Design of VDT operation related upper extremities fatigue detection system and experimental verification / 医疗卫生装备

Objective To design a VDT operation related upper extremities fatigue detection system using keying duration (KD)as an indicator of fatigue and to execute experimental verification.Methods The system included the software part able to calculate,compare and analyze KD and hardware part able to support normal VDT operations.Subjects finished typing task under controlled condition while the system was running. The flexor digitorum superficialis (FDS), extensor digitorum communis(EDC),extensor carpi radialis(ECR),extensor carpi ulnaris(ECU)muscle fatigue were retrieved by sEMG method and standardized questionnaire. Results As the number of keystrokes increased, KD shortened by 1.3%, FDS MVC% dropped by 22.9%,and EDC MVC% decreased by 47.9%.The perceived level of typing fatigue also increased.Conclusion Results revealed KD's change with fatigue,showing the possibility of using KD as an indicator of fatigue and validating the feasibility and effectiveness of the system design.

A new concept of assistive virtual keyboards based on a systematic review of text entry optimization techniques

Abstract Introduction: Due to the increasing popularization of computers and the internet expansion, Alternative and Augmentative Communication technologies have been employed to restore the ability to communicate of people with aphasia and tetraplegia. Virtual keyboards are one of the most primitive mechanisms for alternatively entering text and play a very important role in accomplishing this task. However, the text entry for this kind of keyboard is much slower than entering information through their physical counterparts. Many techniques and layouts have been proposed to improve the typing performance of virtual keyboards, each one concerning a different issue or solving a specific problem. However, not all of them are suitable to assist seriously people with motor impairment. Methods: In order to develop an assistive virtual keyboard with improved typing performance, we performed a systematic review on scientific databases. Results: We found 250 related papers and 52 of them were selected to compose. After that, we identified eight essentials virtual keyboard features, five methods to optimize data entry performance and five metrics to assess typing performance. Conclusion: Based on this review, we introduce a concept of an assistive, optimized, compact and adaptive virtual keyboard that gathers a set of suitable techniques such as: a new ambiguous keyboard layout, disambiguation algorithms, dynamic scan techniques, static text prediction of letters and words and, finally, the use of phonetic and similarity algorithms to reduce the user's typing error rate.

Effects of computer familiarity and computer type on the performance of Korean computerized neurobehavioral test

BACKGROUND: It is thought that computer familiarity has increased significantly since 2004 as well as the use of computers. This study aimed to evaluate the effects of computer familiarity and types of keyboard and computer on the performance of the Korean computerized neurobehavioral test (KCNT), and to identify which parameters of KCNT were affected by aforementioned factors. METHODS: A total of 85 subjects were classified into three groups of computer familiarity by Korean typing speed. Their age, gender and the level of education were also collected. The parameters of KCNT included simple reaction time, choice reaction time, addition, symbol digit, and finger tapping speed. The test was conducted using three types of computers: a laptop computer, a laptop computer with a simplified keyboard, and a desktop computer with a simplified keyboard. RESULTS: Parameters including the simple reaction time, choice reaction time, addition, and symbol digit, and the finger tapping speed of non-dominant hand showed no significant differences in the results among the three groups by computer familiarity after age and educational years were controlled as covariates. The mean reaction time of the simple reaction time and the choice reaction time with a simplified keyboard was significantly shorter compared to that with a typical keyboard. With regard to type of computer, the mean reaction time of the simple reaction time and the choice reaction time was significantly reduced when performed with the desktop computer with a simplified keyboard. CONCLUSIONS: Unlike previous study results, the choice reaction time, the addition, and the finger tapping speed of dominant hand were the only parameters affected by the computer familiarity. Both the type of keyboard and the type of computer significantly influenced the simple reaction time and the choice reaction time. Therefore, it is recommended to use a desktop computer with a simplified keyboard for such parameters.

Bacterial monitoring on ICU bedside notebook computer keyboards and mice before and after comprehensive intervention / 中国感染控制杂志

Objective To evaluate the effect of comprehensive intervention measures on reducing the bacterial colonization of the intensive care unit (ICU)bedside notebook computer keyboards and mice.Methods According to bacterial contamination of ICU bedside notebook computer keyboards and mice,comprehensive intervention meas-ures were taken (including wiping computer keyboards and mice with alcohol twice a day,intensifying hand hy-giene,and monitoring hand-washing compliance),specimens of keyboards and mice were taken,bacterial detection results were analyzed.Results Before intervention,bacterial counts of keyboards and mice of 8 specimens were all>5 CFU/cm2 ,detection rate of Bacillus subtilis was 64.71 %,Micrococcus ,coagulase negative staphylococcus, Acinetobacter baumannii ,and Klebsiella pneumoniae were 17.65%-58.82%,Escherichia coli and Acinetobacter calcoaceticus were both 5.88%.After comprehensive intervention measures were taken,bacterial counts of only two specimens of keyboards and mice were >5 CFU/cm2 ,the qualified rate of monitoring result after intervention was significantly higher than before intervention (88.24% vs 52.94%;χ2 =5.10,P <0.05).Conclusion Compre-hensive intervention measures can significantly reduce bacterial count on ICU bedside notebook computer keyboards and mice,and decrease the occurrence of healthcare-associated infection.

Are dogs sensitive to the human's visual perspective and signs of attention when using a keyboard with arbitrary symbols to communicate?

This study investigated whether dogs take into account the human's direction of attention and visual field when they communicate by means of a keyboard with lexigrams. In order to test this, two dogs, Sofia and Laila, were given the choice between two keyboards, one visible and the other one non-visible from the experimenter's perspective. In one experiment, different barriers were positioned in such way so as to block the experimenter's visibility to one of the keyboards, and, in another experiment we manipulated human's signs of attention, like body orientation and visibility of the eyes. Sofia and Laila consistently preferred to use the keyboard that was in the human's visual field. Laila's choice was also influenced by the human's body orientation. Results suggested that the subjects are sensitive to the human's visual access to the keyboard when they use it to ask for food.

Este estudo investigou se cães levam em conta a direção da atenção e o campo visual do ser humano quando se comunicam por meio de um teclado com lexigramas. Para tanto, duas cadelas, Sofia e Laila, foram submetidas a uma situação em que podiam escolher entre dois teclados, um deles visível e outro não-visível sob a perspectiva do experimentador. Em um experimento, diferentes barreiras foram posicionadas de tal forma a bloquear a visibilidade do experimentador a um dos teclados, e, em outro, experimento manipulamos os sinais de atenção do ser humano, como orientação corporal e visibilidade dos olhos. Sofia e Laila preferiram consistentemente usar o teclado que estava dentro do campo visual do ser humano. A escolha de Laila também foi influenciada pela orientação corporal do ser humano. Os resultados sugerem que as duas são sensíveis ao acesso visual do ser humano ao teclado quando elas o usam para pedir comida.

Layout de teclado para uma prancha de comunicação alternativa e ampliada / Keyboard layout for an augmentative and alternative communication board

O objetivo deste artigo é descrever e discutir a proposta de um novo layout de teclado projetado especialmente para uma prancha de comunicação alternativa com acionamento mecânico e remoto, para ser utilizado por portadores de paralisia cerebral com capacidade cognitiva preservada. Para compor o layout do teclado de comunicação alternativa, realizou-se uma pesquisa envolvendo disposição e conteúdo das teclas. Participaram do estudo onze voluntárias, sendo: cinco professoras de educação especial, quatro pedagogas especializadas em educação especial e duas fonoaudiólogas. O layout é composto por 95 teclas dispostas em grupos de teclas: alfabéticas, de letras acentuadas, numéricas, de funções e de comunicação alternativa e ampliada. As teclas de comunicação alternativa, contêm ícones associados à palavras ou frases, além de teclas acentuadas. Os ícones contemplados fazem parte de uma linguagem visual brasileira de comunicação, em desenvolvimento. Para auxiliar na localização, tanto o tamanho de teclas e caracteres quanto as cores de fundo das teclas diferenciadas foram utilizadas. As teclas com letras acentuadas e as teclas de comunicação alternativa visam facilitar e acelerar a digitação das mensagens, reduzindo assim o tempo de digitação e conseqüentemente, a ocorrência de fadiga muscular.

The aim of this article is to describe and discuss a novel layout proposal for keyboard especially designed for a communication board using mechanical and remote activation to be used by people with cerebral paralysis who present sufficient cognitive skills. In order to design the layout of the augmentative and alternative communication keyboard, a research study involving position and content of the keys was undertaken. Eleven volunteers participated in the study, and they were: five special education teachers, four pedagogues specialized in special education and two speech and language therapists. The layout is made up of 95 keys positioned into key-groups: alphabetical, number, keyboard functions, accented letters and alternative communication. The alternative communication keys contain signs associated with words or phrases, besides keys with accents. These signs are part of a Brazilian visual communication language that is under development. In order to facilitate key finding, both size and background color were considered. The purpose of the accented letters and alternative communication keys is to facilitate key finding and enhance typing speed so as to reduce muscular fatigue.

The Effect of Height and Tilt Adjustable Keyboard Tray on Work-related Musculoskeletal Pain

OBJECTIVE: To evaluate the effect of height and tilt adjustable keyboard tray on work-related musculoskeletal pain in visual display terminal (VDT) workers. METHOD: Twenty-one VDT workers, who had myofascial pain in upper trapezius (UTZ) and extensor carpi radialis longus (ECRL) or brevis (ECRB) during VDT work, were randomly assigned to a control (n=10) that used conventional keyboard or experimental group (n=11) that used height and tilt adjustable keyboard tray. A pretest assessed the visual analog scale (VAS), pain threshold of UTZ and ECRL or ECRB, and grip and tip pinch strength as well as upper extremity function index (UEFI). Post-test was conducted 1 month later. Additionally, differences in working posture between the two groups were evaluated. RESULTS: For the UTZ, the decrease of VAS (p<0.05) and increase of pain threshold (p<0.01) in experimental group were significantly greater than control group after 1 month. Increase of right grip strength (p<0.01) and UEFI (p<0.05) in the experimental group were significantly larger than control group. Experimental group showed lower keyboard height (p<0.01) and smaller elbow angle (p<0.01) as well as more anterior tilted keyboard angle (p<0.01) than the control group. CONCLUSION: Application of height and tilt adjustable keyboard tray seems to affect the working posture, thus reduce the work-related musculoskeletal pain of UTZ as well as enhance the strength of right grip strength and upper extremity function in VDT workers. Additionally, anterior keyboard tilting may help to reduce wrist extension in low keyboard height which contributes to decreasing UTZ muscle tension.

Colonization of nosocomial pathogens on computer keyboards in patient care areas.

Objective: Nosocomial infections are an important cause of morbidity and mortality in hospitalized patients. The role of the hospital environment as a reservoir of nosocomial pathogens is controversial and has not been thoroughly investigated. In the past years at our institution, computers have been widely used in patient care areas, including general wards and intensive care units. There are studies which show that inanimate objects in the hospital environment constitute reservoirs of nosocomial pathogens. Hence, the study is designed to determine whether computer keyboards in the patient care areas in the Department of Medicine, Siriraj Hospital were reservoirs of nosocomial pathogens. Methods: Twenty-six computer keyboards from general medical wards (20) and intensive care units (6) and 26 computer keyboards from secretarial offices were studied from August to September 2003. All the keyboards were cultured for aerobic pathogens by cotton swab technique. Results: The overall colonization rate of pathogens on the keyboards was 96.2% from patient care areas and 92.3% from the offices (p=1). The colonization rates of non-fermentative gram negative bacilli on the keyboards located in the patient care areas and the offices were 11.5% and 0%, respectively (p=0.24). However, if the fungal isolate was considered a potential pathogen, its colonization rate on the keyboard was 4.3% in the patient care areas compared with 1.5 % in the offices (p=0.03). Conclusion: There was a trend in finding potential pathogenic organisms more often from the computer keyboards located in the patient care areas than from those in the offices. The computer keyboards located in the patient care areas should be periodically cleaned.

Effects of Familiarity with Computer and Type of Keyboard on Computerized Neurobehavioral Performance Tests / 대한산업의학회지

OBJECTIVES: A stratified cross-over study was conducted to evaluate the effects of familiarity with computer on the performance of computerized neurobehavioral tests. Effects of keyboard type on the relationship between familiarity with computer and performance of computerized neurobehavioral tests were also examined. METHODS: We tested 70 persons classified into three groups according to degree of familiarity with computer: Group 1 was people with no computer competency, Group 2 had slight working experience on the computer, and Group 3 were highly competent and efficient on the computer. For each group, we executed 4 tests of the Korean version of the Swedish Performance Evaluation System (Simple Reaction Time, Addition, Symbol Digit, and Finger Tapping Speed). Three types of keyboard were applied for all three groups. Type 1 keyboard was a conventional layout with 106 keys. We removed the unused keys except for the 17 which were used in the test and remodeled the normal keyboard into Type 2 keyboard with 17 keys (10 numeric keys, 4 arrow keys, space bar, and both Ctrl keys). Type 3 keyboard with 11 keys consisted of 10 numeric keys and the space bar was newly developed for the computerized neurobehavioral performance test. RESULTS: It was found that Simple Reaction Time, Addition, and Finger Tapping Speed were not affected by familiarity with computer and type of keyboard. The mean reaction time of Symbol Digit adjusted by age and educational level with Type 1 keyboard was found to have significant difference among the three groups (F=3.347, p=0.041). The performance of Symbol Digit in Group 1 was found to be significantly lower than that in Group 2. The performances of Symbol Digit measured with Types 2 and 3 keyboards were not found to have significant differences among the three groups. In Groups 1 and 3, the performances of Symbol Digit measured with Type 1 keyboard were found to be significantly lower than those of other keyboards. CONCLUSIONS: According to the above results, Simple Reaction Time, Addition, and Finger Tapping Speed have high priority over other neurobehavioral tests for the workers having varying degrees of computer familiarity. It is also suggested that familiarity with computer and keyboard type needs to be considered in interpretation of the performance of Symbol Digit. We recommended executing the computerized neurobehavioral test with keyboards 2 or 3 to reduce the effect of computer familiarity.

The Desk Height and Keyboard Design as Determinants of Posture and Trapezius Tension

OBJECTIVE: To test the hypothesis that changing the desk height or keyboard design with fixed neck posture will change posture of the upper extremity and the trapezius tension, and to suggest the appropriate the desk height and the keyboard design to relieve the tension of the trapezius. METHOD: Five men volunteered. Four desk heights (5 cm below, same as, 5 cm above, 10 cm above the olecranon) and three keyboard designs (flat, wrist support, natural) were set up. The posture of the upper extremity was analysed by 3 dimensional Ariel performance analysis system. The tension of trapezius was measured by surface EMG. RESULTS: The trapezius tension was low when the desk height was below the olecranon in 'flat' keyboard, and was low when the desk height was no higher than 5 cm above the olecranon in 'wrist support' and 'natural' keyboard. The trapezius tension went with the change of the shoulder flexion, abduction, elevation and the elbow flexion in 'flat' keyboard, and went with the change of the shoulder flexion and elevation in 'wrist support' and 'natural' keyboard. CONCLUSION: To lessen the tension of the trapezius, the desk height should be below the olecranon in 'flat' keyboard and no higher than 5 cm above the olecranon in 'wrist support' and 'natural' keyboard. The keyboard design should include the wrist support which relieved the tension of trapezius by giving the resting point.