Rapalis Andrius, Piartli Povilas, Jankauskaitė Lina, Marozas Vaidotas, Kaniusas Eugenijus
Biomedical Engineering Institute, Kaunas University of Technology, Kaunas, Lithuania.
Department of Electronics Engineering, Faculty of Electrical and Electronics Engineering, Kaunas University of Technology, Kaunas, Lithuania.
Front Physiol. 2023 Jan 17;14:1090696. doi: 10.3389/fphys.2023.1090696. eCollection 2023.
Pain affects every fifth adult worldwide and is a significant health problem. From a physiological perspective, pain is a protective reaction that restricts physical functions and causes responses in physiological systems. These responses are accessible for evaluation recorded biosignals and can be favorably used as feedback in active pain therapy auricular vagus nerve stimulation (aVNS). The aim of this study is to assess the significance of diverse parameters of biosignals with respect to their deflection from cold stressor to deep breathing and their suitability for use as biofeedback in aVNS stimulator. Seventy-eight volunteers participated in two cold pressors and one deep breathing test. Three targeted physiological parameters ( interval of electrocardiogram, cardiac deflection magnitude of ear impedance signal, and cardiac deflection magnitude of finger photoplethysmogram) and two reference parameters (systolic and diastolic blood pressures and ) were derived and monitored. The results show that the cold water decreases the medians of targeted parameters (by 5.6, 9.3%, and 8.0% of , , and , respectively) and increases the medians of reference parameters (by 7.1% and 6.1% of and , respectively), with opposite changes in deep breathing. Increasing pain level from relatively mild to moderate/strong with cold stressor varies the medians of targeted and reference parameters in the range from 0.5% to 6.0% (e.g., 2.9% for , and 6.0% for ). The physiological footprints of painful cold stressor and relaxing deep breathing were shown for auricular and non-auricular biosignals. The investigated targeted parameters can be used as biofeedback to close the loop in aVNS to personalize the pain therapy and increase its compliance.
疼痛影响着全球五分之一的成年人，是一个重大的健康问题。从生理学角度来看，疼痛是一种保护反应，它会限制身体功能并引发生理系统的反应。这些反应可以通过记录的生物信号进行评估，并且可以在主动疼痛治疗——耳迷走神经刺激（aVNS）中作为反馈得到很好的利用。本研究的目的是评估生物信号的各种参数相对于其从冷应激源到深呼吸的变化的重要性，以及它们在aVNS刺激器中用作生物反馈的适用性。78名志愿者参加了两次冷加压试验和一次深呼吸测试。导出并监测了三个目标生理参数（心电图间期、耳部阻抗信号的心脏偏转幅度和手指光电容积脉搏波描记图的心脏偏转幅度）和两个参考参数（收缩压和舒张压）。结果表明，冷水会降低目标参数的中位数（分别降低心电图间期、耳部阻抗信号的心脏偏转幅度和手指光电容积脉搏波描记图的心脏偏转幅度的5.6%、9.3%和8.0%），并增加参考参数的中位数（分别增加收缩压和舒张压的7.1%和6.1%），而深呼吸时则有相反的变化。随着冷应激源使疼痛程度从相对较轻增加到中度/重度，目标参数和参考参数的中位数在0.5%至6.0%的范围内变化（例如，心电图间期为2.9%，耳部阻抗信号的心脏偏转幅度为6.0%）。展示了耳部和非耳部生物信号中疼痛性冷应激源和放松性深呼吸的生理特征。所研究的目标参数可用作生物反馈，以在aVNS中实现闭环，使疼痛治疗个性化并提高其依从性。
