Integration of Independent Heat Transfer Mechanisms for Non-Contact Cold Sensation Presentation With Low Residual Heat

Thermal sensation is crucial to enhancing our comprehension of the world and enhancing our ability to interact with it. Therefore, the development of thermal sensation presentation technologies holds significant potential, providing a novel method of interaction. Traditional technologies often leave residual heat in the system or the skin, affecting subsequent presentations. Our study focuses on presenting thermal sensations with low residual heat, especially cold sensations. To mitigate the impact of residual heat in the presentation system, we opted for a non-contact method, and to address the influence of residual heat on the skin, we present thermal sensations without significantly altering skin temperature. Specifically, we integrated two highly responsive and independent heat transfer mechanisms: convection via cold air and radiation via visible light, providing non-contact thermal stimuli. By rapidly alternating between perceptible decreases and imperceptible increases in temperature on the same skin area, we maintained near-constant skin temperature while presenting continuous cold sensations. In our experiments involving 15 participants, we observed that when the cooling rate was -0.2 to -0.24 degree celsius per second and the cooling time ratio was 30 to 50 %, more than 86.67 % of the participants perceived only persistent cold without any warmth

Thermal and wind devices for multisensory human-computer interaction: an overview

In order to create immersive experiences in virtual worlds, we need to explore different human senses (sight, hearing, smell, taste, and touch). Many different devices have been developed by both industry and academia towards this aim. In this paper, we focus our attention on the researched area of thermal and wind devices to deliver the sensations of heat and cold against people’s skin and their application to human-computer interaction (HCI). First, we present a review of devices and their features that were identified as relevant. Then, we highlight the users’ experience with thermal and wind devices, highlighting limitations either found or inferred by the authors and studies selected for this survey. Accordingly, from the current literature, we can infer that, in wind and temperature-based haptic systems (i) users experience wind effects produced by fans that move air molecules at room temperature, and (ii) there is no integration of thermal components to devices intended for the production of both cold or hot airflows. Subsequently, an analysis of why thermal wind devices have not been devised yet is undertaken, highlighting the challenges of creating such devices.Espírito Santo Research and Innovation Foundation (FAPES, Brazil) - Finance Code 2021-GL60J), the Coordination for the Improvement of Higher Education Personnel (CAPES, Brazil) - Finance Code 88881.187844/2018-01 and 88887.570688/2020-00 and by the National Council for Scientific and Technological (CNPq, Brazil) - Finance Code 307718/2020-4. The work was also funded by the European Union’s Horizon 2020 Research and Innovation programme under Grant Agreement no. 688503. E. B. Saleme additionally acknowledges aid from the Federal Institute of Espírito Santo

A Controlled Study on Evaluation of Thermal Stimulation Influence on Affective Measures of Uninformed Individuals

Although the relationship between temperature and emotional states has been investigated in the field of haptics, it remains unknown if, or in what direction, temperature affects emotional states. We approach this question at the intersection of haptics and psychology using a custom-built thermal device and emotional responses based on photos from the International Affective Picture System (IAPS) library. Unlike past research, this study incorporates deception and a control (i.e., neutral temperature) condition. One hundred and twenty naive subjects reported their emotional responses to fifty-six images varying on normative arousal and valence ratings while being exposed to a cool~(30{\deg}C), neutral (33{\deg}C), or warm (36{\deg}C) temperature applied to the upper back. Participants exposed to warm temperatures reported higher arousal ratings in some image categories than participants exposed to neutral or cool temperatures. Valence ratings were decreased in warm conditions compared to neutral conditions. The emotion wheel was used as a complementary method of affective response measurement, and exploratory analysis methods were implemented. Although the valence and arousal showed statistical significance, the emotion wheel results did not demonstrate any significant differences between the temperature conditions

A Soft Robotic Cover with Dual Thermal Display and Sensing Capabilities

We propose a new robotic cover prototype that achieves thermal display while also being soft. We focus on the thermal cue because previous human studies have identified it as part of the touch pleasantness. The robotic cover surface can be regulated to the desired temperature by circulating water through a thermally conductive pipe embedded in the cover, of which temperature is controlled. Besides, an observer for estimating heat from human contact is implemented; it can detect human interaction while displaying the desired temperature without temperature sensing on the surface directly. We assessed the validity of the prototype in experiments of temperature control and contact detection by human hand

Artificial Muscles

Course material for "Artificial Muscles" e-course

Augmenting communication technologies with non-primary sensory modalities

Humans combine their senses to enhance the world around them. While computers have evolved to reflect these sensory demands, only the primary senses of vision and audition (and to an extent, touch) are used in modern communication. This thesis investigated how additional information, such as emotion and navigational assistance, might be communicated using technology-based implementations of sensory displays that output the non-primary modalities of smell, vibrotactile touch, and thermo-touch. This thesis explored using a portable atomiser sprayer to deliver emotional information via smell to mobile phone users, a ring-shaped device worn on the finger to display emotional information using vibration and colours, and an array of thermoelectric coolers worn on the arm to create temperature sensations. Additionally, this thesis explored two methods of signalling temperature using the thermal implementation, and finally, used it in a controlled study to augment the perceived emotion of text messages using temperature. There were challenges with using some of these implementations to display information. Smells produced with the scent technology were ambiguous and highly cognitive, and poor delivery to the user produced undesirable cross-adaption effects when smells lingered and mixed in the environment. The device used to communicate vibrotactile and colour lighting cues neutralized emotions in text messages. Furthermore, temperature pattern discrimination using the thermal implementation was difficult due to non-linear interaction effects that occurred on the skin’s surface, as well as latency resulting from the thermal neurological pathway and the technology used to heat and cool the skin. However, the thermal implementation enabled more accurate user discrimination between thermal signals than what a single stimulator design provided. Furthermore, the utility of continuous thermal feedback, in the context of spatial navigation, was demonstrated, which improved user performance compared to when the user was not presented with any thermal information. Finally, temperature was demonstrated to elicit arousal reactions across subjects using the thermal implementation, and could augment the arousal of text messages, especially when the content of the message was strongly neutral. However, no similar statistical significance was observed with valence, demonstrating the complex implications of using thermal cues to convey emotional information

Indoor environmental effects of vertical air temperature gradients in displacement ventilated spaces in the tropics

Ph.DDOCTOR OF PHILOSOPH

Self-Hypnosis and Volitional Control of Finger Temperature Among Adults

Raynaud\u27s disease is a condition in which circulation to the hands becomes restricted, causing an uncomfortable sense of cold and occasionally injury. The cause of Raynaud\u27s disease is unknown. Earlier studies have shown that hetero-hypnosis is effective in the treatment of Raynaud\u27s disease. Cost and access to providers limit such a treatment\u27s availability. Theories of hypnosis suggest that self-hypnosis underlies all hypnotic processes. This study examined the utility of self-hypnosis and focused attention on the volitional control of hand temperature. Forty-three adult participants ranging in age from 19 to 77 years with no hypnosis experience were randomly divided into 2 groups; 20 completed the study. Eleven participants listened to a self-hypnosis recording and 9 listened to a mostly blank recording containing periodic instructions to concentrate on controlling finger temperature. A paired samples t test showed a significant difference in means between pre- and post-treatment ability. A second t test did not show a significant difference in means between the groups\u27 ability. Analysis of survey data did not show a significant relationship between participant demographic data and ability to control finger temperature. However, analysis of participant survey responses did show that self-hypnosis was significantly more enjoyable than conscious concentration, which suggests that self-hypnosis has greater potential for adoption if used in the treatment of Raynaud\u27s disease. Because self-hypnosis was found to be enjoyable and effective it may be superior to other treatments that are unpleasant or have pharmacological side effects. These findings will inform sufferers of Raynaud\u27s disease and researchers in their efforts to treat the disease. The positive social change implications of this study are to expand treatment options for a disease that affects 4% of the world\u27s population

Bridging the translational gap between rodent and human pain research

The treatment of chronic pain is an immense clinical and societal burden rooted in the ineffectiveness and adverse side effects of existing analgesics. Extensive efforts have been directed towards the development of novel pain therapies with maximal efficacy and minimal unwanted effects; however, putative therapeutic targets identified in preclinical rodent models rarely translate in clinical trials. The poor translational record of basic pain research findings has been attributed, in part, to the use of suboptimal rodent pain models and behavioral endpoints used to assess putative analgesics, as well as differences in the pharmacological profiles of rodents and humans. The work presented in this thesis aims to address these limitations. Human pain is defined as a complex sensory and emotional experience, yet rodent pain models have historically used reflex/withdrawal measures of hypersensitivity as the primary outcome. To address this limitation, the first study of this thesis evaluates more complex, voluntary behaviors as indicators of pain-like behavior in rodents. We found that inflammation and nerve injury minimally interfere with physical activity (voluntary wheel running, locomotion, and gait), social interaction, or anxiety-like behavior in mice, indicating that these voluntary behaviors are not reliable pain-related readouts across rodent injury models. As recent findings from other groups align with our results, we further conclude that in contrast to humans, changes in these voluntary behaviors are not characteristic of persistent pain in mice. Although rodents and humans possess different pharmacological profiles, putative analgesics are oftentimes identified and exclusively evaluated in rodent tissues and/or pain models prior to entering clinical trials. In response to this translational gap, we recently developed a protocol to surgically extract dorsal root ganglia from deceased human organ donors and subsequently culture sensory neurons. In the second study of this thesis, we utilize human sensory neurons to assess the translational potential of targeting metabotropic glutamate receptors 2 and 3 (mGluR2/3), which have been identified as modulators of pain in a variety of rodent models. In mouse sensory neurons, we found that activation of mGluR2/3 blocked inflammation-induced sensitization of the nonselective cation channel TRPV1. In contrast, this effect was not observed in human sensory neurons. These results indicate that mechanisms of peripheral analgesia are not entirely conserved across species. More broadly, our findings demonstrate that using human tissue to validate analgesic targets identified in rodents is an important step in the translational research process. Due to poor pain relief from current pharmacological therapies, exercise has been explored as an alternative, nonpharmacological intervention for chronic pain. Indeed, exercise has been shown to improve patient pain ratings and functionality, albeit via largely unknown mechanisms. In the final study of this thesis, we evaluated whether voluntary exercise similarly reduced pain-like behavior in mice, with the goal of using a mouse model to elucidate the molecular mechanisms mediating clinical exercise-induced analgesia. However, we found that voluntary wheel running did not reduce pain-like behavior in common rodent models of inflammation and nerve injury. Previous preclinical studies of exercise-induced analgesia utilized forced exercise paradigms, and thus our findings suggest that voluntary and forced exercise may have different analgesic potential in rodents. Taken together, there are a variety of existing experimental limitations that can be addressed to increase the translatability of basic pain research. Based on our current findings, we conclude that voluntary rodent behavioral endpoints modeled off of the human chronic pain experience have limited utility. In contrast, confirming preclinical findings in human tissue represents a promising approach to bridge the translational gap between rodent and human pain research