for example, altering the frequency from an original 400 Hz to 500 Hz. The frequency can be altered in several steps, if the object continues to approach, as a separate phototransistor and amplifier are provided for this purpose. The frequencies can be selected freely and those given are only examples.
The device now invented differs essentially in its operation from previously known devices. It has no deflection of the laser ray or field of vision. Instead, the ray of light of laser 1 is modulated to a certain frequency which is received directly through a photosensitive element, particularly a phototransistor 5, and an amplifier 10. Besides the actual reception channel, there is thus at least one other channel for altering the modulation frequency of the laser at a set distance from the device. The operating principle relies on the fact that a change in the illuminance of a point in the path of the laser ray causes a change in the sound volume, making it easy to follow an object that is lighter and therefore more reflective.
In practice, the device can be very small - the size of a flashlight, for example - with the transmission optics 9 and reception optics 2 located in the front of the case surrounding the device, and the other components located suitably.
The visually handicapped generally have sensitive fingertips, because they read Braille with their fingers. Advantage can be taken of this, in a device according to the invention, by equipping it with a raised dot 11 , for example, to which a received signal can be fed as vibration in addition to, or instead of, an audible signal. The figure shows how raised dot 11 can be connected externally to a device according to the invention by means of a flexible ring 14, for example, on the finger of the user. However, the raised dot can also be suitably connected to the case of the device itself. If required, it is possible to use a switch, not described here, to select the indicator device, earphones or raised dot. It is obvious that a stronger signal will cause a stronger vibration, which a visually handicapped person can easily feel by touching the raised dot. Such a vibration detector is highly practical, if the user is both blind and deaf, and so unable to hear an audible signal. Converter 6 can convert the frequency of the vibration to a relatively low level that is easy to detect.
Switch 15 which alters the angle of the laser can also be connected to the invention, thus allowing the device to identify contrasts only from an area within a certain, predetermined distance. This characteristic can focus measurement and prevent points farther away from interfering with the signals given by the device.
The construction described above is very simple and cheap to build. Thanks to the small number of components, it is also highly reliable. A particular advantage is that it can be used to read variations in contrast, which no previously known device has been capable of. As stated above, this permits the user to follow, for instance, a line beside a road or other objects by simply moving the laser ray transversely to the line, and to obtain precise information on the direction of the lighter area.
A device according to the invention can also be used to read bar codes in which dark and light areas alternate in a known manner. A device for processing the information contained in a bar code can be included in the device or can form a separate unit, as illustrated by reference number 12 in the figure. In this way, guide signs for the visually handicapped can be easily arranged by sticking bar code labels conveying certain information onto traffic-light posts at the corners of streets. The device can be easily developed to express certain standard codes in the form of speech read by the device.
The invention can be adapted in many ways without deviating from the inventive idea and scope of protection of the accompanying Claims. The case of a device according to the invention can be small and can be shaped as desired.

Claims

Claims
1. A method for facilitating the movements of the visually handicapped and for reading information, characterized in that laser light of a desired frequency is transmitted to a point, and that the amount of reflected light with the above frequency is examined with a photosensitive reception device, and that the amount of reflected light is converted to an audible or tactile signal, the strength of which is in proportion to the amount of reflected light.
2. A method according to Claim 1 , characterized in that the frequency of the transmitted laser light is modulated variably in steps as a function of distance, and that the amount of reflected light of this frequency is heard or felt as a function of varying strength.
3. A method according to Claim 1 , characterized in that the amount of reflected light is heard as a function of the strength of the available signal by using earphones and/or a tactile member, such as a device like a raised dot, whose vibration strength is in proportion to the signal received.
4. A device for facilitating the movements of the visually handicapped and for reading information, including a suitable case, in which there is a source (1) of laser light and a device for receiving or identifying an amplified signal, characterized in that the device also includes an oscillator (7) for modulating the laser to a certain frequency and a photosensitive receiver (5) for measuring the reflected light of the aforemen- tioned frequency and for developing an audible or other signal, the strength of which is in proportion to the amount of reflected light.
5. A device according to Claim 4, characterized in that there is at least one other photosensitive element (4) in the device to convert the modulation frequency of the laser in steps, to correspond with the distance to the point being measured.
6. A device according to Claim 4, characterized in that there are earphones (13) in the device for listening to an audible signal, or a raised dot or corresponding device (11) for creating a tactile signal as, for example, vibration in the raised dot, or both.
7. A device according to Claim 4, characterized in that the device also includes a switch (15), by means of which the operating radius of the device can be limited within a certain, predetermined area.
8. A device according to Claim 4, characterized in that the device includes a device (12) for interpreting bar codes.
PCT/FI1997/000491 1996-09-30 1997-08-27 Method and device for facilitating the movements of the visually handicapped WO1998014149A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU40161/97A AU4016197A (en) 1996-09-30 1997-08-27 Method and device for facilitating the movements of the visually handicapped

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI963918A FI113493B (en) 1996-09-30 1996-09-30 Device to make it easier for the visually impaired to move
FI963918 1996-09-30

Publications (1)

Publication Number Publication Date
WO1998014149A1 true WO1998014149A1 (en) 1998-04-09

Family

ID=8546769

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1997/000491 WO1998014149A1 (en) 1996-09-30 1997-08-27 Method and device for facilitating the movements of the visually handicapped

Country Status (3)

Country Link
AU (1) AU4016197A (en)
FI (1) FI113493B (en)
WO (1) WO1998014149A1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1025828A1 (en) * 1999-02-02 2000-08-09 VISTAC GmbH Orientation aid for blinds and visually impaired
US6298010B1 (en) 1997-04-30 2001-10-02 Maria Ritz Orientation aid for the blind and the visually disabled
RU2256432C1 (en) * 2003-11-13 2005-07-20 Воробьев Андрей Всеволодович Multifunctional device for partial substitution of vision function for blind patients
CZ300785B6 (en) * 2002-05-02 2009-08-12 Method and apparatus for making a piece of information on distance from an obstacle for blinds

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3743696A1 (en) * 1987-12-18 1989-06-29 Kolbatz Klaus Peter Orientation aid for blind persons
WO1991004458A1 (en) * 1989-09-15 1991-04-04 The Australian National University Passive-optoelectronic rangefinding
US5241360A (en) * 1992-02-06 1993-08-31 Cubic Automatic Reveneu Collection Group Distance measuring device utilizing semiconductor laser
US5307137A (en) * 1992-03-16 1994-04-26 Mark F. Jones Terrain imaging apparatus and method
WO1995021595A1 (en) * 1994-02-08 1995-08-17 Farcy Rene A Visual prosthesis for the visually challenged
US5487669A (en) * 1993-03-09 1996-01-30 Kelk; George F. Mobility aid for blind persons
FR2730818A1 (en) * 1995-02-17 1996-08-23 Sopelem Sofretec Laser telemetry system using timing of reflection of modulated light

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3743696A1 (en) * 1987-12-18 1989-06-29 Kolbatz Klaus Peter Orientation aid for blind persons
WO1991004458A1 (en) * 1989-09-15 1991-04-04 The Australian National University Passive-optoelectronic rangefinding
US5241360A (en) * 1992-02-06 1993-08-31 Cubic Automatic Reveneu Collection Group Distance measuring device utilizing semiconductor laser
US5307137A (en) * 1992-03-16 1994-04-26 Mark F. Jones Terrain imaging apparatus and method
US5487669A (en) * 1993-03-09 1996-01-30 Kelk; George F. Mobility aid for blind persons
WO1995021595A1 (en) * 1994-02-08 1995-08-17 Farcy Rene A Visual prosthesis for the visually challenged
FR2730818A1 (en) * 1995-02-17 1996-08-23 Sopelem Sofretec Laser telemetry system using timing of reflection of modulated light

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6298010B1 (en) 1997-04-30 2001-10-02 Maria Ritz Orientation aid for the blind and the visually disabled
EP1025828A1 (en) * 1999-02-02 2000-08-09 VISTAC GmbH Orientation aid for blinds and visually impaired
US6489605B1 (en) 1999-02-02 2002-12-03 Vistac Gmbh Device to aid the orientation of blind and partially sighted people
CZ300785B6 (en) * 2002-05-02 2009-08-12 Method and apparatus for making a piece of information on distance from an obstacle for blinds
RU2256432C1 (en) * 2003-11-13 2005-07-20 Воробьев Андрей Всеволодович Multifunctional device for partial substitution of vision function for blind patients

Also Published As

Publication number Publication date
FI113493B (en) 2004-04-30
FI963918A0 (en) 1996-09-30
AU4016197A (en) 1998-04-24
FI963918L (en) 1998-03-31

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