scholarly journals When Less Is More: Investigating Factors Influencing the Distraction Effect of Virtual Reality From Pain

2022 ◽  
Vol 2 ◽  
Author(s):  
Katharina Barcatta ◽  
Elisabeth Holl ◽  
Layla Battistutta ◽  
Marian van der Meulen ◽  
Katharina M. Rischer
Keyword(s):  
Heart Rate ◽  
Virtual Reality ◽  
Cognitive Load ◽  
Load Condition ◽  
High Load ◽  
Heat Pain ◽  
Distraction Effect ◽  
Pain Thresholds ◽  
High Load Condition ◽  
The Difference

Virtual reality (VR) is a powerful method of redirecting attention away from pain. Yet, little is known about which factors modulate the size of this distraction effect. The aim of this study was to investigate the role of cognitive load and inter-individual differences in the cognitive and affective domain on heat pain thresholds during a VR game. Ninety healthy participants (mean age ± SD: 23.46 ± 3.28; 50% identified as male and 50% as female) played a low and high load version of a VR game while heat pain thresholds and heart rate were recorded. The effects of cognitive load were assessed by computing the difference in pain thresholds between the high and low load condition for each participant. In addition, we computed the difference in heart rate variability (HRV) measures between both conditions to explore whether these would be correlated with the difference in heat pain thresholds. Prior to the VR session, participants completed questionnaires about their emotional distress, pain-related cognitions, and different executive functioning tasks. Contrary to our expectations, not all participants benefitted from a higher load in terms of distraction from pain. Logistic regression analysis revealed that participants who reported more emotional distress were more likely to exhibit higher pain thresholds in the low relative to the high load condition. Accordingly, these participants tended to show marginally higher HRV in the low compared to the high load condition. Our study demonstrates that the potential benefits of an increased cognitive load in VR on pain sensitivity depends on individual differences in affective state.

Hunger is suppressed after resistance exercise with moderate-load compared to high-load resistance exercise: the potential influence of metabolic and autonomic parameters

2020 ◽  
Vol 45 (2) ◽  
pp. 180-186 ◽  
Author(s):  
Marcelo Conrado Freitas ◽  
Valéria Leme Gonçalves Panissa ◽  
Sabrina Alves Lenquiste ◽  
Fernanda de Maria Serra ◽  
Caique Figueiredo ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Resistance Exercise ◽  
Lactate Concentration ◽  
Load Condition ◽  
Load Resistance ◽  
High Load ◽  
Autonomic Modulation ◽  
Rest Interval ◽  
Moderate Load

The purpose of present study was to compare the effects of moderate-load versus high-load resistance exercise (RE) on hunger response, blood lactate, glucose, and autonomic modulation in trained men, and to examine the correlations between these parameters. For this, 11 recreationally resistance-trained males performed 2 randomized trials: moderate-load (6 sets at 70% 1-repetition maximum (1RM) and a 90-s rest interval between sets) and high-load (6 sets at 90% 1RM and a 180-s rest interval between sets) leg-press exercise until movement failure. The subjective rating of hunger was obtained through a visual analog scale. Glucose and lactate concentration were evaluated at rest, immediately after exercise, and 30 min after exercise. Heart rate variability was recorded at baseline and during recovery (until 30 min after exercise) to assess autonomic modulation. The moderate-load condition induced lower subjective hunger ratings than the strength condition immediately after exercise (19.7 ± 16.6 vs 47.3 ± 27.7 mm), 30 min after exercise (33.6 ± 22.9 vs 58.5 ± 29.9 mm), and 60 min after exercise (43.8 ± 26.6 vs 67.8 ± 27.9 mm) (p < 0.05) and lower area under the curve hunger in relation to the high-load condition (p < 0.006). Moderate-load RE presented greater lactate concentration and induced slower heart rate variability recovery in relation to high-load RE (p < 0.05), but no difference was found in glucose, as well as no correlations between any of the variables investigated. In conclusion, moderate-load RE induced lower subjective hunger ratings, slower recovery of the parasympathetic nervous system, and higher lactate concentration in relation to high-load RE, but the metabolic variables were not correlated with hunger suppression.

Effect of Load-Relieving Structure against Overload under High Overload

2013 ◽  
Vol 328 ◽  
pp. 421-425
Author(s):  
Quan Li Ning ◽  
Jun Li ◽  
Dong Chen ◽  
Gao Peng Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Constitutive Equation ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Load Condition ◽  
High Load ◽  
Dynamical Response ◽  
Response Distribution ◽  
High Load Condition

Three-dimensional visco-elastic lame deformation incremental constitutive equation is derived based on Total Lagrangian method, and structural dynamical response distribution in the grain during launching is simulated numerically by finite element method under high load condition for projectile-based equipment, the equivalent stress in the bottom of load-relieving structure and the Y-displacement in the top of load-relieving structure are calculated. The results show that the stress is ameliorated after the function of load-relieving subassembly, and it can decrease impact. Also Y-displacement is accord with limit request, and when reaching the maximum, the transmutation will be comeback.

Study on Combustion and Emission Characteristics of Acidic Oil Biodiesel

2014 ◽  
Vol 541-542 ◽  
pp. 982-988
Author(s):  
Jian Wu ◽  
Yang Hua ◽  
Zhan Cheng Wang ◽  
Li Li Zhu ◽  
Hong Ming Wang
Keyword(s):  
Diesel Engine ◽  
Load Condition ◽  
Pressure Rise ◽  
High Load ◽  
Emission Characteristics ◽  
Combustion Heat ◽  
Pressure Maximum ◽  
High Load Condition ◽  
Blended Fuel ◽  
Hc Emissions

In order to develop a new fuel alternative for the diesel engine, experiment of combustion and emission characteristics was carried on a high pressure common rail diesel engine fueled with diesel and acidic oil biodiesel blends, then the results were compared and analyzed. The results indicate that after adding acidic oil biodiesel, the ignition delay is prolonged, combustion pressure, maximum rate of pressure rise and maximum combustion temperature all increase. The maximum combustion heat release rate of blended fuel is higher than diesel at low and middle loads, and lower at high load condition. Compared with diesel, HC emissions of blends decrease dramatically with the increases of blending ratio. NOX emissions of blends are slightly higher than diesel. CO emissions of blends are almost the same as that of diesel. According to the results, acidic oil biodiesel has wide application prospects as an alternative fuel.

Experimental Study of EGR on Performance and Emissions of a Turbocharged DME Engine

2014 ◽  
Vol 886 ◽  
pp. 257-261
Author(s):  
Jun Hua Wu ◽  
Fu Shan Zuo ◽  
Yong Hui Zhang
Keyword(s):  
Experimental Study ◽  
Fuel Consumption ◽  
Substantial Reduction ◽  
Load Condition ◽  
High Load ◽  
Reduction Of No ◽  
Low Load ◽  
Emission Behavior ◽  
High Load Condition

This paper presents anexperimental study on reduction of NOx emission of a turbochargedengine fuelled with DME by means of EGR. Effects of EGR rate on engineefficiency and emission behavior was evaluated. The results show that the EGRcould be used as an effective way to reduce NOx emission. NOx isreduced almost linearly with increase of EGR rate. At low load condition, theNOx emission is reduced by 80% with 40% EGR rate without any economypenalty. At high load condition, the same substantial reduction of NOx couldbe achieved with only 20% EGR rate. While the HC and CO emissions are increasedwith increase of EGR rate. However, it is worth noting that EGR had a negativeeffect on fuel consumption at high load. Low EGR ratio should be taken at highengine load condition.

Visuo–tactile stimulation, but not type of movement, modulates pain during the vision of a moving virtual limb

2019 ◽  
Vol 9 (5) ◽  
pp. 449-460 ◽  
Author(s):  
Calum Gordon ◽  
Alba Barbullushi ◽  
Stefano Tombolini ◽  
Federica Margiotta ◽  
Alessia Ciacci ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Tactile Stimulation ◽  
Pain Threshold ◽  
Pain Modulation ◽  
Heat Pain ◽  
Immersive Virtual Reality ◽  
Pain Thresholds ◽  
Heat Pain Threshold ◽  
Different Types ◽  
Healthy Participants

Aim: Evidence has revealed a relationship between pain and the observation of limb movement, but it is unknown whether different types of movements have diverse modulating effects. In this immersive virtual reality study, we explored the effect of the vision of different virtual arm movements (arm vs wrist) on heat pain threshold of healthy participants. Patients & methods: 40 healthy participants underwent four conditions in virtual reality, while heat pain thresholds were measured. Visuo–tactile stimulation was used to attempt to modulate the feeling of virtual limb ownership while the participants kept their arms still. Results: Effects on pain threshold were present for type of stimulation but not type of movement. Conclusion: The type of observed movement does not appear to influence pain modulation, at least not during acute pain states.

Control of an anaerobic reactor towards maximum biogas production

2004 ◽  
Vol 50 (11) ◽  
pp. 189-198 ◽  
Author(s):  
J. Liu ◽  
G. Olsson ◽  
B. Mattiasson
Keyword(s):  
Control System ◽  
Biogas Production ◽  
Load Condition ◽  
Good Control ◽  
High Load ◽  
Extremum Seeking ◽  
Organic Load ◽  
Supervisory System ◽  
Start Up ◽  
High Load Condition

A new control strategy is introduced for operating anaerobic digestion processes efficiently at high load. The control system includes a cascade controller embedded into a rule-based supervisory system based on extremum-seeking control. The control system measures pH and biogas production rate and varies the organic load by manipulating the influent flow. Good control performances were achieved during the start-up and steady-state running operations and during rejection of disturbances. The control system can run the process under a high load condition and efficiently reject disturbances without explicit measurement of the influent characteristics.

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