Controlling mouse pointer position using an infrared head-operated joystick

Creating an AI-Enhanced Morse Code Translation System Based on Images for People with Severe Disabilities

(1) Background: Patients with severe physical impairments (spinal cord injury, cerebral palsy, amyotrophic lateral sclerosis) often have limited mobility due to physical limitations, and may even be bedridden all day long, losing the ability to take care of themselves. In more severe cases, the ability to speak may even be lost, making even basic communication very difficult. (2) Methods: This research will design a set of image-assistive communication equipment based on artificial intelligence to solve communication problems of daily needs. Using artificial intelligence for facial positioning, and facial-motion-recognition-generated Morse code, and then translating it into readable characters or commands, it allows users to control computer software by themselves and communicate through wireless networks or a Bluetooth protocol to control environment peripherals. (3) Results: In this study, 23 human-typed data sets were subjected to recognition using fuzzy algorithms. The average recognition rates for expert-generated data and data input by individuals with disabilities were 99.83% and 98.6%, respectively. (4) Conclusions: Through this system, users can express their thoughts and needs through their facial movements, thereby improving their quality of life and having an independent living space. Moreover, the system can be used without touching external switches, greatly improving convenience and safety.

Human-machine interface for two-dimensional steering control with the auricular muscles

Human-machine interfaces (HMIs) can be used to decode a user's motor intention to control an external device. People that suffer from motor disabilities, such as spinal cord injury, can benefit from the uses of these interfaces. While many solutions can be found in this direction, there is still room for improvement both from a decoding, hardware, and subject-motor learning perspective. Here we show, in a series of experiments with non-disabled participants, a novel decoding and training paradigm allowing naïve participants to use their auricular muscles (AM) to control two degrees of freedom with a virtual cursor. AMs are particularly interesting because they are vestigial muscles and are often preserved after neurological diseases. Our method relies on the use of surface electromyographic records and the use of contraction levels of both AMs to modulate the velocity and direction of a cursor in a two-dimensional paradigm. We used a locking mechanism to fix the current position of each axis separately to enable the user to stop the cursor at a certain location. A five-session training procedure (20-30 min per session) with a 2D center-out task was performed by five volunteers. All participants increased their success rate (Initial: 52.78 ± 5.56%; Final: 72.22 ± 6.67%; median ± median absolute deviation) and their trajectory performances throughout the training. We implemented a dual task with visual distractors to assess the mental challenge of controlling while executing another task; our results suggest that the participants could perform the task in cognitively demanding conditions (success rate of 66.67 ± 5.56%). Finally, using the Nasa Task Load Index questionnaire, we found that participants reported lower mental demand and effort in the last two sessions. To summarize, all subjects could learn to control the movement of a cursor with two degrees of freedom using their AM, with a low impact on the cognitive load. Our study is a first step in developing AM-based decoders for HMIs for people with motor disabilities, such as spinal cord injury.

Design of a Wearable Eye-Movement Detection System Based on Electrooculography Signals and Its Experimental Validation

In the assistive research area, human-computer interface (HCI) technology is used to help people with disabilities by conveying their intentions and thoughts to the outside world. Many HCI systems based on eye movement have been proposed to assist people with disabilities. However, due to the complexity of the necessary algorithms and the difficulty of hardware implementation, there are few general-purpose designs that consider practicality and stability in real life. Therefore, to solve these limitations and problems, an HCI system based on electrooculography (EOG) is proposed in this study. The proposed classification algorithm provides eye-state detection, including the fixation, saccade, and blinking states. Moreover, this algorithm can distinguish among ten kinds of saccade movements (i.e., up, down, left, right, farther left, farther right, up-left, down-left, up-right, and down-right). In addition, we developed an HCI system based on an eye-movement classification algorithm. This system provides an eye-dialing interface that can be used to improve the lives of people with disabilities. The results illustrate the good performance of the proposed classification algorithm. Moreover, the EOG-based system, which can detect ten different eye-movement features, can be utilized in real-life applications.

Cursor Click Modality in an Accelerometer-Based Computer Access Device

The purpose of this study is to investigate the effects of different cursor click modalities in an alternative computer access device using accelerometry from head tilt to control cursor movement. Eighteen healthy adults performed a target acquisition task using the device with five different cursor click modalities, while maintaining cursor movement control via accelerometry. Three dwell-based click modalities with dwell times of 0.5 s, 1.0 s, and 1.5 s were tested. Two surface electromyography-based click modalities - with the sensor placed next to the eye for a blink and above the eyebrow for a brow raise - were tested. Performance was evaluated using metrics of target selection accuracy, path efficiency, target selection time, and user effort. Surface electromyography-based click modalities were as fast as the shortest dwell time and as accurate as the longest dwell time, and also minimized user effort. Three of the four performance metrics were not affected by sensor location. Future studies will investigate if these results are similar in individuals with neuromuscular disorders.

Integrated Head-Tilt and Electromyographic Cursor Control

This study evaluated the performance of two alternate computer access methods that could be used for two-dimensional cursor control. The first method, ACC/sEMG, integrates head acceleration and facial surface electromyography. The second method, Camera Mouse, is a free-to-use, computer vision-based access method. Twenty-four healthy adults performed a target acquisition task using each computer access method across two lighting conditions and three computer orientations. Performance in the task was evaluated using metrics of target selection accuracy, movement time, and path efficiency. Using ACC/sEMG resulted in better mean path efficiency and target selection accuracy, whereas using Camera Mouse resulted in faster target selection. Moreover, performance in the task when using Camera Mouse depended on lighting conditions in the room. The findings of this study show that the ACC/sEMG system is an effective computer access method across different lighting conditions and computer orientations. However, there is a tradeoff between speed and accuracy: ACC/sEMG system provided higher target selection accuracy compared to Camera Mouse, while the latter provided faster target selection. Future development should focus on evaluating performance of each method in populations with limited motor abilities.

Application of infrared scanning of the neck muscles to control a cursor in Human-Computer Interface

The feasibility of using infrared (IR) spectroscopy of the neck muscles in controlling a cursor in a 2-dimensional screen was assessed. The proposed technique utilizes two IR photoplethysmography sensors (λ = 940nm) to monitor the morphological changes of the Scalene and Sternocleidomastoid muscles. Since the reflection of the light has valuable information about the type of contraction, the direction of the movement (right/left, up/down) can be simply derived using two sensors. A MATLAB platform was developed in which a cursor moves using the recorded signal. Three scenarios of high/low sensitivity and joystick mode were tested. The results from 4 different healthy subjects shows the feasibility of control in terms of throughput, overshoot, and path efficiency.

Case study: Head orientation and neck electromyography for cursor control in persons with high cervical tetraplegia

We evaluated the ability of an individual with a high cervical spinal cord injury (SCI) to control a cursor on a computer screen using two different user interfaces: (1) head movements measured via a head-mounted orientation sensor and (2) electromyography (EMG) signals from four head and neck muscles acquired using a 4-channel implanted upper-limb neuroprosthesis that had been deployed in an earlier study. The subject moved the cursor to a set of targets on the screen in a two-dimensional, center-out, target-acquisition task, and his performance was evaluated with a variety of performance measures to assess both position and velocity control accuracy. The subject's performance with both command sources was also compared with the performance of a group of nondisabled subjects. Head orientation provided more accurate performance but was less responsive than EMG. Both command sources showed some directionally dependent performance, with movement to diagonally located targets being performed by a series of sequential motions rather than via straight paths. Overall, the SCI subject's performance with each command source was similar to that reported for a nondisabled population using the same interfaces and performing the same task.

Passive wireless tags for tongue controlled assistive technology interfaces

Tongue control with low profile, passive mouth tags is demonstrated as a human-device interface by communicating values of tongue-tag separation over a wireless link. Confusion matrices are provided to demonstrate user accuracy in targeting by tongue position. Accuracy is found to increase dramatically after short training sequences with errors falling close to 1% in magnitude with zero missed targets. The rate at which users are able to learn accurate targeting with high accuracy indicates that this is an intuitive device to operate. The significance of the work is that innovative very unobtrusive, wireless tags can be used to provide intuitive human-computer interfaces based on low cost and disposable mouth mounted technology. With the development of an appropriate reading system, control of assistive devices such as computer mice or wheelchairs could be possible for tetraplegics and others who retain fine motor control capability of their tongues. The tags contain no battery and are intended to fit directly on the hard palate, detecting tongue position in the mouth with no need for tongue piercings.

Resistopalatography as an assistive technology for users with spinal cord injuries

Translating a desired user's input using conventional methods such as a keyboard and mouse for the computer, or a joystick for a wheelchair is a major challenge faced by users whom have no limb control. This paper describes an iteration of Resistopalatography, a method using the tongue as a pointing device to emulate the use of the hand for cursor movement and wheelchair control. The system employs force sensitive sensors located within the mouth on a dental retainer plate to measure the tongue's pressure against the hard palate. The position and force of tongue against the sensors can be translated into mouse cursor or wheelchair joystick equivalents.

The selection of the appropriate computer interface device for patients with high cervical cord injury

In order to determine the most suitable computer interfaces for patients with high cervical cord injury, we report three cases of applications of special input devices. The first was a 49-year-old patient with neurological level of injury (NLI) C4, American Spinal Injury Association Impairment Scale (ASIA)-A. He could move the cursor by using a webcam-based Camera Mouse. Moreover, clicking the mouse could only be performed by pronation of the forearm on the modified Micro Light Switch. The second case was a 41-year-old patient with NLI C3, ASIA-A. The SmartNav 4AT which responds according to head movements could provide stable performance in clicking and dragging. The third was a 13-year-old patient with NLI C1, ASIA-B. The IntegraMouse enabling clicking and dragging with fine movements of the lips. Selecting the appropriate interface device for patients with high cervical cord injury could be considered an important part of rehabilitation. We expect the standard proposed in this study will be helpful.

A novel five degree of freedom user command controller in people with spinal cord injury and non-injured for full upper extremity neuroprostheses, wearable powered orthoses and prosthetics

An independent lifestyle requires the ability to place the hand in the complete workspace in concert with hand grasp and release. A novel user command controller monitoring head position for purpose of controlling hand location and orientation is proposed and demonstrated. The controller detected five degrees of freedom which were applied to upper limb movements including forearm and hand placement in three-dimensional space. The controller was evaluated by having subjects complete tracking tasks manipulating a simulated on-screen upper limb representation. Thirteen of the eighteen subjects assessed using the controller had sustained a spinal cord injury at or above the sixth cervical vertebra. Two of the injured subjects with decreased cervical spine mobility were unable to operate the controller. The remaining subjects performed the tracking tasks effectively after minimal training. This simple five-degree of freedom controller has been proposed for the use by those disabled by upper limb amputation, paralysis, weakness or hypertonicity.

Microswitch and keyboard-emulator technology to facilitate the writing performance of persons with extensive motor disabilities

This study assessed the effectiveness of microswitches for simple responses (i.e., partial hand closure, vocalization, and hand stroking) and a keyboard emulator to facilitate the writing performance of three participants with extensive motor disabilities. The study was carried out according to an ABAB design. During the A phases, the participants (one child and two adults) were to write using the responses and technology available to them prior to this study. During the B phases, they used the new responses and technology. Data showed that two of the three participants had a faster writing performance during the B phases while the third participant had a slower writing performance. All three participants indicated a clear preference for the use of the new responses and technology, which were considered relatively easy and comfortable to manage and did not seem to cause any specific signs of tiredness. Implications of the findings are discussed.

Sensory system for implementing a human-computer interface based on electrooculography

This paper describes a sensory system for implementing a human–computer interface based on electrooculography. An acquisition system captures electrooculograms and transmits them via the ZigBee protocol. The data acquired are analysed in real time using a microcontroller-based platform running the Linux operating system. The continuous wavelet transform and neural network are used to process and analyse the signals to obtain highly reliable results in real time. To enhance system usability, the graphical interface is projected onto special eyewear, which is also used to position the signal-capturing electrodes.

Use of microswitch technology and a keyboard emulator to support literacy performance of persons with extensive neuro-motor disabilities

OBJECTIVE

To assess the effectiveness and acceptability of microswitch technology and a keyboard emulator to enable three participants with extensive neuro-motor disabilities to write words.

METHOD

In Study I, two participants triggered an automatic scanning keyboard and selected/wrote letters via a small sliding movement of their hand(s) activating a touch/pressure panel (microswitch). In Study II, a third participant used the sliding movement and panel and a vocalization response with a voice-detecting microswitch. The sliding movement allowed her to light up the keyboard and select the letters and the vocalization to perform the scanning.

RESULTS

Participants showed a better performance (shorter writing time) or an equally effective but less tiring performance with the new microswitch technology and response(s). They also preferred using this technology, and social validation ratings favoured such technology over previous solutions.

CONCLUSION

The aforementioned technology may be useful to enable persons with extensive neuro-motor disabilities to write successfully.

The design and testing of a novel mechanomyogram-driven switch controlled by small eyebrow movements

Background

Individuals with severe physical disabilities and minimal motor behaviour may be unable to use conventional mechanical switches for access. These persons may benefit from access technologies that harness the volitional activity of muscles. In this study, we describe the design and demonstrate the performance of a binary switch controlled by mechanomyogram (MMG) signals recorded from the frontalis muscle during eyebrow movements.

Methods

Muscle contractions, detected in real-time with a continuous wavelet transform algorithm, were used to control a binary switch for computer access. The automatic selection of scale-specific thresholds reduced the effect of artefact, such as eye blinks and head movement, on the performance of the switch. Switch performance was estimated by cued response-tests performed by eleven participants (one with severe physical disabilities).

Results

The average sensitivity and specificity of the switch was 99.7 ± 0.4% and 99.9 ± 0.1%, respectively. The algorithm performance was robust against typical participant movement.

Conclusions

The results suggest that the frontalis muscle is a suitable site for controlling the MMG-driven switch. The high accuracies combined with the minimal requisite effort and training show that MMG is a promising binary control signal. Further investigation of the potential benefits of MMG-control for the target population is warranted.

Assisting people with multiple disabilities and minimal motor behavior to improve computer pointing efficiency through a mouse wheel

This study evaluated whether two people with multiple disabilities and minimal motor behavior would be able to improve their pointing performance using finger poke ability with a mouse wheel through a Dynamic Pointing Assistive Program (DPAP) and a newly developed mouse driver (i.e., a new mouse driver replaces standard mouse driver, changes a mouse wheel into a thumb/finger poke detector, and intercepts mouse action). Initially, both participants had their baseline sessions. Then intervention started with the first participant. When his performance was consolidated, new baseline and intervention occurred with the second participant. Finally, both participants were exposed to maintenance phase, in which their pointing performance improved significantly. Both participants improved their pointing efficiency with the use of DPAP and remained highly successful through maintenance phase. Implications of the findings are discussed.

Assisting people with developmental disabilities to improve pointing efficiency with an Automatic Pointing Assistive Program

This study evaluated whether two children with developmental disabilities would be able to improve their pointing performance through an Automatic Pointing Assistive Program (APAP) and a newly developed mouse driver (i.e. a new mouse driver replaces standard mouse driver, and is able to intercept mouse click action). Initially, both participants had their baseline sessions. Then intervention started with the first participant. When her performance was consolidated, new baseline and intervention occurred with the second participant. Finally, both participants were exposed to maintenance phase, in which their pointing performance improved significantly. Data indicated that both participants: (a) improved their pointing efficiency with the use of APAP and (b) remained highly successful through maintenance phase. Implications of the findings are discussed.

Assisting people with multiple disabilities to use computers with multiple mice

This study assessed the combination of multiple mice aid with two persons with multiple disabilities. Complete mouse operation which needed the physically functional sound, was distributed among their limbs with remaining ability. Through these decentralized operations, they could still reach complete mouse pointing control. Initially, both participants had their baseline sessions. Then intervention started with the first participant. When his performance was consolidated, new baseline and intervention occurred with the second participant. Finally, both participants were exposed to maintenance phase, in which their pointing performance improved significantly. Data indicated that both participants: (a) learnt to use multi-mice to realize pointing (b) remained highly successful through maintenance phase. Implications of the findings are discussed.

A five-layer users' need hierarchy of computer input device selection: a contextual observation survey of computer users with cervical spinal injuries (CSI)

This article presents how the researcher goes about answering the research question, 'how assistive technology impacts computer use among individuals with cervical spinal cord injury?' through an in-depth investigation into the real-life situations among computer operators with cervical spinal cord injuries (CSI). An in-depth survey was carried out to provide an insight into the function abilities and limitation, habitual practice and preference, choices and utilisation of input devices, personal and/or technical assistance, environmental set-up and arrangements and special requirements among 20 experienced computer users with cervical spinal cord injuries. Following the survey findings, a five-layer CSI users' needs hierarchy of input device selection and use was proposed. These needs were ranked in order: beginning with the most basic criterion at the bottom of the pyramid; lower-level criteria must be met before one moves onto the higher level. The users' needs hierarchy for CSI computer users, which had not been applied by previous research work and which has established a rationale for the development of alternative input devices. If an input device achieves the criteria set up in the needs hierarchy, then a good match of person and technology will be achieved.

A voice-detecting sensor and a scanning keyboard emulator to support word writing by two boys with extensive motor disabilities

The present study assessed the use of a voice-detecting sensor interfaced with a scanning keyboard emulator to allow two boys with extensive motor disabilities to write. Specifically, the study (a) compared the effects of the voice-detecting sensor with those of a familiar pressure sensor on the boys' writing time, (b) checked which of the sensors the boys preferred, and (c) conducted a social validation assessment of the boys' performance with the two sensors, employing psychology students as raters. The difference in the boys' overall mean writing time per letter across sensors was, by the end of the study, about 1.5s. This difference favored the pressure sensor for one of the boys and the voice-detecting sensor for the other boy. Both boys showed preference for the voice-detecting sensor. Moreover, the psychology students involved in the social validation assessment indicated that such sensor was more satisfactory, suitable, and educationally relevant than the pressure sensor, and represented the solution that they as raters supported more.

Evaluation of head orientation and neck muscle EMG signals as command inputs to a human-computer interface for individuals with high tetraplegia

We investigated the performance of three user interfaces for restoration of cursor control in individuals with tetraplegia: head orientation, electromyography (EMG) from face and neck muscles, and a standard computer mouse (for comparison). Subjects engaged in a 2-D, center-out, Fitts' Law style task and performance was evaluated using several measures. Overall, head orientation commanded motion resembled mouse commanded cursor motion (smooth, accurate movements to all targets), although with somewhat lower performance. EMG commanded movements exhibited a higher average speed, but other performance measures were lower, particularly for diagonal targets. Compared to head orientation, EMG as a cursor command source was less accurate, was more affected by target direction and was more prone to overshoot the target. In particular, EMG commands for diagonal targets were more sequential, moving first in one direction and then the other rather than moving simultaneous in the two directions. While the relative performance of each user interface differs, each has specific advantages depending on the application.

Development and evaluation of a head-controlled human-computer interface with mouse-like functions for physically disabled users

OBJECTIVES

The objectives of this study were to develop a pointing device controlled by head movement that had the same functions as a conventional mouse and to evaluate the performance of the proposed device when operated by quadriplegic users.

METHODS

Ten individuals with cervical spinal cord injury participated in functional evaluations of the developed pointing device. The device consisted of a video camera, computer software, and a target attached to the front part of a cap, which was placed on the user's head. The software captured images of the target coming from the video camera and processed them with the aim of determining the displacement from the center of the target and correlating this with the movement of the computer cursor. Evaluation of the interaction between each user and the proposed device was carried out using 24 multidirectional tests with two degrees of difficulty.

RESULTS

According to the parameters of mean throughput and movement time, no statistically significant differences were observed between the repetitions of the tests for either of the studied levels of difficulty.

CONCLUSIONS

The developed pointing device adequately emulates the movement functions of the computer cursor. It is easy to use and can be learned quickly when operated by quadriplegic individuals.

Design and feasibility study of an integrated pointing device apparatus for individuals with spinal cord injury

Despite the commercial availability of numerous computer-pointing devices, many severely disabled individuals still rely on customized equipment to operate computers. This study presents a novel Integrated Pointing Device Apparatus (IPDA) that integrates numerous commercial pointing devices. The novel IPDA, which complies with a standard USB 1.1 interface, is compatible with most tested computer-pointing devices and flexibly integrates commercial computer devices, tailoring them to suit individual needs. By using simple integrated circuit design and low-cost electronic components, this low-cost apparatus is easily maintained. The feasibility of the IPDA was evaluated by four subjects with high-level cervical (C4-5) spinal cord injury (SCI). Participants performed normal move-and-click and drag-and-drop tasks typically performed by computer pointing devices. Each participant not able to use a traditional computer mouse or trackball were able to operate a computer adequately with the IPDA and three including one operating a trackball with his chin, operated computers easily and smoothly. This feasibility study showed that the IPDA effectively integrates commercial pointing devices, thereby providing the possibility for some people with SCI to obtain computer operability. This study demonstrated the advantages of flexibility, low cost, and acceptable efficiency of the novel IPDA.

AN EYE TRACKING SYSTEM AND ITS APPLICATION IN AIDS FOR PEOPLE WITH SEVERE DISABILITIES

The object of this paper is to present a set of techniques integrated into a low-lost eye tracking system. Eye tracking systems have many potential applications such as learning emotion monitoring systems, drivers' fatigue detection systems, etc. In this paper, we report how we use an eye tracking system to implement an "eye mouse" to provide computer access for people with severe disabilities. The proposed eye mouse allows people with severe disabilities to use their eye movements to manipulate computers. It requires only one low-cost Web camera and a personal computer. A five-stage algorithm is developed to estimate the directions of eye movements and then use the direction information to manipulate the computer. Several experiments were conducted to test the performance of the eye tracking system.

A LOW-COST VISION-BASED HUMAN-COMPUTER INTERFACE FOR PEOPLE WITH SEVERE DISABILITIES

The object of this paper is to present a low-lost vision-based computer interface which allows people with disabilities to use their head movements to manipulate computers. Our system requires only one low-cost web camera and a personal computer. Several experiments were conducted to test the performance of the proposed human-computer interface.

POLAR COORDINATE MAPPING METHOD FOR AN IMPROVED INFRARED EYE-TRACKING SYSTEM

In this paper a polar coordinate mapping method for an improved infrared eye-tracking system is described. In the proposed control system for an eye-tracking device, users do not need to wear any equipment. Rather they just ware an infrared light source and an infrared CCD camera to extract the eye images for the computer to analyze, record the information of the moving traces and pupil diameters, control the mouse's cursor and operate many kinds of applied programs. The advantage of this system lies in solving non-contact requirement problems for which the measured system would require whole eye monitoring and a quick response. We also improve the feasibility and the safety of this eye-tracking device by using infrared rays and new coordinate mapping method.

The smart house for older persons and persons with physical disabilities: structure, technology arrangements, and perspectives

Smart houses are considered a good alternative for the independent life of older persons and persons with disabilities. Numerous intelligent devices, embedded into the home environment, can provide the resident with both movement assistance and 24-h health monitoring. Modern home-installed systems tend to be not only physically versatile in functionality but also emotionally human-friendly, i.e., they may be able to perform their functions without disturbing the user and without causing him/her any pain, inconvenience, or movement restriction, instead possibly providing him/her with comfort and pleasure. Through an extensive survey, this paper analyzes the building blocks of smart houses, with particular attention paid to the health monitoring subsystem as an important component, by addressing the basic requirements of various sensors implemented from both research and clinical perspectives. The paper will then discuss some important issues of the future development of an intelligent residential space with a human-friendly health monitoring functional system.

System for assisted mobility using eye movements based on electrooculography

This paper describes an eye-control method based on electrooculography (EOG) to develop a system for assisted mobility. One of its most important features is its modularity, making it adaptable to the particular needs of each user according to the type and degree of handicap involved. An eye model based on electroculographic signal is proposed and its validity is studied. Several human-machine interfaces (HMI) based on EOG are commented, focusing our study on guiding and controlling a wheelchair for disabled people, where the control is actually effected by eye movements within the socket. Different techniques and guidance strategies are then shown with comments on the advantages and disadvantages of each one. The system consists of a standard electric wheelchair with an on-board computer, sensors and a graphic user interface run by the computer. On the other hand, this eye-control method can be applied to handle graphical interfaces, where the eye is used as a mouse computer. Results obtained show that this control technique could be useful in multiple applications, such as mobility and communication aid for handicapped persons.

The camera mouse: visual tracking of body features to provide computer access for people with severe disabilities

The "Camera Mouse" system has been developed to provide computer access for people with severe disabilities. The system tracks the computer user's movements with a video camera and translates them into the movements of the mouse pointer on the screen. Body features such as the tip of the user's nose or finger can be tracked. The visual tracking algorithm is based on cropping an online template of the tracked feature from the current image frame and testing where this template correlates in the subsequent frame. The location of the highest correlation is interpreted as the new location of the feature in the subsequent frame. Various body features are examined for tracking robustness and user convenience. A group of 20 people without disabilities tested the Camera Mouse and quickly learned how to use it to spell out messages or play games. Twelve people with severe cerebral palsy or traumatic brain injury have tried the system, nine of whom have shown success. They interacted with their environment by spelling out messages and exploring the Internet.

Controlling mouse pointer position using an infrared head-operated joystick

This paper describes the motivation for and the design considerations of a low-cost head-operated joystick. The paper briefly summarizes the requirements of head-operated mouse pointer control for people with disabilities before discussing a set of technological approaches that can be used to satisfy these requirements. The paper focuses on the design of a head-operated joystick that uses infrared light emitting diodes (LED's) and photodetectors to determine head position, which is subsequently converted into signals that emulate a Microsoft mouse. There are two significant findings. The first is that, while nonideal device characteristics might appear to make the joystick difficult to use, users naturally compensate for nonlinearities, in a transparent manner, because of visual feedback of mouse pointer position. The second finding, from relatively informal, independent trials, indicates that disabled users prefer a head-operated device that has the characteristics of a joystick (a relative pointing device) to those of a mouse (an absolute pointing device).