Comparing three head-pointing systems using a single subject design

The keyboard is the most commonly used input method for interfacing with computers. When using a keyboard is not possible, alternative computer input methods are needed. Three methods using head control are: Head Master by Prentke Romich, Free Wheel by Pointer Systems, and LROP by Words+. The purpose of this study was to compare these three methods for speed and accuracy using a single subject design for nine individuals with disabilities. Visual inspection of the data revealed that subjects obtained higher scores when using Head Master and LROP than Free Wheel. As a follow-up test, an analysis of variance test for repeated measures showed no difference between using Head Master and LROP but did show a significant difference between Head Master and Free Wheel, and LROP and Free Wheel.     

A pilot study comparing mouse and mouse-emulating interface devices for graphic input

Adaptive interface devices make it possible for individuals with physical disabilities to use microcomputers and thus perform many tasks that they would otherwise be unable to accomplish. Special equipment is available that purports to allow functional access to the computer for users with disabilities. As technology moves from purely keyboard applications to include graphic input, it will be necessary for assistive interface devices to support graphics as well as text entry. Headpointing systems that emulate the mouse in combination with on-screen keyboards are of particular interest to persons with severe physical impairment such as high level quadriplegia. Two such systems currently on the market are the HeadMaster and the Free Wheel. The authors have conducted a pilot study comparing graphic input speed using the mouse and two headpointing interface systems on the Macintosh computer. The study used a single subject design with six able-bodied subjects, to establish a baseline for comparison with persons with severe disabilities. Results of these preliminary data indicated that the HeadMaster was nearly as effective as the mouse and that it was superior to the Free Wheel for graphics input. This pilot study, however, demonstrated several experimental design problems that need to be addressed to make the study more robust. It also demonstrated the need to include the evaluation of text input so that the effectiveness of the interface devices with text and graphic input could be compared.     

Facilitating mathematics learning for students with upper extremity disabilities using touch-input system

Purpose: To investigate the feasibility of using tablet device as user interface for students with upper extremity disabilities to input mathematics efficiently into computer. Methods: A touch-input system using tablet device as user interface was proposed to assist these students to write mathematics. User-switchable and context-specific keyboard layouts were designed to streamline the input process. The system could be integrated with conventional computer systems only with minor software setup. A two-week pre–post test study involving five participants was conducted to evaluate the performance of the system and collect user feedback. Results: The mathematics input efficiency of the participants was found to improve during the experiment sessions. In particular, their performance in entering trigonometric expressions by using the touch-input system was significantly better than that by using conventional mathematics editing software with keyboard and mouse. The participants rated the touch-input system positively and were confident that they could operate at ease with more practice. Conclusions: The proposed touch-input system provides a convenient way for the students with hand impairment to write mathematics and has the potential to facilitate their mathematics learning.

• Implications for Rehabilitation

• Students with upper extremity disabilities often face barriers to learning mathematics which is largely based on handwriting.

• Conventional computer user interfaces are inefficient for them to input mathematics into computer.

• A touch-input system with context-specific and user-switchable keyboard layouts was designed to improve the efficiency of mathematics input.

• Experimental results and user feedback suggested that the system has the potential to facilitate mathematics learning for the students.

     

IOL Master与接触式A型超声测量白内障患者和正常人前房深度及眼轴长度的比较研究

目的通过比较白内障患者与正常人用两种方法测量的前房深度和眼轴长度值,观察IOL Master和接触式A型超声测量是否存在差别及其关联程度。方法选取2010年12月-2011年2月期间行白内障摘除加人工晶状体植入术的年龄相关性白内障患者及除屈光不正外没有其他眼部病变的志愿者共89例。分别用IOL Maste和A型超声测量54例(96只眼)白内障患者和35例(70只眼)正常者的前房深度(ACD)和眼轴长度(AL),应用配对t检验对每组两种方法测得的ACD及AL值进行比较,并应用Pearson相关分析比较两种方法的相关性。应用独立样本t检验比较白内障组和正常者组间两种方法测得的差值是否不同。结果白内障组A型超声和IOL Master测得的ACD值分别是(2.83±0.34)、(3.05±0.39)mm,AL值分别是(23.93±2.46)、(24.27±2.57)mm,差异均有统计学意义(P<0.05);正常者组A型超声和IOL Master测得的ACD值分别是(3.16±0.36)、(3.43±0.46)mm,AL值分别是(24.16±1.61)、(24.49±1.62)mm,差异均有统计学意义(P<0.05)。两种测量方法的相关系数分别是rACD=0.823(P<0.05)和rAL=0.995(P<0.05)。白内障组和正常者组两种方法测得的ACD差值分别是(0.23±0.23)、(0.28±0.30)mm;AL差值分别是(0.34±0.27)、(0.33±0.15)mm;两组间ACD和AL差值的比较,差异均无统计学意义(P=0.243,0.742)。结论不论是白内障组还是正常者组,用IOL Master测得的ACD及AL值均比A型超声测得的相应值高,但是两种方法测得的值高度相关。白内障组和正常者组用两种方法测得的差值相比无差别;在可测到ACD及AL值的情况下,两种测量方法的差值均不受晶状体密度的影响。     

The effects of word completion and word prediction on typing rates using on-screen keyboards

Word prediction is often recommended by therapists as a means to improve typing speed for clients with physical limitations. Although literature suggests that word prediction does have an effect on writing proficiency, increased speed is not one of its benefits when used with a standard keyboard. One reason given for the failure of word prediction to accelerate typing is that the user must look away from any source document to scan the prediction list during typing. Looking away from the source document may slow the typist more than any acceleration offered by word prediction. For input methods that already require the typist to look away from the copy, this effect might be irrelevant. The focus of this research was to determine whether word completion or word prediction programs would increase typing speed when used with an input method (an on-screen keyboard) that also requires looking away from the source document. Ten people, five men and five women, aged 20 to 38 years, participated in this study. The study used a single-subject, successive intervention design to test typing speed and accuracy using an on-screen keyboard with integrated word prediction software. Seven participants had their fastest typing speed with word prediction. Two participants had their fastest typing speed with word completion. Only one participant demonstrated no improvement in speed when using these two programs. Overall, these results show that the use of word prediction and word completion may assist on-screen keyboard users to improve typing speed.     

The Effects of Word Completion and Word Prediction on Typing Rates Using On-Screen Keyboards

Word prediction is often recommended by therapists as a means to improve typing speed for clients with physical limitations. Although literature suggests that word prediction does have an effect on writing proficiency, increased speed is not one of its benefits when used with a standard keyboard. One reason given for the failure of word prediction to accelerate typing is that the user must look away from any source document to scan the prediction list during typing. Looking away from the source document may slow the typist more than any acceleration offered by word prediction. For input methods that already require the typist to look away from the copy, this effect might be irrelevant. The focus of this research was to determine whether word completion or word prediction programs would increase typing speed when used with an input method (an on-screen keyboard) that also requires looking away from the source document. Ten people, five men and five women, aged 20 to 38 years, participated in this study. The study used a single-subject, successive intervention design to test typing speed and accuracy using an on-screen keyboard with integrated word prediction software. Seven participants had their fastest typing speed with word prediction. Two participants had their fastest typing speed with word completion. Only one participant demonstrated no improvement in speed when using these two programs. Overall, these results show that the use of word prediction and word completion may assist on-screen keyboard users to improve typing speed.     

An examination of direct selection typing rate and accuracy for persons with high-level spinal cord injury using QWERTY and default on-screen keyboards.

A single-subject rapid alternating treatment design with replication was used to compare the efficiency of two keyboard layouts, QWERTY and default, for persons with high-level spinal cord injury. The LIAISON system and proportional-drive chin controller provided computer access/writing to four subjects. Three efficiency characteristics were examined: keystrokes per minute, keystroke accuracy, and keystroke corrections. Baseline sessions were followed by 10 to 12 alternating treatment sessions for all subjects. Each alternating treatment session involved six text entry trials--three text entry trials using the QWERTY keyboard layout and three using the default keyboard layout. Four follow-up sessions were completed for each subject using the default keyboard configuration. Data analysis revealed that the default keyboard layout provided greater keystrokes per minute for two of the subjects. The keystroke accuracy was between 98% and 100% for all subjects on both keyboard layouts. The findings of this investigation revealed no clinically significant difference in typing performance across the two keyboard layouts for the participating subjects. The results also indicate that previous experience with a keyboard configuration is an important factor in determining performance. A possible treatment interaction or carryover effect between the two keyboard configurations was noted and has implications for the type of single-subject design used in future investigations.     

Application of SEMG in computer mouse access for the disabilities

PURPOSE: To improve the operating speed of the traditional row-column scanning computer keyboard-mouse composite panel controlled using a single key. METHOD: Using a single mouse input control window can avoid scanning unnecessary keyboard characters, thereby increasing the speed in performing mouse commands. In addition, the surface electromyographic (SEMG) sensing input can also be used to provide an input option for the disabled. RESULTS: Eleven volunteers operated the single mouse input control window using the SEMG input and the traditional computer keyboard-mouse composite panel controlled using a single key. The average operating times were 121.3+/-8.9 sec and 208.6+/-10.7 sec, respectively. The difference was statistically significant (p<0.05). CONCLUSIONS: The row-column scanning method with the single mouse control window using SEMG input can effectively decrease the operating time. Through this system, the disabled can operate a computer and lead an independent life.     

The Relationship between Cognitive Load Measurements and Estimates of Computer Input Control Skills

This paper discusses several methods of estimating task difficulty of onscreen object movement tasks for three subject groups using five standard computer input devices (touchscreen, mouse, keyboard, trackball, and locking trackball). The subject groups are as follows: 19 computer-experienced adults, 39 normally developing children, and 15 children with mental retardation. Three separate measurements of cognitive load (mastery, speed, and user characteristics) are reported between user groups to compare conclusions about input device difficulty across different measurement techniques. Results indicate that speed measurements tend to emphasize similarity in device efficiency for skilled users, but that mastery measurements are essential to represent device effectiveness, particularly for unskilled users. Cognitive as well as physical user characteristics were associated with the successful acquisition of device control skills with training. Because each of the measurements used separately result in different conclusions about cognitive load, a combination of measurement techniques would be essential to select appropriate computer-based assistive technology.     

Therapeutic instrumental music playing in hand rehabilitation for older adults with osteoarthritis: four case studies

The purpose of this study was to examine the effects of keyboard playing on the management of hand osteoarthritis in older adults. Four participants, with diagnoses of hand osteoarthritis, met the investigator 4 days a week, for approximately 30 minutes, for 4 weeks. Participants played folk and big band melodies on a Yamaha PSR-510 touch-sensitive electronic keyboard for 20 minutes each session. Evaluation included pre and poststudy occupational therapy measures of finger pinch meter, and range of motion. Participants assessed arthritic discomfort using a visual Likert scale (1-10) before and after each session. A MIDI sequencing computer program, Master Tracks Pro, measured finger velocity, before and after each session. Results indicated that finger pinch meter and range of motion were positively increased by keyboard playing. Two participants recorded significant decreases in arthritic discomfort after playing, while three participants showed significant improvement in finger velocity and hence, finger strength/dexterity due to treatment. Participants enjoyed the treatment with enjoyment ratings of 3 or higher on a 5-point Likert scale. Additional benefits included improved structure of leisure time and increased socialization for older adults with osteoarthritis who tend to isolate themselves due to disease deterioration.     

全方位M-型与普通M-型超声对比评价左室Tei指数的临床研究

目的 本研究目的旨在比较脉冲多普勒、普通M-型、全方位M-型超声3种方法所得心肌作功指数（Tei指数）的相关性,试图探索一种简便、有效、实用的检测方法。 方法 70例住院患者接受检查。应用脉冲多普勒分别采集二尖瓣口和主动脉瓣口血流频谱,应用普通M-型超声分别记录二尖瓣及主动脉瓣活动曲线,应用全方位M-型超声在同一心动周期内同时记录二尖瓣及主动脉瓣活动曲线,分别测量二尖瓣闭合至下一心动周期开放时间间期（a线）及主动脉瓣开放时间（b线）,计算Tei指数。 结果 普通M-型、全方位M-型与脉冲多普勒超声3种方法测得Tei指数之间的比较差异无统计学意义,且相关性好。 结论 全方位M-型是一种较为简便、理想的测定Tei指数的方法。     

Overuse syndromes of the upper limb and the upper limb tension test: a comparison between patients, asymptomatic keyboard workers and asymptomatic non-keyboard workers

SUMMARY. Overuse syndromes of the upper limb (OSUL), also known as repetitive strain injury (RSI) remains a contentious issue that affects a large number of keyboard workers. This research used the results of a modified upper limb tension test (ULTT) performed on three independent groups to look for any similarities or discrepancies between them. The subjects were all female aged between 25-40 years, with groups consisting of 12 OSUL patients, 20 asymptomatic keyboard users and 19 asymptomatic non-keyboard users. The ULTT was positive in 100% of the patient group supporting several hypotheses that state that the pathology of OSUL is neurogenic in origin. The results of the two asymptomatic control groups were predicted to be the same, however this was not found to be the case. Unrelated t-tests were used to analyse the data showing that the keyboard users had a significantly positive ULTT compared to non-keyboard users, which were viewed as a normal control group. This suggests that a subclinical pathological state exists in the keyboard user group. Various subclinical physiological changes caused by prolonged sitting and keyboard use are suggested as possible causes for these results. This research highlights the need for intervention in an office environment to prevent further cases of OSUL from developing. Copyright 1997 Harcourt Publishers Ltd.     

硅油填充眼IOL-Master与改良A超人工晶体度数测量比较

目的比较非接触光学相关生物的测量仪(IOL-Master)与改良A超在硅油填充眼人工晶体度数测量方面的准确性,了解其各自的特性与临床应用价值。方法选取2011年6月至2012年4月行玻璃体切割硅油填充术患者27例(27眼),分成A、B两组,A组14只眼,B组13只眼。术前分别采用IOL-Master、改良A超和角膜曲率计测量眼轴长和角膜曲率,应用SRK-T公式计算人工晶体度数。A、B两组术前预期术后屈光度为-1.5D。术中分别按上述两种测量方法测得结果植入相应度数可折叠人工晶体,术后3个月检查视力、屈光度,并和预期值之间进行比较。结果IOL-Master和改良A超两组测得的眼轴长精确度比较接近,对比差异无显著性;IOL-Master和角膜曲率仪测量角膜曲率分别为(44.31±1.54)D、(43.96±1.38)D(P>0.05),两者对比差异无显著性;IOL-Master和改良A超两组测得的平均绝对屈光误差值(MAFE),两者对比差异无显著性。结论 IOL-Master和改良A超均可较准确对硅油填充眼进行生物学测量,各有优缺点。临床应用时应结合实际情况,有针对性选择。     

An assessment of methods used to evaluate the adequacy of cancer pain management

This paper assesses different methods of evaluating pain management. We used the established methods of pain prevalence measurement and the Pain Management Index (PMI) to compare pain management between two groups who might be expected to have different outcomes. We also developed and used a method to assess how quickly pain was controlled for each group (time to pain control). We compared a group of cancer patients (n = 712) managed by general practitioners in the community (Community Group) and a group of patients (n = 152) treated in a Specialist Palliative Care Unit (Hospice Group) using all methods. The time to pain control method identified a significant difference between the two groups (P < 0.01 log rank test), with the Hospice Group achieving pain control significantly faster. By contrast, neither the pain prevalence method nor the PMI could detect any difference (P = 0.11 Wilcoxon test). The established methods of pain prevalence measurement and PMI are limited by their inability to measure pain over time and to assess prescribers' response to changing pain. Dynamic methods that evaluate changes in prescribing and pain levels over time must be developed in order to accurately assess pain management.     

Electromyographic analysis of traditional and nontraditional abdominal exercises: implications for rehabilitation and training

BACKGROUND AND PURPOSE: Performing nontraditional abdominal exercises with devices such as abdominal straps, the Power Wheel, and the Ab Revolutionizer has been suggested as a way to activate abdominal and extraneous (nonabdominal) musculature as effectively as more traditional abdominal exercises, such as the crunch and bent-knee sit-up. The purpose of this study was to test the effectiveness of traditional and nontraditional abdominal exercises in activating abdominal and extraneous musculature. SUBJECTS: Twenty-one men and women who were healthy and between 23 and 43 years of age were recruited for this study. METHODS: Surface electromyography (EMG) was used to assess muscle activity from the upper and lower rectus abdominis, external and internal oblique, rectus femoris, latissimus dorsi, and lumbar paraspinal muscles while each exercise was performed. The EMG data were normalized to maximum voluntary muscle contractions. Differences in muscle activity were assessed by a 1-way, repeated-measures analysis of variance. RESULTS: Upper and lower rectus abdominis, internal oblique, and latissimus dorsi muscle EMG activity were highest for the Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees. External oblique muscle EMG activity was highest for the Power Wheel (pike, knee-up, and roll-out) and hanging knee-up with straps. Rectus femoris muscle EMG activity was highest for the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up. Lumbar paraspinal muscle EMG activity was low and similar among exercises. DISCUSSION AND CONCLUSION: The Power Wheel (pike, knee-up, and roll-out), hanging knee-up with straps, and reverse crunch inclined 30 degrees not only were the most effective exercises in activating abdominal musculature but also were the most effective in activating extraneous musculature. The relatively high rectus femoris muscle activity obtained with the Power Wheel (pike and knee-up), reverse crunch inclined 30 degrees, and bent-knee sit-up may be problematic for some people with low back problems.     

Cervical outcome measures: testing for postural stability and balance

BACKGROUND: Clinical tests assessing a correlation between structural pathology and cervical pain have been unsuccessful, leading the way for the development of functionally based tests. The purpose of this narrative is to review 4 promising functional tests for the assessment of sensorimotor dysfunction in patients with neck pain. The Joint Position Error/Head Repositioning Accuracy tests, and the Rod and Frame Test were reviewed. SPECIAL FEATURES: The SPNTT was developed to test proprioceptive mechanisms in the neck by applying torsion to mainly mechanoreceptors in the cervical spine. The Joint Position Error and Head Repositioning Accuracy test cervicocephalic kinesthesia or the ability to perceive both movement and position of the head in space related to the trunk. The Rod and Frame Test assesses patients' perception of the vertical orientation of their head in 3-dimensional space. All of these tests evaluate important mechanisms responsible for maintaining postural stability and balance and are thought to be applicable for use in mechanical neck pain patients. SUMMARY: All of the reviewed tests show clinical promise because they are able to distinguish patients with neck pain, particularly those with whiplash trauma and dizziness from asymptomatic controls. All of the tests assess cervical sensorimotor dysfunction, although considerably more research is needed to more clearly establish the psychometric properties for each test including minimal clinical important difference. Although these tests can be used in routine clinical practice, they should be used in combination with other related tests.     

Finger motion, wrist motion and tendon travel as a function of keyboard angles

OBJECTIVE. This study assessed the impact of keyboard angles (in terms of Pitch, Roll and Yaw) on tendon travel and wrist and finger joint kinematics for the flexor digitorum profundus and flexor digitorum superficialis.DESIGN. A repeated measures, laboratory study was conducted. Independent variables were three Pitch angles, three Roll angles, three Yaw angles, and three keyboard separation distances. Dependent variables were tendon travel, wrist deviation, wrist and finger joint kinematics, and Borg comfort rating. BACKGROUND. The increased usage of computers and the risk of cumulative trauma disorders have led to the development of alternate keyboards. This study is a biomechanical assessment of several keyboard designs.METHODS. Lightweight wrist and finger goniometers were used to measure motion of the wrist in three planes, and for three finger joints. Fifteen experienced typists (eight women, seven men) typed a standard text on 30 keyboard conditions. Regression equations were used to calculate tendon travel from joint positions. RESULTS. Tendon travel is sensitive to changes in Pitch, Roll and Yaw angles with approximately 13% difference between the minimal and maximal tendon travel. A flat keyboard produced more tendon travel than keyboards with greater Pitch and Roll angles.CONCLUSIONS. There is a trade-off between wrist and finger positions; as the wrist extends more, the finger joints flex more to compensate. Keyboards imposed different trade-offs between the wrist and finger positions, affecting the overall tendon travel. Relevance Alternate keyboard designs can significantly affect tendon travel and may address reduced repetitiveness in typing by reducing the amount of tendon travel.     

An assessment of alternate keyboards using finger motion, wrist motion and tendon travel

OBJECTIVE. To assess the biomechanical impact of commercially available alternate keyboard designs.DESIGN. A repeated measures study was conducted in a laboratory setting, with planned comparisons of Pitch, Roll and Yaw angles of the keyboards. Ten keyboard conditions were tested. Dependent measures included tendon travel, wrist deviations, and wrist and finger kinematics.BACKGROUND. Various alternate keyboard designs have recently been introduced, which vary Pitch, Roll and Yaw angles, separation distance between keyboard halves, and include other novel features such as cup-shaped depressions for the keys. Yet little objective research has been conducted regarding the biomechanical implications of these various design features. This study attempts to quantify the keyboard designs in terms of several recognized risk factors associated with cumulative trauma disorders that arise with repetitive typing. METHODS. Wrist and finger goniometers were used to measure joint motions during a standardized typing task. 15 experienced typists (8 women, 7 men) served as subjects. Regression equations were used to generate estimates of tendon travel.RESULTS. Tendon travel was affected primarily by Pitch but not Roll or Yaw angles while wrist deviations responded to changes in all three angles. Males had significantly greater amount of tendon travel than female subjects; this difference was only partially accounted for by anthropometry. Differences in joint motion may have a greater impact on the amount of tendon travel.CONCLUSIONS. Alternate keyboard designs can affect tendon travel by as much as 11%.RelevanceAs various alternate keyboard designs are marketed, quantifiable biomechanical data such as that provided by this study, will help to assess their impact on the risk factors for cumulative trauma disorders.     

A computer-based frozen blood inventory and information system

A computer-based, time-sharing data processing system was developed to assist in maintaining information regarding units of red blood cells frozen for eventual transfusion. An automated system has been programmed to compile and retrieve data concerning stored units, prepare shipping documents as required, and maintain transfusion records in a retrievable manner for thawed or shipped units. Requests for frozen red blood cells are processed through this system. Units are selected by the computer to meet requirements specified by the operator of a keyboard terminal. These requirements include method of cryopreservation, specific antigenic characteristics required, and the number of units requested. The computer prints out on the keyboard terminal the units meeting the requirements and the keyboard operator then indicates to the computer the name of the requesting facility, if these units are to be shipped. This input initiates a programmed routine that generates a shipping invoice and a new file for these units in a permanent transfusion record which can by acessed by either donor number or the frozen blood cell code.