Adhesive Electrodes Research Articles

Batch Fabrication of Paper-Based Waterproof Flexible Pressure Sensors Enabled by Roll-to-Roll Lamination.

Paper is a green and porous material that has been widely used in flexible pressure sensors due to its flexibility, renewability, and lightness. However, these sensors are often susceptible to environmental factors such as moisture and chemicals, leading to degradation or failure of their reliability for practical applications. Herein, we present a roll-to-roll lamination strategy for batch fabrication of paper-based waterproof flexible pressure sensors with good consistency based on single-walled carbon nanotube (SWCNT) coated tissue paper pieces. The pieces are sandwiched between poly(ethylene glycol) terephthalate (PET) films with a hot melt adhesive and screen-printed electrodes, and the layers are bonded reliably using roll-to-roll lamination. This process allows for the rapid fabrication of a batch of waterproof, flexible pressure sensors with high stability over 5000 loading/unloading cycles, an ultrashort response time of 8 ms, and a wide measurement range (450 kPa). These features enable our sensor to be utilized for human physiological signal detection, motion tracking, and drowning detection. Furthermore, the process also allows for the fabrication of sensor arrays for spatial pressure mapping and real-time human-machine interaction, expanding the application field of paper-based pressure sensors. This proposed batch fabrication strategy greatly enhances the consistency and reliability of paper-based pressure sensors, demonstrating endless possibilities for paper-based pressure sensors to be used for various applications.

Continuous intraoperative neuromonitoring of the recurrent laryngeal nerve during lung operations.

The recurrent laryngeal nerve (RLN), especially on the left side, is particularly vulnerable during lung operations. Therefore, continuous intraoperative neuromonitoring (cIONM) would be desirable. With the use of a double-lumen tube (DLT) for single-lung ventilation, there is some uncertainty where the recording electrode should be positioned. The aim of this study was to assess the feasibility of this technique and to predict the ideal position of a single recording electrode. Patients scheduled to undergo left thoracotomy due to pulmonary pathologies, two adhesive electrodes were affixed consecutively above the proximal cuff of the DLT prior to intubation for a precise location of the recording from the vocal cords. Following thoracotomy, the vagus nerve alongside the aortic arch was exposed. A continuous stimulation probe (Saxophone® electrode, Dr. Langer Medical, Waldkirch, Germany) was placed around the nerve. The signals of the respective electrode were recorded and analyzed with regard to previously defined limits of positive signaling. Strong signals with an amplitude of at least 165 µV were recorded in 18 of 20 patients. In these patients 100% of the signals were recorded via the distally located electrode. An additional signal was recorded via the proximal electrode in four patients. cIONM was found to be a safe and reproducible technique. The described technique enables the use of cIONM of the RLN throughout the entire course of the surgical procedure.

Infant heart rate estimation based on non-contact UV photoplethysmography

Non-contact cardio signal monitoring is a requisite for premature infants, as adhesive sensors and electrodes such as that for an electrocardiogram can damage the epidermis. Many types of research on infants in the newborn intensive care unit (NICU) are still in their early stages with many challenges. Therefore, this study aims to use a digital camera as a non-contact photoplethysmography imaging method to measure and compare the heart rate from two experiments (without/with ultraviolet rays (UV)) inside the intensive care unit. The two experiments (without/with UV) rays yielded promising results in comparison with the reference measurements obtained from ten infants. The results reveal a robust correlation using the pearson correlation coefficients (PCC) of 0.99 (for without UV) and 0.96 (for with UV). Also, the spearman correlation coefficient (SCC) test of 0.97 and 0.95 for two experiments, respectively Bland–Altman analysis revealed a strong relationship between measured and reference readings from without and with UV. The experimental results obtained a low error rate for mean absolute error (MAE), and root mean squared error (RMSE). Therefore, this work presents a new aspect of non-contact monitoring, showing promising performance for upcoming medical applications.

#4657 COMPARISON OF TWO BIOIMPEDANCE SPECTROSCOPY DEVICES: A PRACTICAL STEP FORWARD ON THE WAY TO DAILY BIOIMPEDANCE MEASUREMENTS FOR DIALYSIS PATIENTS

Abstract Background and Aims Bioimpedance spectroscopy (BIS) is a non-invasive diagnostic tool to assess volume status and body composition through the measurement of voltage drops in alternating currents and subsequent extrapolation of extracellular (R0), intracellular (Ri), and total body (RInf) resistances. Currently available devices mostly rely on disposable electrodes and require supine body position. Here we tested whether a new, more versatile BIS device with reusable electrodes matches an established system in various setups, aiming to enable daily BIS-measurements in the near future. Method Two BIS devices (“Cella” and the “Body Composition Monitor” [BCM]) were compared both with four resistance testboxes (circuit boards with resistors and capacitors simulating different body conditions) and in 40 healthy volunteers. In-vivo comparisons included supine hand-to-foot (HF) reference measurements with adhesive disposable electrodes and hand-to-hand (HH) measurements with adhesive disposable and prototype reusable electrode sets (Figure 1). Results Analyses of testboxes were reproducible in both devices (intra-device coefficients of variation <1%). Mean differences from testbox components were similar and small for R0 (2-3 Ohm) but not for Ri, where Cella was off by 101 Ohm compared to the BCM's 29 Ohm in a testbox designed with a deliberately low R0/Ri ratio. In-vivo, HF measurements with disposable electrodes differed significantly between both devices (p < 0.001). Prototype reusable HH electrodes exhibited a bias towards larger resistances than HF measurements (R0: 738.36 Ohm vs. 643.09 Ohm; Ri: 1508.18 Ohm vs. 1257.17 Ohm; RInf 500.03 vs. 423.81 Ohm, respectively) and the HH/HF ratio varied between 1.0-1.4 (R0 and RInf) and 0.9-1.6 (Ri). Conclusion While the Cella BIS device was shown to produce results with comparable consistency to the BCM in-vivo, the latter measured more accurately under testbox conditions. Accuracy of in-vivo measurements could not be determined for lack of gold-standard measurements. Implementation of HH reusable electrodes will require per-patient calibration against HF measurements due to the large inter-patient fluctuations in the HH/HF ratio. We recommend further longitudinal analyses of intra-patient HH/HF ratios to investigate long-term variabilities.

Feasibility and safety of a single patch-based device for 30 days of continuous, uninterrupted ambulatory ecg monitoring

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): iRhythm Technologies, Inc. Background 14-day continuous ambulatory ECG monitoring (AEM) has been shown to have superior diagnostic yield to traditional 48-hour Holter monitoring for paroxysmal or undiagnosed atrial fibrillation and a wide range of clinical arrhythmias. 30-day recordings are typically from event recorders (non-continuous) and require frequent adhesive/electrode and battery replacement, all of which can impair patient compliance, wear time, and diagnostic yield. A new, uninterrupted patch-based AEM with next-generation breathable adhesive, storage, and battery life has received FDA clearance for 14-day wear. We evaluated the safety and feasibility of using this device for 30-days of continuous AEM. Methods We enrolled 30 participants with indications for AEM and applied a single Zio Monitor device for 30-days and analyzed wear time, analyzable time, and diagnostic yield, compared to with Zio Monitor 14-day use and with our standard, previous-generation product. Results In the cohort (76% female, 35% non-white, age 37±9 years, BMI 30.6±6.8), the median wear time was 29 continuous days (IQR 28-30) with no device changeouts and no clinically significant skin irritation. Although median analyzable times were high and similar across the previous (XT) and next-generation (Monitor) devices, the mean was significantly higher with Monitor, indicating fewer outliers that experienced premature termination of wear time. Arrhythmia yield (AF ≥30 sec, SVT ≥90 bpm & ≥4 bt, VT ≥100 bpm & ≥4 bt, inc PVT/TdP/VF, Pause ≥3 s, and/or AVB (any 2nd Deg or CHB) was significantly higher with the new Zio Monitor Device compared to Zio XT (80.9% vs 77.1%; p=0.017). Conclusion The application of a single, continuous, patch-based AEM for 30 days without adhesive (electrode) or battery replacement is feasible and safe. Analyzable time was high for 14-day and 30-day wear. The uninterrupted wear time and high compliance could lead to higher diagnostic yield than with traditional 30-day event recorders.

Very-early detection of atrial fibrillation in patients after ablation evaluated by a home-based wearable ECG-patch

Abstract Funding Acknowledgements Type of funding sources: None. Background Evaluation of atrial fibrillation (AF) recurrence after AF ablation has been validated by routine ECG and ambulatory 24-h Holter monitoring after a 3-month blanking period. However, assessment of heart rhythm after AF ablation, conducted with the use of intermittent or continuous recording systems, has shown that early recurrences are common, often asymptomatic, and may predict late AF recurrences. The E-Patch (Bio Tel Heart) is an innovative thin, single-use adhesive electrode with extended continuous ECG monitoring for up to 120 hours. Aim To describe and characterize predictors of early AF recurrence based on the very- early blanking period after AF ablation. Methods Single-centre, prospective, longitudinal study, including consecutive patients (P), 24 hours after AF ablation, monitored with the E- patch. Baseline characteristics at the time of AF ablation as well as the effectiveness of the device in continuously recording within 5 days after ablation were analyzed. A logistic regression model was used to derive predictors of very-early AF recurrence. Results A total of 40P were included (60% male, 62±9 years). AF ablation was performed with radiofrequency energy in 23P and with cryoballoon in 17P. All P were in sinus rhythm at the beginning of the E- patch recording. The mean number of hours of recording was 113±18. During E-patch recording 11P (27.5%) presented AF (AF burden 27.4% of the recording, IQR 5.5-32.3%) and 7P (18%) had sinus pauses. In a multivariate logistic regression model, a higher CHADS2VAS2C index and a higher average heart were associated with an OR 3.0 (95% CI 1.13-8.1, p = 0.027) and OR 1.23 (95% CI 1.02-1.48, p = 0.025) for AF recurrence, respectively. No significant differences were found between ablation modalities. There were no complaints about discomfort in the use of the device, and there were no artefacts compromising the quality or the interpretation. Conclusions The use of the E-patch recording very-early after AF ablation is effective for AF detection. A higher CHADS2VAS2C index and average heart appear to be significantly predictive of very-early AF recurrence post-ablation.

ECG-patch assessment of atrial fibrillation during the very-early blanking predicts late blanking period recurrence: preliminary data from a prospective registry

Abstract Funding Acknowledgements Type of funding sources: None. Background Ablation of atrial fibrillation (AF) is a procedure that causes significant atrial tissue lesions, with transient, albeit significant tissue oedema and inflammation. These mechanisms may trigger early rhythm abnormalities that do not necessarily correlate with future arrhythmias, and, therefore, evaluation of AF recurrence is currently validated by routine ECG and ambulatory 24h Holter monitoring, only after a 3-month blanking period. However, recent data have shown that AF episodes occurring during the blanking period are common and may predict late AF recurrences. The E-Patch (Bio Tel Heart) is an innovative, thin single-use adhesive electrode with extended continuous ECG monitoring for up to 120h. Aim To assess if continuous extended monitoring in the very-early blanking period can be associated with event recorder data performed in the late blanking period after AF ablation. Methods Single-centre, prospective, longitudinal study, including consecutive patients (P) 24h after AF ablation, monitored with the E-patch. The effectiveness of the device in continuously recording within 5 days after ablation was analyzed, as well as the occurrence of AF episodes during an external 7- day loop-recorder, obtained in the 2nd-month post-ablation. Results A total of 30P were included (57% male, 63±8 years). AF ablation was performed with radiofrequency (RF) energy in 14P and with a balloon of cryoenergy in 16P. All P were in sinus rhythm at the beginning of the recording. The mean number of hours of recording was 113±16, with no discomfort complaints in the use of the device or interpretation artefacts. During the E-patch monitoring, a total of 10P (33%) presented AF (AF burden 6.8% of the recording, IQR 3.0-20%). All 30P underwent an external loop recorder for 7 days 2 months post-ablation, with 40% showing AF periods (> 30 seconds duration). All 10P that had AF detection in the very-early E-patch recording had also recurrence in the 2 nd month of extended 7-day continuous recording. Very- early AF detection had a sensitivity of 83.3% and a specificity of 100% to detect late blanking period AF (ROC 0.916±0.06; 95%CI 080-1.0). Conclusions The use of the E-patch very-early after AF ablation is effective for AF detection and is highly predictive of AF recurrence in the late blanking period. These findings require validation in larger studies to assess the potential of very-early assessment in the determination of a higher risk for AF recurrence.

Temperature-Triggered Adhesive Bioelectric Electrodes with Long-Term Dynamic Stability and Reusability.

Bioelectric electrodes with low modulus and high adhesion have been intensively pursued, as they afford conformal and strong bonding at skin-electrode interface to improve the fidelity and stability of electrophysiological signals. However, during detachment, tough adhesion can cause pain or skin allergy; worse still, the soft electrodes can suffer damage due to excessive stretch/torsion, hampering long-term, dynamic, and multiple uses. Herein, a bioelectric electrode is proposed by transferring silver nanowires (AgNWs) network to the surface of bistable adhesive polymer (BAP). The phase transition temperature of BAP is tuned to be slightly below skin temperature at 30 °C. Triggered by skin heat, the BAP electrode achieves low modulus and high adhesion within seconds, allowing robust skin-electrode interface under dry, wet, and body-moving conditions. Ice bag treatment can dramatically stiffen the electrode and reduce the adhesion, which allows painless detachment and avoids electrode damage. Meanwhile, the AgNWs network with biaxial wrinkled microstructure remarkably promotes the electro-mechanical stability of the BAP electrode. The BAP electrode successfully combines long-term (7 days) and dynamic (body movements, sweat, underwater) stability, reusability (at least ten times), and minimized skin irritation during electrophysiological monitoring. The high signal-to-noise ratio and dynamic stability are demonstrated in the application of piano-playing training.

Asymmetric “Janus” Biogel for Human‐Machine Interfaces

AbstractHuman‐machine interfaces (HMIs) are essential for effective communication between machines and tissues. However, mechanical and biological mismatches, along with weak adhesion between rigid electronic devices and soft tissue, often cause unreliable responses and affect the signal recording of HMIs. In this study, an asymmetrical “Janus” biogel patch with one side firmly adhering to tissues, and the other surface having little adhesion and minimal interactions with surrounding environments has been developed. A series of analytical, mechanical, and electrical tests are performed to investigate the “Janus” biogel patch as a functional and biocompatible HMI. It is found that the gallic acid‐modified gelatin adhesive surface on one side exhibits body temperature‐dependent tissue adhesion, enabling low modulus and seamless skin contact. The other side is a tough gelatin/glycerol gel layer, which is thermally welded into the adhesive layer and functions as an encapsulant to prevent external interference due to adhesion. The encapsulation layer also exhibits a low friction coefficient when wet and proves to be a reliable alternative barrier to conventional encapsulation materials. The scientific insights and engineering principles revealed in this type of “Janus” biogel will be applicable to a broad range of biomedical applications, such as epidermal adhesive electrodes or skin‐adhesive wearable devices.

36 Validation of a smart textile device for heart rate variability in horses at rest

Electrocardiography (ECG) and associated heart rate variability (HRV) are important in the assessment of equine cardiac health, welfare, and performance. Smart textiles have gained popularity as a method to replace standard adhesive electrodes, though limited validation work has been conducted, particularly in veterinary species. Therefore, the objective of this study was to assess the validity of a smart textile ECG device for heart rate (HR) and HRV assessment in horses at rest. Seven mixed-breed, healthy competition horses were recruited for a controlled clinical trial. Horses wore a smart textile ECG device (Skiin Equine) and a standard telemetric device (Televet 100) equipped with adhesive electrodes for simultaneous ECG recordings while unrestrained in stalls for 15 min. Raw data from both devices were analyzed using Kubios Premium to calculate HR and HRV metrics [average and standard deviationof RR intervals, the axial and perpendicular dispersions from the line of identity from the Poincaré plot (SD1 and SD2, respectively), root mean square of successive differences (RMSSD), percentage of successive RR interval differences (pNN50), and oscillations in the very-low frequency (VLF), low-frequency (LF), and high-frequency (HF) bands]. Data were compared using a Bland-Altman analysis with Pearson coefficients. Excellent agreement with small biases were observed between the 2 devices and perfect correlations (r = 1.0, P < 0.0001 for all) were found for all metrics assessed. This study demonstrates that a novel smart textile device can be used interchangeably with the standard telemetric system for assessment of HR and HRV in resting horses.

A supramolecular gel-elastomer system for soft iontronic adhesives

Electroadhesion provides a promising route to augment robotic functionalities with continuous, astrictive, and reversible adhesion force. However, the lack of suitable conductive/dielectric materials and processing capabilities have impeded the integration of electroadhesive modules into soft robots requiring both mechanical compliance and robustness. We present herein an iontronic adhesive based on a dynamically crosslinked gel-elastomer system, including an ionic organohydrogel as adhesive electrodes and a resilient polyurethane with high electrostatic energy density as dielectric layers. Through supramolecular design and synthesis, the dual-material system exhibits cohesive heterolayer bonding and autonomous self-healing from damages. Iontronic soft grippers that seamlessly integrate actuation, adhesive prehension, and exteroceptive sensation are devised via additive manufacturing. The grippers can capture soft and deformable items, bear high payload under reduced voltage input, and rapidly release foreign objects in contrast to electroadhesives. Our materials and iontronic mechanisms pave the way for future advancement in adhesive-enhanced multifunctional soft devices.

Modeling the Design Characteristics of Woven Textile Electrodes for long-Term ECG Monitoring.

An electrocardiograph records the periodic voltage generated by the heart over time. There is growing demand to continuously monitor the ECG for proactive health care and human performance optimization. To meet this demand, new conductive textile electrodes are being developed which offer an attractive alternative to adhesive gel electrodes but they come with their own challenges. The key challenge with textile electrodes is that the relationship between the manufacturing parameters and the ECG measurement is not well understood, making design an iterative process without the ability to prospectively develop woven electrodes with optimized performance. Here we address this challenge by applying the traditional skin-electrode interface circuit model to woven electrodes by constructing a parameterized model of the ECG system. Then the unknown parameters of the system are solved for with an iterative MATLAB optimizer using measured data captured with the woven electrodes. The results of this novel analysis confirm that yarn conductivity and total conductive area reduce skin electrode impedance. The results also indicate that electrode skin pressure and moisture require further investigation. By closing this gap in development, textile electrodes can be better designed and manufactured to meet the demands of long-term ECG capture.

Direct ink writing of PEDOT eutectogels as substrate-free dry electrodes for electromyography.

Deep Eutectic Solvents (DES) are a new class of ionic conductive compounds attracting significant attention as greener alternatives to costly ionic liquids. Herein, we developed novel mixed ionic-electronic conducting materials by simple mixing of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) and various DES as additives. The DES addition induces the supramolecular assembly and gelification of PEDOT:PSS forming eutectogels triggered by extensive hydrogen bonding and charge stabilization. The eutectogels feature boosts the mixed ionic-electronic conductivity of PEDOT:PSS up to 368 S cm-1, unveiling great potential as flexible bioelectronics. All the PEDOT:PSS/DES gels showed shear-thinning behavior and viscosity values ranging from 100 to 1000 Pa s. The eutectogels show good injectability with almost instantaneous elastic recovery, making them ideal materials for direct ink writing (DIW). As proof of that, PEDOT:PSS/DES (choline chloride:lactic acid) was 3D printed in different patterns, annealed at high temperature, and assembled into adhesive electrodes. This way tattoos-like electrodes, denoted as Eutecta2 were fabricated and placed in vivo on the forearm and the thumb of human volunteers for electromyography measurements. Eutecta2 hexagonal patterns showed excellent conformability, and their signal-to-noise ratio (SNR) was higher than Ag/AgCl commercial electrodes for thumb motion measurements. Furthermore, forearm motion was measured after 14 days with similar values of SNR, demonstrating long-term stability and reusability. All in all, our findings revealed that DES could be used as inexpensive and safe additives to direct the self-assembly of PEDOT:PSS into supramolecular eutectogels inks for flexible bioelectronics.

A comparison of a precordial belt ECG and a gel-adhesive electrode in terms of ECG acquisition time and usability in emergency department patients

An electrocardiogram (ECG) is a fast, valuable, and non-invasive test that has a wide range of uses in the diagnosis, examination, screening, and prognosis of many cardiac and non-cardiac morbidities. The study was designed as a prospective, single-blind randomized controlled, single center. The CONSORT (Consolidated Standards of Reporting Trials) statement is used. The patients were divided into two groups: Group Gel Adhesive Electrode (GAE) and Group precordial belt ECG (PBE), according to the ECG recording technique. The results between the two groups were compared. A total of 250 patients were included in the study. 127 patients were included in the Group GAE and 123 patients were included in the Group PBE. The mean ECG recording time of patients in the Group GAE was 86.83 ± 22.53 seconds, while it was 59.56 ± 15.08 seconds in the Group PBE. When the ECG recording time is evaluated, the mean of the patients in the Group PBE is shorter, and there is a statistically significant difference between the two groups (p &lt; 0.001). When evaluated in terms of the need for repeat ECG acquisitions of the ECG (Group PBE: 9.75%, Group GAE: 14.96%), there is no statistically significant difference between the groups (p = 0.251). Causes of a repeat ECG were chest hair (Group GAE: 3.15%, Group PBE: 6.50%; p = 0.215), perspiration (Group GAE: 8.66%, Group PBE: 3.15%; p = 0.108), shaking (Group GAE: 15%, Group PBE: 0%; p = 0.122). Compared to the GAE, the precordial ECG Belt may be more advantageous in terms of examination time.

Intraoperative Neuromonitoring of Recurrent Laryngeal Nerve Using Adhesive Skin Electrodes during Minimally Invasive Open Hemithyroidectomy

Intraoperative Neuromonitoring of Recurrent Laryngeal Nerve Using Adhesive Skin Electrodes during Minimally Invasive Open Hemithyroidectomy

Intraoperative Neuromonitoring with Adhesive Skin Electrodes for a Patient with Papillary Thyroid Carcinoma with Lateral Neck Metastasis: a Case Report

Intraoperative Neuromonitoring with Adhesive Skin Electrodes for a Patient with Papillary Thyroid Carcinoma with Lateral Neck Metastasis: a Case Report

Wireless, closed-loop, smart bandage with integrated sensors and stimulators for advanced wound care and accelerated healing.

'Smart' bandages based on multimodal wearable devices could enable real-time physiological monitoring and active intervention to promote healing of chronic wounds. However, there has been limited development in incorporation of both sensors and stimulators for the current smart bandage technologies. Additionally, while adhesive electrodes are essential for robust signal transduction, detachment of existing adhesive dressings can lead to secondary damage to delicate wound tissues without switchable adhesion. Here we overcome these issues by developing a flexible bioelectronic system consisting of wirelessly powered, closed-loop sensing and stimulation circuits with skin-interfacing hydrogel electrodes capable of on-demand adhesion and detachment. In mice, we demonstrate that our wound care system can continuously monitor skin impedance and temperature and deliver electrical stimulation in response to the wound environment. Across preclinical wound models, the treatment group healed ~25% more rapidly and with ~50% enhancement in dermal remodeling compared with control. Further, we observed activation of proregenerative genes in monocyte and macrophage cell populations, which may enhance tissue regeneration, neovascularization and dermal recovery.

A Smart Textile Band Achieves High-Quality Electrocardiograms in Unrestrained Horses.

Electrocardiography (ECG) is an essential tool in assessing equine health and fitness. However, standard ECG devices are expensive and rely on the use of adhesive electrodes, which may become detached and are associated with reduced ECG quality over time. Smart textile electrodes composed of stainless-steel fibers have previously been shown to be a suitable alternative in horses at rest and during exercise. The objective of this study was to compare ECG quality using a smart textile girth band knit with silver and carbon yarns to standard adhesive silver/silver chloride (Ag/AgCl) electrodes. Simultaneous three-lead ECGs were recorded using a smart textile band and Ag/AgCl electrodes in 22 healthy, mixed-breed horses that were unrestrained in stalls. ECGs were compared using the following quality metrics: Kurtosis (k) value, Kurtosis signal quality index (kSQI), percentage of motion artifacts (%MA), peak signal amplitude, and heart rate (HR). Two-way ANOVA with Tukey's multiple comparison tests was conducted to compare each metric. No significant differences were found in any of the assessed metrics between the smart textile band and Ag/AgCl electrodes, with the exception of peak amplitude. Kurtosis and kSQI values were excellent for both methods (textile mean k = 21.8 ± 6.1, median kSQI = 0.98 [0.92-1.0]; Ag/AgCl k = 21.2 ± 7.6, kSQI = 0.99 [0.97-1.0]) with &lt;0.5% (&lt;1 min) of the recording being corrupted by MAs for both. This study demonstrates that smart textiles are a practical and reliable alternative to the standard electrodes typically used in ECG monitoring of horses.

A flexible adhesive surface electrode array capable of cervical electroneurography during a sequential autonomic stress challenge

This study introduces a flexible, adhesive-integrated electrode array that was developed to enable non-invasive monitoring of cervical nerve activity. The device uses silver-silver chloride as the electrode material of choice and combines it with an electrode array consisting of a customized biopotential data acquisition unit and integrated graphical user interface (GUI) for visualization of real-time monitoring. Preliminary testing demonstrated this electrode design can achieve a high signal to noise ratio during cervical neural recordings. To demonstrate the capability of the surface electrodes to detect changes in cervical neuronal activity, the cold-pressor test (CPT) and a timed respiratory challenge were employed as stressors to the autonomic nervous system. This sensor system recording, a new technique, was termed Cervical Electroneurography (CEN). By applying a custom spike sorting algorithm to the electrode measurements, neural activity was classified in two ways: (1) pre-to-post CPT, and (2) during a timed respiratory challenge. Unique to this work: (1) rostral to caudal channel position-specific (cephalad to caudal) firing patterns and (2) cross challenge biotype-specific change in average CEN firing, were observed with both CPT and the timed respiratory challenge. Future work is planned to develop an ambulatory CEN recording device that could provide immediate notification of autonomic nervous system activity changes that might indicate autonomic dysregulation in healthy subjects and clinical disease states.

Feasibility of facial nerve monitoring using adhesive surface electrodes during parotidectomy: a comparative study with needle electrodes.

Electrophysiological monitoring of the facial nerve during parotidectomy has been reported as an adjunctive method to prevent facial nerve injury. Classically, a needle electrode is used to obtain electromyographic (EMG) signals from facial muscles during facial nerve monitoring (FNM) of parotid surgery, likewise adhesive surface electrodes. This study aimed to investigate the feasibility of performing FNM with surface electrodes during parotid surgery and to compare EMG values with needle electrodes. Thirty patients who underwent parotidectomy under FNM using adhesive surface and needle electrodes were included. Two pairs of adhesive surface electrodes and needle electrodes were used for FNM during parotid surgery. Mean amplitudes were collected after electrical facial nerve stimulation at 1mA after specimen removal. The mean amplitude of the adhesive surface electrodes was 226.50 ± 118.44μV (orbicularis oculi muscle) and 469.6 ± 306.06μV (orbicularis oris muscle), respectively. The mean amplitude of the needle electrodes was 449.85 ± 248.10μV (orbicularis oculi muscle) and 654.66 ± 395.71μV (orbicularis oris muscle), respectively. The mean amplitude of the orbicularis oris muscle was significantly greater than that of the orbicularis oculi. The amplitude values measured in the orbicularis oculi muscle showed significant differences between the needle and skin electrodes. Facial nerve monitoring (FNM) using adhesive surface electrodes is feasible in parotid surgery. Although the mean amplitude value of the surface electrode was relatively lower than that of the needle electrode, the surface electrode is considered a feasible and safe EMG recording device for FNM in parotid surgery.