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Pacing and Clinical Electrophysiology :... Jun 2024Electromagnetic interference (EMI) encompasses electromagnetic field signals that can be detected by a device's circuitry, potentially resulting in adverse effects such...
BACKGROUND
Electromagnetic interference (EMI) encompasses electromagnetic field signals that can be detected by a device's circuitry, potentially resulting in adverse effects such as inaccurate sensing, pacing, device mode switching, and defibrillation. EMI may impact the functioning of Cardiac Implantable Electronic Devices (CIEDs) and lead to inappropriate therapy.
METHOD
An experimental measuring device, a loop antenna mimicking the implantable cardioverted defibrillator (ICD) antenna, was developed, and validated at the US Food and Drug Administration (FDA) and sent to Wright State University for testing. Two sets of measurements were conducted while the vehicle was connected to a 220-Volt outlet with charging at ON and OFF. Each measurement set involved three readings at various locations, with the antenna oriented in three different positions to account for diverse patient postures. The experiment utilized a Tesla Model 3 electric vehicle (EV), assessing scenarios both inside and outside the car, including the driver's seat, driver's seat floor, passenger's seat, rear seat, rear seat floor, cup holder, charging port (car), and near the charging station.
RESULTS
The detected voltage (max 400 to 504 millivolts) around the cup holder inside the car differed from all other measurement scenarios.
CONCLUSION
The investigation highlights the identification of EMI signals originating from an EV) that could potentially interrupt the functionality of a Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD). These signals fell within the R-wave Spectrum of 30-300 Hz. Further in-vivo studies are essential to determine accurately the level of interference between S-ICDs and EMI from Electric Vehicles.
PubMed: 38830796
DOI: 10.1111/pace.15019 -
Nano-micro Letters Apr 2023Ionic thermoelectrics (i-TE) possesses great potential in powering distributed electronics because it can generate thermopower up to tens of millivolts per Kelvin....
Ionic thermoelectrics (i-TE) possesses great potential in powering distributed electronics because it can generate thermopower up to tens of millivolts per Kelvin. However, as ions cannot enter external circuit, the utilization of i-TE is currently based on capacitive charge/discharge, which results in discontinuous working mode and low energy density. Here, we introduce an ion-electron thermoelectric synergistic (IETS) effect by utilizing an ion-electron conductor. Electrons/holes can drift under the electric field generated by thermodiffusion of ions, thus converting the ionic current into electrical current that can pass through the external circuit. Due to the IETS effect, i-TE is able to operate continuously for over 3000 min. Moreover, our i-TE exhibits a thermopower of 32.7 mV K and an energy density of 553.9 J m, which is more than 6.9 times of the highest reported value. Consequently, direct powering of electronics is achieved with i-TE. This work provides a novel strategy for the design of high-performance i-TE materials.
PubMed: 37052861
DOI: 10.1007/s40820-023-01077-7 -
Frontiers in Cellular Neuroscience 2019Axonal spike initiation at sites far from somatodendritic integration occurs in a range of systems, but its contribution to neuronal output activity is not well...
Axonal spike initiation at sites far from somatodendritic integration occurs in a range of systems, but its contribution to neuronal output activity is not well understood. We studied the interactions of distal and proximal spike initiation in an unmyelinated motor axon of the stomatogastric nervous system in the lobster, . The peripheral axons of the pyloric dilator (PD) neurons generate tonic spiking in response to dopamine application. Centrally generated bursting activity and peripheral spike initiation had mutually suppressive effects. The two PD neurons and the electrically coupled oscillatory anterior burster (AB) neuron form the pacemaker ensemble of the pyloric central pattern generator, and antidromic invasion of central compartments by peripherally generated spikes caused spikelets in AB. Antidromic spikes suppressed burst generation in an activity-dependent manner: slower rhythms were diminished or completely disrupted, while fast rhythmic activity remained robust. Suppression of bursting was based on interference with the underlying slow wave oscillations in AB and PD, rather than a direct effect on spike initiation. A simplified multi-compartment circuit model of the pacemaker ensemble replicated this behavior. Antidromic activity disrupted slow wave oscillations by resetting the inward and outward current trajectories in each spike interval. Centrally generated bursting activity in turn suppressed peripheral spike initiation in an activity-dependent manner. Fast bursting eliminated peripheral spike initiation, while slower bursting allowed peripheral spike initiation to continue during the intervals between bursts. The suppression of peripheral spike initiation was associated with a small after-hyperpolarization in the sub-millivolt range. A realistic model of the PD axon replicated this behavior and showed that a sub-millivolt cumulative after-hyperpolarization across bursts was sufficient to eliminate peripheral spike initiation. This effect was based on the dynamic interaction between slow activity-dependent hyperpolarization caused by the Na/K-pump and inward rectification through the hyperpolarization-activated inward current, . These results demonstrate that interactions between different spike initiation sites based on spike propagation can shift the relative contributions of different types of activity in an activity-dependent manner. Therefore, distal axonal spike initiation can play an important role in shaping neural output, conditional on the relative level of centrally generated activity.
PubMed: 31708748
DOI: 10.3389/fncel.2019.00477 -
Nanoscale Advances Mar 2022Harvesting ocean wave energy through carbon-based materials, particularly graphene, is receiving increasing attention. However, the complicated fabrication process and...
Harvesting ocean wave energy through carbon-based materials, particularly graphene, is receiving increasing attention. However, the complicated fabrication process and the low output power of the present monolayer graphene-based wave energy generators limit their further application. Here, we demonstrate the facile fabrication of a new type of wave energy generator based on graphene/TiO nanoparticle composite films using the doctor-blading method. The developed wave energy harvesting device exhibits a high open-circuit voltage of up to 75 millivolts and a high output power up to 1.8 microwatts. A systematic study was conducted to explore the optimal conditions for the energy harvesting performance.
PubMed: 36134363
DOI: 10.1039/d1na00658d -
Sensors (Basel, Switzerland) Jan 2023Levels of lead (Pb) in tap water that are well below established guidelines are now considered harmful, so the detection of sub-parts-per-billion (ppb) Pb levels is...
Levels of lead (Pb) in tap water that are well below established guidelines are now considered harmful, so the detection of sub-parts-per-billion (ppb) Pb levels is crucial. In this work, we developed a two-step, facile, and inexpensive fabrication approach that involves direct bonding of copper (Cu) and liquid crystal polymer (LCP) followed by polyester resin printing for masking onto Cu/LCP to fabricate Cu thin-film-based Pb sensors. The oxygen plasma-treated surfaces resulted in strongly bonded Cu/LCP with a high peel strength of 500 N/m due to the highly hydrophilic nature of both surfaces. The bonded specimen can withstand wet etching of the electrode and can address delamination of the electrode for prolonged use in application environments. The Cu-foil-based electrochemical sensor showed sensitivity of ~11 nA/ppb/cm and a limit of detection (LOD) of 0.2 ppb (0.2 µg/L) Pb ions in water. The sensor required only 30 s and a 100 µL sample to detect Pb. To date, this is the most rapid detection of Pb performed using an all-Cu-based sensor. The selectivity test of Cu to Pb with interferences from cadmium and zinc showed that their peaks were separated by a few hundred millivolts. This approach has strong potential towards realizing low-cost, highly reliable integrated water quality monitoring systems.
PubMed: 36772462
DOI: 10.3390/s23031424 -
Ophthalmology Nov 2020To investigate 24-hour nyctohemeral intraocular pressure (IOP)-related patterns with contact lens sensors (CLSs) in eyes with primary open-angle glaucoma (POAG) with...
Twenty-four-Hour Intraocular Pressure-Related Patterns from Contact Lens Sensors in Normal-Tension Glaucoma and Healthy Eyes: The Exploring Nyctohemeral Intraocular pressure related pattern for Glaucoma Management (ENIGMA) Study.
PURPOSE
To investigate 24-hour nyctohemeral intraocular pressure (IOP)-related patterns with contact lens sensors (CLSs) in eyes with primary open-angle glaucoma (POAG) with normal baseline IOP (i.e., normal-tension glaucoma [NTG]) and healthy controls.
DESIGN
Prospective, case-control study.
PARTICIPANTS
Thirty eyes of 30 patients with NTG, who had had a wash-out period for their IOP-lowering treatment, and 20 eyes of 20 healthy volunteer subjects.
METHODS
Patients and subjects were hospitalized for the purposes of 24-hour CLS (SENSIMED Triggerfish; Sensimed AG, Lausanne, Switzerland) measurement. The IOP-related patterns during wake and sleep times over the course of the 24 hours were compared between the 2 groups. The 24-hour ambulatory blood pressure and posture were monitored simultaneously. A generalized linear model was used to find the factors associated with NTG.
MAIN OUTCOME MEASURES
The IOP-related patterns, including mean and standard deviation (SD) of measurements, amplitude of cosine-fit curve, acrophase (signal peak), and bathyphase (signal trough) values (millivolt equivalents [mVEq]).
RESULTS
The SDs of the 24-hour CLS measurements were significantly greater in NTG eyes than in healthy controls (112.51±26.90 vs. 85.18±29.61 mVEq, P = 0.002). The amplitudes of cosine-fit curve (141.88±39.96 vs. 106.08±41.49 mVEq, P = 0.004) and acrophase values (277.74±129.80 vs. 190.58±127.88 mVEq, P = 0.024), mostly measured during nocturnal period, were significantly greater in NTG eyes than in healthy controls. The NTG subjects slept longer in the lateral decubitus posture than the healthy controls (199.1±137.8 vs. 113.2±86.2 minutes, P = 0.009). In the multivariable generalized linear model, the greater amplitude of cosine-fit curve (β = 0.218, P = 0.012) and greater time of decubitus posture during sleep (β = 0.180, P = 0.004) were found to be significantly associated with NTG.
CONCLUSIONS
Continuous monitoring of 24-hour IOP-related values with CLS can be useful for assessment of glaucoma risk, especially for patients with NTG whose IOP appears to be in the normal range. Fluctuation of 24-hour IOP-related values and posture during sleep time might be associated with NTG.
Topics: Aged; Case-Control Studies; Circadian Rhythm; Contact Lenses; Equipment Design; Female; Follow-Up Studies; Glaucoma, Open-Angle; Humans; Intraocular Pressure; Low Tension Glaucoma; Male; Middle Aged; Prospective Studies; Tonometry, Ocular
PubMed: 32417391
DOI: 10.1016/j.ophtha.2020.05.010 -
Chemistry, An Asian Journal Nov 2022Ionic thermoelectric (i-TE) materials have attracted much attention due to their ability to generate ionic Seebeck coefficient of tens of millivolts per Kelvin. In this...
Ionic thermoelectric (i-TE) materials have attracted much attention due to their ability to generate ionic Seebeck coefficient of tens of millivolts per Kelvin. In this work, we demonstrate that the ionic thermopower can be enhanced by the introduction of multiple ions. The multi-ionic hydrogel possesses a record thermal-to-electrical energy conversion factor (TtoE factor) of 89.6 mV K and an ionic conductivity of 6.8 mS cm , which are both better than single salt control hydrogel. Subsequently we build a model to explain thermal diffusion of the ions in multi-ionic hydrogels. Finally, the possibility of large-scale integrated applications of multi-ionic hydrogels is demonstrated. By connecting 7 i-TEs hydrogels, we obtained an open-circuit voltage of 1.86 V at ΔT=3 K. Our work provides a new pathway for the design of i-TEs and low-grade heat harvesting.
PubMed: 36074542
DOI: 10.1002/asia.202200850 -
Scandinavian Cardiovascular Journal :... Jun 2020. Catheter ablation is an effective method in the treatment of idiopathic ventricular arrhythmias. The mapping methods used for predicting the original site of...
. Catheter ablation is an effective method in the treatment of idiopathic ventricular arrhythmias. The mapping methods used for predicting the original site of arrhythmias are difficult to use and time-consuming. Consequently, developing methods using surface ECG for guiding the location is important. Here, we have tested a new ECG criterion to differentiate the left from the right ventricular originated complexes (PVCs) or tachycardias (VTs). . Sixty patients with idiopathic PVC or VT who had undergone a successful radiofrequency catheter ablation (RFA) of arrhythmia were enrolled. The surface ECG during sinus rhythm and arrhythmia was analyzed. Initial r wave Surface Area (ISA) index was measured by multiplying the R wave duration in milliseconds by the R wave amplitude in terms of millivolt in V1 or V2 leads. . Thirty-seven patients with right ventricular (RVOT) and 23 with left ventricular outflow tract (LVOT) originated VT or PVC were enrolled. The ISA index was significantly greater in LVOT-VT/PVC compared to RVOTs (63.6 ± 78.9 8.3 ± 7.3, < .001). With a cut off value of ≥15, the index could differentiate a left from right arrhythmia with 94.6% specificity and 78.2% sensitivity (Area on the curve, 0.81; < .001). Compared to other previously reported indices, ISA is the most specific one. . ISA index can serve as a very useful ECG criterion for differentiating a LVOT- from RVOT-originated VTs or PVCs.
Topics: Action Potentials; Adult; Catheter Ablation; Cross-Sectional Studies; Diagnosis, Differential; Electrocardiography; Female; Heart Rate; Humans; Male; Middle Aged; Predictive Value of Tests; Reproducibility of Results; Retrospective Studies; Tachycardia, Ventricular; Ventricular Function, Left; Ventricular Function, Right; Ventricular Premature Complexes
PubMed: 31752558
DOI: 10.1080/14017431.2019.1693616 -
RSC Advances Apr 2021Lithium plating/stripping was investigated under constant current mode using a copper powder electrode in a super-concentrated electrolyte of lithium...
Lithium plating/stripping was investigated under constant current mode using a copper powder electrode in a super-concentrated electrolyte of lithium bis(fluorosulfonyl)amide (LiFSA) with methylphenylamino-di(trifluoroethyl) phosphate (PNMePh) and vinylene carbonate (VC) as additives. Typical Li plating/stripping for Cu electrodes in organic electrolytes of conventional lithium batteries proceeds at potentials of several millivolts a Li counter electrode. In contrast, a large overpotential of hundreds of millivolts was observed for Li plating/stripping with the super-concentrated electrolyte. When Li stripping started immediately after Li plating and with no rest time between plating and stripping, two potential plateaus, , two-step Li stripping, was observed. The potential plateau for the 1 stripping step appeared at -0.2 V a Li metal counter electrode. The electrical capacity for the 1 stripping step was 0.04 mA h cm, which indicates irregular Li stripping. Two-step Li stripping was also recorded using cyclic voltammetry. The electrochemical impedance spectroscopy (EIS) studies indicated that the two-step Li stripping behaviour reflected two different solid electrolyte interphases (SEIs) on electrodeposited Li in a Cu electrode. The SEI for the 1-step stripping was in a transition period of the SEI formation. The open circuit voltage (OCV) relaxation with an order of tens of hours was detected after Li plating and before Li stripping. The EIS study suggested a decrease of the charge transfer resistance in the Cu powder electrode during the OCV relaxation. Since the capacitance for the voltage relaxation was a dozen microfarads, it had a slight contribution to the 1-step Li stripping behaviour. The voltage relaxation indicated the possibility that it is difficult for Li ions to be electrodeposited or that the Li plating is in a quasi-stable state.
PubMed: 35423877
DOI: 10.1039/d1ra01490k -
Scientific Reports Jun 2020Scalable, low power, high speed data transfer between cryogenic (0.1-4 K) and room temperature environments is essential for the realization of practical, large-scale...
Scalable, low power, high speed data transfer between cryogenic (0.1-4 K) and room temperature environments is essential for the realization of practical, large-scale systems based on superconducting technologies. A promising approach to overcome the limitations of conventional wire-based readout is the use of optical fiber communication. Optical fiber presents a 100-1,000x lower heat load than conventional electrical wiring, relaxing the requirements for thermal anchoring, and is also immune to electromagnetic interference, which allows routing of sensitive signals with improved robustness to noise and crosstalk. Most importantly, optical fibers allow for very high bandwidth densities (in the Tbps/mm range) by carrying multiple signals through the same physical fiber (Wavelength Division Multiplexing, WDM). Here, we demonstrate for the first time optical readout of a superconducting nanowire single-photon detector (SNSPD) directly coupled to a CMOS photonic modulator, without the need for an interfacing device. By operating the modulator in the forward bias regime at a temperature of 3.6 K, we achieve very high modulation efficiency (1,000-10,000 pm/V) and a low input impedance of 500 Ω with a low power dissipation of 40 μW. This allows us to obtain optical modulation with the low, millivolt-level signal generated by the SNSPD.
PubMed: 32528067
DOI: 10.1038/s41598-020-65971-5