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Electrodermal activity (EDA) is a widely used psychophysiological measurement in laboratory-based studies. In recent times, these measurements have seen a transfer from the laboratory to wearable devices due to the simplicity of EDA measurement as well as modern electronics. However, proper conditions for EDA measurement are recommended once wearable devices are used, and the ambient conditions may influence such measurements. It is not completely known how different types of ambient noise impact EDA measurement and how this translates to wearable EDA measurement. Therefore, this study explored the effects of various noise disturbances on the generation of EDA responses using a system for the simultaneous recording of all measures of EDA, i.e., skin conductance responses (SCRs), skin susceptance responses (SSRs), and skin potential responses (SPRs), at the same skin site. The SCRs, SSRs, and SPRs due to five types of noise stimuli at different sound pressure levels (70, 75, 80, 85, and 90 dB) were measured from 40 participants. The obtained results showed that EDA responses were generated at all levels and that the EDA response magnitudes were significantly ( p < 0.001) influenced by the increasing noise levels. Different types of environmental noise may elicit EDA responses and influence wearable recordings outside the laboratory, where such noises are more likely than in standardized laboratory tests. Depending on the application, it is recommended to prevent these types of unwanted variation, presenting a challenge for the quality of wearable EDA measurement in real-world conditions. Future developments to shorten the quality gap between standardized laboratory-based and wearable EDA measurements may include adding microphone sensors and algorithms to detect, classify, and process the noise-related EDA.

Electrodermal activity (EDA) usually relates to variations in the electrical properties of palmar or plantar skin sites. EDA responses, namely skin conductance responses (SCRs), skin potential responses (SPRs) and skin susceptance responses (SSRs) are shown to be sensitive indexes of sympathetic nervous system activation and are studied in many research projects. However, the association between EDA responses and the five basic human senses has not been investigated yet. Our study aimed to explore the relationship between the three EDA responses (SCRs, SSRs and SPRs) and the five basic human senses. These three EDA responses were measured simultaneously at the same skin site on each of the 38 volunteers. The tested five senses were sight, hearing, touch, taste and smell. The results showed that the different tested senses led to different degrees of EDA responses due to activation of the sympathetic nervous system and corresponding secretion of sweat. Although a controlled study on the degree of EDA as a function of the strength of each stimulus was not performed, we noted that the largest EDA responses were typically associated with the smell sense test. We conclude that EDA responses could be utilized as measures for examining the sensitivity of the human senses. Hence, EDA devices may have important roles in sensory systems for future clinical applications.

Background/aim: The skin conductance responses (SCRs) are a well-accepted indicator of physiological arousal for both research purposes and clinical approaches. The shape of SCRs is analyzed by various features. However, the estimation of how much (in %) one feature can explain another is still an open issue. The aim of this study was to assess whether variation in one SCR feature predicts changes in other features., Methods: Skin conductance (SC) was measured during relaxation and mental stress in 40 subjects. SCRs were induced by three external stimuli, which were deep breath, a mental arithmetic, task and a visual task., Results: The findings of this study showed that about 55% (R 2  = 0.55) of the variation in the half recovery time (SCRs&#95;rec 50%) can be explained by the rise time (SCRs&#95;ris), whereas variation in amplitude of the skin conductance responses (SCRs&#95;amp) and the skin conductance level (SCL) is independent and cannot be explained by the other features, as R 2 values obtained from all analyses among these SCR features in average were lower 0.19., Conclusions: The study results suggest that the two timing phases (SCRs&#95;rec and SCRs&#95;ris) are not completely independent from each other, although they might be governed by different sweating mechanisms (secretion and reabsorption). However, SCRs&#95;amp and SCL were independent. These findings can help in choosing the optimal set of features of an automated system for processing EDA, which reflect the alterations in the activation level generated during an emotional episode., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objectives: This study aimed to evaluate the correlations between by-products of extracorporeal shock wave lithotripsy (ESWL) and some physical parameters such as abdominal fat, energy levels, and shock wave pulses., Methods: A total of 40 patients (20 men and 20 women), aged 37.18 ± 10.64 years, with renal or ureteral stones were recruited. All patients were treated with ESWL, and their abdominal fat was measured using an Omron body fat monitor and the body mass index (BMI). Parameters such as the levels of malondialdehyde (MDA), ketones, and protein in urine were measured before and after ESWL using a Bio Doctor Analyzer. The wave characteristics of the lithotripsy procedure and the wave pulses were determined., Results: The mean levels of urinary MDA and ketones showed statistically significant increases in post-ESWL compared with pre-ESWL values. The results showed significant elevations in MDA and ketones in both male and female patients. In addition, there was a significant correlation between MDA/ketones and energy levels and between ketones and BMI in female patients. The analysis also revealed that the shock wave pulse had an insignificant impact on the by-product parameters., Conclusion: An energy level of ≤4 J is recommended for overweight and obese patients undergoing ESWL. In addition, measurement of the post-ESWL MDA urinary level should be performed as a routine test, especially in obese male patients.

Accurate assessment of experienced pain is a well-known problem in the clinical practices. Therefore, a proper method for pain detection is highly desirable. Electrodermal activity (EDA) is known as a measure of the sympathetic nervous system activity, which changes during various mental stresses. As pain causes mental stress, EDA measures may reflect the felt pain. This study aims to evaluate changes in skin conductance responses (SCRs), skin potential responses (SPRs), and skin susceptance responses (SSRs) simultaneously as a result of sequences of electrical (painful) stimuli with different intensities. EDA responses as results of painful stimuli were recorded from 40 healthy volunteers. The stimuli with three different intensities were produced by using an electrical stimulator. EDA responses significantly changed (increased) with respect to the intensity of the stimuli. Both SCRs and SSRs showed linear relationship with the painful stimuli. It was found that the EDA responses, particularly SCRs ( p < 0.001) and SSRs ( p = 0.001) were linearly affected by the intensity of the painful stimuli. EDA responses, in particular SCRs, may be used as a useful indicator for assessment of experienced pain in clinical settings., Competing Interests: Conflict of interest Ø.G. Martinsen is involved with a company (Biogauge AS, Norway), which produces instruments for electrodermal activity measurements. Authors state no other conflict of interest., (© 2018 Dindar S. Bari, Haval Y. Yacoob Aldosky, Christian Tronstad, Håvard Kalvøy, Ørjan G. Martinsen published by Sciendo.)

Background/aim: Presently, electrodermal activity (EDA) is the preferred term for changes in electrical properties of the skin. Change in the skin conductance responses (SCRs) and skin potential responses (SPRs) due to external stimuli have previously been investigated in a number of studies, but very little for skin susceptance responses (SSRs) recorded simultaneously at the same skin site. This study aimed to investigate the association between the three parameters of EDA, skin conductance (SC), skin potential (SP), and skin susceptance (SS) responses generated by different types of psychological stimuli., Methods: SCRs, SPRs, and SSRs were recorded from 20 healthy test subjects simultaneously at the same skin area. EDA responses were induced by five different external stimuli, which were shown in the form of PowerPoint slides on a PC monitor that situated in front of participants., Results: All stimuli evoked EDA responses, but with significantly different magnitudes, dependent on stimulus type. Both SC and SP waveforms yielded positive responses with respect to the stimuli; however, SS showed negative response and its role was found to be significant at low frequency (20 Hz)., Conclusions: This study illustrated that different discrete stimuli showed different passive and active electrodermal responses at the same skin site. SCRs, SPRs, and SSRs were dependent on the stimulus type, and the highest response was associated with the sound stimulus, which can be attributed to orienting response or startle reflex. In addition, it was found that the SSRs have a significant contribution at 20 Hz. In spite of a high correlation found between average amplitude values of SCRs and SSRs, no significant association was seen between average amplitudes values of SPRs and SSRs, and between SCRs and SPRs., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background/aim: Electrodermal activity (EDA) is a widely used measure in psychophysiological research, and its use in wearable devices has grown in recent times. It is recommended to have proper conditions for EDA measurement, and skin hydration is one factor that has a significant influence. It is, however, not known to what extent the ambient humidity influences the recording. This study explored the influence of relative humidity (RH) on EDA levels, and also the responses using a new technique for simultaneous recording of all measures of EDA: skin conductance (SC), skin susceptance (SS), and skin potential (SP) at the same skin site., Methods: A total of 10 healthy subjects were exposed to environments of low and high RH while EDA measures were recorded, including cognitive, visual and breathing stimuli for evoking electrodermal responses of different origin. EDA levels and responses were compared between the two humidity levels for all stimuli and all EDA measures., Results: It was found that EDA levels, in particular for SC and SS, were significantly increased during high humidity exposure, but that the change in EDA responses (SC, SS, and SP) was not statistically significant (p > 0.05, paired t test)., Conclusion: This suggests that ambient humidity influences the recording of EDA levels and is important to consider when these parameters are used, but is not important in the recording or analysis of EDA responses., (© 2018 S. Karger AG, Basel.)