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Variety of skin devices covered in this review.

Variety of skin devices covered in this review.

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Article
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Skin is one of the indispensable organs for life. The epidermis at the outermost surface provides a permeability barrier to infectious agents, chemicals, and excessive loss of water, while the dermis and subcutaneous tissue mechanically support the structure of the skin and appendages, including hairs and secretory glands. The integrity of the inte...

Citations

... However, other parameters such as surface area of contact, applied pressure, and moisture presence can influence resistance [21,22]. The skin's electrical conductivity experiences significant fluctuations due to moisture, which subsequently impacts the flow of electric current and the generation of heat [7,23]. It is important to note that the word "electric current" refers to the flow of electrons through a conductive material. ...
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This study investigates the frequency of electric shocks among Nigerians and the resulting effects on those affected. A survey tool and verbal questionnaire were utilised to arrive at reliable testimonials from both victims and witnesses of comparable incidents. This study reveals that Nigerians encounter electric shock on a daily basis, yet a significant fraction of these incidents remains unreported. Furthermore, a significant portion of the Nigerian population has limited understanding of electricity and shows indifference towards the potential consequences of electric shocks. The survey findings unearthed multiple instances of electric shock over a thirteen-week period, previously not sufficiently documented. This study undertook meticulous analysis and documentation of multiple instances of electric shock, providing a full report on the resulting consequences and their level of severity. Many of the individuals who are affected intentionally choose not to wear protective equipment, fully aware that their lack of expertise and contempt for safety measures may result in an electric shock. Nevertheless, they demonstrate a reluctance to seek assistance from proficient experts or adopt proactive efforts to avert such occurrences. This study additionally investigates sustainable preventative approaches and proposes strategies for educating the public on suitable safety precautions. This study aims to address a significant and comprehensive educational gap concerning the prevention of electric shock and its associated consequences. This topic, which is a longstanding worry in Nigeria, has not received sufficient attention thus far.
... The development of technology consisting of micro-electro-mechanical systems coupled with advances in materials science has enabled the production of small bioelectronics devices, allowing biomonitoring and therapy with implantable devices. The SC plays a crucial role in the overall electrical resistance of skin [26][27][28][29], so that a high EP voltage should be necessary to achieve enough electrical field to deliver macromolecules into cells when EP is applied on the skin surface. Pavselj et al. reported that a high electric field was observed in the SC, whereas the electric field in the deeper layer was below the permeabilization threshold [30,31]. ...
Article
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Objectives: Non-viral mediated plasmid DNA transfection by electroporation (EP) is an established method for gene transfection. In this study, the usefulness of direct EP at an intradermal (i.d.) site (DEP) with implanted electrodes to achieve a high protein expression level was investigated. In addition, DEP application with various intervals with a low application voltage was also evaluated to confirm its effect on protein expression. Methods: Green fluorescent protein (GFP)- and luciferase-encoding DNA were administrated, and GFP and luciferase were evaluated. Results: A higher protein expression level was observed after green fluorescent protein (GFP)- and luciferase-encoding DNA were delivered by i.d. injection followed by DEP application. When luciferase expression was observed with an in vivo imaging system, continuous expression was confirmed over 21 days after i.d. injection followed by DEP at 100 V. This approach provided increased gene expression levels compared with conventional EP methods via the stratum corneum layer. In addition, the effect of application voltage on luciferase expression was investigated; two-time applications (repeated DEP) at 20 V with 5 min intervals showed similar luciferase expression level to single DEP application with 100 V. Histological observations showed the skin became thicker after a single DEP at 100 V, whereas no apparent thickness changes were confirmed after repeated DEP at 20 V with 5 min intervals. Conclusions: This study revealed that direct i.d. voltage application achieved high protein expression levels even at low voltages. Skin is a promising administration site for DNA vaccines, so this approach may be effective for DNA vaccine delivery into skin tissue.
... The development of technology consisting of Micro-Electro-Mechanical-Systems coupled with advances in materials science has enabled the production of small bioelectronics devices, allowing biomonitoring and therapy with implantable devices. The SC plays a crucial role in the overall electrical resistance of skin [26][27][28][29], so that a high EP voltage should be necessary to achieve enough electrical field to deliver macromolecules into cells when EP is applied on the skin surface. Pavselj et al. reported that a high electric field was observed in the SC, whereas the electric field in the deeper layer was below the permeabilization threshold [30,31]. ...
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Full-text available
Non-viral mediated plasmid DNA transfection by electroporation (EP) is an established method for gene transfection. In this study, the usefulness of direct EP at an intradermal (i.d.) site (DEP) with implanted electrodes to achieve a high protein expression level was investigated. In addition, DEP application with various intervals with a low application voltage was also evaluated to confirm its effect on protein expression. A higher protein expression level was observed after green fluorescent protein (GFP)- and luciferase-encoding DNA were delivered by i.d. injection followed by DEP application. When luciferase expression was observed with an in vivo imaging system, continuous expression was confirmed over 21 days after i.d. injection followed by DEP at 100 V. This approach provided increased gene expression levels compared with conventional EP methods via the stratum corneum layer. In addition, the effect of application voltage on luciferase expression was investigated; two-time applications (repeated DEP) at 20 V with 5 min intervals showed similar luciferase expression level to single DEP application with 100 V. Histological observations showed the skin became thicker after a single DEP at 100 V, whereas no apparent thickness changes was confirmed after repeated DEP at 20 V with 5 min intervals. This study revealed that direct i.d. voltage application achieved high protein expression levels even at low voltages. Skin is a promising administration site for DNA vaccines, so this approach may be effective in DNA vaccine delivery into skin tissue.
... The measurements are frequent, occurring every few minutes, allowing for a continuous stream of data on glucose levels throughout the day and night. The skin's electrically charged structure has been exploited for transdermal drug delivery and chemical extraction [99]. This principle could be applied to the development of minimally invasive or non-invasive Continuous Glucose Monitoring (CGM) systems. ...
... This principle could be applied to the development of minimally invasive or non-invasive Continuous Glucose Monitoring (CGM) systems. By leveraging the skin's electrical properties, it may be possible to extract interstitial fluid or measure glucose levels through the skin without the need for invasive sensors [99]. Such advancements could greatly improve patient comfort and acceptance of CGM systems, leading to better diabetes management outcomes. ...
Article
Glucose monitoring is essential for managing diabetes, and continuous glucose monitoring biosensors can offer real-time monitoring with little invasiveness. However, challenges remain in improving sensor accuracy, selectivity, and overall performance. This article aims to review current trends and recent advancements in glucose-monitoring biosensors while evaluating their benefits and limitations for diabetes monitoring. An analysis of current literature on transdermal glucose sensors was conducted, focusing on detection techniques, novel nanomaterials, and integrated sensor systems. Recent research has led to advancements in electrochemical, optical, electromagnetic, and sonochemical sensors for transdermal glucose detection. The use of novel nanomaterials and integrated sensor designs has improved sensitivity, selectivity, and accuracy. However, issues like calibration requirements, motion artifacts, and skin irritation persist. Transdermal glucose sensors show promise for non-invasive, convenient diabetes monitoring but require further enhancements to address limitations in accuracy, reliability, and biocompatibility. Continued research and innovation focusing on sensor materials, designs, and surface chemistry is needed to optimize biosensor performance and utility. The study offers a comprehensive analysis of the present status of technological advancement and highlights areas that need more research.
... *Transdermal drug delivery (TDD) stands at the forefront of pharmaceutical innovation, offering a revolutionary approach to drug administration by providing a non-invasive means of delivering therapeutic agents through the skin's epidermal layer (Yu et al., 2021). The epidermis, serving as the body's vigilant guardian against external threats like bacteria and harmful substances, presents an imposing barrier to drug penetration (Abe and Nishizawa, 2021). Within the epidermis, the stratum corneum (SC), the outermost layer, assumes the role of a major permeability barrier. ...
Article
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This study explores the design and simulation of specialized sonophoretic transducers aimed at enhancing the transdermal delivery of large drugs. We examine different elements of the transducer's design, such as the choice of materials, its dimensions, and the matching of acoustic impedance. We selected PZT-4, from the lead zirconate titanate (PZT) group, as the main material due to its excellent piezoelectric features and durability. We also use polymer matrices to make the transducer less rigid. The simulation outcomes, using COMSOL Multiphysics, cover five different transducer array sizes (8x5, 10x6, 12x8, 14x9, and 16x10) within the frequency range of 20-40 kHz. We measure the acoustic pressure at a depth of 0.1 mm under the skin, which is key for successful drug delivery through the skin. Our results show how increasing the size of the array affects the transducer's efficiency. We confirm our simulation results by comparing them with a previously published ANSYS simulation and finding good alignment. This comparison adds reliability to our methods and outcomes. The study also proposes creating a small, wrist-mounted device for drug delivery that could be combined with drug patches, making it user-friendly. Moreover, we stress the need to follow Mechanical Index (MI) guidelines to avoid damaging the skin. Overall, our findings highlight the importance of the array size in the performance of the transducer and confirm the validity of our simulation approach, paving the way for innovative solutions in drug delivery that could have wide applications in healthcare.
... Pulse electric fields have also become increasingly utilised in the biomedical space, with established roles in the non-thermal ablation of cancerous tissue, in electrochemotherapy by facilitating the transport of drugs across cell membranes and transdermal barriers, and in gene therapy and DNA vaccination through gene electrotransfer to cells or tissues, including cutaneous wounds (Prausnitz and Langer, 2008;Thomson et al., 2011;Yarmush et al., 2014;Gibot and Rols, 2016). Further the application of PEF to the skin is supported by its transepidermal potential which forms during development, as this generates endogenous electric fields upon injury which direct the migration of numerous skin cells to facilitate wound closure (Reid and Zhao, 2013;Abe and Nishizawa, 2021). This has led to exogenous electrical fields being increasingly applied to promote healing of skin wounds. ...
Article
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Tissue engineering encompasses a range of techniques that direct the growth of cells into a living tissue construct for regenerative medicine applications, disease models, drug discovery, and safety testing. These techniques have been implemented to alleviate the clinical burdens of impaired healing of skin, bone, and other tissues. Construct development requires the integration of tissue-specific cells and/or an extracellular matrix-mimicking biomaterial for structural support. Production of such constructs is generally expensive and environmentally costly, thus eco-sustainable approaches should be explored. Pulsed electric field (PEF) technology is a nonthermal physical processing method commonly used in food production and biomedical applications. In this review, the key principles of PEF and the application of PEF technology for skin engineering will be discussed, with an emphasis on how PEF can be applied to skin cells to modify their behaviour, and to biomaterials to assist in their isolation or sterilisation, or to modify their physical properties. The findings indicate that the success of PEF in tissue engineering will be reliant on systematic evaluation of key parameters, such as electric field strength, and their impact on different skin cell and biomaterial types. Linking tangible input parameters to biological responses critical to healing will assist with the development of PEF as a sustainable tool for skin repair and other tissue engineering applications.
... This section provides a brief overview of the potential use of integrating FES and robot arm technology to perform clinical repair and identify muscle activity using EMG signals. Several clinical evaluations were identified, such as the Fugl-Meyer Assessment (FMA) clinical evaluation, which is used for performance-based measurements of multisensory function in post-stroke hemiplegia [34], the Action Research Arm Test (ARAT), which is used to measure the function of a person's hand with various parameters of size, weight, and shape (43), the Function Independence Measurement (FIM), which is used to evaluate the patient's daily living activities (ADL) (44), and the Modified Ashworth The MAS scale was applied to evaluate post-stroke spasticity of the elbows, wrists, and fingers (40). The Wolf Motor Function Test (WMFT) was applied before and after training, and the Structure Domain and ADL (MAL) were performed to assess the strength and number of movements during 30 ADLs. ...
... Each amplitude quantity used has a weakness, namely that if excessive amplitude is used, it can limit signal input to the patient's central nervous system and can cause pain in the patient [39]. According to Abe et al. [40], Skin impedance and other physical properties of skin tissue have a strong influence on the current path. The skin exhibits both resistive and capacitive properties. ...
Article
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Interface technology development for human-robot interaction (HRI) in rehabilitation systems has increased in recent years. HRI can effectively achieve specific motor goals desired in rehabilitation, such as combining human intentions and actions with robotic devices to perform the desired stroke rehabilitation movements. Rehabilitation devices are starting to be directed towards using devices that integrate functional electrical stimulation (FES) with robotic arms because they have succeeded in providing promising interventions to restore arm function by intensively activating the muscles of post-stroke patients. However, FES requires a high level of accuracy to position the limbs for the functional tasks given because excessive electrical stimulation can cause fatigue in the patient, so it is necessary to provide electrical stimulation with an amplitude that suits the patient's needs. Unfortunately, most studies have a constant voltage amplitude and do not consider the voltage that matches the patient's muscle needs; this treatment can cause fatigue in the patient. Robotic devices as rehabilitation aids have the potential to support external power and adapt electrical stimulation needs to the voltage amplitude applied to the FES. Integrating FES with a robotic arm support system into one hybrid neuroprosthesis is attractive because the mechanical device can complement muscle action and increase rehabilitation's repeatability and accuracy rate. The integration of FES and robotic arms is a promising approach in the future. This article reviews the state of the art regarding motor rehabilitation using functional electrical stimulation (FES) devices and robotic arms for the upper limbs of post-stroke patients. A narrative review was done through a literature search using the IEEE-Xplore, Scopus, and PubMed databases. Nine different rehabilitation system articles were identified. The selected systems were compared critically by considering the design and actuators, components, technological aspects, and technological challenges that could be developed in the future. This article also examines the development of HRI and emerging research trends in HRI-based rehabilitation.
... It reveals that EDA is an effective indicator for quantitative evaluation of sympathetic nerve function. 1 Skin-related diseases often lead to dehydration of the affected area 2 and abnormal peripheral nerve function, resulting in significant fluctuations in EDA. While skin biopsy is the gold standard for diagnosing the morphology of peripheral nerves and some dermatoses in the clinic, the analysis of EDA can provide a non-invasive diagnostic basis for sudomotor disorders. ...
... Human sweat glands are categorized into eccrine and apocrine glands. Apocrine glands are only sparsely distributed in select areas such as the axillae, and their activities are not highly pertinent to EDA. 1 Eccrine sweat glands are distributed throughout the body and are innervated by the sympathetic nervous system. The nerve control of sweating originates from the anterior hypothalamus, descends through the brainstem, forms synapses with the mediolateral cell columns of the spinal cord, and connects the preganglionic sympathetic efferent nerve fibers. ...
... The epidermal layer is represented by the resistance Rsc in parallel with the capacitance Csc, while the dermis is represented by the resistance Rs, connected to the epidermal layer. 1 However, it has been noted that the barrier function of the stratum corneum in regions with sweat gland and hair follicle outlets can be weakened by secretions containing water, potentially creating a preferential pathway for current flow under low frequency and low voltage conditions, leading to non-uniform distribution of current density within the skin. ...
Article
Electrodermal activity (EDA) refers to the changes in electrical potential recorded on the skin surface, which mainly reflect the electrical properties of the skin and sympathetic nerve activity reflected by sweat secretion. Various dermatoses impair the skin barrier and alter the function of innervated nerves, resulting in significant fluctuations in EDA. This manuscript aims to provide a comprehensive overview of the molecular mechanisms underlying representative skin symptoms related to inflammation, fibrosis, and sweat gland disorders, and to explore the correlation of these mechanisms with EDA components. The physiological significance of EDA is discussed to provide a new perspective for the clinical application of EDA.
... Fluid from underlying skin are good electrical conductors. One challenge is the insensitivity associated with the electrical signal linking the skin (Abe & Nishizawaa, 2021). At certain conditions which affects wearable devices due to electrical properties of the underlying skin. ...
... Chemical impedance and interaction: The skin serves as a barrier to transport of chemicals. The superficial layers of the epidermis are the major domains to chemical impedance of the skin layer (Heikenfeld et al., 2018;Abe & Nishizawaa, 2021). The skin also contaminates analyte concentrations during the collection of sweat, blood and interstitial fluid samples (Heikenfeld et al., 2018). ...
Article
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Wearable Internet-of-things (IoTs) monitoring systems provide several benefits that tend to secure diagnostic connection with health care providers thereby potentially influencing people’s orientation to accessing healthcare services. The goal of this overview is to explore the challenges associated with wearable Internet-of-Things (IoT) monitoring Systems for e-health. Wearable devices are integrated with IoT to enable health managers provide hospital setting to many localities, groups and individuals. Thus, wearable devices become imminent infrastructure for IoT deployment. To develop wearable-based IoT ecosystem, enabling techniques, architecture and other matters relating to IoT should be investigated and then their integration should be embraced. In this paper, we look at the challenges connected with wearable health monitors by system functionality, enabling technologies, security and privacy issues, and the prospect of integration of wearable technology and applications. Finally, we envisage that with the growth of e-health ideas, wearable devices will perform superior role in the arena of health care service and become well integrated into patients’ regular lives. Device interoperability, secured connection/communication to mitigate intermittent signal outages for point-to-point networks, providing advocacy in its usage among the generality of the populace and its deployment in requisite institutions – government and private, are some declared recommendations.
... Skin is a multi-layer dielectric medium with different electrical properties related to structural characteristics [1], chemical composition variations [2], and different biological functions, in which the assessment of each layer leads to a better understanding of its pathophysiology. As a common modality to measure dielectric characteristics in biological tissue, bioelectrical impedance spectroscopy (BIS) is wellknown as low-cost, sensitive to chemical composition, and portable for clinical measurement, which is capable of measuring the electrical conductivity of the human skin layer [3]. ...
... In this study, the three objectives have been proposed for skin layer classification of conductivity change in skin layer, which are (1) to predict the validation accuracy of dermis classification by implementing feedforward neural network (FNN), (2) to minimize the unnecessary training data of FNN using four impedance inputs , which are the magnitude input | | , phase angle input , resistance input , and reactance input , and (3) to select the frequency pair ℎ . ...
Article
Full-text available
Conductivity change in skin layers has been classified by source indicator o k ( k =1: Stratum corneum, k =2: Epidermis, k =3: Dermis, k =4: Fat, and k =5: Stratum corneum + Epidermis) trained from feedforward neural network (FNN) in bioelectrical impedance spectroscopy (BIS). In BIS studies, treating the skin as a bulk, limits the differentiation of conductivity changes in individual skin layers, however skin layer classification using FNN shows promise in accurately categorizing skin layers, which is essential for predicting source indicators o k and initiating skin dielectric characteristics diagnosis. The o k is trained by three main conceptual points which are (i) implementing FNN for predicting k in conductivity change, (ii) profiling four impedance inputs α ξ consisting of magnitude input α | z |, phase angle input α θ , resistance input α R , and reactance input α x for filtering nonessential input, and (iii) selecting low and high frequency pair ( f r l h ) (frlh)(f_{r}^{lh}) by distribution of relaxation time (DRT) for eliminating parasitic noise effect. The training data set of FNN is generated to obtain the α ξ ∈ R 10×17×10 by 10,200 cases by simulation under configuration and measurement parameters. The trained skin layer classification is validated through experiments with porcine skin under various sodium chloride (NaCl) solutions C NaCl = {15, 20, 25, 30, 35}[mM] in the dermis layer. FNN successfully classified conductivity change in the dermis layer from experiment with accuracy of 90.6% for the bipolar set-up at f 6 l h = 10 & 100 [ kHz] f6lh=10&100[kHz]f_{6}^{lh}=10\,\And 100\,[kHz] and with the same accuracy for the tetrapolar at f 8 l h = 35 & 100 [ kHz] f8lh=35&100[kHz]f_{8}^{lh}=35\,\And 100\,[kHz] . The measurement noise and systematic error in the experimental results are minimized by the proposed method using the feature extraction based on α ξ at f r l h frlhf_{r}^{lh} .