Figure 1 - available from: Scientific Reports
This content is subject to copyright. Terms and conditions apply.
Three types of EEG electrodes on human skin. On the left, a relatively flat hydrogel electrode, the PEDOT polymer electrode (4 mm diameter) in the middle and on the right side a Ag/AgCl cup electrode with conductive gel (photograph created by Jürgen Bergeler).
Source publication
We invented the first non-metallic, self-adhesive and dry biosignalling electrode. The PEDOT polymer electrode changes its aggregate state and conductivity by a light curing procedure. The electrode can be applied as a gel underneath hair without shaving. With the aid of blue light, the electrode can be hardened within a few seconds at the desired...
Contexts in source publication
Context 1
... directly on the skin with blue light, the electrode is highly conductive and stable but still nearly invisible. This makes the elec- trode ideal for everyday use, for example, in the case of epilepsy diagnostics or stroke prevention. The miniatur- ized flat and smooth characteristics of the electrodes make them extremely comfortable for the user (Fig. 1). This is important to prevent pressure marks in the case of young children, those in the neonatal intensive care unit or for sleep diagnostics. The electrode can easily be removed by the application of pressure from two sides. We performed mechanical measurements with this new electrode material (Figs 7-9). The high degree of variance ...
Context 2
... We performed mechanical measurements with this new electrode material (Figs 7-9). The high degree of variance may be due to the curing with a dental handheld blue LED light. A sample size of 10 × 2 × 20 mm was necessary for the experimental design. For application on the human skin, the overall size of the electrodes is substantially smaller (Fig. 1). The low forces required for material destruction ensure the prevention of skin injury. On the other hand, the strength is high enough for proper use and adhesion on the skin. Furthermore, these material characteristics enable a pain-free removal of the PEDOT polymer electrodes after use. Residues, if present, can easily be brushed ...
Similar publications
Despite complaints of difficulties in waking socioemotional functioning by individuals with insomnia, only a few studies have investigated emotion processing performance in this group. Additionally, the role of sleep in socioemotional processing has not been investigated extensively nor using quantitative measures of sleep. Individuals with insomni...
Sleep is a key phenomenon to both understanding, diagnosing and treatment of many illnesses, as well as for studying health and well being in general. Today, the only widely accepted method for clinically monitoring sleep is the polysomnography (PSG), which is, however, both expensive to perform and influences the sleep. This has led to investigati...
Citations
... Furthermore, Camp et al. proposed an electrode made from PEDOT polymer for the monitoring of EEG signals. As an alternative to standard EEG electrodes that lose conductivity when they are dried, the proposed electrodes are self-adhesive and do not lose conductivity after drying (de Camp et al., 2018). A new system for non-invasive, portable, and functional near-infrared spectroscopy (fNIRS) has been proposed by Saikia et al. to measure the hemodynamic response of the prefrontal cortex using fNIRS. ...
... They directly record current on the scalp and convert it into voltage, which has the advantage of high signal amplitude, but also has the disadvantage of large noise interference. Capacitive mode skin electrodes generally refer to electrodes made of semiconductor materials such as carbon nanomaterials, metal oxides, biomembranes, and conductive polymers [14][15][16]. The working principle of these electrodes is based on the capacitor mode, which records EEG signals by converting the ion current into an electronic current, which reduces the interference noise of electrical signals but also has the disadvantage of low-amplitude signals. ...
Scalp electroencephalogram (EEG) electrodes are non-invasive and directly connect the human brain with the external world; however, established dry and wet electrodes coated with conductive gels have the disadvantage of high scalp-contact resistance (Rscalp) and poor wearing comfort, respectively. In this study, a vertical few-layer graphene (FLG)/TiO2 nanotube array electrode combined with highly industrialized chemical vapor deposition and anodization technologies was developed to record EEG signals and control peripherals. The FLG/TiO2 electrode recorded scalp EEG signals in non-contact capacitive mode using a saturated aqueous NaCl solution or sweat as the electronic medium. The electrode can be worn quickly and comfortably, and the Rscalp placed in the hair area was only 13.4 kΩ; the spontaneous EEG had a high signal-to-noise ratio (SNR) of 76.8 dB with excellent stability in nearly 2 h of continuous use and a month of long-term use. In addition, the EEG electrode successfully recorded visually evoked EEG signals in non-training mode. For the 16 stimulation frequencies of the steady-state visually evoked potential, the electrode fed back the evoked EEG signals with an SNR of > 5.9 dB. Additionally, it allowed an online control robot arm to write letters with an average accuracy of 90.3%. The FLG/TiO2 electrode has the advantages of wearing comfort, low Rscalp, and excellent stability and is suitable for use in biological research and medical care, such as brain-controlled peripherals and long-term EEG collection for disabled people with impaired mobility.
... Electrode. 1 Magnetic resonance tomograph. A 3 Tesla MRI scanner (Siemens Magnetom Verio) was used to test the electrode. ...
The PEDOT polymer electrode is a metal-free electrode, consisting of an acrylate (dental composite) and the conductive polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The electrode is applied as gel onto the skin and cured with blue light for 10–20 s in order to achieve a conductive bond to the skin. The electrodes are used in combination with polymer cables consisting of a textile backbone and PEDOT:PSS. To test this new electrode and cable type under different conditions we designed two stress-tests: highly sensitive temperature recordings within a head phantom during Magnetic Resonance Imaging (MRI) and long-term stability inside a climate chamber with high humidity. To study the physical behavior inside the strong magnetic field (3 Tesla), the PEDOT polymer electrode was attached to an agarose head-phantom inside a magnetic resonance tomograph during an image sequence. MRI-safe temperature sensors were placed nearby in order to measure possible heating effects. In comparison to a metal cable, nearly no rise in temperature could be observed if the electrode was used in combination with a conductive textile cable. Furthermore, the electrode showed stable impedance values inside a climate chamber for 4 consecutive days. These results pave the way for testing the PEDOT polymer electrode as biosignal recording electrode during MRI, especially for cardio MRI and Electroencephalography in combination with functional MRI (EEG–fMRI).
... The use of non-invasive brain stimulation is widespread in studies of neuroscience [125]. The non-invasive neuroscience methods are: transcranial magnetic stimulation (TMS), electroencephalography (EEG), magnetoencephalography (MEG), positron emission tomography (PET), functional magnetic resonance imaging (fMRI), near infrared spectroscopy (NIRS), diffusion tensor imaging (DTI), steady-state topography (SST), and others [126][127][128][129][130][131][132][133][134]. These non-invasive neuroscience methods are described in detail in Section 3. In the future, the authors of this article plan to analyze invasive neuroscience methods, too. ...
Affective, emotional, and physiological states (AFFECT) detection and recognition by capturing human signals is a fast-growing area, which has been applied across numerous domains. The research aim is to review publications on how techniques that use brain and biometric sensors can be used for AFFECT recognition, consolidate the findings, provide a rationale for the current methods, compare the effectiveness of existing methods, and quantify how likely they are to address the issues/challenges in the field. In efforts to achieve the key goals of Society 5.0, Industry 5.0, and human-centered design better, the recognition of emotional, affective, and physiological states is progressively becoming an important matter and offers tremendous growth of knowledge and progress in these and other related fields. In this research, a review of AFFECT recognition brain and biometric sensors, methods, and applications was performed, based on Plutchik’s wheel of emotions. Due to the immense variety of existing sensors and sensing systems, this study aimed to provide an analysis of the available sensors that can be used to define human AFFECT, and to classify them based on the type of sensing area and their efficiency in real implementations. Based on statistical and multiple criteria analysis across 169 nations, our outcomes introduce a connection between a nation’s success, its number of Web of Science articles published, and its frequency of citation on AFFECT recognition. The principal conclusions present how this research contributes to the big picture in the field under analysis and explore forthcoming study trends.
... 94 ) and new, more widely and easily applicable EEG electrodes have also been developed (e.g. dry, non-metallic, self-adhesive electrodes 95 ). ...
Sleep research greatly benefits from comparative studies to understand the underlying physiological and environmental factors affecting the different features of sleep, also informing us about the possible evolutionary changes shaping them. Recently, the domestic dog became an exceedingly valuable model species in sleep studies, as the use of non-invasive polysomnography methodologies enables direct comparison with human sleep data. In this study, we applied the same polysomnography protocol to record the sleep of dog’s closest wild relative, the wolf. We measured the sleep of seven captive (six young and one senior), extensively socialized wolves using a fully non-invasive sleep EEG methodology, originally developed for family dogs. We provide the first descriptive analysis of the sleep macrostructure and NREM spectral power density of wolves using a completely non-invasive methodology. For (non-statistical) comparison, we included the same sleep data of similarly aged dogs. Although our sample size was inadequate to perform statistical analyses, we suggest that it may form the basis of an international, multi-site collection of similar samples using our methodology, allowing for generalizable, unbiased conclusions. As we managed to register both macrostructural and spectral sleep data, our procedure appears to be suitable for collecting valid data in other species too, increasing the comparability of non-invasive sleep studies.
... A recent report demonstrated a PEDOT-based electrode that is cured, by illumination, directly onto a patient's scalp and was used to demonstrate EEG recordings on freely moving animals. 80 Additionally, electrochemical PEDOT:PSS deposition has allowed the fabrication of conducting strings, with the potential to easily incorporate EEG into wearables. 81 PEDOT:PSS dry microneedle electrodes have also been shown to reduce skin impedance compared to conventional wet electrodes. ...
Electronically interfacing with the nervous system for the purposes of health diagnostics and therapy, sports performance monitoring, or device control has been a subject of intense academic and industrial research for decades. This trend has only increased in recent years, with numerous high-profile research initiatives and commercial endeavors. An important research theme has emerged as a result, which is the incorporation of semiconducting polymers in various devices that communicate with the nervous system─from wearable brain-monitoring caps to penetrating implantable microelectrodes. This has been driven by the potential of this broad class of materials to improve the electrical and mechanical properties of the tissue-device interface, along with possibilities for increased biocompatibility. In this review we first begin with a tutorial on neural interfacing, by reviewing the basics of nervous system function, device physics, and neuroelectrophysiological techniques and their demands, and finally we give a brief perspective on how material improvements can address current deficiencies in this system. The second part is a detailed review of past work on semiconducting polymers, covering electrical properties, structure, synthesis, and processing.
... PEDOT: PSS, a well-known conducting polymer, can be easily processed into films using traditional techniques such as inkjet printing, brush printing, and screen printing. Recently, PEDOT:PSS has been successfully integrated into textiles (cotton, polyester, nylon, etc.) [76][77][78][79][80] or paper-based materials [81]. PEDOT:PSS coatings were used on the surface to enhance the electrical conductivity and reduce EII. ...
Bioelectrical or electrophysiological signals generated by living cells or tissues during daily physiological activities are closely related to the state of the body and organ functions, and therefore are widely used in clinical diagnosis, health monitoring, intelligent control and human-computer interaction. Ag/AgCl electrodes with wet conductive gels are widely used to pick up these bioelectrical signals using electrodes and record them in the form of electroencephalograms, electrocardiograms, electromyography, electrooculograms, etc. However, the inconvenience, instability and infection problems resulting from the use of gel with Ag/AgCl wet electrodes can’t meet the needs of long-term signal acquisition, especially in wearable applications. Hence, focus has shifted toward the study of dry electrodes that can work without gels or adhesives. In this paper, a retrospective overview of the development of dry electrodes used for monitoring bioelectrical signals is provided, including the sensing principles, material selection, device preparation, and measurement performance. In addition, the challenges regarding the limitations of materials, fabrication technologies and wearable performance of dry electrodes are discussed. Finally, the development obstacles and application advantages of different dry electrodes are analyzed to make a comparison and reveal research directions for future studies.
... Another important factor is the miniaturization of EEG amplifiers as well as comfortable electrodes that are as small as possible. For our future studies with a higher number of electrodes, we developed light curing polymer electrodes (De Camp, Kalinka & Bergeler, 2018). Furthermore, in a current project, the amplifier with eight Channels will be miniaturized to 9 × 12 mm. ...
As has been hypothesized more than 20 years ago, data derived from Electroencephalography (EEG) measurements can be used to distinguish between behavioral states associated with animal welfare. In our current study we found a high degree of correlation between the modulation index of phase related amplitude changes in the EEG of horses (n = 6 measurements with three different horses, mare and gelding) and their facial expression, measured by the use of the horse grimace scale. Furthermore, the pattern of phase amplitude coupling (PAC) was significantly different between a rest condition and a stress condition in horses. This pilot study paves the way for a possible use of EEG derived PAC as an objective tool for the assessment of animal welfare. Beyond that, the method might be useful to assess welfare aspects in the clinical setting for human patients, as for example in the neonatal intensive care unit.
... Another important factor is the miniaturization of EEG amplifiers as well as comfortable electrodes that are as small as possible. For our future studies with a higher number of electrodes, we developed light curing polymer electrodes (De Camp, Kalinka & Bergeler, 2018). Furthermore, in a current project, the amplifier with eight Channels will be miniaturized to 9 × 12 mm. ...
As has been hypothesized more than 20 years ago, data derived from Electroencephalography (EEG) measurements can be used to distinguish between behavioral states associated with animal welfare. In our current study we found a high degree of correlation between the modulation index of phase related amplitude changes in the EEG of horses ( n = 6 measurements with three different horses, mare and gelding) and their facial expression, measured by the use of the horse grimace scale. Furthermore, the pattern of phase amplitude coupling (PAC) was significantly different between a rest condition and a stress condition in horses. This pilot study paves the way for a possible use of EEG derived PAC as an objective tool for the assessment of animal welfare. Beyond that, the method might be useful to assess welfare aspects in the clinical setting for human patients, as for example in the neonatal intensive care unit.
... Current VR headsets provide a logical, convenient, and unobtrusive framework for mounting EEG sensors. Additionally, recent advances in dry/wireless EEG electrodes (Wang et al., 2016;Zander et al., 2017;de Camp et al., 2018;Lee et al., 2018;Kam et al., 2019) and motion artifact suppression (Gwin et al., 2010;Daly et al., 2015;Kline et al., 2015;Snyder et al., 2015;Arad et al., 2018) further increase the practicality of integrating EEG into VR headsets. ...
With the recent surge of affordable, high-performance virtual reality (VR) headsets, there is unlimited potential for applications ranging from education, to training, to entertainment, to fitness and beyond. As these interfaces continue to evolve, passive user-state monitoring can play a key role in expanding the immersive VR experience, and tracking activity for user well-being. By recording physiological signals such as the electroencephalogram (EEG) during use of a VR device, the user's interactions in the virtual environment could be adapted in real-time based on the user's cognitive state. Current VR headsets provide a logical, convenient, and unobtrusive framework for mounting EEG sensors. The present study evaluates the feasibility of passively monitoring cognitive workload via EEG while performing a classical n-back task in an interactive VR environment. Data were collected from 15 participants and the spatio-spectral EEG features were analyzed with respect to task performance. The results indicate that scalp measurements of electrical activity can effectively discriminate three workload levels, even after suppression of a co-varying high-frequency activity.
