Jungmann Manuela, Vencatachellum Shervin, Van Ryckeghem Dimitri, Vögele Claus
Institute for Health and Behaviour, Faculty of Language and Literature, Humanities, Arts and Education, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
JMIR Form Res. 2018 Oct 9;2(2):e10257. doi: 10.2196/10257.
The experience of psychological stress has not yet been adequately tackled with digital technology by catering to healthy individuals who wish to reduce their acute stress levels. For the design of digitally mediated solutions, physiological mechanisms need to be investigated that have the potential to induce relaxation with the help of technology. Research has shown that physiological mechanisms embodied in the face and neck regions are effective for diminishing stress-related symptoms. Our study expands on these areas with the design for a wearable in mind. As this study charts new territory in research, it also is a first evaluation of the viability for a wearables concept to reduce stress.
The objectives of this study were to assess whether (1) heart rate variability would increase and (2) heart rate would decrease during cold stimulation using a thermode device compared with a (nonstimulated) control condition. We expected effects in particular in the neck and cheek regions and less in the forearm area.
The study was a fully randomized, within-participant design. Volunteer participants were seated in a laboratory chair and tested with cold stimulation on the right side of the body. A thermode was placed on the neck, cheek, and forearm. We recorded and subsequently analyzed participants' electrocardiogram. The cold stimulation was applied in 16-second intervals over 4 trials per testing location. The control condition proceeded exactly like the cold condition, except we manipulated the temperature variable to remain at the baseline temperature. We measured heart rate as interbeat intervals in milliseconds and analyzed root mean square of successive differences to index heart rate variability. We analyzed data using a repeated-measures ANOVA (analysis of variance) approach with 2 repeated-measures factors: body location (neck, cheek, forearm) and condition (cold, control).
Data analysis of 61 participants (after exclusion of outliers) showed a main effect and an interaction effect for body location and for condition, for both heart rate and heart rate variability. The results demonstrate a pattern of cardiovascular reactivity to cold stimulation, suggesting an increase in cardiac-vagal activation. The effect was significant for cold stimulation in the lateral neck area.
The results confirmed our main hypothesis that cold stimulation at the lateral neck region would result in higher heart rate variability and lower heart rate than in the control condition. This sets the stage for further investigations of stress reduction potential in the neck region by developing a wearable prototype that can be used for cold application. Future studies should include a stress condition, test for a range of temperatures and durations, and collect self-report data on perceived stress levels to advance findings.
对于希望降低急性应激水平的健康个体，数字技术尚未充分应对心理应激体验。在设计数字介导的解决方案时，需要研究有可能借助技术诱导放松的生理机制。研究表明，面部和颈部区域所体现的生理机制对于减轻与压力相关的症状是有效的。我们的研究在考虑可穿戴设备设计的情况下拓展了这些领域。由于本研究在研究领域开辟了新的天地，它也是对可穿戴设备概念减轻压力可行性的首次评估。
本研究的目的是评估与（非刺激）对照条件相比，使用热刺激装置进行冷刺激期间，（1）心率变异性是否会增加以及（2）心率是否会降低。我们预期在颈部和脸颊区域会有特别的效果，而在前臂区域效果较小。
该研究采用完全随机的被试内设计。志愿者参与者坐在实验室椅子上，在身体右侧进行冷刺激测试。将一个热刺激装置放置在颈部、脸颊和前臂上。我们记录并随后分析参与者的心电图。每个测试部位在4次试验中以16秒的间隔施加冷刺激。对照条件的操作与冷刺激条件完全相同，只是我们将温度变量控制在基线温度。我们将心率测量为以毫秒为单位的心跳间隔，并分析连续差值的均方根以衡量心率变异性。我们使用重复测量方差分析方法分析数据，该方法有两个重复测量因素：身体部位（颈部、脸颊、前臂）和条件（冷刺激、对照）。
对61名参与者（排除异常值后）的数据分析显示，对于心率和心率变异性，身体部位和条件均存在主效应和交互效应。结果表明了心血管系统对冷刺激的反应模式，提示心脏迷走神经激活增加。这种效应在颈部外侧区域的冷刺激中显著。
结果证实了我们的主要假设，即与对照条件相比，颈部外侧区域的冷刺激会导致更高的心率变异性和更低的心率。这为通过开发可用于冷刺激的可穿戴原型进一步研究颈部区域的减压潜力奠定了基础。未来的研究应包括应激条件，测试一系列温度和持续时间，并收集关于感知应激水平的自我报告数据以推进研究结果。
