Investigation of the effects of Extra Vehicular Activity (EVA) and Launch and Entry (LES) gloves on performance

Human capabilities such as dexterity, manipulability, and tactile perception are unique and render the hand as a very versatile, effective and a multipurpose tool. This is especially true for unknown environments such as the EVA environment. In the microgravity environment interfaces, procedures, and activities are too complex, diverse, and defy advance definition. Under these conditions the hand becomes the primary means of locomotion, restraint, and material handling. Facilitation of these activities, with simultaneous protection from the cruel EVA environment are the two, often conflicting, objectives of glove design. The objectives of this study was (1) to assess the effects of EVA gloves at different pressures on human hand capabilities, (2) to devise a protocol for evaluating EVA gloves, (3) to develop force time relations for a number of EVA glove pressure combinations, and (4) to evaluate two types of launch and entry suit gloves. The objectives were achieved through three experiments. The experiments for achieving objectives 1, 2, and 3 were performed in the glove box in building 34. In experiment 1 three types of EVA gloves were tested at five pressure differentials. A number of performance measures were recorded. In experiment 2 the same gloves as in experiment 1 were evaluated in a reduced number of pressure conditions. The performance measure was endurance time. Six subjects participated in both the experiments. In experiment 3 two types of launch and entry suit gloves were evaluated using a paradigm similar to experiment 1. Currently the data is being analyzed. However for this report some summary analyses have been performed. The results indicate that a) With EVA gloves strength is reduced by nearly 50 percent, b) performance decrements increase with increasing pressure differential, c) TMG effects are not consistent across the three gloves tested, d) some interesting gender glove interactions were observed, some of which may have been due to the extent (or lack of) fit of the glove to the hand, and e) differences in performance exist between partial pressure suit glove and full pressure suit glove, especially in the unpressurized condition

Investigation of hand capabilities under a variety of performance conditions and an attempt to explain performance differences

Human capabilities such as dexterity, manipulability, and tactile perception are unique and render the hands as a very versatile, effective and a multipurpose tool. This is especially true for environments such as the EVA environment. However, with the use of the protective EVA gloves, there is much evidence to suggest that human performance decreases. In order to determine the nature and cause of this performance decrement, several performance tests were run which studied the effects of gloves on strength, tactile feedback, and range of motion. Tactile sensitivity was measured as a function of grip strength, and the results are discussed. Equipment which was developed to measure finger range of motion along with corresponding finger strength values is discussed. The results of these studies have useful implications for improved glove design

Investigation of the effects of extravehicular activity (EVA) gloves on performance

The objective was to assess the effects of extravehicular activity (EVA) gloves at different pressures on human hand capabilities. A factorial experiment was performed in which three types of EVA gloves were tested at five pressure differentials. The independent variables tested in this experiment were gender, glove type, pressure differential, and glove make. Six subjects participated in an experiment where a number of dexterity measures, namely time to tie a rope, and the time to assemble a nut and bolt were recorded. Tactility was measured through a two point discrimination test. The results indicate that with EVA gloves strength is reduced by nearly 50 percent, there is a considerable reduction in dexterity, performance decrements increase with increasing pressure differential, and some interesting gender glove interactions were observed, some of which may have been due to the extent (or lack of) fit of the glove to the hand. The implications for the designer are discussed

Force-endurance capabilities of extravehicular activity (EVA) gloves at different pressure levels

The human hand is a very useful multipurpose tool in all environments. However, performance capabilities are compromised considerably when gloves are donned. This is especially true to extravehicular activity (EVA) gloves. The primary intent was to answer the question of how long a person can perform tasks requiring certain levels of exertion. The objective was to develop grip force-endurance relations. Six subjects participated in a factorial experiment involving three hand conditions, three pressure differentials, and four levels of force exertion. The results indicate that, while the force that could be exerted depended on the glove, pressure differential, and the level of exertion, the endurance time at any exertion level depended just on the level of exertion expressed as a percentage of maximum exertion possible at that condition. The impact of these findings for practitioners as well as theoreticians is discussed

Evaluation of Team Quality

Competitive pressure and increasing market size have forced organizations to rely more on teams. This study has three objectives: to structure a list of attributes affecting the overall quality of a team; to use a survey tool to determine the significant ones among those attributes; and to compare between manufacturing and healthcare sectors. The data gathered were from employees working in teams in USA and China. A one-way analysis of variance and stepwise regression analysis was performed on the responses to determine team quality attributes. The ANOVA results for attributes versus teams revealed team efficacy, team trust, personality and skills & knowledge as significant. The stepwise regression analysis for team quality versus other attributes (for all the teams combined) showed that job satisfaction and team trust were significantly affecting the overall team quality. Analyses showed differences between China and USA. 

Tactility as a function of grasp force: Effects of glove, orientation, pressure, load, and handle

One of the reasons for reduction in performance when gloves are donned is the lack of tactile sensitivity. It was argued that grasping force for a weight to be grasped will be a function of the weight to be lifted and the hand conditions. It was further reasoned that the differences in grasping force for various hand conditions will be a correlate of the tactile sensitivity of the corresponding hand conditions. The objective of this experiment, therefore, was to determine the effects of glove type, pressure, and weight of load on the initial grasping force and stable grasping force. It was hypothesized that when a person grasps an object, he/she grasps very firmly initially and then releases the grasp slightly after realizing what force is needed to maintain a steady grasp. This would seem to be particularly true when a person is wearing a glove and has lost some tactile sensitivity and force feedback during the grasp. Therefore, the ratio of initial force and stable force and the stable force itself would represent the amount of tactile adjustment that is made when picking up an object, and this adjustment should vary with the use of gloves. A dynamometer was fabricated to measure the grasping force; the tests were performed inside a glove box. Four female and four male subjects participated in the study, which measured the effects of four variables: load effect, gender effect, glove type, and pressure variance. The only significant effects on the peak and stable force were caused by gender and the weight of the load lifted. Neither gloves nor pressure altered these forces when compared to a bare-handed condition, as was suspected before the test. It is possible that gloves facilitate in holding due to coefficient of friction while they deter in peak grasp strength

The effects of extra vehicular activity (EVA) gloves on human performance

Human strength and capabilities such as dexterity, manipulability, and tactile perception are unique and render the hand as a very versatile, effective, multipurpose tool. This is especially true for unknown microgravity environments such as the EVA environment. Facilitation of these activities, with simultaneous protection from the cruel EVA environment, are the two, often conflicting, objectives of glove design. The objective of this study was to assess the effects of EVA gloves at different pressures on human hand capabilities. A factorial experiment was performed in which three types of EVA gloves were tested at five pressure differentials. The independent variables tested in this experiment were gender, glove type, pressure differential, and glove make. Six subjects participated in an experiment in which a number of dexterity measures such as time to tie a rope, and the time to assemble a nut and bolt, were recorded. Tactility was measured through a two-point discrimination test. The results indicate that (a) With EVA gloves there is a considerable reduction in both strength and dexterity performance; and (b) performance decrements increase with increasing pressure differential. Some interesting gender glove interactions were observed, some of which may have been due to the extent (or lack of) fit of the glove to the hand. The implications for the designer are discussed

Force-endurance relationship: does it matter if gloves are donned?

The human hand is a very useful multipurpose tool in all environments. However, performance capabilities are compromised considerably when gloves are donned. This is especially true for extra-vehicular activity (EVA) gloves used in a space environment. The primary aim of this study was to establish exertion and endurance limits for specific tasks. The objective of this study was to develop grip force endurance relations. Six subjects participated in a factorial experiment involving three hand conditions, three pressure differentials, and four levels of force exertion. The results indicate that while the force that could be exerted depended on the glove, pressure differential, and the level of exertion, the endurance time at any exertion level depended just on the level of exertion expressed as a percentage of maximum exertion possible at that condition. The impact of these findings for practitioners as well as theoreticians is discussed

DEAPS-An Alternative to DMAIC? – A Case Study

“To provide leadership in the promotion and protection of the health and social well being of the community through advocacy, education and community-based health services” is a sample mission statement of a prominent Department of Health and Human Services in large metropolitan city. Creating an effective, innovative and modern Information Technology (IT) division driven strategy to support hardware, desktop software, and health department applications which are specifically aligned to goals of health department programs is a necessary but daunting task for management. A strategy based on Lean tools and a revised Six Sigma approach, DEAPS was created to implement Integrated Health Care Systems (IHCS) and the results were demonstrated in a public health and human services department. Discussion includes an economic analysis to demonstrate how health care operations can be enhanced with the implementation of IHCS

ADVANCED MACHINE TOOLS: HOW BEST TO TRAIN OPERATORS

Modern machine tools are very intelligent and capable of fine levels of adaptive control. Without proper training, the ability to operate these machine tools is difficult and critical in operator’s day to day schedule. A mental model developed by the operator’s to understand the work flow can be simplified for the better understanding of the work flow with training. With the developments in the current technology, computer based interactive training seems to be the future and effective way for organizations. A relevant issue is the question of displaying the image appropriately on the computer screen, so that operator control action is facilitated /learned has been discussed briefly. The purpose of this study was to compare different training methodologies assisting the operators and equip them with new set of skills to improve work efficiency. The results from the comparison have been discussed by implementing training procedure on two machines to train the operators in handling the machine. A detailed comparison methodology has been illustrated. The results indicate that training using simulation methods are the best in all measures of performance. However, experienced operators preferred traditional methods compared to computer based methods. More research is needed for generalizing the findings