GB2542394A

GB2542394A - Accessibility Switch

Info

Publication number: GB2542394A
Application number: GB1516537.6A
Authority: GB
Inventors: Papadakis Georgios; Papamichalis Pavlos; Chountas Georgios
Original assignee: Filisia Interfaces Ltd
Current assignee: Filisia Interfaces Ltd
Priority date: 2015-09-18
Filing date: 2015-09-18
Publication date: 2017-03-22
Also published as: WO2017046610A1; GB201516537D0

Abstract

An accessibility switch 1 for use by people having a physical and/or learning disability or impairment comprises an activation element 10, a base 12 and a force sensor 16 monitoring a force between them and configured to detect a change in force to a sensitivity of 25 gram-force (approximately 0.245N), wherein when detecting a change of force greater than or equal to the sensitivity the switch is changed between a first and second state and provides sensory feedback with feedback unit 18. The force sensor may be sensitive to a change in force of 2.5 gram-force (approximately 0.0245N) or less. A controller 24 may detect a change in force by receiving data from the force sensor, which may be a load cell, a strain gauge load cell or a single point load cell. The switch may change between first and second states only when the force applied is either at least a minimum magnitude, or equal to or less than a maximum magnitude. The minimum and maximum magnitudes may be adjustable. The feedback unit may comprise a light 182 and/or speaker 184. The switch may comprise a rechargeable power supply and a wireless connector to connect the switch to a computer and/or at least one other switch.

Description

Accessibility Switch

Field of the invention

The present invention relates to accessibility switches, in particular to accessibility switches for augmentative and alternative communication by users with disabilities or impairments, such as impaired mobility.

Background

Individuals with a disability or impairment commonly have difficulty communicating with others, responding and reacting to everyday situations or operating standard appliances and devices. To address these issues assistive technology, such as augmentative and alternative communication devices, are employed to allow the individual to overcome the difficulties they have by using some form of supplementary equipment.

In many situations, an accessibility switch is able to be used, and although a wide variety of accessibility switches exists, they are usually push buttons that are about the size of a user’s hand and are connected to, and used to operate, a computer or other device. For example, a single accessibility switch or a combination of accessibility switches are used in place of a keyboard and mouse for people who find it difficult to operate the keyboard and the mouse. Additionally, accessibility switches are used to access a variety of systems, including electronic toys, computers, tablets, to control mobility or interact with the environment for people with cognitive difficulties, developmental delays and physical limitations, and they can be used as a form of therapy to overcome or reduce the limitations of an impairment or disability.

As well as varying in shape and size, for push or press switches, the amount of force required to operate the switch varies. Switches range from those that only require a touch (i.e. using touch sensitive technology) to operate, to some that are designed to be kicked to operate. Due to the disabilities and impairments these switches are designed to assist with, there are also switches designed to be operated by a particular body part that is able to produce voluntary movement.

An individual with complex physical or learning needs may be dependent on technology to access education, recreation and managing their lives. Switches can connect to a variety of devices for example: Augmentative and Alternative Communication devices, switch adapted toys, switch interfaces for computer access, sensory room equipment and environmental control devices. These switches use well-established technology and enable access to different applications. However, they usually have a binary range of input (they are either “on” or “off’) and are only capable of activation when the appropriate load is applied to the switch (such as to a touch, or a kick, but not both). This therefore places a limit on the type of interactions available to a user and their therapist or carer when using any one switch, and many switches may be needed to allow a variety of activities to be carried out.

Recently this has been addressed by using mechanisms that allow an accessibility switch to be sensitive to a range of input loads. However, these switches have a disadvantage in that the user is not able to activate the switch in a consistent and comfortable way because the mechanisms used do not have a broad enough operable load range to be able to respond to soft touches as well as more forceful pushes, such as a kick.

Thus, there is a desire for an accessibility switch that is operable over a range of input loads that has improved reliability of activation.

Summary of Invention

According to a first aspect of the invention there is provided an accessibility switch, comprising: an activation element, a base and a force sensor configured to monitor a force between the activation element and the base, wherein the accessibility switch is configured to detect a change in force monitored by the force sensor to a sensitivity of 25.0 grammes force or less; and wherein the accessibility switch is configured to change between a first state and a second state in response to detection of a change in force monitored by the force sensor of a magnitude greater than or equal to the sensitivity of the accessibility switch, the accessibility switch further comprising a feedback unit configured to provide sensory feedback when the accessibility switch changes between the first state and the second state.

This allows the accessibility switch to be highly sensitive to forces applied by a user, which means the reliability of activation (i.e. changing from one state to another) is improved because small forces are able to be detected as well as large forces. Accordingly, the switch assists a user with a disability or impairment, as it will consistently function without them needing to be concerned about applying the appropriate force, especially when they may find this difficult, for example, when they have impaired mobility or a tremor. The ability to identify small changes in the magnitude of forces applied also provides a capability to use the accessibility switch in a wide range of applications, and for the accessibility switch’s use to be tailored to the intended application and to operate with a high degree of precision.

Furthermore, by monitoring and detecting the change in force instead of determining whether a force is applied or not, as in a binary system, the force applied can be continuously monitored to detect multiple changes in force of a magnitude greater than or equal to the sensitivity of the accessibility switch, allowing multiple changes between states. The accessibility switch of the first aspect thereby differs from known accessibility switches as known switches are either only capable of binary (i.e. “on” and “off”) states and can only be used in applications suitable for such binary states; are capable of accepting limited variable input loads, but do not have the same level of sensitivity as the accessibility switch of the first aspect thereby limiting their usefulness to users with a disability and/or impairment; or measure different parameters such as proximity to the switch, which a user with a disability and/or impairment are unlikely be able to reproduce in a consistent manner. This gives the accessibility switch of the first aspect a greater versatility than known switches, as well as improving the possible analysis of the input loads applied by a user.

The accessibility switch can have a sensitivity of less than 25.0 grammes (g) force, such as 20.Og force, 10.Og force, or 5.0g force or less. Typically however, the change in force monitored by force sensor to which the accessibility switch is sensitive is 2.5 grammes force or less (such as 2.0 grammes force or 0.5 grammes force). This level of sensitivity provides a further significant improvement in the reliability, since the switch is adapted to respond to a force equivalent to 2.5g force, as well as further significant improvements in the level of detail available when the input loads of a user are analysed and the level of precision to which changes in force can be detected. This allows a user to lightly press the switch or to tap it but avoids a user accidentally causing the switch to change state by an unintentional brush as would be the case with touch sensitive or proximity activated switches.

Of course, 25.Og force is equivalent to about 0.2452 Newtons (N), 20.Og force is equivalent to about 0.1961 N, 10.Og force is equivalent to 0.0981 N, 5.0g force is equivalent to 0.0490N, and 2.5g force is equivalent to 0.0245N, and any particular force the unit of which is provided in grammes force will have an equivalent value in Newtons.

As an example of the change in force detectable by the accessibility switch, an increase in the force applied to the force sensor from a force equivalent to 40g to a force equivalent to 42.5g is detectable, as is a change in force from a force equivalent to O.Og to a force equivalent to 2.5g; and a decrease in the force applied to the force sensor from a force equivalent to 110.0g to 107.5g, as well as from 2.5g to O.Og.

The accessibility switch may further comprise a controller configured to detect a change in force monitored by the force sensor. This provides the accessibility switch with a component that is able to analyse the force monitored by the force sensor and determine when a change in force of at least the sensitivity of the accessibility switch occurs. Typically, the controller is configured to receive monitored force data from the force sensor, which provides the controller with information that is able to be used to detect a change in force.

The force sensor may be a magnetic force sensor or any other type of sensor that is capable of monitoring force and change in force. Typically, the force sensor is a load cell. This allows the force sensor to be highly sensitive while only using a relatively simple component. This means that the sensor is highly durable and requires little or no maintenance whilst ensuring small magnitude forces are monitorable. This is advantageous as the amount of force a user is able to apply is likely to be unpredictable, and the durability allows the accessibility switch to maintain functionality should it be treated roughly by a user, as can be the case with users with a disability.

The load cell may be any one of a number of types of load cell, though typically, the load cell is a strain gauge load cell. Strain gauge load cells have long life cycles meaning the life of the accessibility switch is extended when such a load cell is used. Additionally, while strain gauge load cells are simple components, they are increasingly sensitive allowing highly sensitive monitoring to be conducted using a simple, and inexpensive, component. Preferably, the strain gauge load cell is a single point load cell, as using a such a load cell allows a force or load to be applied at a single location whilst maintaining the ability to monitor force.

The accessibility switch will usually have an upper limit to the magnitude of the force that it can withstand due to the mechanical constraints of the materials used. In this case, this may be about 3 kilogram (kg) (equivalent to about 29.4200N). However, the accessibility switch is typically further configured to change between a first state and a second state only when the magnitude of the force applied between the activation element and the base is equal to or less than a maximum magnitude. This allows the maximum magnitude to be below the upper magnitude, which will protect the accessibility switch from being damaged whilst also allowing the switch to be used to assist a user in improving their motor functions. This is because to cause the change in state, the user needs to apply a force in a controlled manner to ensure they do not exceed the maximum magnitude.

Preferably, the maximum magnitude is adjustable. This allows the maximum magnitude at which the accessibility switch will change state to be changed depending on its intended use.

Instead of relying on the sensitivity of the accessibility switch to provide a lower limit of the magnitude of the force below which the accessibility switch will not change states, the accessibility switch is typically further configured to change between a first state and a second state only when the magnitude of the force applied between the activation element and the base is at least a minimum magnitude. As with the maximum magnitude, this allows the switch to be used to assist a user in improving their motor functions, as to cause the change in state, the user needs to apply a force in a controlled manner to ensure the force applied has a magnitude of at least the minimum magnitude.

Preferably, the minimum magnitude is adjustable. Again, this allows the minimum magnitude at which the accessibility switch will change state to be adapted to make it suitable for its intended use at any particular time.

Of course, the accessibility switch may be configured to change between the first state and second state when a force is applied of a magnitude between a maximum magnitude and a minimum magnitude, and one or both of the maximum and minimum magnitudes may be adjustable. This is achieved by the accessibility switch being capable of dynamic monitoring due to the sensitivity of the accessibility switch and the ability of the accessibility switch to detect changes in force over a wide range (such as O.Og to 3000.Og), which allows the accessibility switch to provide an adjustable range of magnitudes of force that can be adapted to an intended use of the switch. Due to the high sensitivity of the accessibility switch, precise force magnitudes can be selected so that the range can be adapted with high precision over time as the user’s motor functions improve. This allows the accessibility switch to be used to help a user reduce the severity of, and potentially overcome, an impairment.

Additionally, the adjustable nature of the magnitudes between which the switch will change states provides an advantage of allowing a user to lightly press the switch or to tap it to cause the change in state, but avoids a user accidentally causing the switch to change state by an unintentional brush, as would be the case with touch sensitive or proximity activated switches.

The sensory feedback provided by the feedback unit may be visual, audio, touch/feel or any other form of sensory feedback. Typically, the feedback unit comprises a light and/or speaker, wherein the light and/or speaker is configured to change between a first mode and a second mode in response the accessibility switch changing between the first state and the second state to provide sensory feedback. This provides easily noticeable sensory feedback to a user as light and/or sound output or a change in light and/or sound output will likely cause the most obvious feedback to a user.

As well as the light or speaker changing from a first mode where the light and/or speaker is in an “off” state to a second mode where the light and/or speaker is in an “on” state, a first mode of a light or speaker may be an “on” state, and the change in mode may be to change to an “off” state. In such a case, it is the change to a lack of light and/or sound that is the sensory feedback. Of course, as an alternative, any light may change colour, and/or may start to fluctuate or cease fluctuating, and any sound may change pitch, tone, volume, and/or may start to fluctuate or cease fluctuating when the mode is changed.

As mentioned above, the accessibility switch is configured to change between a first state and a second state. These states may be determined by sensory feedback being provided, and each state can be defined as a distinct output condition, and a change in state is a change between one distinct output condition and another distinct output condition. Accordingly, the sensory feedback can also be provided by the change that occurs as well as the state to which the feedback unit changes. As such, preferably, the accessibility switch is programmable to customise the sensory feedback provided when the accessibility switch changes between the first state and the second state. This allows the sensory feedback to be adapted to the situation in which the accessibility switch is to be used, increasing the versatility of the switch, and extending the situations in which it would be suitable to use such a switch.

The components of the accessibility switch will normally be powered in some manner. This is usually achieved by the components of known accessibility switches being connected in a circuit with an external power source that is held open until the switch is pushed, which latches the circuit closed thereby passing power to the components. However, the accessibility switch of the first aspect typically further comprises a power supply, and wherein preferably the power supply is rechargeable. This allows the accessibility switch to be self-powered removing the need for an external power supply and any connection to such a power supply, meaning that the accessibility switch is able to operate wirelessly. This is advantageous as wires that may be hazardous to users, particularly to users with an impairment or disability, are not required for the accessibility switch to function. Additionally, being able to operate without wires makes the accessibility switch more portable and increases the ease of use.

In addition to wires that supply power, the wires of known accessibility switches are also used to transmit data to and from a computer or another accessibility switch. The accessibility switch of the first aspect typically further comprises a wireless connector configured in use to connect the accessibility switch to a computer and/or at least one other accessibility switch with a wireless connector. This allows data to be sent to and from the accessibility switch wirelessly without using wires, which may be hazardous to a user, and increases the portability and ease of use.

Accordingly, in a configuration where the accessibility switch is programmable, such as where the accessibility switch has a maximum or minimum magnitude of force to which it will respond, the appropriate parameters can be set remotely.

Although other forms of wireless connector and connection are available, preferably, the wireless connector is a Bluetooth connector or a Wi-Fi connector. These types of connector are advantageous as, due to the range and materials through which the signal produced by such connectors can pass, they allow connection through non-transparent materials. Furthermore, Bluetooth and W-Fi connection also provide fast data transfer rates (such as up to a theoretical maximum of about 1 Mbit/s for Bluetooth, with the actual speed being determined by the way the data is coded and decoded for the application(s) in use, and about 600Mbits/s for W-Fi). This means that when a user interacts with the switch to cause it to change state, any external effect caused by the change in state facilitated by the wireless connection appears to be instantaneous to the user. If a connection type with a slower data transfer rate were used, this would cause delays, which can cause problems for users with cognitive or behavioural difficulties.

The term “W-Fi connector” is intended to represent wireless local area network connectors using the IEEE 802.11 standard.

The activation element and base may be moveable relative to each other, though typically, the position of each of the activation element and the base is fixed relative to each other. This makes the accessibility switch more hard wearing, as there is no wear on parts that allow the two components to move relative to each other. This also allows the force sensor to monitor deformation instead of movement, which reduces the range of movement over which the force sensor is required to function allowing smaller movements, and therefore smaller forces to be monitorable.

Typically, the activation element and the base form a closed body. This allows the other components to be contained within the closed body to protect them from damage by a user.

In summary, major benefits of the accessibility switch according to the first aspect are that the high sensitivity makes the accessibility switch easier to use by a disabled and/or impaired user; allows the accessibility switch to have a wide range of functionality and to be highly adaptable, which reduces the problems experienced by a user with a tremor in using everyday devices; and allows for improved interoperability with other similar accessibility switches to help improve or overcome disabilities and/or impairments, including expressional impairments. Additionally, the accessibility switch allows motor functions to be more accurately monitored.

Brief description of figures

Examples of an accessibility switch are described in detail below, with reference to the accompanying figures, in which:

Figure 1 shows a sectional view of a first example accessibility switch;

Figure 2 shows a perspective view of the first example accessibility switch;

Figure 3 shows a plan view of the first example accessibility switch from below;

Figure 4 shows a sectional view of a second example accessibility switch; and

Figure 5 shows a block diagram illustrating an architecture of a system using an example accessibility switch.

Detailed description

The accessibility switches according to the invention referred to herein are generally for use by disabled and/or impaired users, and are used to assist the user in some manner. While the accessibility switches according to the invention are of greatest assistance to disabled and impaired users, there are uses of the accessibility switches that also make them useful to users without a disability and/or impairment.

More detail on the uses of the accessibility switches according to the invention is provided below. However, it is the structure of these accessibility switches that allows them to have such a wide range of uses.

Figure 1 shows a first embodiment of an accessibility switch 1. The accessibility switch in this embodiment has a circular footprint and has an activation element 10 and a base 12, which footprint may be a different shape in other embodiments.

In the embodiment shown in Figure 1, the activation element 10 has a domed circular plate 102 with a skirt 104 around its circumference. In other embodiments, the plate may be a different shape, such as flat, but in this embodiment, the plate is domed as this forms a complimentary fit for the shape of the palm of a hand, and is ergonomically optimised for this shape. As an example of the size of the accessibility switch 1, the accessibility switch has a diameter of about 10 centimetres (cm). Of course, in other embodiments, the diameter may be between about 5cm and about 15cm.

The base 12 in the embodiment shown in Figure 1 has a body 123, one side of which has a recess for a circular sticker 122, and is placeable against a surface in use. The body 123 is circular and due to the recess, the body has a lip 125 around its circumference . Additionally, there are feet 28 located in the recess that project from the body and through the sticker that are adapted to engage the surface in use. For example, rubber feet are able to grip the surface.

The body 123 has two walls around its circumference, an inner wall 124A and an outer wall 124B, with the walls and the body being formed of a single piece of material. Each wall is ring shaped and extends from an opposite side of the body from which the recess is located so that each wall is upright when the accessibility switch 1 is placed on a horizontal surface with the recess and lip 125 against said surface.

The inner wall 124A has a smaller outer diameter than the inner diameter of the outer wall 124B. This leaves a cavity 124C between the walls. In this embodiment, the cavity is approximately equal in thickness to the thickness (i.e. the difference between the inner and outer diameters of each of the inner wall and the outer wall) of the walls.

The skirt 104 of the activation element 10 has a base 105 from which a projection 107 extends. The projection has the same inner diameter as the skirt, but has a smaller outer diameter, so that it has a smaller thickness than the skirt.

The cavity 124C between the walls 124A, 124B of the body 123 of the base 12 acts as a guide for the projection 107, as it is positioned in the cavity, and is free to move towards and away from the opposing side of the body 123. Due to the shape of the cavity, the possible movement of the projection is generally one-dimensional (although there will of course be some degree of two-dimensional movement due to design constraints). Additionally, the difference in outer diameters between the skirt 104 and the projection 107 also restricts the range of movement of the activation element, as the difference in outer diameters of the skirt and projection forms a step at the base 105 of the skirt that acts as a stop to restrict movement of the activation element 10 towards the base 12.

Due to the arrangement of the skirt 104 and the walls 124A, 124B, the activation element 10 and the base 12 form a closed body. This is because at least a part of the projection 107 from the skirt of the activation element is located within the cavity 124C between the walls of the base in use. This makes the interior of the closed body inaccessible unless the activation element and the base are separated. As is explained in more detail below, the activation element and base cannot be separated unintentionally, so the components inside the body are protected when the accessibility switch 1 is in use.

The base 12 also has aligned apertures in the body 123 and sticker 122 that provide a through-hole through which a button 128 projects. This button is used to switch the accessibility switch on and off.

The activation element 10 and the base 12 are made of a sanitiseable, hardwearing material that is not harmful to a user if put to their mouth. An example of such a material is polycarbonate, which has an additional benefit that it is translucent.

The activation element 10 has a stem 106 that projects towards the base 12 from the centre of an interior surface of the domed circular plate 102. The stem is connected at an end distal to the domed plate to a force sensor 16. The connection is a screw connection, which prevents the activation element being removed from the accessibility switch 1 unintentionally.

The force sensor 16 is a single-point strain gauge load cell. This comprises a deformable metal bar 162 with a hole 164 through a portion of the bar shaped to provide sections of the bar with reduced thickness. In the embodiment shown in Figure 1, there are four sections of the bar with reduced thickness, but in other embodiments, there may be fewer or more sections with reduced thickness.

In the embodiment shown in Figure 1, a strain gauge (not shown) is located at each of two of the four sections of reduced thickness on the bar 162 of the force sensor 16. The strain gauges are connected together with resistors in a Wheatstone bridge circuit configuration. This allows mechanical deformation of the strain gauge to be converted into an electrical signal. In this manner, the force that is applied to the sensor can be monitored as the electrical resistance is proportional to the amount of deformation of the bar and hence magnitude of the force applied to the bar. In other embodiments, one or more of the resistors is replaced with a further strain gauge (of further strain gauges, each of which is) located at one of the four sections of reduced thickness, or one of the strain gauges may be replaced with a resistor.

The stem 106 of the activation element 10 is connected to one end of the bar 162 of the force sensor 16. The other end of the bar is connected to a pedestal 126 on an interior side of the body 123 of the base 12, which holds the bar in position so that there is a separation maintained between the base and part of the bar to allow the bar to deform when the accessibility switch 1 is in use. The bar is connected to the pedestal by a screw connection similar to the connection between the stem 106 of the activation element 10 and the bar.

The connection of the activation element 10 to the base 12 via the force sensor 16 provides a fixed connection between the activation element and the base, which means the only relative movement between the activation element and the base towards or away from each other that is possible is movement through deformation of the activation element, base or force sensor. In other embodiments, the activation element and the base are able to move towards and away from each other. However, this would require a different connection to the force sensor or a different force sensor.

In use, force is applied across the force sensor 16 by pressure being applied between the activation element 10 and the base 12. Although a number of ways of applying suitable pressure exist, usually this pressure will be applied by a user pushing the activation switch 1, and in particular the activation element 10, when the accessibility switch is placed on a surface.

As mentioned above, pressure applied between the activation element 10 and base 12 causes the force sensor 16 to deform. This deformation is monitored, thereby causing the force that produces the deformation to be monitored. When the accessibility switch is active (i.e. on), the force sensor continuously monitors force applied across it. This generates a data stream that is passed to a controller 24, which determines whether any change in force occurs and determines whether any response is required by analysing the data stream. Of course, the ability of the controller to determine whether any change in force occurs is limited by how sensitive the controller is to changes in force, which is affected by several factors.

Firstly, the controller 24 is a digital controller, so the data stream generated from the force monitoring, which is an analogue data stream as it is produced from the output of the Wheatstone bridge circuit, needs to be converted into a digital data stream.

The analogue data stream is converted to a digital data stream by an analogue-to-digital converter 17 (ADC) (shown in Figure 1), which has a predetermined “bit” resolution (for example, 12-bit, 14-bit or 16-bit) indicating the number of discrete values it can produce over the range of possible analogue values. For example, a 12-bit ADC has 4096 discrete values it can produce, a 14-bit ADC has 16384 discrete values and a 16-bit ADC has 65536 discrete values. This means that as the force sensor 16 has an operable range of O.OOOOOg force to 3000.00000g force, after analogue-to-digital conversion, a minimum change in force that is resolvable when a 12-bit ADC, 14-bit ADC or 16-bit ADC is used is 0.7324g force, 0.18311g force or 0.045776g force respectively due to the number of discrete values available. Accordingly, even though the force sensor has a greater sensitivity than any of these minimum changes in force, the ADC used sets a minimum detectable change in force for the accessibility switch 1.

Secondly, in practice, the sensor is unlikely to be used at its maximum value, and the activation element 10 itself has some weight, which causes deformation of the force sensor 16. This reduces the minimum detectable change in force, as calibration of the sensor output is required. For example, when a 12-bit ADC is used, this raises the minimum detectable change in force from 0.7324g force to about 1,0g force, as the calibration reduces the sensitivity of the controller when it operates.

Thirdly, the signal containing the data stream is amplified to ensure it can be analysed in a suitable manner by the controller. This causes some loss in sensitivity because the amplifier (not shown) cannot amplify the signal at the top end of range that the ADC can digitise. This means that in the embodiment shown in Figure 1, where the ADC 17 is a 12-bit ADC, due to the reductions in sensitivity described above, the minimum change in force that is resolvable by the controller is between 2.0g force and 2.5g force, and as such, the controller has a sensitivity of between 2.0g force and 2.5g force.

However, the sensitivity of the controller can be adjusted, by modifying various components. At its most sensitive, the controller is able to detect (i.e. is sensitive to) a change in force of as little as 0.5g force. This is achievable when a higher bit ADC (such as 14-bit) than is used in this embodiment is used. The reason that a change in force detectable by the controller (i.e. the sensitivity of the controller) has been chosen to be between 2.0g and 2.5g in this case is that this sensitivity offers versatility to the users while ensuring the level of sensitivity is still of practical use to the users.

As well as the force sensor 16, ADC 17 and controller 24, inside the body provided by the activation element 10 and the base 12, there is also a feedback unit 18, a power supply 20 and a wireless connector 22,.

In this embodiment, the feedback unit 18 has an LED (Light Emitting Diode) 182 and a speaker 184. In alternative embodiments, the feedback unit can have either an LED or a speaker. Additionally, instead of an LED, some embodiments have different type of light, an LED array or an RGB LED (i.e. a Red-Green-Blue LED). An LED array or RGB LED allows LEDs of different colours to be used allowing the colour of light emitted from the accessibility switch 1 to change and to be changed.

The power supply 20 is a rechargeable battery that provides power to all the components of the accessibility switch 1 that require power when in use. In this embodiment, a Lithium Polymer battery is used.

The wireless connector 22 enables the accessibility switch 1 to connect wirelessly to at least one other accessibility switch, and there are examples in which the accessibility switch will connect wirelessly to a plurality of other accessibility switches (as is mentioned in relation to Figure 5). The wireless connector also allows the accessibility switch to connect to a computer such as a desktop computer, laptop, mobile device, such as smartphone or tablet, or a server. In the embodiments of the accessibility switch shown in the figures, the wireless connector is either a Bluetooth connector, or a Wi-Fi connector. In an alternative embodiment, another type of connector may be used, such as an Infrared (IR) connector. However, Bluetooth and W-Fi connectors are preferred due to the range over which a connection is able to be maintained and the materials through which a connection can be maintained. Of course, when a W-Fi connector is used, the accessibility switch usually connects to a wireless router to connect to other devices connected in some manner to that wireless router.

An advantage of using a Bluetooth connector is that a Bluetooth connector and connection is easy to set up and allows direct connection to other devices. This means that the system as a whole is more portable allowing it to be used in a number of locations such as in the home, in a therapist’s office or in a care home. An advantage of a Wi-Fi connector and connection is that the connection is stable, and the connection supports a large number of connected devices simultaneously. Additionally, a W-Fi connector and connection does not necessarily need a computer to be connected to the system in order for the connection to work. A Bluetooth connector is used in the embodiment shown in Figure 1. This is a 12-bit transceiver, which is why a 12-bit ADC is used in this embodiment. When a W-Fi connector is used, a higher bit ADC is used, as a different transceiver can be used. This allows the minimum detectable change in force that can be detected by the controller to be reduced to about 0.5g force, thereby lowering the sensitivity of the accessibility switch to 0.5g force. This higher sensitivity is achievable using W-Fi because it has a larger data transmission rate than Bluetooth, more channels and the data packets are large enough to hold the amount of data required without changing the packet rates, whereas the lower data transmission rate limit of Bluetooth and the lower number of devices to which a Bluetooth connector can connect to at any one time makes this better sensitivity more difficult to achieve.

In other embodiments, the accessibility switch can be made even more sensitive (such as to be sensitive to a change in force of 0.2g force), but this usually requires use of a force sensor with a lower upper weight limit (i.e. lower than 3000g, such as 500g) as the signal produced would otherwise be less accurate due to noise on the signal becoming a significant factor at this level of sensitivity.

The controller 24 has a processor (not shown) and is able to store information, such as a program, in memory (not shown). This provides the accessibility switch 1 with its range of capabilities and determines how the accessibility switch functions when in use.

As mentioned above, the controller 24 has a sensitivity of between 2.0g force and 2.5g force and monitors the change in force applied between the activation element 10 and the base 12. When a change in the force monitored occurs that is of a magnitude greater than or equal to the controller’s sensitivity, unless there is some other criteria to meet, then the controller passes an instruction to the feedback unit 18 to provide sensory feedback thereby changing the state of the accessibility switch 1 from one state to another.

Examples of sensory feedback provided by the feedback unit 18 to change the accessibility switch 1 between states is to turn the LED 182 from “off” to “on”, turn the LED from “on” to “off”, change the colour of the light emitted from one colour to another colour, to start/stop emitting light in a particular sequence, or change the light emission sequence; and/or turn the speaker from “off’ to “on”, turn the speaker from “on” to “off”, to start or stop emitting a particular sound arrangement through the speaker, or to change the sound arrangement being emitted. What sensory feedback is provided by the feedback unit is based on instructions from the controller 24.

As mentioned above, the material that the accessibility switch is made of is translucent, which allows light to pass through the activation element 10 and the base 12, so that it is visible from outside the accessibility switch 1. Sound emitted by the speaker is also audible outside of the accessibility switch. Therefore, as the user is able to see light and hear sound from the accessibility switch or will be able to see and/or hear a change in the light and/or sound from the accessibility switch when pressure is applied to the accessibility switch, they will immediately know that the accessibility switch has changed state by the sensory feedback provided.

In addition to the change in force monitored by the controller 24 being greater than or equal to the sensitivity of the controller, in some embodiments, there are other criteria that are to be met before the controller will instruct the feedback unit to provide sensory feedback. Such criteria are for the force (or change in force) applied to the accessibility switch 1 to be at least a minimum magnitude, and/or the force (or change in force) applied to the accessibility switch to be equal to or less than a maximum magnitude. Of course, the maximum and minimum magnitudes are adjustable in various embodiments. These additional criteria allow the range of force or range in change in force within which a user is able to cause the accessibility switch to change state to be adapted, expanded or constrained, which can be used in training exercises for the user, for example, to improve motor control.

The sensitivity of the controller provides the capability for actively monitoring small changes in force and allows for dynamic high precision versatility in when and how the accessibility switch will react to a user by changing between states. This gives the accessibility switch a wide range of uses, on which more detail is provided below.

Figure 2 shows a view of the exterior of the embodiment of the accessibility switch 1 shown in Figure 1. This shows the domed shape of the circular plate 102 and skirt 104 of the activation element 10 and the outer wall 124B of the base 12. There is an aperture in the side of the wall for a connector 26. This aperture passes through the body 123 of the base 12 into the interior of the body provided by the base and the activation element and can be seen in Figure 1 as well as in Figure 2. In this embodiment, the connector is a USB connector to which a USB cable is able to be connected. By connecting a USB cable to the connector, power can be supplied to the power supply 20 and data can be transmitted to and from the accessibility switch without using the wireless connector 22. Of course, in other embodiments other connector types are able to be used.

Figure 3 shows a view of the base 12 of the embodiment of the accessibility switch 1 shown in Figure 1 and Figure 2. This shows the sticker 122 and the lip 125 provided by the body 123 around the circumference of the sticker.

Additionally, Figure 3 shows the feet 28 attached to the base 12 of the accessibility switch 1 and the button 128 that is positioned through the base. The feet provide a gripping element so that the switch is less able to slide sideways on a surface when pushed from the side. Different types of gripping elements are used in other embodiments to provide the same function.

Figure 3 also shows a speaker grille 30 in the base 12. This is an optional feature but allows the accessibility switch 1 to emit higher quality sound, as sound is not muffled due to it being contained within the switch with no channel through which to be emitted. The speaker grille comprises multiple holes through the base, and is preferably located in the area of the base in which the speaker 184 is situated. A second embodiment of the accessibility switch 1000 is shown in Figure 4. The accessibility switch of the second embodiment is similar to the first embodiment of the accessibility switch 1 shown in Figures 1 to 3, and where the features are the same as those shown in Figures 1 to 3, the same reference numerals are used.

In this second embodiment, the accessibility switch 1000 has a circular footprint and has an activation element 1010 and a base 1012, and again, the activation element has a domed circular plate 1102 with a skirt 1104 around its circumference that has a similar shape to the corresponding elements in the first embodiment.

The base 1012 in the embodiment shown in Figure 4 has a flat circular panel 1122, one side of which is be placeable against a surface in use. The circular panel has a wall 1124 connected to it around its circumference extending from an opposite side of the panel to the side that is placeable against a surface in use. Although not shown in Figure 4, as in the first embodiment, there are apertures through the base for components, such as the connector and button used to turn the accessibility switch on and off.

The wall 1124 is a single piece ring that has two portions. One portion 1124A has a smaller outer diameter than the other portion 1124B. The portion with the smaller outer diameter is distal to the circular panel 1122. In this embodiment, there is a step change in the outer diameter, but in other embodiments, the transition in outer diameter is more gradual, such as a slope. A portion of the skirt 1104 of the activation element 1010 is fitted coaxially around the smaller outer diameter portion 1124A of the wall 1124, with the skirt 1104 of the activation element 1010 being fitted concentrically round the wall 1124 of the base 1012. In this embodiment, there is a gap between the skirt and the wall, but in an alternative embodiment, there is a connection between the skirt and wall, such as a clip connection.

In Figure 4, there is a gap between the end of the skirt 1104 and a surface of the wall 1124 where the diameter changes. This gap provides a circumferential groove around the outer circumference of this part of the accessibility switch 1000. A cover 1014 is fitted over and has a complimentary shape to the exterior of the activation element 1010. Accordingly, the cover has a domed section and a skirt. The cover also has a lip 1142 that projects radially inward from the base of the skirt. The lip is shaped to fit in the circumferential groove around the accessibility switch 1000, which assists in keeping the cover on the activation element.

The cover 1014 is made out of silicone. Other materials would also be suitable; however, silicone is used in this embodiment as it is easily sanitiseable, hardwearing and is not harmful if put to a user’s mouth. This makes the cover suitable for use with children and for use with users with a disability or impairment where other materials may not be suitable. The activation element 1010 and the base 1012 are also made of a sanitiseable and hardwearing material for the same reasons. An additional benefit of having a silicone cover is that it is translucent.

The cover 1014 is also changeable with covers with alternative textures. This engages users with sensor challenges such as a user with an autistic spectrum disorder.

The accessibility switch 1000 of the second embodiment has the same functionality and uses as are described herein for the accessibility switch 1 of the first embodiment and uses the same features to provide that functionality. The use of the cover can limit the sensitivity of the accessibility switch using the cover to equal to or less than 20.Og force, but the controller is the same as is used in the first embodiment so the same changes in force are detectable by the controller, and the controller is still able to detect the same changes in force as is possible in the first embodiment. Of course, where pressure would be applied to the activation element 10 in the first embodiment, this is applied to the cover 1014 in the second embodiment, as the cover is over the activation element 1010.

Uses of embodiments of the accessibility switch

The high sensitivity of the embodiments of the accessibility switch described herein allows comfortable use by a user, as the accessibility switch is able to be responsive over a wide range of input loads. Furthermore, the accessibility switch can be used by users only capable of applying very limited force. For example, users with neurodegenerative conditions eventually lose much of their ability to apply force and range of movement, and can only use very sensitive devices. This is also the case for users that have suffered a severe injury (such as spinal cord injury, or traumatic brain injury).

Additionally, for many users (such as users with a tremor or spasticity), high sensitivity is very important. This is because although such users can use a less sensitive device, after using a less sensitive device for some time (such as for 10 to 15 minutes) their body becomes tired and this brings out muscle contractions and causes involuntary writhing movements. As a result, they need to stop using the device after a while, they often feel pain, and might require the intervention of a carer that will help them relax their muscles. The high sensitive of the embodiments of the accessibility switch enables them not to have to exert themselves to such an extend to operate the switch, which allows them to use the switch for longer and for any issues caused by tiredness to be less severe.

The high sensitivity of the accessibility switch combined with the range of input loads it is capable of operating over also allows users (and their therapist and/or carer) to be able to monitor input readings to a high level of precision. For example, for a user with a tremor, details such as how strong the tremor is; how the tremor evolves over a period time (such as being able see if the tremor increases by a particular percentage in a specified period); and how the tremor evolves between sessions (such as after a certain number of months of interventions, it can be seen whether the tremor has reduced, for example by a particular percentage, or that it takes longer for it to appear).

There are similar examples for other impairments, and this is beneficial because it helps a specialist (such as a therapist, doctor or carer) to make more informed decisions about needed medication or interventions, and it helps any interventions be evaluated to see if they are effective for that particular user or patient.

The ability to conduct continuous analysis of the input load (as opposed to binary on/off states) combined with the high sensitivity is also beneficial in rehabilitation exercises. Taking the example of a user that has suffered a stroke or traumatic brain injury, the accessibility switch can be used in a scenario where the user needs to control the amount of force they apply to the switch in a continuous manner to improve their fine motor skills, which is often difficult for such users. This is achieved by setting the user a task (which can be in the form of a game to keep the user engaged) that requires them to make small changes to the force they are applying to the accessibility switch over a period of time to complete or reach a certain stage in the task. Additionally, a therapist can adjust the magnitude of force that is required to carry out a task to alter the task’s level of difficulty for the user. It is also possible to utilize data related to the user’s input load for machine learning purposes so that the magnitude of force required can be customised according to the evolution of the user’s capacities.

To improve a user’s width, speed and control of their movements, a number of the accessibility switches placed around a room can be used that are configured to be hit in a sequence. This allows a user to improve their gross and fine motor skills due to the ability to apply and adjust the maximum and minimum magnitudes of force at which each accessibility switch will change between states. For example, in some cases, the maximum magnitude can be set to 50.Og force requiring fine motor control, or the minimum change in magnitude can be set to 1000.0g force requiring gross motor control.

As another example, there is a strong evidence base that active musical engagement catalyses cerebral reorganisation after cases of stroke or traumatic brain injury, and studies have shown that musical expression is also very beneficial to the user’s self-esteem and perception of selfaccomplishment. The accessibility switch facilities this as each of a number of accessibility switches can be configured to play a particular musical note so that a musical arrangement can be played, or a switch can be configured to change an expressive parameter such as sound volume, brightness, texture or pan in response to an adjustment of the force on the switch. Additionally, a switch can be configured so that by touching it, a user can turn a loop of a particular instrument on or off to build an orchestral arrangement with a number of similarly configured switches; or by applying different levels of force to a switch, the user can control the volume or complexity of the audio loop. A further example is that by using a number of accessibility switches with music playing, the switches can be configured to light up to show the user what note comes next, so that the user can play along with the music by pressing on an illuminated switch to play a note.

As a final example, the adjustable input load range of the accessibility switch can be used to teach notions of strong and soft to a user with cognitive challenges. For example, the accessibility switch can be used to teach people with autism to be gentle with things and not hit them very hard, by making the switch only responsive to soft touches and providing rewarding sounds and visuals when the appropriate level of force is used, therefore reinforcing certain behaviours.

Figure 5 shows an embodiment of an architecture of an example system used to connect the accessibility switch 1 shown in Figures 1 to 3 or the accessibility switch 1000 shown in Figure 4 to other accessibility switches and a computer. For ease of reference, only the accessibility switch of the first embodiment is referred to in relation to Figure 4. However, there will be no difference if the accessibility switch of the second embodiment is used instead. As such, using the accessibility switch of the second embodiment is possible.

In the embodiment shown in Figure 5, the accessibility switch 1 has a wireless two-way data connection 32 with a computer 34. The two-way data connection allows data to pass from the accessibility switch to the computer and also from the computer to the accessibility switch. In alternative embodiments, a one-way data connection is usable, which only allows data to pass from the accessibility switch to the computer or from the computer to the accessibility switch, but not both.

The data connection 32 is provided by a Bluetooth or Wi-Fi connection between the accessibility switch 1 and the computer 34. When the data connection is provided by a W-Fi connection, each of the accessibility switch and the computer are connected to a wireless router (not shown), which facilitates the connection.

As well as having a data connection with a computer, the accessibility switch 1 has a two-way data connection 36 with one or more of a plurality of other accessibility switches. This data connection is similar to the two-way data connection 32 with the computer. The two-way data connection 36 with one or more other accessibility switches allows multiple accessibility switches to be used simultaneously for the same purpose. Additionally, the two-way data connection with one or more other accessibility switches is optionally able to be maintained at the same time as the two-way data connection with the computer, and each accessibility switch that has a two-way data connection with another accessibility switch is optionally able to maintain a two-way data connection 37 with the computer. As explained above, if the two-way data connections are provided by a Wi-Fi connection, then the Wi-Fi connections are facilitated by a wireless router.

The computer 34 has access to a data routing program 38 that provides connection between the accessibility switch(es) and other devices; sends and receives data from the devices, the accessibility switch(es) and applications or programs; and is able to control or program the accessibility switch. In this embodiment, the computer has direct access to the data routing program, but in other embodiments the program is held elsewhere, such as on a server, and the computer accesses the program remotely.

To send and receive data from applications and programs, two-way data connections are provided. Of the applications and programs to which the data routing program 38 is able to send and receive data, a first example is a two-way data connection 40A to a training application 42.

The training application 42 provides rehabilitation and training operations such as those detailed above. These are then able to be arranged and run on the accessibility switch(es) using the training application as it can connect to the accessibility switch(es) through the data routing program 38.

An example training operation is one that teaches or helps improve a user’s social interaction skills. Such an operation is of particular relevance to users with autistic spectrum disorders, and is able to be used in group therapy. For example, each user in a group of users, such as six or eight users, has an accessibility switch. The accessibility switches each start in a state with no light or sound being emitted and then two of the accessibility switches change to a state in which light is emitted. A user whose accessibility switch is illuminated must then look around the group to find the other accessibility switch that is illuminated and the two users must then apply pressure to their accessibility switch at the same time. When this is achieved, there is a reaction from the accessibility switches, such as to play music or emit a light sequence. This helps to improve the user’s ability to interact with others, and is run and managed by the training application 42 and the data routing program 38.

Another example is a rehabilitation operation where a user has suffered a loss of motor function. Such an operation involves the user applying pressure to an accessibility switch equivalent to a particular magnitude of force. When this occurs, the accessibility switch will change states. By setting the maximum and minimum magnitude of force to which the accessibility switch will react and adapting the magnitudes as the user progresses through their rehabilitation, the user is able to improve their motor skills as the range of magnitude can be adjusted or restricted as finer motor control is achieved.

As part of an operation, the training application 42 is able to conduct data analysis to monitor the user’s progress, which a therapist and the user may find beneficial, and their future training and rehabilitation can be adapted accordingly. Each training and rehabilitation operation helps improve specific cognitive or kinetic impairments and facilitates socialisation, memory and turn taking interactions. Therapists and educators can select among musical operations such as improvisation and orchestration, memory, speed, coordination and reaction to stimuli exercises. The interaction modes have a variety of objectives and are designed to address people with impairments of various types and severity levels, and physical and cognitive data is able to be collected to provide reports to users, their therapists and families about the evolution of their mobilisation and cognitive abilities. A second example of the application and programs to which the data routing program 38 is able to send and receive data is a two-way data connection 40B to a third party API 44 (Application Programming Interface), such as Skype (RTM). This data connection facilitates connection to third party applications installed on the computer 34 running the data routing program.

This enables the accessibility switch to be used to operate functions on the third party application. An example where this is useful is for a user with poor eyesight who cannot adequately see a computer screen to operate it, or a user with motor control difficulties meaning that use of a keyboard or mouse is difficult or impossible. Users such as these are able to use the accessibility switch to conduct operations such as answering a call on Skype by applying pressure to the button when they have been alerted to an incoming Skype call by the accessibility switch changing to a colour previously determined to alert a user to an incoming call by the data routing program 38. With other third party APIs, the uses will be different, but generally, the accessibility switch will take the place of a computer accessory. A third example of the application and programs to which the data routing program 38 is able to send and receive data is a two-way data connection 40C to a web server. The connection to the web server 46 requires a web connection, so the connection will usually be connected through a router.

The connection to a web server allows remote tools and/or web tools to be operated by the accessibility switch. For example, IfTTT and Temboo are cloud-based connection facilitators that allow devices to be connected together over the web to allow a device to operate another device over the web. An example where this is useful is for a deaf user that uses a service such as this to connect their doorbell to an accessibility switch that is configured to light up when the doorbell is pushed. As a further example, the accessibility switch can be linked to a transport network, such as a rail and/or road network, and the accessibility switch can inform a user (with or without disability and/or impairment) that there is a transportation strike or traffic and they should leave soon for their next appointment.

Other example uses of the accessibility switch disclosed herein is as a controller for a video game or other game; as a habit formation enabler, as it can be configured to adapt to a user’s needs and habits and provide reinforcement through sound and light output/input whenever the desired action is performed, such as reminding a user to drink water, take medication, or to exercise by lighting up in a particular colour; or as an ambient information and real-time data indicator, such as allowing a user to visualise at a glance important information with colours, such as providing information about the weather.

Accordingly, as well as providing the ability to train and rehabilitate impaired users by assisting directly with therapy, the accessibility switch is able to be used to improve the quality of their everyday life by taking the place of things that unimpaired users take for granted. Furthermore, as the performance of the accessibility switch is customisable and there are several interactions, training and rehabilitation operations available the accessibility switch is versatile and can be used for numerous functions, which means that non-disabled or impaired users will also find the accessibility switch useful in a number of applications.

Claims

1. An accessibility switch, comprising: an activation element, a base and a force sensor configured to monitor a force between the activation element and the base, wherein the accessibility switch is configured to detect a change in force monitored by the force sensor to a sensitivity of 25.0 grammes force or less; and wherein the accessibility switch is configured to change between a first state and a second state in response to detection of a change in force monitored by the force sensor of a magnitude greater than or equal to the sensitivity of the accessibility switch, the accessibility switch further comprising a feedback unit configured to provide sensory feedback when the accessibility switch changes between the first state and the second state.

2. The accessibility switch according to claim 1, wherein the change in force monitored by the force sensor to which the accessibility switch is sensitive is 2.5 grammes force or less.

3. The accessibility switch according to claim 1 or claim 2, wherein the accessibility switch further comprises a controller configured to detect a change in force monitored by the force sensor.

4. The accessibility switch according to claim 3, wherein the controller is configured to receive monitored force data from the force sensor.

5. The accessibility switch according to any one of the preceding claims, wherein the force sensor is a load cell.

6. The accessibility switch according to claim 5, wherein the load cell is a strain gauge load cell.

7. The accessibility switch according to claim 6, wherein the strain gauge load cell is a single point load cell.

8. The accessibility switch according to any one of the preceding claims, wherein the accessibility switch is further configured to change between a first state and a second state only when the magnitude of the force applied between the activation element and the base is equal to or less than a maximum magnitude.

9. The accessibility switch according to claim 8, wherein the maximum magnitude is adjustable.

10. The accessibility switch according to any one of the preceding claims, wherein the accessibility switch is further configured to change between a first state and a second state only when the magnitude of the force applied between the activation element and the base is at least a minimum magnitude.

11. The accessibility switch according to claim 10, wherein the minimum magnitude is adjustable.

12. The accessibility switch according to any one of the preceding claims, wherein the feedback unit comprises a light and/or speaker, wherein the light and/or speaker is configured to change between a first mode and a second mode in response the accessibility switch changing between the first state and the second state to provide sensory feedback.

13. The accessibility switch according to any one of the preceding claims, wherein the accessibility switch is programmable to customise the sensory feedback provided when the accessibility switch changes between the first state and the second state.

14. The accessibility switch according to any one of the preceding claims, further comprising a power supply, and wherein preferably the power supply is rechargeable.

15. The accessibility switch according to any one of the preceding claims, further comprising a wireless connector configured in use to connect the accessibility switch to a computer and/or at least one other accessibility switch with a wireless connector.

16. The accessibility switch according to claim 15, wherein the wireless connector is a Bluetooth connector or a Wi-Fi connector.

17. The accessibility switch according to any one of the preceding claims, wherein the position of each of the activation element and the base is fixed relative to each other.

18. The accessibility switch according to any one of the preceding claims, wherein the activation element and the base form a closed body.

19. An accessibility switch substantially as described herein, with reference to and as illustrated in the accompanying drawings, Figure 1 to Figure 4.