NASA Task Load Index Questionnaire Research Articles

Virtual reality simulator for speeding up research on assisted power wheelchair navigation

Some people are prevented from driving a power wheelchair because of cognitive and/or visual impairments. In order to improve their access to mobility, we have developed a driving assistance solution. However, developing and testing such systems require a significant amount of material and clinician time. With the deployment of new technologies, it is now possible to speed up the research process by developing the solution on a simulator in a safe and highly flexible virtual environment before equipping and testing a physical prototype. The objective of this preliminary study was to evaluate the power wheelchair driving simulator developed by INSA Rennes, enabling the user to navigate in an immersive 3D environment. The goal of this preliminary study was to validate the simulator and to assess the quality of experience and user satisfaction. We asked able-bodied people to participate in an experiment which involved navigating in a virtual environment consisting of two obstacle courses while sitting on an actual power wheelchair placed on the immersive platform. The experiment was carried out each time in a random order, with and without driving assistance. We studied the number of collisions and user satisfaction with the simulator. Participants’ sense of immersion and cognitive burden were assessed using the I-Group Presence Questionnaire (IPQ) and NASA-Task Load Index questionnaire (NASA-TLX). Nine able-bodies aged from 11 to 38 years old participated in the study. Our simulator seemed to be accepted by the participants as it generated a good sense of immersion. Participants scored 27.2 ± 18.2 on the NASA-TLX questionnaire and 3.7 ± 1.1 on the IPQ questionnaire. The total number of collisions decreased from 24 without assistance to only 1 with assistance. This preliminary study validated the simulator. People who participated in the experiment felt sufficiently immersed in the virtual environment to feel that they were navigate with a power wheelchair while the wheelchair in which they were sitting was motionless. This first validation step was very important and it is now possible to consider testing with people who are unsuccessful in driving power wheelchairs.

Use of in-situ simulation to investigate latent safety threats prior to opening a new emergency department

IntroductionThe opening of a new emergency department creates numerous unknowns that can become latent safety threats (LSTs) to patient welfare. Healthcare providers can also experience increased stress working in a novel environment, which has been shown to negatively affect decision making, teamwork, and ultimately patient safety. MethodsIn order to identify LSTs and orient staff, multidisciplinary teams participated in 15 in-situ simulations followed by focused debriefing sessions that stressed uncovering LSTs prior to the ED’s opening. Participants also received an electronic, de-identified survey requesting feedback and recollection of any additional LSTs not mentioned during the debriefing. Staff members were then sent the NASA-Task Load Index questionnaire during the first week of opening, which focused on the staff members stress level. ResultsOver 100 healthcare workers of various disciplines participated in 15 in-situ simulations over the course of one day. Thirty-five LSTs were identified and modified before the opening of the new emergency department. The majority (93%) of participants felt that simulations helped them orient to the new space. While the absolute level of stress was the same between cohorts, irritation and discouragement were 16% less in the group completing the simulation. DiscussionIn-situ simulations performed prior to the opening of a new emergency department identified 35 modifiable latent safety threats. Simulations were an effective way to orient staff to the new space and seemed to decrease the level of discouragement and irritation of healthcare workers during the first few weeks of the emergency department’s opening.

A spaceflight operation complexity measure and its experimental validation

A measure of operation complexity in spaceflight is proposed using a weighted Euclidean norm based on four factors: complexity of operation step size (COSS), complexity of operation logic structure (COLS), complexity of operation instrument information (COII), and complexity of space mission information (CSMI). The development of the operation complexity measure followed four steps. First, four factors were identified to be reflected in the operation complexity measure for spaceflight. Second, the entropy theory was adopted to measure the four factors. Then, the weights of the four factors were determined based on a questionnaire survey of 10 astronauts. Finally, the operation complexity values of spaceflight operations were determined by the weighted Euclidean norm of the four factors. To verify the validity of this complexity measure, a one-factor experiment was designed to test the proposed hypotheses. Ten subjects participated in the experiment and performed 179 trials. Both objective indexes (operation time and error rate) and subjective indexes (workload evaluated by NASA Task Load Index questionnaire and subjective complexity rating) were used in the experiment. The data analysis showed that the average operation time, subjective complexity rating, and subjective workload could be predicted well from the operation complexity value ( R = 0.876, 0.802, and 0.698, respectively); and the error rate could only be partly explained by the operation complexity value ( R = 0.343). Relevance to industry The proposed operation complexity measure can be used for ergonomics evaluation of spaceflight operation design. It can also be used for astronaut training planning. Training resources can be allocated to spaceflight tasks according to their operation complexity.

Validation of a Novel Virtual Reality Robotic Simulator

We evaluated the face, content, and construct validity of what is, to our knowledge, the only available virtual reality simulator based on a complete kinematic representation of the da Vinci surgical system. A total of 5 experts (EPs) and 15 novices (NVs) completed exercises on the Mimic dV-Trainer (MdVT). All participants completed three repetitions of the following tasks: (1) Ring and Cone, (2) String Walk, and (3) Letterboard. Participants rated parameters of face and content validity on a five-point Likert-scale questionnaire. Workload imposed by the simulator was assessed using a NASA Task Load Index questionnaire (TLX). Face validity of the MdVT was established as all 20 participants rated the simulator between average to easy-to-use and above-average to high in all parameters of realism. Participants in both EP and NV groups rated the MdVT's overall relevance to robotic surgery as very high. All five EPs assessed the simulator to be a very good practice format and very useful for training residents, thereby affirming content validity. A preliminary assessment of construct validity suggested that the MdVT could differentiate EPs from NVs. The overall TLX workload scores were lower in the EP group for all parameters except for temporal demand. The MdVT demonstrated excellent face and content validity as well as reasonable workload parameters. The use of this simulator in resident training may help bridge the gap between the safe acquisition of surgical skills and effective performance during live robot-assisted surgery.

An Experimental Investigation into Wayfinding Directions for Visually Impaired People

In recent years, there has been an escalation of orientation and wayfinding technologies and systems for visually impaired people. These technological advancements, however, have not been matched by a suitable investigation of human-computer interaction (e.g. designing navigation aids for people who form different cognitive maps for navigation). The aim of this study is to investigate whether a group of sighted participants and a group of visually impaired participants experience a difference in mental and physical demands when given two different sets of verbal instructions directing them to four landmarks. The content of the first set of instructions was proportioned to route descriptions derived from sighted people, and the second set proportioned to descriptions derived from visually impaired people. The objective assessment involved measuring the time taken by participants to reach landmarks and the number of deviations that occurred. A NASA–Task Load Index questionnaire provided an indication of participants subjective perception of workload. The results revealed that instructions formed from visually impaired people resulted in a lower weighted workload score, less minor deviations, and quicker times for visually impaired participants. In contrast, these instructions were found to cause a higher weighted workload score for sighted participants. The results are discussed in relation to the issue of personalisation of mobile context-aware systems for visually impaired people.