Skin Resistance Research Articles

Analysis of Electroencephalogram, Electrodermal Activities, and Heart Rate Changes Under Varied Degree of Mental Arithmetic Tasks

Mental calculation demanding tasks cause changes in the autonomic modulation of the cardiac function, along with changes in skin resistance and brain activity. This experiment is designed to examine the changes in autonomic response parameters, the heart rate tachogram, and electrodermal activity (EDA), along with the electroencephalogram in young individuals in the performance of 2 levels of arithmetic mental calculation tasks. Three male participants had performed the 2 levels of mental arithmetic (MA) calculations, that is, 15 easy and 15 calculative. Each task was for 10 seconds, for both easy and calculative, and presented in a random manner, and digital data of electrocardiogram, EDA, and electroencephalogram were acquired. Decreased heart rate in the calculative task as compared with easy task was obtained in tachogram. Electrodermal activity from the easy MA task showed higher values when compared with those obtained during the calculative MA task. α Waves from the Cz and Pz positions showed synchronization and a higher power in the power spectrum analysis for the calculative task in comparison to the easy task. With increased complexity in MA assignments, the involvement of brain is evaluated with synchronized alpha activities. Furthermore, with synchronized neuronal firing, the heart rate was also found unchanged, and EDA decreases are influenced by the autonomic nervous system under increased complexity of the MA task.

System for measuring electric resistance skin

Introduction. To measure the electrical resistance of leather frequently used system for applying testing signals from external current sources or voltage. Power testing signals the maximum limit, when they Electro studies still have a negative impact on the human body. Formulation of the problem. To achieve this task the authors conducted research and developed a system, which is based to measure electrical skin resistance (ESR) responsible allocation and measurement noise variance bioelectric signal is proportional to the resistance area of research. Main body. The paper studied and developed a system, based on measuring electrical skin resistance on the identification and measurement of the noise variance from the BAP bioelectric signal that is proportional to the resistance of the investigation. A functional block diagram of an automated algorithm for converting the useful and noise signal BAP, whose range does not differ fundamentally from those of the intrinsic noise of the input elements in ESR. The proposed method will improve the accuracy of the measurements ESR without the use of test pacing signal. The simulation results and experimental studies correlate that confirms the adequacy of this method the results of experimental measurements. Conclusions. For noise voltage BAT can measure their electrical resistance without signals tested, external sources of electric current or voltage and thereby completely eliminate the harmful effect of probing. Thanks to one of the Inverting periodic noise voltages multiplied and simultaneous detection variable component switching frequency, provided the allocation and measurement noise voltage acupuncture points, which is proportional to the resistance, and the intensity of the same order or less than the intrinsic noise of the measuring system. Use as medical acupuncture needle electrodes allows to measure not only the skin but also deep resistivity, which reflects the physiological state of internal organs and tissues. The introduction of computer processing allows to analyze not only data on absolute or relative value measured ESHO, but also show the deviation from the established norm.

Denticle-embedded ampullary organs in a Cretaceous shark provide unique insight into the evolution of elasmobranch electroreceptors.

Here, we report a novel type of dermal denticle (or placoid scale), unknown among both living and fossil chondrichthyan fishes, in a Cretaceous lamniform shark. By their morphology and location, these dermal denticles, grouped into clusters in the cephalic region, appear to have been directly associated with the electrosensory ampullary system. These denticles have a relatively enlarged (∼350 μm in diameter), ornamented crown with a small (∼100 μm) asterisk- or cross-shaped central perforation connected to a multi-alveolate internal cavity. The formation of such a complex structure can be explained by the annular coalescence and fusion, around an ampullary vesicle, of several developmental units still at papillary stage (i.e. before mineralization), leading to a single denticle embedding an alveolar ampulla devoid of canal. This differs from larger typical ampullae of Lorenzini with a well-developed canal opening in a pore of the skin and may represent another adaptive response to low skin resistance. Since it has been recently demonstrated that ampullary organs arise from lateral line placodes in chondrichthyans, this highly specialized type of dermal denticle (most likely non-deciduous) may be derived from the modified placoid scales covering the superficial neuromasts (pit organs) of the mechanosensory lateral line system of many modern sharks.

No stress after 24-hour on-call shifts?

Irregular sleep patterns can adversely affect physiological functions and have been associated with increased physiological and psychological stress. Nocturnal work of physicians during 24-hour on-call shifts (OCS) disrupts the sleep/wake cycle. Chronic exposure to distress has been shown to affect cardiovascular homeostasis and to impair performance in neurocognitive and simulated clinical tasks. In a prospective cohort study, biochemical and physiological stress parameters were assessed in 11 female and 9 male physicians (median age: 32 years, range 26-42 years) before a normal working day and after a 24-hour OCS in internal medicine. In addition, various tests of attentional performance (TAP) were conducted. The levels of thyroid stimulating hormone (TSH) were significantly higher after a 24- hour OCS, while there were no significant changes in cortisol, epinephrine, and norepinephrine levels. Heart rate variability and skin resistance increased following an OCS, although the differences were not statistically significant. Intrinsic alertness was comparable, while phasic alertness was significantly improved following a 24-hour OCS. Focused attention tended to be better following a night shift. There was no correlation with age or medical working experience; however, men experienced more stress than women. Following a 24-hour OCS, (i) TSH may be an early and sensitive biochemical predictor of stress; (ii) other classical biochemical stress parameters do not depict the psychological stress perceived by physicians; (iii) there may be a mismatch between experienced and objective stress levels; (iv) neurocognitive functions are not impaired, while performance may even be improved; and (v) men might be more sensitive to distress.

Preliminary analysis of the use of smartwatches for longitudinal health monitoring.

New generations of smartwatches feature continuous measurement of physiological parameters, such as heart rate, galvanic skin resistance (GSR), and temperature. In this paper we present the results of preliminary analysis of the use of Basis Peak smartwatch for longitudinal health monitoring during a 4 month period. Physiological measurements during sleep are validated using Zephyr Bioharness 3 monitor and SOMNOscreen+ polysomnographic monitoring system from SOMNOmedics. Average duration of sequences with no missed data was 49.9 minutes, with maximum length of 17 hours, and they represent 88.88% of recording time. Average duration of the charging event was 221.9 min, and average time between charges was 54 hours, with maximum duration of the charging event of 16.3 hours. Preliminary results indicate that the physiological monitoring performance of existing smartwatches provides sufficient performance for longitudinal monitoring of health status and analysis of health and wellness trends.

P‐146: Skin Resistance Measurement using Static Capacitive Touch Panel

We present a novel touch‐sensing system that detects the skin resistance of a touched finger using a static capacitive touch panel. The employed frequency‐scan method enables us to measure skin resistance regardless of touching conditions. The proposed system can create new touch‐sensor applications such as multiuser system and bioelectrical sensing.

Association of auricular reflective points and the status of lower urinary tract symptoms in aging males

Objective: This study aimed to investigate the association between auricular reflective points and the status of lower urinary tract symptoms (LUTS) among Chinese aging males.Methods: A total of 113 male participants, with 69 having LUTS (LUTS+ve) and 44 having no LUTS (LUTS−ve), were recruited for this case–control study. Ear diagnosis was conducted in three ways: inspection, electrical skin resistance measurement, and tenderness testing.Results: Quality of life was lower among the LUTS+ve cases than among the LUTS−ve cases. The tenderness and electrical conductivity of a number of auricular points, including the “angle of superior concha”, the “urinary bladder”, the “ureter”, the “kidney”, the “urethra”, and the “internal genitals” were associated with LUTS in the Chinese aging males. In terms of electrical conductivity, the “angle of superior concha” on both ears exhibited the highest sensitivity among the other auricular points under testing. This auricular point also demonstrated considerable sensitivity, specificity, and positive/negative predictive values for both ears during the tenderness testing.Conclusions: Auricular diagnosis has a pre-diagnostic value and could be considered as a screening method for the aging population with relatively high LUTS risk.

Clindamycin resistant emm33 Streptococcus pyogenes emerged among invasive infections in Helsinki metropolitan area, Finland, 2012 to 2013.

In 2012, blood, skin and soft tissue infections caused by clindamycin resistant Streptococcus pyogenes (group A streptococcus; GAS) appeared to be increasing in the Helsinki metropolitan area. We compared monthly percentages of clindamycin resistant isolates in the area between 2012 and 2013, with those in 2010 and 2011. Resistance frequency in terms of patient age was also studied. We reviewed the medical records of bacteraemic cases in 2012 and 2013 and linked the data to emm types. To inform on the emm distribution among GAS isolated from skin and soft tissue infections during the epidemic, GAS isolates of one month (March 2013) were emm typed. For GAS blood, skin, and soft tissue isolates taken together, the proportions of clindamycin resistant isolates were significantly higher in 2012 and 2013 (23% and 17%, respectively) compared with the two previous years (3%, p<0,001). The erythromycin resistance percentages were almost equal to clindamycin (22% and 17%) in 2012 and 2013, respectively. Clindamycin resistance was most frequent in GAS isolates of 40 to 60 year-old patients (148/417; 36%). Among clindamycin resistant isolates, 12 of 14 blood isolates from 2012 to 2013, and 11 of 13 skin and soft tissue isolates from March 2013, were emm33. Emm33 GAS bacteraemia was associated with clindamycin and erythromycin resistance (odds ratio (OR): 7.0; 95% confidence interval (CI): 1.9-25.3). Infection focus was mainly the skin; either cellulitis (7/12) or necrotising fasciitis (3/12). All emm33 GAS isolates harboured the ermTR resistance gene with constitutive macrolides, lincosamides and streptogramines B (MLS(B)) phenotype. Emm33 GAS was responsible for the higher proportion of clindamycin resistance in skin, soft tissue, and blood isolates locally in 2012 and 2013.

Bearing capacity of open-ended pipe piles with restricted soil plug

The present study investigates the behaviour of plug on pile load capacity and effect of plug removal. The sand used as a foundation soil is poorly graded clean sand. It was prepared at different densities using a raining technique. To simulate the pile load test in the field, a new apparatus was manufactured. A driving–pressing system for pile installation was manufactured. The soil plug is removed by a device manufactured to remove the soil column entrapped inside the pipe piles during installation by driving and pressing devices. The present study focuses on the determination of effect of soil plug on the ultimate compression capacity of single open-ended steel pipe pile, and makes a comparison with closed-ended pipe pile. A new type of pipe piles is suggested; it is closed–open-ended pipe piles driven and pressed into sandy soil of different densities (medium and dense) in which axial compression load tests were performed on model piles. The pile end will be open to a predetermined depth in order to make pile penetration easy and closed at a distance in order to increase the pile base resistance. Twenty-four models of open-ended piles have been modified by closing the pile ends by a plate welded at a distance of 2D, 3D and 4D (where D is the diameter of the pile) from tip of the pile. These piles have been installed in sand by two types of installation, driving or pressing. It was concluded that the pile load carrying capacity in dense sand is several times greater than those in loose and medium sands, especially in the case of closed-ended or open-ended piles, since the pipe pile can produce external and internal skin friction in addition to end-bearing resistance that makes the total pile capacity close to that of closed-ended pile. On the other hand, the removal of soil plug decreases the pile load capacity. This decrease becomes apparent in dense sand. The decrease in load capacity is about 45%–63%, 55%–63% and 51%–79% in loose, medium and dense sands, respectively. Open-ended pipe piles behave as closed-ended, if the soil plug formed inside piles in a state of partial plug or full plug. The length of soil plug depends on the type of installation and relative density.For the type of pile proposed in this study, open-ended piles are closed with a plate welded at a distance of 2D, 3D and 4D from the tip of the pile, and the open part of the pipe pile has a limited length, which was found to be 3D. This length revealed the maximum pile capacity due to the development of both interior and exterior skin friction in addition to end resistance. In addition, at this length, the soil column is pressed inside the pipe and hence the soil was densified leading to increase the skin resistance.

On the tear resistance of skin.

Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip.

Game design to measure reflexes and attention based on biofeedback multi-sensor interaction.

This paper presents a multi-sensor system for implementing biofeedback as a human-computer interaction technique in a game involving driving cars in risky situations. The sensors used are: Eye Tracker, Kinect, pulsometer, respirometer, electromiography (EMG) and galvanic skin resistance (GSR). An algorithm has been designed which gives rise to an interaction logic with the game according to the set of physiological constants obtained from the sensors. The results reflect a 72.333 response to the System Usability Scale (SUS), a significant difference of p = 0.026 in GSR values in terms of the difference between the start and end of the game, and an r = 0.659 and p = 0.008 correlation while playing with the Kinect between the breathing level and the energy and joy factor. All the sensors used had an impact on the end results, whereby none of them should be disregarded in future lines of research, even though it would be interesting to obtain separate breathing values from that of the cardio.

Equilibrium Isotherm and Mass Transfer Coefficient for Adsorption of Pure Argon on Small Particles of Pelletized Lithium-Exchanged Low Silica X Zeolite

New experimental data are reported for equilibrium adsorption isotherm and mass transfer of pure argon on a sample of pelletized lithium-exchanged low silica X (LiLSX) zeolite. Model analysis of the data indicate that the zeolite behaved like a nearly homogeneous adsorbent for Ar adsorption while it exhibited substantial heterogeneity for adsorption of N2 and milder heterogeneity for adsorption of O2. The overall mass transfer coefficient for Ar adsorption was comparable in magnitude with those of N2 and O2. The coefficient increased with increasing pressure and decreased with increasing temperature like those for N2 and O2. A large skin resistance at the adsorbent particle surface was observed for Ar mass transfer like that for adsorption of O2 and N2.

Effect of continuous vs pulsed iontophoresis of treprostinil on skin blood flow

IntroductionSystemic sclerosis (SSc) is a rare disease affecting digital microcirculation, leading to finger ulcers and in some cases to amputation. Prostacyclin analogues can be used intravenously but their therapeutic effect is counterbalanced by potentially serious vasodilatation-induced side effects. Iontophoresis of treprostinil could be a promising local therapeutic alternative for SSc-related digital ulcers. Iontophoretic drug delivery is complex, and whether continuous or periodic current should be used remains debated. The objective of the present work is to compare the effect of continuous vs pulsed iontophoresis of treprostinil in rats. Materials and methodsTreprostinil (0.64mM and 0.064mM) and NaCl were delivered by cathodal iontophoresis onto the hindquarters of anaesthetized rats. Three protocols delivering the same quantity of current were compared: one was continuous (100μA during 20min) and two were periodic (B: twenty 1-min cycles with 200μA during 30s followed by 30s Off; and C: twenty 1-min cycles with 600μA during 10s followed by 50s Off) (n=8 for each protocol with each concentration). Skin blood flow was quantified using laser Doppler imaging and skin resistance was calculated with Ohm’s law. ResultsAll protocols induced a significant increase in skin blood flow. At the lower concentration (0.064mM treprostinil) the pulsed 10/50 sequence significantly enhanced cutaneous blood flow (Table 1; Fig. 1B) compared to continuous iontophoresis or the 30/30 sequence. We noted that the pulsed iontophoresis of NaCl (10/50 sequence) induced a significant early increase in cutaneous blood flow in comparison with continuous iontophoresis. Skin resistance measures were negatively correlated with current intensity delivered. ConclusionIn conclusion, pulsed iontophoresis of treprostinil with a 10s/50s (On/Off) protocol at 600μA increases the efficacy of iontophoresis at 0.064mM but not at a tenfold higher concentration. Pulsed iontophoresis could be used to optimize treprostinil iontophoresis, to provide similar efficacy with decreased costs, and should now be tested on humans.

Sexual maturation and administration of 17β-estradiol and testosterone induce complex gene expression changes in skin and increase resistance of Atlantic salmon to ectoparasite salmon louse

The crustacean ectoparasitic salmon louse (Lepeophtheirus salmonis) is a major problem of Atlantic salmon aquaculture in the Northern hemisphere. Host–pathogen interactions in this system are highly complex. Resistance to the parasite involves variations in genetic background, nutrition, properties of skin, and status of the endocrine and immune systems. This study addressed the relationship between sex hormones and lice infection. Field observation revealed a sharp reduction of lice prevalence during sexual maturation with no difference between male and female fish. To determine if higher resistance against lice was related to sex hormones, post-smolt salmon were administered control feed and feeds containing 17β-estradiol (20mg/kg) and testosterone (25mg/kg) during a 3-week pre-challenge period. After challenge with lice, counts were reduced 2-fold and 1.5-fold in fish that received 17β-estradiol and testosterone, respectively. Gene expression analyses were performed from skin of salmon collected in the field trial and from the controlled lab experiment at three time points (end of feeding-before challenge, 3days post challenge (dpc) and 16dpc) using oligonucleotide microarray and qPCR. Differential expression was observed in genes associated with diverse biological processes. Both studies revealed similar changes of several antibacterial acute phase proteins; of note was induction of cathelicidin and down-regulation of a defensin gene. Treatment with hormones revealed their ability to modulate T helper cell (Th)-mediated immunity in skin. Enhanced protection achieved by 17β-estradiol administration might in part be due to the skewing of Th responses away from the prototypic anti-parasitic Th2 immunity and towards the more effective Th1 responses. Multiple genes involved in wound healing, differentiation and remodelling of skin tissue were stimulated during maturation but suppressed with sex hormones. Such opposite regulation suggested that these processes were not associated with resistance to the parasite under the studied conditions. Both studies revealed regulation of a suite of genes encoding putative large mucosal proteins found exclusively in fish. Marked decrease of erythrocyte markers indicated reduced circulation while down-regulation of multiple zymogen granule membrane proteins and transporters of cholesterol and other compounds suggested limited availability of nutrients for the parasites.

Skin Resistivity Value of Upper Trapezius Latent Trigger Points.

Introduction. The skin resistivity (SkR) measurement is commonly recommended for acupoints measurement, but for trigger points (TrPs) only one study is available. The purpose of the study was to evaluate SkR for latent TrPs compared to non-TrPs and the surrounding tissue. Material and Methods. Forty-two healthy volunteers with unilateral latent upper trapezius TrPs (12 men, 30 women) aged 21–23 (mean age: 22.1 ± 0.6 y) participated in the study. Keithley electrometer 610B was used for measuring SkR (Ag/AgCl self-adhesive, disposable ground electrode: 30 mm diameter). SkR was measured for latent TrPs and compared to opposite non-TrPs sites and the surrounding tissue. Results. The SkR decrease of TrPs-positive sites as compared to TrPs-negative sites and the surrounding tissue was confirmed. However, no statistically significant difference in the SkR value occurred when all data were analyzed. The same was confirmed after gender division and for TrPs-positive subjects examined for referred pain and twitch response presence. Conclusion. SkR reactive changes at latent TrPs are possible but the results were not consistent with the previous study. Thus, caution in applying SkR to latent TrPs isolation is recommended and its clinical use should not be encouraged yet. Further studies, especially on active TrPs, are yet required.

The Electrodermal Activity in Rats with Sleep Deprivation

Sleep deprivation causes a wide range of cognitive deficits like impairments in vigilance, memory and physiological processes. To our knowledge, few chronic sleep deprivation studies have related the possible electrodermal activity (EDA) changes that show sympathetic activation. In this study, we aimed to investigate the effects of a 21-days sleep deprivation on EDA and neurobehavioral changes in open field area. The study was occurred with young and young adult Wistar Albino rats in Physiology laboratoryof Erciyes University Medical Faculty. The rats were randomly divided in six groups in total as a sleep deprivation group, pedestal control group and cages control group, and three of aged-matched groups. The skin resistance levels (SRL) and skin resistance response (SRR) were significantly decreased in substantive level in young and young adults sleep deprivation groups according to control groups. In open field test evaluations in young and young adult sleep deprivation groups significant increase in the number of crossline, rear and defecation. Sleep deprivation caused a decline in the electrodermal activity due to giving rise to increase in sympathetic tonus and anxiety in young and young adult rats.

Investigation of respiratory and heart rate variability in hypertensive patients

In this paper, in order to examine the effect of respiration on heart rate variability (HRV), signal processing analyses were performed between the signal received from the periodic movement of the chest of respiration and the pulse plethysmograph (PPS) signal, providing the calculation of both the time and frequency behavior of HRV and also including pulse rate information at the same time. Respiration is used as the comparison parameter in both healthy subjects and in hypertensive patients, not only with the time and frequency components of the HRV, but also with the galvanic skin resistance simultaneously taken with body temperature and by calculating these signal changes. In our study, we aim to not only investigate the relationship between hypertension and HRV, but also to investigate the effect of respiration. Hence, in this study, 19 hypertensive patients and 19 healthy controls, who are all women, are used as subjects. As a result of the data received and analyzed from the subjects, HRV both in hypertensive and healthy subjects, the mean value of the high-frequency component and respiratory signal (RSP), and the mean value of the low-frequency/high-frequency ratio accepted as a sympathovagal balance index of the heart rate and RSP are statistically associated.

Peptides as skin penetration enhancers: Mechanisms of action

Skin penetrating peptides (SPPs) have garnered wide attention in recent years and emerged as a simple and effective noninvasive strategy for macromolecule delivery into the skin. Although SPPs have demonstrated their potential in enhancing skin delivery, they are still evolving as a new class of skin penetration enhancers. Detailed studies elucidating their mechanisms of action are still lacking. Using five SPPs (SPACE peptide, TD-1, polyarginine, a dermis-localizing peptide and a skin penetrating linear peptide) and a model hydrophobic macromolecule (Cyclosporine A, CsA), herein we provide a mechanistic understanding of SPPs. To evaluate the mechanism and safety of SPPs, their effects on skin lipids, proteins and keratinocyte cells were evaluated. Three SPPs (SPACE, Polyarginine and TD-1) significantly enhanced CsA penetration into the skin. SPPs did not alter the skin lipid barrier as measured by skin resistance, transepidermal water loss (TEWL) and Fourier transform infrared (FTIR) spectroscopic analysis. In contrast, SPPs interacted with skin proteins and induced changes in skin protein secondary structures (α-helices, β-sheet, random coils and turns), as evaluated by FTIR analysis and confirmed by in-silico docking. SPPs enhanced CsA skin penetration, via a transcellular pathway, enhancing its partitioning into keratin-rich corneocytes through concurrent binding of SPP with keratin and CsA. Interaction between SPP and keratin best correlated with measured CsA skin transport. Many SPPs appeared to be safe as shown by negligible effect on skin integrity, nominal skin irritation potential and cytotoxicity. Among the peptides tested, SPACE peptide was found to be least toxic to keratinocytes, and among the most effective at delivering CsA into the skin.

Skin Resistance Measurement in Japanese Acupuncture

In the last century, the Western clinicians initiated the use of skin resistance measurements for quantifying sweat gland activity as well as assessing anxiety levels. At the same time, acupuncturists used the measurement of skin resistance as a modern diagnostic tool to augment the thousand-year-old acupuncture therapy in Japan. This unique measurement has been called Ryodoraku since 1950. The present article is a brief description of historical aspects of the Ryodoraku and the correlations between skin resistance and various medical conditions.

Column Dynamic Study of Mass Transfer of Pure N2 and O2 into Small Particles of Pelletized LiLSX Zeolite

Effective mass transfer coefficients (κe,s–1) for adsorption of pure N2 and O2 into small particles of a pelletized sample of lithium exchanged low silica X (LiLSX) zeolite were estimated as functions of gas pressure (P) and temperature (T) by analysis of experimental column dynamic data using a specific protocol based on assumptions of a constant pattern mass transfer zone (MTZ) formation and a linear driving force model for mass transport. New column breakthrough data at different P and T for displacements of pure inert helium by pure N2 or O2 in an isobaric–isothermal adsorber were used. The mass transfer coefficients decreased linearly with increasing P and increased with increasing T. Data interpretation using a “resistances in series” model for isothermal–isobaric mass transport of an adsorbate having a linear adsorption isotherm into a pelletized zeolite particle suggested the presence of a skin resistance at the pellet surface, which in combination with resistances created by axial dispersion in t...