GB2448166A

GB2448166A - Ultrasonic substitute vision device with tactile feedback

Info

Publication number: GB2448166A
Application number: GB0706598A
Authority: GB
Inventors: Jessica Lucy Baker; Peter Roger Davies; Karan Keswani; Samaan Syed Rahman
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-04
Filing date: 2007-04-04
Publication date: 2008-10-08
Also published as: GB0706598D0

Abstract

A device for providing a substitute vision sense to a visually impaired person (e.g. blind person, firefighter, diver) comprises a glove or cuff to attach to a hand or arm of the person. At least one directional sensor 2 (e.g. ultrasonic sensor, radar) is mounted on said glove or cuff; and a transducer 1 coupled to the sensor provides a tactile indication (e.g. vibration) of the presence of a sensed object in a sensing direction of said directional sensor. The directional sensor performs a scanning motion due to the natural swinging motion of the hand and arm during walking. The sensor may also detect range and direction of objects in the vicinity of the person. The duration or intensity of the tactile information represents the distance or rate of change of distance.

Description

FIELD OF THE iNVENTION

This invention relates to devices and methods for providing a substitute vision sense to a visually impaired person

BACKGROUND TO THE INVENTION

Known devices for aiding blind and visually impaired persons include the BatCane from Sound Alert Technology plc and the Ultracane from Sound Foresight. These aim to provide electronic enhancements to a traditional blind person's cane. However there remains a need for improvement.

SUMMARY OF THE INVENTION

According to the invention there is therefore provided a device for providing a substitute vision sense to a visually impaired person, the device comprising: a glove or cuff to attach to a hand or arm of said visually impaired person; at least one directional sensor mounted on said glove or cuff and a transducer coupled to said at least one sensor to provide for said visually impaired person a tactile indication of the presence of a sensed object in a sensing direction of said directional sensor; whereby, in use, during ambulatory motion of said visually impaired person, said directional sensor performs a scanning motion of said sensing direction and said transducer provides a tactile indication of objections in the vicinity of said visually impaired person located by said sensing direction scan.

Embodiments of the device have been found to be very convenient and intuitive to use in practice. In embodiments, mounting the sensor on the arm, and particularly on the lower arm, wrist or hand (cuff or glove) enables the device to take advantage of the natural, unconscious swinging motion of the hand and ann during walking to scan the local environment. A suitable glove need not have fingers; preferably it has a hook-and-loop opening on one side or edge so that it may be attached around a hand without needing to insert the hand into the glove.

Preferably the directional sensor is configured to determine a distance to a sensed object iii the sensing direction and the transducer is configured to provide a tactile indication of the distance of the sensed object in the scanning direction. The transducer may be configured to convey the tactile indication of the distance of the seiised object by a duration or an intensity of the tactile indication.

The device may also determine a rate of change of the distance during the scanning motion, for example over a timescale of0.1 second; a tactile indication of the rate of change of the distance may then be provided. This can help to differentiate between, say the edge of a bollard and a flat wall. It can also help "see" an approaching corner in a wall.

Preferably when the person is quiescent (in particular, standing still, facing forwards, hand dangling) the sensing direction of one directional sensor is configured to point generally forwards. Preferably, when the person is quiescent the sensing direction of the at least one directional sensor is configured to point at an angle of between 25 and 75 outwards from a direction perpendicular to the shoulders of the person. Preferably another directional sensor points generally downwards, for example at an angle of between 150 and 500 to a vertical axis of the person. Thus preferably the device has two directional sensors each coupled to a respective, the transducers being positioned on the glove to provide spatially distinguishable tactile indications to the person. For example the transducers may be separated by at least 3cm (although depending on their siting they ay be closer).

In embodiments a transducer comprises a device to provide a vibration, for example a commercial off-the-shelf vibration transducer. The directional sensor may comprise a radar sensor, in particular an ultrasonic radar sensor. This may be a commercial off-the-shelf ultrasonic sensor module which provides ranging in formation.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a first view of an embodiment of a device according to the invention, mounted on a hand, for example attached to a glove; Figure 1 shows a second view oan embodiment of a device according to the invention, mounted on a hand, for example attached to a glove; Figure 3 shows a view from above of first sensor directions and their movement during walking; and Figure 4 shows a view from the side illustrating lateral and downwards sensor directions.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the Figures, these show: 1. Vibration feedback actuators (eccentrics).

2. Ultrasonic distance sensors.

3. Extent of area swept by sensors in normal use -i.e. from arm swing in normal walking -side sensor.

4. Extent of area swept by sensors in normal use -i.e. from arm swing in normal walking -front sensor.

5. Visualisation of instantaneous sensor field at one point in the sweep cycle -side seiisor.

6. Visualisation of instantaneous sensor field at one point in the sweep cycle -front sensor.

Figures 1 and 2 show a device for converting some changes in a person's solid spatial environment by detecting the distance of objects from a person into a tactile representation of the distance of objects or change of distance.

The device includes beam distance sensors attached to the device, which would be mounted on the back of the hand at certain angles (but could be used on other parts of the body).

The hand provides a natural scanning motion that enables the user to map their immediate surroundings by moving and rotating the sensors.

Embedded software with memory processes these changes and feeds back to the user via tactile methods on the hand (or other body part if relevant), using small vibrations

for example.

The tactile feedback is felt by the user enabling them to obtain distance information about their surroundings that would otherwise be obtained through vision.

Applications of embodiments of the device are not limited to blind and partially sighted people; they also include, for example, firefighters, divers and other people who may need work in visually restricted environments.

No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto.

Claims

CLAIMS: 1. A device for providing a substitute vision sense to a

visually impaired person, the device comprising: a glove or cuff to attach to a hand or arm of said visually impaired person; at least one directional sensor mounted on said glove or cuff; and a transducer coupled to said at least one sensor to provide for said visually impaired person a tactile indication of the presence of a sensed object in a sensing direction of said directional sensor; whereby, in use, during ambulatory motion of said visually impaired person, said directional sensor performs a scanning motion of said sensing direction and said transducer provides a tactile indication of objections in the vicinity of said visually impaired person located by said sensing direction scan.
2. A device as claimed in claim I wherein said directional sensor is configured to determine a distance to a sensed object in said sensing direction and wherein said transducer is configured to provide a tactile indication of said distance of said sensed object in said scanning direction.
3. A device as claimed in claim 2 wherein said transducer is configured to convey said tactile indication of said distance of said sensed object by a duration or an intensity of said tactile indication.
4. A device as claimed in claim 2 or 3 further configured to determine a rate of change of said distance during said scanning motion, and wherein said transducer is configured to provide a tactile indication of said rate of change of said distance.
5. A device as claimed in claim 4 wherein said transducer is configured to convey said tactile indication of said distance of said sensed object by an intensity or duration of said tactile indication.
6. A device as claimed in any preceding claim wherein when said glove or cuff is attached to said hand or arm and said person is quiescent said sensing direction of said at least one directional sensor is configured to point generally forwards.
7. A device as claimed in claim 6 wherein when said glove or cuff is attached to said hand or arm said sensing direction of said at least one directional sensor is configured to point at an angle of between 25 and 75 outwards from a direction perpendicular to the shoulders of said visually impaired person when said person is quiescent.
8. A device as claimed in any preceding claim comprising at least one said directional sensor mounted on said glove or cuff such that when said glove or cuff is attached to said hand or arm and said person is quiescent said sensing direction points generally downwards.
9. A device as claimed in claim 8 wherein said sensing direction of said generally downwards pointing directional sensor is at an angle of between 15 and 50 to a vertical axis of said person.
10. A device as claimed in any preceding claim comprising two said directional sensors each coupled to a respective said transducer and wherein said transducers are positioned on said glove to provide spatially distinguishable tactile indications to said person.
11. A device as claimed in claim 10 wherein said transducers are separated by at least 3cm.
12. A device as claimed in any preceding claim wherein a said transducer comprises a device to provide a vibration as said tactile indication.
13. A device as claimed in any preceding claim wherein said directional sensor comprises a radar sensor.
14. A device as claimed in claim 13 wherein said radar sensor comprises an ultrasonic radar sensor.
15. A method of providing a substitute vision sense to a visually impaired person, the method comprising attaching at least one directional sensor to a hand or arm of said person, said sensor being coupled to a transducer to provide a tactile indication of the prescnce of a sensed object in a sensing direction of said directional sensor such that during ambulatory motion of said visually impaired person said directional sensor performs a scanning motion of said sensing direction and said transducer provides a tactile indication of objections in the vicinity of said visually impaired person located by said sensing direction scan.
16. A method of providing a substitute vision sense to a visually impaired person, the method comprising attaching at least one directional sensor to a body part of said person, said sensor being configured to provide both direction and range information for a sensed object in a sensing direction of said directional sensor, said sensor being coupled to a transducer to provide a tactile indication of both the presence of a sensed object in a sensing direction of said directional sensor and a range of said sensed object, such that said person is able to perform a scanning motion of said sensing direction to build up a picture of sensed objects and their ranges in the vicinity of said person from their tactile indications.
17. A method as claimed in claim 16 wherein said body part comprises a hand or lower arm of said person.