Skin Resistance Measurements Research Articles

Wearable non‐invasive blood glucose monitor system based on galvanic skin resistance measurement

This work proposes a wearable system for the non-invasive measurement of the blood glucose level. In particular, the blood glucose variations are related with the skin resistance measured with a suitable sensor. A microcontroller is aimed to measure, store and transmits on a wireless channel, the blood glucose level in a simple, non-invasive and unsupervised way. The system is particularly useful to monitoring the glucose level in diabetic patients, and to perform the oral glucose tolerance test (OGTT) useful to identify metabolic diseases and to diagnose diabetes mellitus in the early stage. The preliminary obtained results are quite promising and demonstrated the potentialities of the device as diagnostic and home care tool.

Skin Electrical Resistance as a Diagnostic and Therapeutic Biomarker of Breast Cancer Measuring Lymphatic Regions.

Skin changes associated with alterations in the interstitial matrix and lymph system might provide significant and measurable effects due to the presence of breast cancer. This study aimed to determine if skin electrical resistance changes could serve as a diagnostic and therapeutic biomarker associated with physiological changes in patients with malignant versus benign breast cancer lesions. Forty-eight women (24 with malignant cancer, 23 with benign lesions) were enrolled in this study. Repeated skin resistance measurements were performed within the same session and 1 week after the first measurement in the breast lymphatic region and non-breast lymphathic regions. Intraclass correlation coefficients were calculated to determine the technique’s intrasession and intersession reproducibility. Data were then normalized as a mean of comparing cross-sectional differences between malignant and benign lesions of the breast. Six months longitudinal data from six patients that received therapy were analyzed to detect the effect of therapy. Standard descriptive statistics were used to compare ratiometric differences between groups. Skin resistance data were used to train a machine learning random forest classification algorithm to diagnose breast cancer lesions. Significant differences between malignant and benign breast lesions were obtained (p<0.01), also pre- and post-treatment (p<0.05). The diagnostic algorithm demonstrated the capability to classify breast cancer with an area under the curve of 0.68, sensitivity of 66.3%, specificity of 78.5%, positive predictive value 70.7% and negative predictive value 75.1%. Measurement of skin resistance in patients with breast cancer may serve as a convenient screening tool for breast cancer and evaluation of therapy. Further work is warranted to improve our approach and further investigate the biophysical mechanisms leading to the observed changes.

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.

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.

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.

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.

A method for measuring the volume of transdermally extracted interstitial fluid by a three-electrode skin resistance sensor.

It is difficult to accurately measure the volume of transdermally extracted interstitial fluid (ISF), which is important for improving blood glucose prediction accuracy. Skin resistance, which is a good indicator of skin permeability, can be used to determine the volume of extracted ISF. However, it is a challenge to realize in vivo longitudinal skin resistance measurements of microareas. In this study, a three-electrode sensor was presented for measuring single-point skin resistance in vivo, and a method for determining the volume of transdermally extracted ISF using this sensor was proposed. Skin resistance was measured under static and dynamic conditions. The correlation between the skin resistance and the permeation rate of transdermally extracted ISF was proven. The volume of transdermally extracted ISF was determined using skin resistance. Factors affecting the volume prediction accuracy of transdermally extracted ISF were discussed. This method is expected to improve the accuracy of blood glucose prediction, and is of great significance for the clinical application of minimally invasive blood glucose measurement.

Auricular Diagnosis in Chronic Illnesses

Abstract Background: Auricular diagnosis has been used as a complementary approach that is simple, effective, and inexpensive for identifying chronic illnesses. This diagnostic method has prediagnostic value and is important for a secondary level of prevention, so that earlier treatment can be provided. Objective: This article describes how this diagnostic method was applied in cases with coronary heart disease (CHD) or lower urinary-tract symptoms (LUTS), which are common chronic illnesses among the adult population. Materials and Methods: Design: A case-control study approach was adopted, with the utilization of visual inspection, electrical skin-resistance measurement, and tenderness testing to investigate the auricular signals and their relationship with specific chronic illnesses. The practitioners who conducted the auricular diagnosis were blinded to the known medical conditions of the subjects. Setting and Subjects: Subjects from the CHD +ve (positive) group (n=50) were recruited from the cardiac u...

Do changes in electrical skin resistance of acupuncture points reflect menstrual pain? A comparative study in healthy volunteers and primary dysmenorrhea patients.

Electrical skin resistance (ESR) measurements were performed with a four-electrode impedance detector at 10 points bilaterally on the first day of and the third day after menstruation in 48 healthy volunteers and 46 primary dysmenorrhea (PD) patients, to assess whether ESR changes of acupuncture points can reflect menstrual pain or not. The results showed statistical reductions in ESR imbalance ratio between left and right side that were detected at SP8 (Diji) and GB39 (Xuanzhong) (P < 0.05), and a statistical increase was detected at SP6 (Sanyinjiao) (P = 0.05) on the first day of menstruation compared with those values on the third day after menstruation in dysmenorrhea group. No significant differences were detected at other points within and between two groups (P > 0.05). This study showed that the imbalance of ESR at uterine-relevant points in PD patients is not significantly different from those of healthy women on both the 1st day of and the 3rd day after menstruation. The ESR imbalance ratio of certain points can either be lower or higher during menstruation in PD patients. The ESR property of acupuncture points needs to be investigated in further clinical trials with appropriate points, diseases, larger sample sizes, and optimal device.

Pain Induced by Rheumatoid Arthritis and Acupoint Skin Resistance

Dear Professor Andrasik, I enjoyed reading a recent article by Turner et al. (2013) in your journal. The article was a comparison between the acupoint-skin resistance of patients with Rheumatoid Arthritis (RA) and that of healthy counterparts in which the skin resistance was found higher in the RA group; the authors concluded that the measurement of skin resistance at the acupoints can differentiate between the pain (RA) and the non-pain (healthy) groups. But, I would like to express my opinions on their interpretations.

Evaluation of the effectiveness of thoracic sympathectomy in the treatment of primary hyperhidrosis of hands and armpits using the measurement of skin resistance.

IntroductionHyperhidrosis is excessive sweating beyond the needs of thermoregulation. It is disease which mostly affects young people, often carrying a considerable amount of socio-economic implications. Thoracic sympathectomy is now considered to be the "gold standard" in the treatment of idiopathic hyperhidrosis of hands and armpits.AimAssessment of early effectiveness of thoracic sympathectomy using skin resistance measurements performed before surgery and in the postoperative period.Material and methodsA group of 20 patients with idiopathic excessive sweating of hands and the armpit was enrolled in the study. Patients underwent two-stage thoracic sympathectomy with resection of Th2-Th4 ganglions. The skin resistance measurements were made at six previously designated points on the day of surgery and the first day after the operation.ResultsIn all operated patients we obtained complete remission of symptoms on the first day after the surgery. Inhibition of sweating was confirmed using the standard starch iodine (Minor) test. At all measurement points we obtained a statistically significant increase of skin resistance, assuming p < 0.05. To check whether there is a statistically significant difference in the results before and after surgery we used sequence pairs Wilcoxon test.ConclusionsThoracic sympathectomy is an effective curative treatment for primary hyperhidrosis of hands and armpits. Statistically significant increase of skin resistance in all cases is a good method of assessing the effectiveness of the above surgery in the early postoperative period.

Predictive Value of Auricular Diagnosis on Coronary Heart Disease

The ear has a reflexive property; therefore, various physical attributes may appear on the auricle when disorders of the internal organs or other parts of the body exist. Auricular diagnostics is an objective, painless, and noninvasive method that provides rapid access to information. Thus, the association between auricular signals and coronary heart disease (CHD) should be further investigated. A case control study was conducted to determine the predictive value of auricular signals on 100 cases of CHD (CHD+ve = 50; CHD−ve = 50) via visual inspection, electrical skin resistance measurement, and tenderness testing. The results showed that the presence of an ear lobe crease (ELC) was significantly associated with coronary heart disease. The “heart” zone of the CHD+ve group significantly exhibited higher conductivity on both ears than that of the controls. The CHD+ve group experienced significant tenderness in the “heart” region compared with those in the CHD−ve group in both acute and chronic conditions. Further studies that take into consideration the impact of age, race, and earlobe shape on ELC prevalence in a larger sample should be done.

Electrodermal mapping: A new technology.

To provide the first objective data to show that the electrical conditions of an acupuncture point and a non acupuncture point are different. A newly developed multi-channel skin resistance measuring system is used to characterize the variability in electrical resistance measurements in and around an acupoint, a non-acupoint and a scar. The system measures the electrical skin resistance at 48 points, both absolutely and continuously. The study was performed at the Medical University of Graz in 10 male volunteers, aged between 20 and 30 years and of eurocaucasian descent. With software developed along with the hardware, both a high-resolution measurement and a graphical presentation of possible changes in electrical resistance in the region of interest are possible. Using the new electrodermal mapping system, differences in skin resistance of an acupoint, a non-acupoint and around a scar could be observed. The values varied within a range of up to 100-500 kOhm. Thermography measurements for control reasons in the same spot did not show these changes. Electrodermal mapping is an innovative method for highly precise skin resistance measurements.

Quantification of human skin barrier function and susceptibility to quantum dot skin penetration

In this study, we utilize in vivo human skin and a viable ex-vivo human skin model to investigate the effect of a commercial depilatory agent on barrier function. Tape stripping was used as a positive control. The magnitude of skin barrier was quantified by measuring transepidermal water loss values on in vivo human skin and transepithelial electrical resistance measurements and tissue histology on ex vivo skin. The susceptibility to carboxylated quantum dot penetration through ex vivo skin was investigated using fluorescent microcopy analysis of microtomed skin sections and flow cytometry to quantify quantum dot association with live epidermal cells. Results show that depilatory treatment modifies the outside-in barrier sufficiently to allow quantum dots to penetrate the stratum corneum but to a lesser extent than tape stripping. The implications of these finding are discussed.

Características de la resistencia eléctrica de la piel en los puntos de acupuntura de humanos sanos

The aim of this study was to evaluate the phenomenon of electrical skin resistance (ESR) changes at different acupuncture points (APs). This single-blinded study was performed at the hospital of the University of Munich. Six common APs were measured (TE5, PC6, LU6, ST36, SP6, GB39) in 53 subjects. Subgroups were formed with varying time intervals for follow-ups (1 minute, 1 hour, 1 week) and a varying grade of reduction of the stratum corneum. Electrical skin resistance measurements (ESRMs) were taken from a skin area of 6 × 6 cm using an array consisting of 64 (8 × 8) electrodes. The electrodes corresponding to the AP were located and the ESRM results were compared to those of the surrounding electrodes. The methodological setting made it possible to minimize major influence factors on electrical skin impedance measurements. A total of 631 ESRMs was evaluated: In 62.8% of the measured APs, no significant ESR difference was found. In 234 (37.2%) of the ESRMs, the ESR at the AP was significantly different from the surrounding skin area, with 163 (25.9%) points showing a lower and 71 (11.3%) points showing a higher ESR. Reproducibility was extremely high after 1 minute but was low after 1 hour and 1 week. This study shows that electrical skin resistance at APs can either be lower or higher compared to the surrounding area. The phenomenon is characterized by high short-term and low long-term reproducibility. Therefore, we conclude that APs might possess specific transient electrical properties. However, as the majority of the measured APs did not show a changed ESR, it cannot be concluded from our data that electrical skin resistance measurements can be used for acupuncture point localization or diagnostic/therapeutic purposes.

A Multichannel System for Continuous Measurements of Skin Resistance and Capacitance at Acupuncture Points

Electrodermal screening (EDS) is based on three commonly held assumptions: acupuncture points (APs) have lower electrical resistance than non-APs; resistance at APs varies with health and disease; and effective acupuncture treatments are associated with normalization of resistance at APs. Although evidence confirming these assumptions is limited, EDS is frequently practiced worldwide. Researchers are also beginning to assess EDS' utility as an outcome measure in acupuncture trials. Fundamental in developing EDS as a research tool is the need for an accurate and reliable measurement. We developed an automated multichannel prototype system, the Octopus, and recorded electrical resistance and capacitance at eight skin sites in 33 healthy participants over 2 hours. The Octopus accurately measured against known resistors (within 2.5% of the mean value) and capacitors (within 10% of the mean value), and yielded repeatable readings at all eight skin sites: LR 1 (r=0.79), SP 1 (r=0.79), toe non-AP (r=0.77), LU 9 (r=0.97), PC 6 (r=0.96), wrist non-APs (r=0.97), SP 6 (r=0.96), and leg non-APs (r=0.97). Resistance at APs was significantly lower than the nearby non-APs in one out of three comparisons.

Poly(amidoamine) dendrimers as skin penetration enhancers: Influence of charge, generation, and concentration

The study investigates the influence of surface charge, generation and concentration of poly(amidoamine) (PAMAM) dendrimers on skin permeation of a model hydrophilic drug, 5-fluorouracil (5FU). Permeation studies were performed using excised porcine skin in a Franz diffusion cell. Saturated concentration of 5FU in isopropyl myristate was applied on the skin after pretreatment with dendrimers and (14)C labeled 5FU was analyzed using a liquid scintillation counter. The influence of dendrimer surface charge (G4-NH(2), G3.5-COOH, and G4-OH), generations (G2-G6-NH(2)) and concentration (0.1-10 mM of G4-NH(2)) on skin permeation of 5FU were studied. The enhancement in drug permeability coefficient (K(p)) was in the following decreasing order G4-NH(2) > G4-OH > G3.5-COOH. Dendrimer increased the skin permeation by increasing the skin partitioning of 5FU. Transepidermal water loss, skin resistance measurements and ATR-FTIR studies revealed that cationic dendrimers act by interacting with the skin lipid bilayers. Increase in G4-NH(2) concentration did not proportionally increase the skin permeation of 5FU. The 5FU K(p) was inversely related to the molecular weight of the dendrimer. G2-NH(2) dendrimer reduced skin resistance to a greater extent than higher generation dendrimers. Overall, the study showed that lower generation cationic dendrimer is more effective in enhancing the skin permeation of hydrophilic drugs.

Simultaneous measurement of ethane diffusivity and skin resistance of ‘Jonica’ apples by efflux experiment

An experiment was carried out to simultaneously measure the diffusivity and skin resistance of ethane in ‘Jonica’ apples by equilibrating them in an ethane–air mixture, transferring them to an ethane-free jar and monitoring the concentration of the air in the jar as the ethane is released. The concentration curve is then curve fitted by a finite element model using a realistic axisymmetric geometry to determine the diffusivity and mass transfer coefficient (inverse of skin resistance). The solubility (Henry’s law constant) of ethane in apple tissue was determined at equilibrium and was the same as that of ethane in water. The diffusivity of ethane in apple tissue was 19.4 × 10 −8 m 2 s −1, the skin resistance 1.26 × 10 6 s m −1 and the mass transfer Biot number (ratio of internal to external resistance) 0.61. The values of these parameters for O 2, CO 2 and neon were calculated from those for ethane using a two phase co-diffusion model. They disagree with results from previous efflux experiments but are consistent with direct measurement on cut tissue samples using the diffusion cell method. This can be explained by the hypothesis that the diffusivity determined by curve fitting is that of the inner cortex, while the resistance of the outer cortex is treated as part of skin resistance. Taken in combination with previous tests, the present results give an indication of the diffusivity profile across the apples.

Characteristics of Electrical Skin Resistance at Acupuncture Points in Healthy Humans

The aim of this study was to evaluate the phenomenon of electrical skin resistance (ESR) changes at different acupuncture points (APs). This single-blinded study was performed at the hospital of the University of Munich. Six common APs were measured (TE5, PC6, LU6, ST36, SP6, GB39) in 53 subjects. Subgroups were formed with varying time intervals for follow-ups (1 minute, 1 hour, 1 week) and a varying grade of reduction of the stratum corneum. Electrical skin resistance measurements (ESRMs) were taken from a skin area of 6 x 6 cm using an array consisting of 64 (8 x 8) electrodes. The electrodes corresponding to the AP were located and the ESRM results were compared to those of the surrounding electrodes. The methodological setting made it possible to minimize major influence factors on electrical skin impedance measurements. A total of 631 ESRMs was evaluated: In 62.8% of the measured APs, no significant ESR difference was found. In 234 (37.2%) of the ESRMs, the ESR at the AP was significantly different from the surrounding skin area, with 163 (25.9%) points showing a lower and 71 (11.3%) points showing a higher ESR. Reproducibility was extremely high after 1 minute but was low after 1 hour and 1 week. This study shows that electrical skin resistance at APs can either be lower or higher compared to the surrounding area. The phenomenon is characterized by high short-term and low long-term reproducibility. Therefore, we conclude that APs might possess specific transient electrical properties. However, as the majority of the measured APs did not show a changed ESR, it cannot be concluded from our data that electrical skin resistance measurements can be used for acupuncture point localization or diagnostic/therapeutic purposes.

The Use of Auricular Examination for Screening Hepatic Disorders

Researches on auricular acupuncture (AA) have examined mainly its treatment effects. This study aimed to investigate the accuracy and precision of using auricular examination (AE) as a complementary diagnostic tool for screening hepatic disorders. Twenty patients suffering from liver dysfunction and 25 controls aged 18–60 years were recruited from an acute hospital. Participants were examined using three AE methods including visual inspection, electrical skin resistance measurement, and tenderness testing on the liver AA zone of both ears. Significant differences were found in visual inspection and electrical skin resistance on the AA zones between the two groups. Patients suffering from liver dysfunction tended to have at least one abnormality in skin color, appearance, presence of papules, abundance of capillary and desquamation on the ear (Relative Risk—Right ear: RR = 2.9, 95% confidence interval (CI) 1.4, 6.2; Left: RR = 1.8, 95% CI, 1.01, 3.1). The sensitivity for visual inspection was 0.7 for both ears; specificity was 0.76 for the (R) and 0.6 for the (L) ear. The mean difference in electrical skin resistance was 4.3 MΩ (95% CI, 1.7, 6.9) for the (L) ear; 4.5 MΩ (95% CI, 1.5, 7.6) for the (R) ear. Our results suggest that malfunction of the liver appeared to be reflected by the presence of morphological changes on the liver AA zone. Visual inspection and electrical skin resistance on the liver AA zone are potentially sensitive to screen hepatic disorders.