A Design Contribution to Ergonomic PC Mice Development.

Developing new manual computer pointing devices abiding to the requirements set out in ergonomic product design literature necessitates joining contributions from several areas, including the ergonomic guidelines applicable to hand tool design, human-system interaction, and certain user characteristics such as anthropometric data. Computer mice are hand tools enabling the interaction with the computer, for use by people from both sexes and practically all ages. Moreover, the PC mouse's intensive usage is able to cause musculoskeletal disorders. This paper reports on a study aimed at developing new computer mouse shapes, reducing forearm pronation, and providing hand-palm holding, supported by a literature review and an adequate design methodology, starting from known shapes of commercial products, the traditional (horizontal) computer mouse, and the vertical computer mouse. In this regard, potential concepts were generated as solutions to the previously specified problem through a set of creative tasks based on the specifications. Four new shapes were proposed to be evaluated through an assessment matrix; as a result, two new PC mice geometries were designed and fully prototyped. This study also reports on selected results of usability and an electromyographic evaluation of the prototypes against three commercial PC mice (horizontal, slanted, and vertical) by a sample of 20 participants, supporting validation of the development process and the newly developed geometries, with emphasis on the slanted conical innovative shape.

Usability Evaluation of Slanted Computer Mice.

Prevention of musculoskeletal disorders is supported by use of slanted rather than horizontal pointing devices, but user acceptance of the former may be compromised due to lower perceived ease of use. This study compares subjectively rated usability (N = 37) for three sizes of slanted computer mice and includes a horizontal small conventional device as a reference. For a random subset of the sample (n = 10), objective usability parameters were also elicited. Participants followed a standard protocol which is based on executing graphical pointing, steering, and dragging tasks generated by a purpose-built software. Subjective ratings were collected for each of the four pointing devices tested. The three slanted devices differed in size but were chosen because of an approximately similar slant angle (around 50-60 degrees relative to the horizontal plane). Additionally, effectiveness and efficiency were objectively calculated based on data recorded for the graphical tasks' software for a random subset of the participants (n = 10). The results unveil small differences in preference in some of the subjective usability parameters across hand size groups. This notwithstanding, the objective efficiency results are aligned with the subjective results, indicating consistency with the hypothesis that smaller slanted devices relative to the user's hand size are easier to use than larger ones. Mean values of weighted efficiency recorded in the study range from 68% to 75%, with differences across devices coherent with preference rank orders.

Dynamics of forearm muscle activity in slanted computer mice use.

BACKGROUND: Static muscular activity of muscles activated in the use of the conventional PC mouse is believed to represent a higher risk for the musculoskeletal health of the user than dynamic muscular activity. OBJECTIVE: This paper presents a compounded muscular activity dynamics indicator (akin to percent relative range), enabling comparison between computer handheld pointing devices. METHODS: This muscular dynamism approach considers baseline muscular activity (APL, ECR, ECU and ED) relative to the Maximum Voluntary Contraction as well as the dynamics of muscular activation. The latter is computed as the ratio of the difference between APDF90 and APDF10 divided by APDF50 (APDF-Amplitude Probability Distribution Function for the 90th, 50th and 10th percentiles). The paper demonstrates the approach with results of comparative evaluation of a horizontal, a slanted and a vertical PC mouse, through surface EMG monitoring of 20 participants performing standardized graphical task with the devices. RESULTS: Hand size impacts muscular activity dynamics in these four muscles, which supersedes differences in device geometry, across the range of devices tested. CONCLUSION: Smaller devices relative to hand size foster more dynamic muscular activity.

Laing early-onset distal myopathy with subsarcolemmal hyaline bodies caused by a novel variant in the MYH7 gene.

Myopathies caused by MYH7 gene mutations are clinically and pathologically heterogeneous and, until recently, difficult to diagnose. The availability of NGS panels for hereditary neuromuscular diseases changed our insight regarding their frequency and allowed a better perception of the different phenotypes and morphological abnormalities associated. We present a male Portuguese patient with the classical phenotype of Laing early-onset distal myopathy (MPD1) beginning at 6 years of age, very slowly progressive, and with a mild to moderate impact on daily life by the age of 56. Muscle biopsy showed a myopathic pattern with hyaline bodies and cores. The NGS panel for structural myopathies identified a novel missense heterozygous variant, c.T4652C (p.Leu1551Pro), in the exon 34 of the MYH7 gene.

White-matter commissures: a clinically focused anatomical review.

PURPOSE: The objective of this review is to provide a structured approach to the main white matter commissures, their anatomic and radiological definition and disease implications. METHODS: The Pubmed database and The JAMA Network were used for the literature review and the following terms were searched using Sort by: Best Match and Sort by: Most Recent: telencephalic commissure, forebrain commissure anatomy, fornix anatomy, commissure of fornix, posterior commissure, corpus callosum, commissural agenesis, Probst bundle, corpus callosum disorders review, corpus callosum diseases review, Marchiafava-Bignami, Alzheimer's disease and Forel commissure; 36 papers were selected, one excluded due to the language barrier. RESULTS: The interhemispheric communication in the brain is achieved via the brain commissures, bundles of white matter linking the two cerebral hemispheres. Anterior white commissure (AWC)-related with olfactory and non-visual communication, hippocampal commissure-main efferent pathway of the hippocampus, connecting the hippocampal formation to structures beyond the temporal lobe, crucial in declarative memory formation and consolidation-and the corpus callosum (CC)-from the anterior commissure to the hippocampal commissure-are the main telencephalic commissures. Supramammilary commissure, posterior commissure, supraoptic commissure and habenular commissure are diencephalic commissures-unknown function, probably related to involuntary eye movements. Commissural agenesis (AWC is absent or impossible to recognize), Alzheimer's Disease (hippocampal commissure may contribute for disease dissemination) and agenesis of corpus callosum are some of the disturbances that involve the telenchephalic commissures. CONCLUSIONS: A comprehensive understanding of the clinic-anatomic correlation is pivotal to understand the pathology and therefore improve our diagnostic accuracy and treatment options, in the background of all patient management.

A tentative efficiency index for pointing device use in computer aided design: A pilot study.

BACKGROUND: Focusing on the efficiency aspect of computer pointing devices' usability, this paper reports on a novel and tentative empirically derived efficiency index for 3D CAD. OBJECTIVE: Three commercially available computer pointing devices were compared: a standard horizontal computer mouse, a vertical device (supporting neutral pronation of the forearm) and a slanted device. METHODS: Pilot structured observations of 10 subjects' activity were carried out to estimate the proportion of each unique computer mouse operation during CAD modelling with a 3D parametric software. Pointing, dragging and steering standardized tasks were implemented by software and performed by 20 users. Effectiveness and efficiency were calculated and discomfort, effort and ease of use were subjectively assessed. RESULTS: The mean efficiency index value was lower for the vertical device. Assessments of discomfort, effort and ease of use also supported considering preference for the horizontal and slanted devices, providing limited internal validation. CONCLUSION: Results suggest the tentative index may offer a valid means of ranking performance of alternative pointing devices regarding operation efficiency.

Psychosocial and ergonomic survey of office and field jobs in a utility company.

INTRODUCTION: The effect of different kinds of work on the psychosocial assessment of workers under the same management and organizational environment is investigated. METHODS: A voluntary assessment in a utility company was carried out using the short version of the Copenhagen psychosocial questionnaire (CoPsoQ) on two occasions, 1.5 years apart. Initially, 25 office workers (11 men and 14 women) participated, while 14 of those workers (8 women and 6 men) participated in the second assessment together with 32 field workers. The sewage, water treatment and maintenance workers, totaling 32 men, also participated in a field ergonomics assessment using the Washington State Department of Labor and Industries field work ergonomic checklist. RESULTS: The longitudinal outlook was fairly stable, with sustained severe scores in many CoPsoQ subscales and intensification of severity of workers' control over work and esteem for men. A significantly higher esteem score resulted for field rather than office workers. Workers subjected to foul odors showed similar severity of psychosocial factors. DISCUSSION: For most psychosocial dimensions, the organizational design and management system in place, as well as the overall cultural environment in which it operates, create a much stronger and more decisive impact than job-specific factors.

Corpus Callosum and Neglect Syndrome: Clinical Findings After Meningioma Removal and Anatomical Review.

Two types of neglect are described: hemispatial and motivational neglect syndromes. Neglect syndrome is a neurophysiologic condition characterized by a malfunction in one hemisphere of the brain, resulting in contralateral hemispatial neglect in the absence of sensory loss and the right parietal lobe lesion being the most common anatomical site leading to it. In motivational neglect, the less emotional input is considered from the neglected side where anterior cingulate cortex harbors the most frequent lesions. Nevertheless, there are reports of injuries in the corpus callosum (CC) causing hemispatial neglect syndrome, particularly located in the splenium. It is essential for a neurosurgeon to recognize this clinical syndrome as it can be either a primary manifestation of neurosurgical pathology (tumor, vascular lesion) or as a postoperative iatrogenic clinical finding. The authors report a postoperative hemispatial neglect syndrome after a falcotentorial meningioma removal that recovered 10 months after surgery and performs a clinical, anatomical, and histological review centered in CC as key agent in neglect syndrome.

Working conditions under multiple exposures: A cross-sectional study of private sector administrative workers.

BACKGROUND: Office workers are increasingly exposed to physical and psychosocial risk factors. OBJECTIVE: To assess the association between environmental, physical and organizational working conditions and the physical and psychosocial well-being of a sample of private sector office workers. METHODS: Musculoskeletal pain was collected from a body map and the Disabilities of the Arms, Shoulders and Hands questionnaire. The short version of the Copenhagen Psychosocial Questionnaire enabled collecting information on six job related satisfaction and dissatisfaction subscales. A checklist for ergonomics in computer work guided the analysis of ergonomic factors and measurements were taken to characterize environmental conditions. Association between exposures and outcomes was calculated using IBM SPSS Statistics 20 software. RESULTS: Significant moderate positive association was found between dissatisfaction with job psychological demands and musculoskeletal pain in the upper body (0.40; p= 0.05), as well as between postural ergonomic mismatches and dissatisfaction with job insecurity towards the future (0.42; p= 0.04). A significant moderate negative association (-0,47; p= 0.02) was found as well between satisfaction with job social support and with leadership quality and location of the work station in an open-plan office as opposed to smaller office rooms. CONCLUSIONS: The results show how raising awareness of the risk factors encountered in contemporary office work is still necessary to promote widespread improvement of working conditions, from both a physical and a psychosocial perspective.

Continuous zoom calibration by tracking salient points in endoscopic video.

Many image-based systems for aiding the surgeon during minimally invasive surgery require the endoscopic camera to be calibrated at all times. This article proposes a method for accomplishing this goal whenever the camera has optical zoom and the focal length changes during the procedure. Our solution for online calibration builds on recent developments in tracking salient points using differential image alignment, is well suited for continuous operation, and makes no assumptions about the camera motion or scene rigidity. Experimental validation using both a phantom model and in vivo data shows that the method enables accurate estimation of focal length when the zoom varies, avoiding the need to explicitly recalibrate during surgery. To the best of our knowledge this the first work proposing a practical solution for online zoom calibration in the operation room.

Impact of positive surgical margins on biochemical relapse after radical retropubic prostatectomy (RRP).

INTRODUCTION: RP (radical prostatectomy) technique continues the major treatment option for men with potential cure and life expectancy exceeding 10 years. The aim of the study is to assess the impact of PSM on BR (biochemical relapse), to identify PSM risk factors, to clarify the factors involved in BR in the absence of PSM. MATERIAL AND METHODS: Consultation of 171 medical-records from patients submitted to RRP (radical retropubic prostatectomy) between January/2000-December/2005. Mean-age: 64 yr. Mean - PSA (positive surgical margin): 11.88 ng/ml. Clinical staging: 67.8% cT1, 32.2% cT2. GS: ≤6 (66.1%), =7 (21.1%), 8-10 (12.3%). PS: pT0 1.2%, pT2 50.3%, pT3a 36.3%, pT3b 12.9%, pT4 0.6%. pathological Gleason score: ≤6 39.2%, =7 40.9%, 8-10 19.3%. RB definition was PSA ≥0.2 ng/ml. Adjusted Odds-Ratios with 95% confidence intervals (CI) were estimated through univariate logistic regression. RESULTS: There were PSM in 46 specimens, 28 had single PSM and 18 multiple PSM (≥2). BR occurred in 57 patients (33.3%), with an average time after surgery of 23.5 months - 26 patients had PSM and 31 had not. Statistical significant results for BR in variables PSA, PS and PSM. Quadruples if PSM (p <0.0001), triples in single PSM (p = 0.01) and is 6x higher in multiple PSM (p = 0.001). Regarding factors that influence the presence of PSM, only PS ≥pT3a reach statistical significance (p <0.0001). Patients with BR but without PSM (54.38%), variables statistically significant were: initial PSA >10, (p = 0.029) and pathological Gleason score ≥8 with a risk nearly 4x higher than pathological Gleason score ≤6 (p = 0.027). CONCLUSIONS: Statistical risk analysis concluded that the presence of PSM in RRP is strongly influenced by PS ≥pT3a. The presence of PSM and their number increase significantly the risk of BR compared to other factors. In the absence of PSM, the factors that seem to be crucial and with greater impact on BR are initial PSA>10 and pathological Gleason score ≥8.