scholarly journals Flexible ECG circuit fabrication and application using vinyl cutting technique

2020 ◽  
Vol 9 (6) ◽  
pp. 2319-2325
Author(s):  
Noor Syazwana Sahar ◽  
Nurul Ashikin Abdul-Kadir ◽  
Fauzan Khairi Che Harun
Keyword(s):  
Signal To Noise Ratio ◽  
Human Subjects ◽  
Flexible Substrate ◽  
Patient Simulator ◽  
Cutting Method ◽  
Circuit Performance ◽  
Circuit Fabrication ◽  
Scale Particle ◽  
Pet Substrate ◽  
Copper Tape

The aim of this study is to prove the capability of vinyl cutting technique to cut the conductive traces of electronic circuit layout which used a copper tape (Copper tape 1181 from 3M) on flexible substrate to replace the method of using nano-scale particle material. A wireless electrocardiography (ECG) circuit was integrated and fabricated on flexible substrate, namely a polyethylene terephthalate (PET) substrate by using vinyl cutting method to produce the conductive line traces. After that, the fabricated circuit is used for acquiring ECG signals from a patient simulator and human subjects to measure the performance differences and compatibility as a wearable device. In the data processing stage, ECG data were denoised using sym20 from Wavelet Transform tool provided by MATLAB. Then, Signal-to-noise-ratio (SNR) was calculated and used as the signal quality indicator. At the end of the study, flexible circuit performance was compared to MIT-BIH Arrhythmia database and it shows that there is no significance difference between both. In conclusion, vinyl cutting method shows a promising fabrication output on PET substrate as the performance of both flexible ECG circuit is comparable with rigid ECG circuit by a previous study.

scholarly journals Propagating Wave and Irregular Dynamics: Spatiotemporal Patterns of Cholinergic Theta Oscillations in Neocortex In Vitro

2003 ◽  
Vol 90 (1) ◽  
pp. 333-341 ◽  
Author(s):  
Weili Bao ◽  
Jian-Young Wu
Keyword(s):  
Phase Distribution ◽  
Signal To Noise Ratio ◽  
Human Subjects ◽  
Local Oscillator ◽  
Spatiotemporal Patterns ◽  
Spatiotemporal Pattern ◽  
Large Signal ◽  
Local Oscillators ◽  
Theta Oscillation

Neocortical “theta” oscillation (5–12 Hz) has been observed in animals and human subjects but little is known about how the oscillation is organized in the cortical intrinsic networks. Here we use voltage-sensitive dye and optical imaging to study a carbachol/bicuculline induced theta (∼8 Hz) oscillation in rat neocortical slices. The imaging has large signal-to-noise ratio, allowing us to map the phase distribution over the neocortical tissue during the oscillation. The oscillation was organized as spontaneous epochs and each epoch was composed of a “first spike,” a “regular” period (with relatively stable frequency and amplitude), and an “irregular” period (with variable frequency and amplitude) of oscillations. During each cycle of the regular oscillation, one wave of activation propagated horizontally (parallel to the cortical lamina) across the cortical section at a velocity of ∼50 mm/s. Vertically the activity was synchronized through all cortical layers. This pattern of one propagating wave associated with one oscillation cycle was seen during all the regular cycles. The oscillation frequency varied noticeably at two neighboring horizontal locations (330 μm apart), suggesting that the oscillation is locally organized and each local oscillator is about ≤300 μm wide horizontally. During irregular oscillations, the spatiotemporal patterns were complex and sometimes the vertical synchronization decomposed, suggesting a de-coupling among local oscillators. Our data suggested that neocortical theta oscillation is sustained by multiple local oscillators. The coupling regime among the oscillators may determine the spatiotemporal pattern and switching between propagating waves and irregular patterns.

scholarly journals Longevity and reliability of chronic unit recordings using the Utah, intracortical multi-electrode arrays

2021 ◽  
Author(s):  
Caleb Scheffer Sponheim ◽  
Vasileios Papadourakis ◽  
Jennifer Collinger ◽  
John Downey ◽  
Jeffrey M Weiss ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Rhesus Macaques ◽  
Human Subjects ◽  
Electrode Arrays ◽  
Computer Interfaces ◽  
Somatosensory Cortices ◽  
Large Numbers ◽  
Electrode Length ◽  
Human Participants

Abstract Objective. Microelectrode arrays are standard tools for conducting chronic electrophysiological experiments, allowing researchers to simultaneously record from large numbers of neurons. Specifically, Utah electrode arrays (UEAs) have been utilized by scientists in many species, including rodents, rhesus macaques, marmosets, and human participants. The field of clinical human brain-computer interfaces currently relies on the UEA as a number of research groups have FDA clearance for this device through the investigational device exemption pathway. Despite its widespread usage in systems neuroscience, few studies have comprehensively evaluated the reliability and signal quality of the Utah array over long periods of time in a large dataset. Approach. We collected and analyzed over 6000 recorded datasets from various cortical areas spanning almost 9 years of experiments, totaling 17 rhesus macaques (Macaca Mulatta) and 2 human subjects, and 55 separate microelectrode Utah arrays. The scale of this dataset allowed us to evaluate the average life of these arrays, based primarily on the signal-to-noise ratio of each electrode over time. Main Results. Using implants in primary motor, premotor, prefrontal, and somatosensory cortices, we found that the average lifespan of available recordings from UEAs was 622 days, although we provide several examples of these UEAs lasting over 1000 days and one up to 9 years; human implants were also shown to last longer than non-human primate implants. We also found that electrode length did not affect longevity and quality, but iridium oxide metallization on the electrode tip exhibited superior yield as compared to platinum metallization.

scholarly journals A Novel Analog Front End with Voltage-Dependent Input Impedance and Bandpass Amplification for Capacitive Biopotential Measurements

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2476 ◽  
Author(s):  
Hajime Nakamura ◽  
Yuichiro Sakajiri ◽  
Hiroshi Ishigami ◽  
Akinori Ueno
Keyword(s):  
Input Impedance ◽  
Biceps Brachii ◽  
Signal To Noise Ratio ◽  
Human Subjects ◽  
Healthy Weight ◽  
Front End ◽  
Analog Front End ◽  
Voltage Dependent ◽  
Voltage Follower ◽  
Dc Component

This paper proposes a novel analogue front end (AFE) that has three features: voltage-dependent input impedance, bandpass amplification, and stray capacitance reduction. With a view to applying the AFE to capacitive biopotential measurements (CBMs), the three features were investigated separately in a schematic and mathematical manner. Capacitive electrocardiogram (cECG) or capacitive electromyogram (cEMG) measurements using the AFE were performed in low-humidity conditions (below 35% relative humidity) for a total of seven human subjects. Performance evaluation of the AFE revealed the following: (1) the proposed AFE in cECG measurement with 1.70-mm thick clothing reduced the baseline recovery time and root mean square voltage of respiratory interference in subjects with healthy-weight body mass index (BMI), and increased R-wave amplitude for overweight-BMI subjects; and (2) the proposed AFE in cEMG measurement of biceps brachii muscle yielded stable electromyographic waveforms without the marked DC component for all subjects and a significant (p < 0.01) increase in the signal-to-noise ratio. These results indicate that the proposed AFE can provide a feasible balance between sensitivity and stability in CBMs, and it could be a versatile replacement for the conventional voltage follower used in CBMs.

An Approach to a Flexible Thermoelectric Generator Fabricated using Bulk Materials

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
B. Geppert ◽  
A. Feldhoff
Keyword(s):  
Thermoelectric Materials ◽  
Thermoelectric Generator ◽  
Flexible Substrate ◽  
Thermoelectric Device ◽  
Bulk Materials ◽  
Mineral Fiber ◽  
Flexible Thermoelectric ◽  
Copper Tape

AbstractA prototype flexible thermoelectric generator fabricated with bulk materials is presented. Mineral-fiber band and copper tape are used as flexible substrate and electric connectors, respectively, to coil up the constructed thermoelectric device under investigation. The applied active thermoelectric materials are

scholarly journals System introduction and evaluation of the first Chinese chest EIT device for ICU applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuo-Yao Qu ◽  
Meng Dai ◽  
Shuo Wu ◽  
Zhi-Rang Lv ◽  
Xin-Yu Ti ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Human Subjects ◽  
Current Source ◽  
Impedance Measurement ◽  
Measurement Unit ◽  
Voltage Measurement ◽  
Impedance Tomography ◽  
Promising Application ◽  
One Machine ◽  
Ventilation And Perfusion

AbstractChest electrical impedance tomography (EIT) is a promising application which is used to monitor the ventilation and perfusion of the lung at the bedside dynamically. The aim of the study was to introduce the first Chinese made chest EIT device for ICU application (Pulmo EIT-100). The system design of the hardware and software was briefly introduced. The performance of the system was compared to PulmoVista 500 (Dräger Medical) in healthy volunteers. The EIT system Pulmo EIT-100 consists of impedance measurement module, power supply module, PC all-in-one machine, medical cart and accessories. The performance of the system current source and voltage measurement unit was tested. A total of 50 healthy lung volunteers were prospectively examined. Subjects were asked to perform repetitive slow vital capacity (SVC) maneuvers with a spirometer. EIT measurements were performed in the following sequence during each SVC with: (1) Pulmo EIT-100, (2) PulmonVista500, (3) Pulmo EIT-100 and (4) PulmonVista500. Linearity and regional ventilation distribution of the reconstructed images from two devices were compared. The output frequency stability of the current source was 2 ppm. The amplitude error within one hour was less than 0.32‰. The output impedance of the current source was about 50kΩ. The signal-to-noise ratio of each measurement channel was ≥ 60 dB. For fixed resistance measurements, the measured values drifted about 0.08% within one hour. For human subjects, the correlations between the spirometry volume and EIT impedance from two devices were both 0.99 ± 0.01. No statistical significances were found in the parameters investigated. The repeatability (variability) of measures from the same device was comparable. Our EIT device delivers reliable data and might be used for patient measurement in a clinical setting.

scholarly journals Design of a Flexible PET Based Yagi Dipole Antenna

2019 ◽  
Vol 9 (1) ◽  
pp. 2505-2510
Keyword(s):  
Return Loss ◽  
Glass Fibers ◽  
Flexible Substrate ◽  
Dipole Antenna ◽  
Strip Line ◽  
Polyethylene Terephtalate ◽  
Linearly Polarized ◽  
Rf Antenna ◽  
5 Ghz ◽  
Pet Substrate

In the proposed paper, a flexible Yagi Dipole Antenna based on PET Substrate is designed for the RF system-on-package (RF SOP) applications. RF antenna as a smart sensor is designed on a Flexible substrate Polyethylene Terephtalate (PET). It is the more popular and universally accepted thermoplastic polymer belonging to the family of the polyester. It is generally employed in textiles, thermoforming packaging along with glass fibers. In the proposed design Coplanar Strip line (CPS) is used as a feeder and the RF antenna is a Yagi dipole Antenna with a single driven element i.e. director, and a single reflecting element i.e. reflector. It is a linearly polarized antenna which means it radiates in a single direction. The antenna is designed at a resonating frequency of 5 GHz with a return loss of -23 dB. Simulations of the flexible PET based Yagi Dipole Antenna is carried out by using CST Studio Suite software for Return loss, Radiation plot with varied curvatures. The results for designed flexible Yagi Dipole Antenna imprinted with a PET substrate for portable wireless electronics are analyzed.

scholarly journals Brain potentials evoked by intraepidermal electrical stimuli reflect the central sensitization of nociceptive pathways

2016 ◽  
Vol 116 (2) ◽  
pp. 286-295 ◽  
Author(s):  
M. Liang ◽  
M. C. Lee ◽  
J. O'Neill ◽  
A. H. Dickenson ◽  
G. D. Iannetti
Keyword(s):  
Central Sensitization ◽  
Signal To Noise Ratio ◽  
Human Subjects ◽  
Secondary Hyperalgesia ◽  
Healthy Human ◽  
Brain Potentials ◽  
Characteristics Analysis ◽  
Increased Sensitivity ◽  
Nociceptive Input ◽  
Clinical Conditions

Central sensitization (CS), the increased sensitivity of the central nervous system to somatosensory inputs, accounts for secondary hyperalgesia, a typical sign of several painful clinical conditions. Brain potentials elicited by mechanical punctate stimulation using flat-tip probes can provide neural correlates of CS, but their signal-to-noise ratio is limited by poor synchronization of the afferent nociceptive input. Additionally, mechanical punctate stimulation does not activate nociceptors exclusively. In contrast, low-intensity intraepidermal electrical stimulation (IES) allows selective activation of type II Aδ-mechano-heat nociceptors (II-AMHs) and elicits reproducible brain potentials. However, it is unclear whether hyperalgesia from IES occurs and coexists with secondary mechanical punctate hyperalgesia, and whether the magnitude of the electroencephalographic (EEG) responses evoked by IES within the hyperalgesic area is increased. To address these questions, we explored the modulation of the psychophysical and EEG responses to IES by intraepidermal injection of capsaicin in healthy human subjects. We obtained three main results. First, the intensity of the sensation elicited by IES was significantly increased in participants who developed robust mechanical punctate hyperalgesia after capsaicin injection (i.e., responders), indicating that hyperalgesia from IES coexists with punctate mechanical hyperalgesia. Second, the N2 peak magnitude of the EEG responses elicited by IES was significantly increased after the intraepidermal injection of capsaicin in responders only. Third, a receiver-operator characteristics analysis showed that the N2 peak amplitude is clearly predictive of the presence of CS. These findings suggest that the EEG responses elicited by IES reflect secondary hyperalgesia and therefore represent an objective correlate of CS.

Fabrication Techniques for the Processing of Adhesiveless ULTEM® Polyetherimide Dielectric Film

2004 ◽  
Vol 814 ◽  
Author(s):  
Kevin M. Durocher ◽  
Irene Dris ◽  
Stacey Goodwin ◽  
Nicholas Abbatiello
Keyword(s):  
Mobile Communications ◽  
High Performance ◽  
Flexible Substrate ◽  
Dissipation Factor ◽  
Electrical Performance ◽  
Advantages And Disadvantages ◽  
Circuit Fabrication ◽  
Flexible Printed Circuit ◽  
Tear Propagation ◽  
Key Steps

AbstractFlexible printed circuits are a technology and product enabler for miniature, high density electronic systems, especially mobile communications and automotive applications. Over the past ten years, flexible printed circuit densities have increased, dramatically, while the area they occupy has decreased. The ever shrinking circuit form factor and increasing I/O and interconnect densities are driving flex circuit configurations from single sided to double sided constructions. In addition, the need for high performance steers circuit construction towards thinner dielectrics. Adhesiveless flex circuit constructions, for example, enable direct metal and lamination bonding without the use of added adhesive materials. Removing adhesive layers, such as epoxies or acrylics allows for a thinner more flexible device with a homogeneous dielectric stack (e.g., all polyimide construction), resulting in superior electrical performance. High resolution flexible circuit processes established using General Electric ULTEM [registered trademark] polyetherimide materials have shown ULTEM resin to have excellent electrical properties including dielectric constant and dissipation factor. Adhesiveless single and double sided flexible circuits have been fabricated and tested for performance (electrical, mechanical, thermal) and reliability (thermal cycling, tear propagation, flexural endurance, and solderability). Critical flex circuit fabrication processes such as metal adhesion, micro-via formation, lamination, photolithography, and module singulation have been evaluated. This paper addresses the key steps for flexible substrate fabrication describing the key advantages and disadvantages of the approach.

scholarly journals Fully Solution-Processable Fabrication of Multi-Layered Circuits on Flexible Substrate Using Laser

2018 ◽  
Author(s):  
Seok Young Ji ◽  
Wonsuk Choi ◽  
Hoon-Young Kim ◽  
Jin-Woo Jeon ◽  
Sung-Hak Cho ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Flexible Substrate ◽  
Selective Laser Sintering ◽  
Single Layer ◽  
Electric Circuit ◽  
Laser Sintering ◽  
Insulating Layer ◽  
Circuit Fabrication ◽  
Chip Size ◽  
Solution Processable

The development of printing technologies has enabled the realization of electric circuit fabrication on flexible substrate. However, the current technique remains restricted to single-layer patterning. In this paper, we demonstrate a fully solution-processable patterning approach for multi-layer circuits using a combined method of laser sintering and ablation. Selective laser sintering of silver (Ag) nanoparticle-based ink is applied to make conductive patterns on a heat-sensitive substrate and insulating layer. The laser beam path and irradiation fluence are controlled to create circuit patterns for flexible electronics. Microvia drilling using femtosecond laser through the polyvinylphenol-film insulating layer by laser ablation, as well as sequential coating of Ag ink and laser sintering, achieves an interlayer interconnection between multi-layer circuits. The dimension of microvia is determined by a sophisticated adjustment of laser focal position and intensity. Based on these methods, the flexible electronic circuit with chip-size-package light-emitting diodes was successfully fabricated and demonstrated with functional operations.

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