Assessment of Urban Railway Transit Driver Workload and Fatigue under Real Working Conditions

2019 ◽  
Vol 2673 (11) ◽  
pp. 891-900
Author(s):  
Yuan-chun Huang ◽  
Lan-peng Li ◽  
Zhi-gang Liu ◽  
Hai-yan Zhu ◽  
Lin Zhu
Keyword(s):  
Reaction Time ◽  
Working Conditions ◽  
Night Shift ◽  
Driving Mode ◽  
Autonomous Mode ◽  
Driver Workload ◽  
Driving Workload ◽  
Significant Regression ◽  
Time Changes ◽  
Fatigue Driving

This paper describes an experiment conducted to establish a workload model by employing physiological methods to measure driver workload and fatigue under real working conditions. Experienced healthy metro drivers were selected as subjects; they performed normal schedules during which simultaneous electrocardiogram (ECG) recording was used to assess their levels of fatigue. Then, subjective workload assessment and reaction time tests were conducted during each break interval to monitor the drivers’ physiological and psychological performance. Based on task analysis, driving workload models with time weight parameters of four types of tasks were established and the workload real-time changes during different shifts were evaluated. The results demonstrate that workload tends to increase over time and it is significantly higher during manual driving mode than autonomous mode ( p = 0.015 < 0.05). Driving fatigue occurs earlier in the night shift than in the day shift according to ECG spectrum analysis results. Although the results of reaction time tests show no significance ( p = 0.917 > 0.05), the increase in the number of reaction errors after fatigue driving indicates a reduction in drivers’ cognitive ability. Regression analysis shows a significant regression relationship with a mutual incentive effect between workload and fatigue in three shifts ( R2 > 0.4). These will be used as a future reference for fatigue research and to help develop reasonable schedules to ensure operational safety.

scholarly journals Driver seat comfort for level 3-4 autonomous vehicles

Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S111-S118
Author(s):  
Neil J. Mansfield ◽  
Kartikeya Walia ◽  
Aditya Singh
Keyword(s):  
Autonomous Vehicles ◽  
Driving Simulator ◽  
Case Methods ◽  
Driving Mode ◽  
Full Control ◽  
Seat Comfort ◽  
Autonomous Mode ◽  
Different Types ◽  
Level 3 ◽  
Level 2

BACKGROUND: Autonomous vehicles can be classified on a scale of automation from 0 to 5, where level 0 corresponds to vehicles that have no automation to level 5 where the vehicle is fully autonomous and it is not possible for the human occupant to take control. At level 2, the driver needs to retain attention as they are in control of at least some systems. Level 3-4 vehicles are capable of full control but the human occupant might be required to, or desire to, intervene in some circumstances. This means that there could be extended periods of time where the driver is relaxed, but other periods of time when they need to drive. OBJECTIVE: The seat must therefore be designed to be comfortable in at least two different types of use case. METHODS: This driving simulator study compares the comfort experienced in a seat from a production hybrid vehicle whilst being used in a manual driving mode and in autonomous mode for a range of postures. RESULTS: It highlights how discomfort is worse for cases where the posture is non-optimal for the task. It also investigates the design of head and neckrests to mitigate neck discomfort, and shows that a well-designed neckrest is beneficial for drivers in autonomous mode.

Assessing the Effect of Countdown Featured TOR Signal on Drivers in Automated Driving Mode Change

2020 ◽  
Vol 64 (1) ◽  
pp. 1213-1217
Author(s):  
HyunJoo Park ◽  
HyunJae Park ◽  
Sang-Hwan Kim
Keyword(s):  
Reaction Time ◽  
Situation Awareness ◽  
Time Preference ◽  
Automated Driving ◽  
Mode Change ◽  
Driving Mode

In conditional automated driving, drivers may be required starting manual driving from automated driving mode after take-over request (TOR). The objective of the study was to investigate different TOR features for drivers to engage in manual driving effectively in terms of reaction time, preference, and situation awareness (SA). Five TOR features, including four features using countdown, were designed and evaluated, consisted of combinations of different modalities and codes. Results revealed the use of non-verbal sound cue (beep) yielded shorter reaction time while participants preferred verbal sound cue (speech). Drivers' SA was not different for TOR features, but the level of SA was affected by different aspects of SA. The results may provide insights into designing multimodal TOR along with drivers' behavior during take-over tasks.

scholarly journals Evaluation of the Effect of Time Change in Cognitive Function in Volunteers in Tehran

2016 ◽  
Vol 9 (2) ◽  
pp. 119 ◽  
Author(s):  
Marjan Erfani ◽  
Hedayat Sahraei ◽  
Zahra Bahari ◽  
Gholam Hossein Meftahi ◽  
Boshra Hatef ◽  
...  
Keyword(s):  
Mental Health ◽  
Reaction Time ◽  
Cognitive Functions ◽  
Reduction Reaction ◽  
Plasma Cortisol Level ◽  
Mental Fatigue ◽  
Time Change ◽  
General Mental Health ◽  
Before And After ◽  
Time Changes

<strong></strong><p><strong>BACKGROUND:</strong> Time change (which can lead to sleep duration decrements) can lead to brain dysfunction if repeated. In the present study, cognitive functions of the volunteers were evaluated before and after the time changes in Tehran.</p><p><strong>METHODS:</strong> Eleven, voluntary healthy persons (21±2 year old) were evaluated for their cognitive functions including sustain attention, reaction time, and mental fatigue twenty-one days before the time changes and thirty-eight days after time change using PASAT software. In addition, plasma cortisol level was measured before and after the time changes.</p><p><strong>RESULTS:</strong> After the time changes salivary cortisol concentration increase, but general mental health was decreased. Sustain attention was shortened after time change which was significantly different compared with before the time changes. Reaction time was increased after the time changes in comparison with the before the time changes, but was not statistically significant. In addition, mental fatigue was increased after the time changes.</p><p><strong>CONCLUSION:</strong> It seems that time change may reduce brain cognitive functions which are manifested by general mental health, sustain attention reduction, reaction time as well as mental fatigue.</p>

Research on Tunnel Interior Zone Luminance Evaluation Method and its Application

2013 ◽  
Vol 779-780 ◽  
pp. 929-934
Author(s):  
Jing Bi Hu ◽  
Da Guo ◽  
Xiao Qin Zhang
Keyword(s):  
South China ◽  
Evaluation Method ◽  
Operating Speed ◽  
Safe Operation ◽  
Luminance Threshold ◽  
Traffic Environment ◽  
Interior Zone ◽  
Driver Workload ◽  
Driving Workload ◽  
Driving Fatigue

Because of the special traffic environment, the tunnel is called a bottleneck on the highway sections; there is a huge risk of safe operation. Tunnel interior zone lighting plays an important role in the tunnel; good lighting can eliminate depression and driving fatigue of the driver in the tunnel. In this paper, freeway tunnel interior zone lighting is as the research object. We analyzed the driver's demand for freeway tunnel interior zone lighting and transformed illumination to luminance in the model of driver workload, operating speed and the illumination. And this model is established by our group. According to comfortable and relatively comfortable driving workload intense threshold, we can get the safe and comfortable luminance threshold of tunnel interior zone. This paper proposed a detection and evaluation method in freeway tunnel interior zone luminance, and the method have been applied and verified on one freeway in south China.

Effects of sleepiness on clinical decision making among paramedic students: a simulated night shift study

2021 ◽  
pp. emermed-2019-209211
Author(s):  
Danielle Bartlett ◽  
Sara Hansen ◽  
Travis Cruickshank ◽  
Timothy Rankin ◽  
Pauline Zaenker ◽  
...  
Keyword(s):  
Decision Making ◽  
Reaction Time ◽  
Shift Work ◽  
Clinical Decision Making ◽  
Clinical Performance ◽  
Night Shift ◽  
Clinical Decision ◽  
Night Shift Work ◽  
Clinical Scenarios ◽  
Perceived Workload

ObjectiveParamedics are at the forefront of emergency healthcare. Quick and careful decision making is required to effectively care for their patients; however, excessive sleepiness has the potential to impact on clinical decision making. Studies investigating the effects of night shift work on sleepiness, cognitive function and clinical performance in the prehospital setting are limited. Here, we aimed to determine the extent to which sleepiness is experienced over the course of a simulation-based 13-hour night shift and how this impacts on clinical performance and reaction time.MethodsTwenty-four second year paramedic students undertook a 13-hour night shift simulation study in August 2017. The study consisted of 10 real-to-life clinical scenarios. Sleepiness, perceived workload and motivation were self-reported, and clinical performance graded for each scenario. Reaction time, visual attention and task switching were also evaluated following each block of two scenarios.ResultsThe accuracy of participants’ clinical decision making declined significantly over the 13-hour night shift simulation. This was accompanied by an increase in sleepiness and a steady decline in motivation. Participants performed significantly better on the cognitive flexibility task across the duration of the simulated night shift and no changes were observed on the reaction time task. Perceived workload varied across the course of the night.ConclusionOverall, increased sleepiness and decreased clinical decision making were noted towards the end of the 13-hour simulated night shift. It is unclear the extent to which these results are reflective of practising paramedics who have endured several years of night shift work, however, this could have serious implications for patient outcomes and warrants further investigation.

Determination Of Reaction Time Changes Per Time Unit In Clot Assays

1981 ◽  
Author(s):  
Lj Popović
Keyword(s):  
Reaction Time ◽  
Standard Sample ◽  
Reaction Times ◽  
Test Sample ◽  
Total Reaction ◽  
The Difference ◽  
Time Changes ◽  
Total Reaction Time

Changes in reaction time of clot assays are usually expressed only in time units, which fails to indicate the extent of the increase or decrease of the reaction time of the tested specimens against that of the basic sample. Reaction time increases of, e.g. , 6 seconds in tested samples, compared to basic sample reaction times of 12 and 24 seconds respectively, signify an increase twice as large in the first as in the second instance.Changes in reaction time of clot assays can be expressed as the increment or decrement of the reaction time per time unit. This amount of increase or decrease (positive or negative alteration of reaction time, T a ) can be expressed as the quotient of the difference between the reaction times of the tested (T x ) and basic (To) samples and of the basic sample, e.g. in seconds per second, T a =T x -To/To. A test sample reaction time 6 seconds longer than basic sample reaction times of 12 and 2k seconds would mean an increase of 0.5 and 0.25 seconds per second, respectively.Reaction time changes of tested samples against that of the standard sample (T std ) can be calculated in a similar way, T a =T x -T std /T std .It can be assumed that this parameter reflects the intensity of the increase or decrease of reaction time per time unit. The quotient of the tested and basic samples can be considered as the coefficient of the increase or decrease of the total reaction time (CT=T x /To).

scholarly journals The Comorbidity of Musculoskeletal Disorders and Depression: Associations with Working Conditions Among Hospital Nurses

2020 ◽  
Vol 68 (7) ◽  
pp. 346-354 ◽  
Author(s):  
Yuan Zhang ◽  
Mazen ElGhaziri ◽  
Sarah Nasuti ◽  
Jeanne F. Duffy
Keyword(s):  
Musculoskeletal Disorders ◽  
Working Conditions ◽  
Family Conflict ◽  
Night Shift ◽  
Cross Sectional Study ◽  
Hospital Nurses ◽  
Work Family Conflict ◽  
Cross Sectional ◽  
Increased Risk ◽  
Work Family

Background: Musculoskeletal disorders (MSDs) are the leading cause of pain and disability among nurses and are frequently accompanied by depression. However, the association between the comorbidity of MSDs and depression and working conditions has not been studied, which was the aim of this study. Methods: In 2015, all nurses ( n = 1,102) employed at a community hospital in the Northeast United States were invited to participate in this cross-sectional study. A survey was distributed in which participants were asked to report on MSDs, depressive symptoms, as well as subjective working conditions assessed including physical demands, psychological demands, decision authority, social support, and work–family conflict. Findings: 397 nurses responded (36%), and the prevalence of the comorbidity of MSDs and depression was 14.5%. Poisson regression (PR) models suggested that work–family conflict was associated with increased risk of the comorbidity (PR = 2.18; 95% confidence interval [CI] = 1.33–3.58), as was 8-hour night shift (PR = 2.77; 95% CI = [1.22, 6.31]) or 12-hour day shift (PR = 2.20; 95% CI = [1.07, 4.50]). Other working conditions were not directly associated with the comorbidity. Conclusions/Application to Practice: The comorbidity of MSDs and depression is prevalent among hospital nurses, and work–family conflict and working night shift or longer shifts were significantly associated with this. Effective workplace programs are needed to address nurses’ working conditions to reduce their work–family conflict, thereby improving their musculoskeletal and mental health.

Simple reaction-time changes in patients with unilateral brain damage

1986 ◽  
Vol 24 (5) ◽  
pp. 649-658 ◽  
Author(s):  
Antonio Tartaglione ◽  
Giovanni Bino ◽  
Marcello Manzino ◽  
Luciano Spadavecchia ◽  
Emilio Favale
Keyword(s):  
Reaction Time ◽  
Brain Damage ◽  
Simple Reaction Time ◽  
Simple Reaction ◽  
Unilateral Brain Damage ◽  
Time Changes ◽  
Unilateral Brain

Immediate-term chemotherapy-related cognitive impairment (CRCI) following administration of intravenous (IV) chemotherapy.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 10084-10084
Author(s):  
Omar Farooq Khan ◽  
Ellen R. Cusano ◽  
Soundouss Raissouni ◽  
Mica Pabia ◽  
Johanna Haeseker ◽  
...  
Keyword(s):  
Reaction Time ◽  
Peripheral Neuropathy ◽  
A Priori ◽  
Reaction Times ◽  
Vigilance Task ◽  
Prior Chemotherapy ◽  
Chemotherapy Administration ◽  
Stanford Sleepiness Scale ◽  
Time Changes ◽  
Psychomotor Vigilance

10084 Background: The acute impact of chemotherapy on cognition is unknown. This study utilized performance on the psychomotor vigilance task (PVT) and trail-making test B (TMT) to assess CRCI immediately following chemotherapy administration. Methods: Patients aged 18-80 years receiving first-line IV chemotherapy for any stage of breast or colorectal cancer were eligible. Patients with brain metastases, neurologic disorders or allergic reactions to chemotherapy were excluded. Patient symptoms, peripheral neuropathy and Stanford Sleepiness Scale were assessed. A five-minute PVT and TMT were completed on a tablet computer pre-chemotherapy and immediately post-chemotherapy. Paired Wilcoxon Rank Sum tests were used to assess change in median PVT reaction time, TMT completion time, TMT errors and PVT lapses. A priori, an increase in median PVT reaction times by over 20 ms (approximating reaction time changes with blood alcohol concentrations of 0.04 to 0.05 g%) was considered a clinically relevant change. Results: 144 patients (74 breast, 70 colorectal, median age 55.5 years) were tested. Post-chemotherapy, median PVT reaction time slowed by an average of 12.4 ms ( p = 0.01). Post-chemotherapy median PVT times slowed by over 20 ms in 59 patients (40.9%). TMT completion post-chemotherapy was faster by an average of 6.1 seconds ( p < 0.001). No differences were seen in TMT errors ( p = 0.417) or PVT lapses ( p = 0.845). Change in median PVT reaction time was not associated with age, gender, number of prior chemotherapy cycles, peripheral neuropathy grade, self-reported symptoms (anxiety, fatigue or depression). Change in median PVT reaction time was also not significantly associated with use of any specific chemotherapeutic drug or class, including paclitaxel (which includes ethanol as an excipient). Conclusions: Median PVT reaction time was significantly slower immediately after chemotherapy compared to a pre-chemotherapy baseline, and impairment correlating to effects of alcohol was seen in 41% of patients. This effect appears independent of age, self-reported symptoms or prior chemotherapy cycles. Further studies assessing functional impact of immediate-term CRCI are warranted.

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