GB2466240A - Wireless apparatus with proximity sensor switches allowing a disabled person to control an electronic device. - Google Patents

Abstract

Disclosed is a proximity sensor switch operated control unit for electronic devices to be used by disabled persons with limited motor skills. The control unit consists of switches that sends signals to electronic units which process the signals and send secondary signals wirelessly to a computing device eg a home computer, a mobile phone or a PDA. The computing device is coupled to a visual display which displays text, icons and other visual cues to show the user the current function setting of the switches. The computer processes the received signals and sends on control signals to the devices to be controlled, based on the information displayed on the screen. The switch may be a Hall effect switch operated by a magnet, with the magnet being wearable as part the user's clothing or jewellery. The sensors, switches and/or the electronic units may be mounted on a wheelchair or other such mobility device.

Description

CONTROL SYSTEM

DESCRIPTION

BACKGROUND

Electronic devices provide an ever-increasing range of services and assistance.

However their benefits are not always accessible to people with disabilities, particularly those with limited finger motor control. So, frustratingly, the full use of such devices, and potential gains in terms of independence and empowerment are denied to a group who could benefit greatly.

It is the object of the present invention to overcome these barriers.

CURRENT STATE OF THE ART

Consider the mobile phone as an example device. It provides a range of useful functionality, but increasingly requires the user to press small buttons (of the order of 5mm). This is not possible for people with limited motor control, and therefore to whom the benefits of the technology are denied. Some phones are available with large buttons (see for example http.!/www.basicmobile.co.uk referenced 11 December 2008) but still require the user to press physical buttons.

To address the generic problem, a range of technology has been developed over time.

A selection is available at http://www.enablemart.com (referenced 11 December 2008), but almost all still requires the user physically to press a button.

US2008284736 teaches use of a proximity switch to emulate keystrokes from a keyboard "Proximity sensor device and Method with keyboard emulation" The present invention advances the art by (1) using a proximity switch rather than a pressure switch, (2) using wireless communication to free the user from a wired connection to the controlled equipment, and (3) being generic to allow a plurality of systems to be controlled.

ESSENTIAL FEATURES OF THE PRESENT INVENTION

Overview The core of the present invention is an electronic unit which is controlled by a least one switch. The switches are specifically designed to allow operation by users with physical disabilities.

The electronic unit processes the status data from the switch(es) and sends signals wirelessly to a mobile phone or a computer (preferably via the Bluetooth� protocol).

The phone or computer is loaded with special software which shows the user a dynamic menu of choices. Rather than pressing buttons on the phone (which they may find physically impossible), the user operates the aforementioned switch(es), sending signal(s) to the phone via the electronic unit. An important operational feature is that the function of the switch(es) changes with context (similarly to the buttons on a computer mouse), allowing a wide range of operations from a single hardware component.

Brief Description of the Drawings

Figure 1 shows a high-level block diagram of the whole invention.

Figure 2 shows the principle of operation of an embodiment of the switch using a Hall Effect device Figures 3a and 3b show typical circuitry for embodiments using magnetic switches Figure 4 shows a high-level block diagram of the computing device

Detailed Description

Figure 1 shows a high-level block diagram of the whole invention.

The core of the system is an electronic unit (103). The user interacts with one or more switches (101) connected to the electronic unit (103). These switches (101) may be digital (Boolean) on/off switches, or may be devices generating an analogue output which the electronic unit (103) digitises either into a Boolean signal or categorized into a range of levels. The electronic unit (103) may also derive a rate-of-change signal. The detailed internal functioning of this unit (103) is discussed in more detail below.

The electronic unit (103) sends wireless signals (105) to a computing device (107). The computing device (107) includes a display device (109, which may be integral or separate) which shows the user the current functions of the switch(es) (101) via menu software (111). Although Figure 1 shows only one for simplicity, there may be more than one electronic unit (103) communicating with each computing device (107). For example in one embodiment the present invention allows disabled people to play multi-player computer games.

Based on the user's action, the computing device (107) sends signals either by wired (113) or wireless (115) means to further devices (117) to cause the desired effects.

In some embodiments the computing device (107) and the controlled device (117) where the effects occur are the same physical device. For example in one embodiment a mobile phone contains both the menu software (111) and the display unit (109), and may generate telecommunication actions as a result of user actions, including without limitation starting a voice call, sending a text message and/or starting an application on the controlled device (117). This configuration may be used as an alarm device.

In other embodiments these two devices (107, 117) are physically distinct, for example in one embodiment the computing device (107) is a mobile phone which sends signals to an electronic control system (117) to control room lighting and other environmental conditioning equipment Figure 2 illustrates operation of an embodiment of the invention using one or more Hall Effect Devices ("HEDs") (303) as the switch (101). In such embodiments, to operate these switches (101) the user moves a magnet (301) into proximity with the sensor (303). The magnets (301) are shown as rectangular bars with north and south magnetic poles ("N" and "S"). This is for clarity only and other shapes and forms may be used.

Care is needed to minimise or eliminate any stray magnetic fields, ferrous or high permeability materials in the vicinity of the HED (303) as this could compromise its operation and affect the interface performance.

A HED (303) is physically small enough for encapsulation in a suitably ergonomic casing with its associated electronics. The casing may take different physical forms but preferably accommodates the HED (303) in an appropriate position and orientation to make maximum use of the field strength of the magnet (301).

The sensors (303) are mounted wherever easily accessible for each user. This may be a fixed point on a building, or on furniture such as a desk or table, or on a movable object such as a wheelchair. When the sensors (303) are mounted on a movable object the electronic unit (103) is preferably also mounted there, and because the electronic unit (103) communicates wirelessly, this gives the user of the movable object a greater degree of mobility and independence. Optionally the sensors may be on stalks to make them more accessible.

Hall Effect devices (303) are a preferred solution, but other switches (101) are equally applicable. Some users may be able to use large surface-mounted buttons, and these are used in certain embodiments.

The magnets (301) are mounted separately in any form to suit the individual person using the invention. These include clothing, jewellery, badges and straps (and also within the casing that houses the HED (303)). These articles are worn by the user on any part of the body appropriate to the abilities of that person.

The type and shape of the magnet (301) is chosen to suit the application. Significant flux density is achieved from sintered Alnico, which may be cast, ground or pressed to shape. Rare earth metals such as neodymium and samarium and/or alloys produce extremely strong fields and are more suitable for jewellery integration. In certain embodiments mechanical amplification of the motion of the magnet (301) is used to enhance the desired tactile and haptic interface.

Figure 2 illustrates typical achievable output voltage swing of the HED (303). These are designed to give a substantially linear output swing within a range determined by the supply voltage, the polarity of the magnet (301) and magnetic flux density. The HED (303) is typically powered from a +5V DC supply (Vss) and its quiescent output voltage point is approximately half Vss. Depending on the orientation of the HED (303), an approaching south pole of a magnet (301) produces an output voltage swing from Vss/2 to zero, and an approaching north pole of a magnet (301) causes a swing from Vss/2 to Vss. Whilst not entirely linear, the characteristic does produce an excellent analogue of displacement.

A switching threshold may be chosen and set at any point on the output characteristic of the HED (303). For example, the point (Vt) corresponds to a threshold voltage that transmits a switched signal at a specified displacement of (dt) between the HED (303) and the magnet (301).

Figure 3a is a block diagram of the internal structure of the electronic unit (103) used to process input from a HED (303) operated by a magnet (301).

On each switch channel, the output voltage of the HED (303) is buffered by an electronic circuit (305) that also amplifies the signal. The additional gain serves to increase the working distance between the magnet (301) and the HED (303) and can extend it until electrical noise and drift become a problem. Output of the amplifier (305) is passed into a pulse generator (307) with a voltage eveI detector that triggers a digital voltage pulse (Vp) when a specific proximity between the magnet (301) and the HED (303) is reached. Technically (refer back to Figure 2) at distance dt, the voltage Vt triggers the pulse.

The pulse is destined ultimately as a command for the controlled equipment (117). The electronic components pass both the raw analogue signal (Va) and the digital pulse (Vp) into a Programmable Integrated Circuit Transmitter ("PICT", 309) that processes one or both signals under control of embedded firmware before transmitting a formatted signal (105) to the computing device (107).

Because it receives both signals Va and Vp, the PICT can generate signals (105) either based on linear control or bipolar switching. The hardware therefore provides the ability for a user to control equipment (117) using as little as one simple magnet (301), An important feature of the design is that the electronic unit (103) and its components (305, 307, 309) have no concept of the final technical effect of the user action. The messages have semantics at the level of "Switch N off/on" and/or "Device X Level Y".

This feature means that the electronic unit (103) is very flexible and is applicable to a plurality of applications.

One way to obtain a greater degree of interactive control is by adding more switches (101) in parallel to one electronic unit (103), shown as channel-i to channel-n (Ch#i, CH#n). An array or matrix of HEDs (303) further extends this input sensing flexibility and control of applications (117).

Figure 3b shows more detail of the amplifier (305) and pulse generator (307). The circuit operates in the following way. TP1 is held at approximately half Vss (eg 2.5V if Vss is 5.OV), which is the quiescent point of the HED when zero or minimal magnetic field is sensed by the HED (303).

IC1 is a non-inverting DC amplifier having a gain of typically 5 (and set by R2 and R3).

CCT1 is a Schmitt trigger circuit. When the voltage increases at TP2 as the magnet (301) approaches the HED (303), at the threshold of the Schmitt, a fast falling edge sufficient for the differentiator (Cl and R5) to create a negative-going AC coupled pulse triggers lC2 a 555 timer. A hysteresis of about 10% is used in the Schmitt trigger to eliminate spurious triggering. The HED (303) is DC coupled as far as Cl but the AC trigger pulse at pin 2 of 1C2 means that the magnet (301) must be taken out of range of the HED (303) then returned in range for a second trigger pulse to be generated. This is an important interface consideration. AC coupling thus eliminates continuous switching (that could occur if the circuit was DC coupled) and simplifies the movement demanded of the user.

VR1 is adjusted to offset the output of IC1 to a voltage on TP2 sufficient not to trigger CCT1 under quiescent conditions. The rate of change of output voltage at TP2 is set by the gain of IC1 affecting overall sensitivity. A margin of about 20% at TP2 takes care of any thermal drift or variations in Vss.

The 555 timer (lC2) is optional (but preferred) and improves the signal to noise performance. It generates a positive going output pulse of magnitude Vp and width T determined by VR2 and C2.

The pulse width rp must be sufficient to ensure that the PICT successfully and reliably polls and/or senses the output pulse of 1C2. Typical ranges span 5Oms to 1.2s depending on the PICT configuration.

Figure 4 shows the components in the computing device (107). The messages (105, not shown in Figure 4) from the electronic unit(s) (103, not shown in Figure 4) are received by a wireless antenna (401) and associated components (403) and passed to the main application (407). Based on the context, this application (407) may send tertiary signals over wires (including networks, 411) and/or by wireless means (413) to controlled systems (117, not shown in Figure 4), and/or send tertiary signals to local applications (409) co-located within the computing device (107).

Also on receipt of a signal (105, not shown in Figure 4), the application (407) may require to update the menu display (111), for example to indicate receipt of the users action and/or to present a new menu of options. In Figure 4 the display unit (109) is shown as an integral part of the computing device (107), but where the user is visually impaired, they may be unable to read a small screen, and an external larger display unit is preferred.

In one embodiment the computing device (107) and controlled device (117) are one and the same mobile phone, and the software application (407) is specially written software for the mobile phone (107). The software uses the display (109) to show icons (111) for sending pre-defined text messages and/or making voice calls to other phones. When the user selects the respective icons, the application (407) instructs the mobile phone software (409) to take the appropriate action. The user preferably wears a wireless headset or uses a loudspeaker-phone to hear and speak during the call.

In one embodiment the application software (407) sends signals wirelessly (413) to a remote control unit (here 117, not shown in Figure 4) for a television.

In one embodiment the application software (407) sends signals wirelessly (413) to an electronic unit controlling room lighting and other environmental conditioning (here 177).

In one embodiment the computing device (107) and controlled device (117) are one and the same personal media player, and the software application (407) is specially written software for the player (107). The software uses the display (109) to show icons (111) representing media (eg audio, video, etc) tracks and/or a directory hierarchy of the same. When the user selects the respective icons, the application (407) instructs the player (409) to play the respective media track.

While the present invention has been described in generic terms, those skilled in the art will recognize that the present invention is not limited to the cases described, but can be practised with modification and alteration within the spirit and scope of the appended claims. The Description and Figures are thus to be regarded as illustrative instead of limiting.

Claims (1)

1. CLAIMS1 Apparatus and method providing control of at least one electrical device and/or system, where: the apparatus consists of at least one switch sending signals to one or more electronic units which process the signals and send secondary signals wirelessly to one or more computing devices (each optionally incorporating a visual display and/or using an external visual display) which perform(s) further processing and send(s) tertiary signals to the controlled device(s) and/or system(s); and where: the method consists of displaying (on the visual display(s)) text and/or icons and/or other visual cues to show the user the current function of the switch(es), and accordingly formatting and routing the said signals to achieve the desired effects; and where at least one switch is a proximity device suitable for operation by a person with limited motor skills 2 Apparatus and method as in any previous Claim where the computing device and controlled device are the same physical device 3 Apparatus and method as in any previous Claim where at least one switch is a non-contact Hall-effect switch operated by a magnet 4 Apparatus and method as in Claim 3 where the magnet is in a wearable article including without limitation clothing and/or jewellery Apparatus and method as in any previous Claim where the computing device is a mobile telephone, a computer, a personal digital assistant, a media player, a games console and/or a navigation system 6 Apparatus and method as in any previous Claim where the controlled device is a mobile telephone and/or other device enabled for mobile telephony 7 Apparatus and method as in Claim 6 where actions of the controlled device include dialling at least one pre-defined number for a voice call 8 Apparatus and method as in Claim 6 where actions of the controlled device include sending at least one pre-defined message (including without limitation text messages) to at least one pre-defined number 9 Apparatus and method as in any previous Claim where the controlled device is a media player, electrical equipment, navigational system, alarm system, environmental conditioning equipment, a games console and/or other personal and/or domestic and! or workplace device Apparatus and method as in any previous Claim where the means of signalling from the electronic unit to the controlled device is Bluetooth� and/or Zigbee and/or W1Fi 11 Apparatus and method as in any previous Claim where the switch(es) and/or the electronic unit(s) are mounted on a wheelchair or similar mobility device