Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose c...Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose cell-electrode interface.To investigate intracellular electrophysiological signals with high sensitivity,electroporation was used to obtain intracellular recordings.In this study,a biosensing system based on a nanoporous electrode array(NPEA)integrating electrical perforation and signal acquisition was established to dynamically and sensitively record the intracellular potential of cardiomyocytes over a long period of time.Moreover,nanoporous electrodes can induce the protrusion of cell membranes and enhance cell-electrode interfacial coupling,thereby facilitating effective electroporation.Electrophysiological signals over the entire recording process can be quantitatively and segmentally analyzed according to the signal changes,which can equivalently reflect the dynamic evolution of the electroporated cardiomyocyte membrane.We believe that the low-cost and high-performance nanoporous biosensing platform suggested in this study can dynamically record intracellular action potential,evaluate cardiomyocyte electroporation,and provide a new strategy for investigating cardiology pharmacological science.展开更多
Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the p...Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation.To activate lower-limb muscles precisely by epidural spinal cord stimulation,we proposed a high-density,flexible electrode array.We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord,which was established by a transection method.For evaluating the effect of stimulation,the evoked potentials were recorded from bilateral lowerlimb muscles,including the vastus lateralis,semitendinosus,tibialis anterior,and medial gastrocnemius.To determine the appropriate stimulation sites and parameters of the lower muscles,the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation.In the vastus lateralis and medial gastrocnemius,these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment,respectively.The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles.The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius.Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array.They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury.This study was approved by the Animal Research Committee of Southeast University,China(approval No.20190720001) on July 20,2019.展开更多
Process technology of multiple cylindrical micro-pins by wire-electrical discharge machining （wire-EDM） and electrochemical etching was presented. A row of rectangular micro-columns were machined by wire-EDM and the...Process technology of multiple cylindrical micro-pins by wire-electrical discharge machining （wire-EDM） and electrochemical etching was presented. A row of rectangular micro-columns were machined by wire-EDM and then machined into cylindrical shape by electrochemical etching. However, the shape of the multiple electrodes and the consistent sizes of the electrodes row are not easy to be controlled. In the electrochemical process, the shape of the cathode electrode determines the current density distribution on the anode and so the forming of multiple electrodes. This paper proposes a finite element method （FEM） to accurately optimize the electrode profile. The microelectrodes row with uniformity diameters with size from hundreds micrometers to several decades could be fabricated, and mathematical model controlling the shape and diameter of multiple microelectrodes was provided. Furthermore, a good agreement between experimental and theoretical results was confirmed.展开更多
A global optimum location algorithm called Variable Step-Size Generalized Simulated Annealing(VSGSA) was applied to treating the data obtained by using an array of ion-electrodes in solutions containing mixtures of Na...A global optimum location algorithm called Variable Step-Size Generalized Simulated Annealing(VSGSA) was applied to treating the data obtained by using an array of ion-electrodes in solutions containing mixtures of Na+, K+, Ca2+. Unlike traditional optimization algorithms such as simplex procedure, VSGSA can be used to determine the model parameters without any priori information about the analytical system under investigation and overcome the disadvantage of simplex method which might converge to local extrema depending on the starting positions. The algorithm was applied to po-tentiometric determination of ions in mixture solutions.展开更多
Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,...Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,and easy-to-perform solution for muscle health monitoring.However,current EIM platforms face a number of limitations,including large device size,wired connections,and instability of the electrode-skin interface,which limit their applicability for monitoring mus-cle movement.In this study,a miniature wireless EIM platform with a user-friendly smartphone app is proposed and devel-oped.The miniature,wireless,multi-frequency(20 kHz-1 MHz)EIM platform is equipped with flexible microneedle array elec-trodes(MAE).The advantages of MAEs over conventional electrodes were demonstrated by physical field modeling simula-tions and skin-electrode contact impedance comparison tests.The smartphone APP was developed to wirelessly operate the EIM platform,and to transmit and process real-time muscle impedance data.To validate its effectiveness,a seven-day adaptive fatigue training study was conducted,which demonstrated that the EIM platform was able to detect muscle adaptations and serve as a reliable indicator of fatigue.This study presents an innovative approach to applying EIM technology to muscle health monitoring and exercise testing,thereby advancing the development of personalized health management and athletic performance assessment.展开更多
Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays...Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays an important role during anesthesia.Currently,a high spatiotemporal resolution microdevice technology for the accurate detection of deep brain nuclei is lacking.In this research,four-shank 32-channel implantable microelectrode arrays(MEAs)were developed for the real-time recording of single-cell level neural information in rat hippocampal CA1.Platinum nanoparticles were modified onto the microelectrodes to substantially enhance the electrical properties of the microelectrode arrays.The modified MEAs exhibited low impedance(11.5±1 kΩ)and small phase delay(-18.5°±2.54°),which enabled the MEAs to record single-cell level neural information with a high signal-to-noise ratio.The MEAs were implanted into the CA1 nuclei of the anesthetized rats,and the electrophysiological signals were recorded under different degrees of anesthesia mediated by low-dose concentrations of isoflurane.The recorded signals were analyzed in depth.Isoflurane caused an inhibition of spike firing rate in hippocampal CA1 neurons,while inducing low-frequency oscillations in CA1,thus enhancing the low-frequency power of local field potentials.In this manner,the spike firing rate and the power of local field potentials in CA1 could characterize the degree of isoflurane anesthesia.The present study provides a technical tool to study the neural mechanisms of isoflurane anesthesia and a research method for monitoring the depth of isoflurane anesthesia in clinical practice.展开更多
Monitoring multiplexed biochemical markers is beneficial for the comprehensive evaluation of diabetes-associated complications.Techniques for multiplexed analyses in interstitial fluids have often been restricted by t...Monitoring multiplexed biochemical markers is beneficial for the comprehensive evaluation of diabetes-associated complications.Techniques for multiplexed analyses in interstitial fluids have often been restricted by the difficulties of electrode materials in accurately detecting chemicals in complex subcutaneous spaces.In particular,the signal stability of enzyme-based sensing electrodes often inevitably decreases due to enzyme degradation or interference in vivo.In this study,we developed a self-calibrating multiplexed microneedle(MN)electrode array(SC-MMNEA)capable of continuous,real-time monitoring of multiple types of bioanalytes(glucose,cholesterol,uric acid,lactate,reactive oxygen species[ROSs],Na+,K+,Ca2+,and pH)in the subcutaneous space.Each type of analyte was detected by a discrete MN electrode assembled in an integrated array with single-MN resolution.Moreover,this device utilized an MN-delivery-mediated self-calibration technique to address the inherent problem of decreased accuracy of implantable electrodes caused by long-term tissue variation and enzyme degradation,and this technique might increase the reliability of the MN sensors.Our results indicated that SC-MMNEA could provide real-time monitoring of multiplexed analyte concentrations in a rat model with good accuracy,especially after self-calibration.SC-MMNEA has the advantages of in situ and minimally invasive monitoring of physiological states and the potential to promote wearable devices for long-term monitoring of chemical species in vivo.展开更多
The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to s...The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice sig- nals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequen- cy analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to dis- tinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes＇ hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized.展开更多
The pursuit of precisely recording and localizing neural activities in brain cortical regions drives the development of advanced electrocorticography(ECoG)devices.Remarkable progress has led to the emergence of micro-...The pursuit of precisely recording and localizing neural activities in brain cortical regions drives the development of advanced electrocorticography(ECoG)devices.Remarkable progress has led to the emergence of micro-ECoG(μECoG)devices with sub-millimeter resolutions.This review presents the current research status,development directions,potential innovations and applications of high-density,high-throughputμECoG devices.First,we summarize the challenges associated with accurately recording single or multiple neurons using existingμECoG devices,including passive multielectrode and active transistor arrays.Second,we focus on cutting-edge advancements in passiveμECoG devices by discussing the design principles and fabrication strategies to optimize three key parameters:impedance,mechanical flexibility,and biocompatibility.Furthermore,recent findings highlight the need for further research and development in active transistor arrays,including silicon,metal oxide,and solution-gated transistors.These active transistor arrays have the potential to unlock the capabilities of high-density,high-throughputμECoG devices and overcome the limitations of passive multielectrode arrays.The review explores the potential innovations and applications ofμECoG devices,showcasing their effectiveness for both brain science research and clinical applications.展开更多
The corrosion behavior of B10 copper-nickel alloy welded joints in seawater pipeline system was analyzed under local turbulence induced by weld residual height.The corrosion behavior was evaluated by array electrode t...The corrosion behavior of B10 copper-nickel alloy welded joints in seawater pipeline system was analyzed under local turbulence induced by weld residual height.The corrosion behavior was evaluated by array electrode technology,mor-phology and elemental characterization,and COMSOL Multiphysics simulation.The results provide a theoretical basis for the corrosion and leakage of B10 alloy in seawater pipeline under the action of turbulence.The results show that residual height-induced turbulence exhibits a significant effect on the corrosion behavior in different areas of welded joints in B10 alloy.Turbulence can damage some surfaces,causing polarity deflection followed by acceleration of corrosion,or it is easier to form a protective film to slow down corrosion.COMSOL Multiphysics results show that the shear rate and turbulent kinetic energy increase linearly with the increase in residual height and velocity.The corrosion behavior of alloy surface is influenced by controlling the mass transfer rate and surface state.展开更多
We investigated erosion-corrosion(E-C) and its mitigation on the internal surface of the expansion segment of N80 steel tube in a loop system using array electrode technique, weight-loss measurement, computational-flu...We investigated erosion-corrosion(E-C) and its mitigation on the internal surface of the expansion segment of N80 steel tube in a loop system using array electrode technique, weight-loss measurement, computational-fluid-dynamics simulation, and surface characterization techniques.The results show that high E-C rates can occur at locations where there is a high flow velocity and/or a strong impact from sand particles, which results in different E-C rates at various locations.Consequently, it can be expected that localized corrosion often occurs in such segments.The E-C rate at each location in the expansion segment can be significantly mitigated with an imidazoline derivative inhibitor, as the resulting inhibitor layer significantly impedes the electrochemical reaction rate.However, we found that this inhibitor layer could not effectively reduce the difference in the erosion rates at different locations on the internal surface of the expansion segment.This means that localized corrosion can still occur at the expansion segment despite the presence of the inhibitor.展开更多
A novel disposable paper-based bipolar electrode （BPE） array is fabricated for multiplexed electrochemiluminescence （ECL） detection of pathogenic DNAs. This proposed BPE array device consists of 15 units, each con...A novel disposable paper-based bipolar electrode （BPE） array is fabricated for multiplexed electrochemiluminescence （ECL） detection of pathogenic DNAs. This proposed BPE array device consists of 15 units, each consisting of six sensing cells and two reporting cells patterned using hydrophobic wax. A hairpin structure DNA assembled on the cathodes of BPEs hybridizes with Pt nanoparticles （NPs） labeled probe DNA in the presence of complementary target DNA. The introduction of Pt NPs catalyzes the reduction of dissolved 02 at cathodes and induces an enhanced ECL signal from Ru（bpy）32＋/tripropylamine （TPrA） at the anodes of BPEs. The dissolved 02 lost in reduction reaction could be promptly replenished due to the relatively large contact area of the paper-based cells with air, which ensures the stability of ECL signal. This obtained paper-based BPE array sensor showed excellent performances for the multiplexed analysis of the syphilis （Treponema pallidum） gene, the immunodeficiency virus gene （HIV） and hepatitis B virus gene （HBV）.展开更多
The electronic excitation temperature in a direct current positive streamer discharge based on ultra-thin sheet electrodes was measured by optical emission spectrometry in order to deposit materials for potential futu...The electronic excitation temperature in a direct current positive streamer discharge based on ultra-thin sheet electrodes was measured by optical emission spectrometry in order to deposit materials for potential future applications. It was remarkable that the electronic excitation temperature （Text） did not vary monotonically with the discharge current, but demonstrated a peak at a certain position. In a mixture of oxygen and argon （80% oxygen）, the maximum Texc reached about 6300 K at an average current of 600 pA. Both the positive ions accumulation in the discharge region and the increase of the local temperature around the streamer channel caused by Joule heating are considered to be the main reasons for the variations of Texc.展开更多
AIM To test of the implantable-cardioverter-defibrillator is done at the time of implantation. We investigate if any testing should be performed.METHODS All consecutive patients between January 2006 and December 2008 ...AIM To test of the implantable-cardioverter-defibrillator is done at the time of implantation. We investigate if any testing should be performed.METHODS All consecutive patients between January 2006 and December 2008 undergoing implantable cardioverterdefibrillator(ICD) implantation/replacement(a total of 634 patients) were included in the retrospective study.RESULTS Sixteen patients(2.5%) were not tested(9 with LA/LVthrombus, 7 due to operator's decision). Analyzed were 618 patients [76% men, 66.4 + 11 years, 24% secondary prevention(SP), 46% with left ventricular ejection fraction(LVEF) < 20%, 56% had coronary artery disease(CAD)] undergoing defibrillation safety testing(SMT) with an energy of 21 + 2.3 J. In 22/618 patients(3.6%) induced ventricular fibrillation(VF) could not be terminated with maximum energy of the ICD. Six of those(27%) had successful SMT after system modification or shock lead repositioning, 14 patients(64%) received a subcutaneous electrode array. Younger age(P = 0.0003), non-CAD(P = 0.007) and VF as index event for SP(P = 0.05) were associated with a higher incidence of ineffective SMT. LVEF < 20% and incomplete revascularisation in patients with CAD had no impact on SMT.CONCLUSION Defibrillation testing is well-tolerated. An ineffective SMT occurred in 4% and two third of those needed implantation of a subcutaneous electrode array to passa SMT > 10 J.展开更多
Background and objective:The size of the cochlea varies a lot among the human population bringing the necessity for electrode arrays to be available in various lengths irrespective of the cochlear implant(CI)brand.Thi...Background and objective:The size of the cochlea varies a lot among the human population bringing the necessity for electrode arrays to be available in various lengths irrespective of the cochlear implant(CI)brand.This research software helps in the estimation of the patient’s cochlear duct length(CDL)which is then used for the simulation of the correct length electrode array matching the patient’s cochlear size and as well in getting the patient specific cochlear frequency map.Methods:Visual Studio Express 2012 for Windows Desktop is used in the architecture of this research software.The basal turn diameter of the cochlea("A"value)needs to be measured from the pre-operative computed tomography(CT)image of the patient’s temporal bone.This"A"will be taken as the input for the CDL equations proposed by Alexiades et al for estimating the CDL along the basilar membrane for various insertion depths.Greenwood’s equation is then used in combination with the CDL for the full length of the cochlea in getting the patient specific frequency map.Results:The research software with the help of the"A"value as input,with few button clicks,gives the patient specific CDL for various insertion depths and the Greenwood’s frequency map.The users have the choice to select any electrode array of their choice and place it under the frequency map to see how good it fits to that particular patient’s cochlea.Also,given the possibility to drag and move the electrode array picture to mimic the post-operative actual electrode insertion depth.Conclusions:This research software simplifies the overall process of CDL estimation and in getting the patient specific cochlear frequency map.The clinicians get the chance to simulate placing the various electrode array lengths in patient cochlea in identifying the best fit electrode.This could help in pushing the CI field into the concept of individualized CI electrode array solution that ultimately benefits the patients.展开更多
NiCoP_(4)O_(12)/NiCoP nanorod-like arrays with tunable grain boundary density and pores were synthesized by the processes composed of hydrothermal and pyrolysis,in which,the electron structure of Ni and Co atoms chara...NiCoP_(4)O_(12)/NiCoP nanorod-like arrays with tunable grain boundary density and pores were synthesized by the processes composed of hydrothermal and pyrolysis,in which,the electron structure of Ni and Co atoms characterized by X-ray photoelectron spectroscopy was contemporaneous inverse manipulated.The optimized NiCoP_(4)O_(12)/NiCoP arrays have a high specific capacitance of 507.8μAh∙cm^(–2)at 1 mA∙cm^(–2),and good rate ability of 64.7%retention at 30-folds increased current density.Importantly,an ultra-stable ability,88.5%of retention after 10000 cycles,was achieved in an asymmetric cell assembled of the NiCoP_(4)O_(12)/NiCoP arrays with activated carbon.In addition,the energy and power densities of an asymmetric cell were higher than those of other work,demonstrating as-prepared NiCoP_(4)O_(12)/NiCoP arrays are promising electrodes for supercapacitors.展开更多
Electrodes based on composites of silver nanowires(AgNWs)and elastic polymers have been widely studied and applied in various stretchable electronic devices.However,due to the high aspect ratio of nanowires,the patter...Electrodes based on composites of silver nanowires(AgNWs)and elastic polymers have been widely studied and applied in various stretchable electronic devices.However,due to the high aspect ratio of nanowires,the patterning of AgNW-based composite electrodes remains a huge challenge,especially for high-resolution complex circuit wiring on large-size elastic substrates.In this paper,we propose a method for preparing large-size stretchable circuit boards with high-resolution electrodes by the combination of screen printing and vacuum filtration of AgNWs/polydimethylsiloxane(PDMS)composite.The as-prepared stretchable electrodes have smooth edges with patterning resolution up to-50 μm.The conductivity of the composite electrode can be precisely controlled by varying deposition densities of AgNWs and have reached to 1.07 x 10^(4) S/cm when the deposition density was 2.0 mg/cm^(2).In addition,the uniformity of conductivity and the resistance-strain characteristics of composite electrodes were systematically evaluated with different AgNWs deposition densities.The composite electrodes have been successfully employed to construct a large-size programmable display system and an 18-channel surface electromyography(EMG)recording,showing great potentials for some strain-insensitive stretchable circuits in wearable and health-related electronic applications.展开更多
The auditory brainstem implant(ABI)was originally developed to provide rehabilitation of retrocochlear deafness caused by neurofibromatosis type 2(NF2).Recent studies of the ABI have investigated outcomes in non-NF2 c...The auditory brainstem implant(ABI)was originally developed to provide rehabilitation of retrocochlear deafness caused by neurofibromatosis type 2(NF2).Recent studies of the ABI have investigated outcomes in non-NF2 cohorts,such as patients with cochlear nerve aplasia or cochlear ossification and more recently,intractable tinnitus.New technologies that improve the ABI-neural tissue interface are being explored as means to improve performance and decrease side effects.Innovative discoveries in optogenetics and bioengineering present opportunities to continually evolve this technology into the future,enhancing spatial selectivity of neuronal activation in the cochlear nucleus and preventing side effects through reduction in activation of non-target neuronal circuitry.These advances will improve surgical planning and ultimately improve patients1 audiological capabilities.ABI research has rapidly increased in the 21st century and applications of this technology are likely to continually evolve.Herein,we aim to characterize ongoing clinical,basic science,and bioengineering advances in ABIs and discuss future directions of this technology.展开更多
This pilot study presents a novel application of high density surface electromyography(EMG)decomposition in pediatric patients,with a view toward promoting its potential clinical application for examination of pediatr...This pilot study presents a novel application of high density surface electromyography(EMG)decomposition in pediatric patients,with a view toward promoting its potential clinical application for examination of pediatricneuromuscular diseases.Automatic progressive FastICA peel-off(APFP)framework was used to decompose high density surface EMG signals recorded from the first dorsal interosseous and abductor pollicis brevis muscles ofchildren with spinal muscular atrophy.The performance of the decomposition with reduced EMG recordingchannels was also investigated.In total 131 motor units were extracted from 15 trials of 64-channel(8×8)surface EMG.The decomposition yield reduced to 102 motor units when 36-channel(6×6)was used,amongwhich 84 motor units were common ones with an average matching rate of(95.68±5.26)%.The decompositionyield further reduced to 65 motor units when only 16-channel(4×4)was used,among which 57 were common ones with an average matching rate of(95.99±4.56)%.These results indicate that using the APFP frameworksingle motor unit activity can be reliably and automatically extracted from pediatric surface EMG signals recordedby an electrode array,which can facilitate potential clinical application of surface EMG as an alternative or supplement to invasive needle EMG for examination of neuromuscular diseases in children.展开更多
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ23E010004)the National Key Research and Development Program of China(No.2021YFB3200801)。
文摘Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose cell-electrode interface.To investigate intracellular electrophysiological signals with high sensitivity,electroporation was used to obtain intracellular recordings.In this study,a biosensing system based on a nanoporous electrode array(NPEA)integrating electrical perforation and signal acquisition was established to dynamically and sensitively record the intracellular potential of cardiomyocytes over a long period of time.Moreover,nanoporous electrodes can induce the protrusion of cell membranes and enhance cell-electrode interfacial coupling,thereby facilitating effective electroporation.Electrophysiological signals over the entire recording process can be quantitatively and segmentally analyzed according to the signal changes,which can equivalently reflect the dynamic evolution of the electroporated cardiomyocyte membrane.We believe that the low-cost and high-performance nanoporous biosensing platform suggested in this study can dynamically record intracellular action potential,evaluate cardiomyocyte electroporation,and provide a new strategy for investigating cardiology pharmacological science.
基金supported by the National Natural Science Foundation of China,Nos.61534003 (to ZGW) and 61874024 (to ZGW)。
文摘Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation.To activate lower-limb muscles precisely by epidural spinal cord stimulation,we proposed a high-density,flexible electrode array.We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord,which was established by a transection method.For evaluating the effect of stimulation,the evoked potentials were recorded from bilateral lowerlimb muscles,including the vastus lateralis,semitendinosus,tibialis anterior,and medial gastrocnemius.To determine the appropriate stimulation sites and parameters of the lower muscles,the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation.In the vastus lateralis and medial gastrocnemius,these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment,respectively.The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles.The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius.Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array.They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury.This study was approved by the Animal Research Committee of Southeast University,China(approval No.20190720001) on July 20,2019.
基金the financial support from China Aviation Science Foundation (04H52055).
文摘Process technology of multiple cylindrical micro-pins by wire-electrical discharge machining （wire-EDM） and electrochemical etching was presented. A row of rectangular micro-columns were machined by wire-EDM and then machined into cylindrical shape by electrochemical etching. However, the shape of the multiple electrodes and the consistent sizes of the electrodes row are not easy to be controlled. In the electrochemical process, the shape of the cathode electrode determines the current density distribution on the anode and so the forming of multiple electrodes. This paper proposes a finite element method （FEM） to accurately optimize the electrode profile. The microelectrodes row with uniformity diameters with size from hundreds micrometers to several decades could be fabricated, and mathematical model controlling the shape and diameter of multiple microelectrodes was provided. Furthermore, a good agreement between experimental and theoretical results was confirmed.
基金Supported by the National Natural Science Foundation of China Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Academia Sinica
文摘A global optimum location algorithm called Variable Step-Size Generalized Simulated Annealing(VSGSA) was applied to treating the data obtained by using an array of ion-electrodes in solutions containing mixtures of Na+, K+, Ca2+. Unlike traditional optimization algorithms such as simplex procedure, VSGSA can be used to determine the model parameters without any priori information about the analytical system under investigation and overcome the disadvantage of simplex method which might converge to local extrema depending on the starting positions. The algorithm was applied to po-tentiometric determination of ions in mixture solutions.
文摘Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,and easy-to-perform solution for muscle health monitoring.However,current EIM platforms face a number of limitations,including large device size,wired connections,and instability of the electrode-skin interface,which limit their applicability for monitoring mus-cle movement.In this study,a miniature wireless EIM platform with a user-friendly smartphone app is proposed and devel-oped.The miniature,wireless,multi-frequency(20 kHz-1 MHz)EIM platform is equipped with flexible microneedle array elec-trodes(MAE).The advantages of MAEs over conventional electrodes were demonstrated by physical field modeling simula-tions and skin-electrode contact impedance comparison tests.The smartphone APP was developed to wirelessly operate the EIM platform,and to transmit and process real-time muscle impedance data.To validate its effectiveness,a seven-day adaptive fatigue training study was conducted,which demonstrated that the EIM platform was able to detect muscle adaptations and serve as a reliable indicator of fatigue.This study presents an innovative approach to applying EIM technology to muscle health monitoring and exercise testing,thereby advancing the development of personalized health management and athletic performance assessment.
基金sponsored by the National Natural Science Foundation of China(T2293731,61960206012,62121003,62171434,61971400,61975206,and 61973292)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(GJJSTD20210004)+1 种基金the National Key Research and Development Program(2022YFC2402501,2022YFB3205602)Major Program of Scientific and Technical Innovation 2030(2021ZD0201603).
文摘Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays an important role during anesthesia.Currently,a high spatiotemporal resolution microdevice technology for the accurate detection of deep brain nuclei is lacking.In this research,four-shank 32-channel implantable microelectrode arrays(MEAs)were developed for the real-time recording of single-cell level neural information in rat hippocampal CA1.Platinum nanoparticles were modified onto the microelectrodes to substantially enhance the electrical properties of the microelectrode arrays.The modified MEAs exhibited low impedance(11.5±1 kΩ)and small phase delay(-18.5°±2.54°),which enabled the MEAs to record single-cell level neural information with a high signal-to-noise ratio.The MEAs were implanted into the CA1 nuclei of the anesthetized rats,and the electrophysiological signals were recorded under different degrees of anesthesia mediated by low-dose concentrations of isoflurane.The recorded signals were analyzed in depth.Isoflurane caused an inhibition of spike firing rate in hippocampal CA1 neurons,while inducing low-frequency oscillations in CA1,thus enhancing the low-frequency power of local field potentials.In this manner,the spike firing rate and the power of local field potentials in CA1 could characterize the degree of isoflurane anesthesia.The present study provides a technical tool to study the neural mechanisms of isoflurane anesthesia and a research method for monitoring the depth of isoflurane anesthesia in clinical practice.
基金support from the National Natural Sci-ence Foundation of China(grant nos.T2225010,32171399,and 32171456)Guangdong Basic and Applied Basic Research Foundation(grant no.2023A1515011267)+1 种基金Science and Technalogy Program of Guangzhou,China(grant nos.2024B03J0121 and 2024B03J1284)the Independent Fund of the State Key Laboratory of Optoelectronic Ma-terials and Technologies(Sun YatSen University)under grant no.
文摘Monitoring multiplexed biochemical markers is beneficial for the comprehensive evaluation of diabetes-associated complications.Techniques for multiplexed analyses in interstitial fluids have often been restricted by the difficulties of electrode materials in accurately detecting chemicals in complex subcutaneous spaces.In particular,the signal stability of enzyme-based sensing electrodes often inevitably decreases due to enzyme degradation or interference in vivo.In this study,we developed a self-calibrating multiplexed microneedle(MN)electrode array(SC-MMNEA)capable of continuous,real-time monitoring of multiple types of bioanalytes(glucose,cholesterol,uric acid,lactate,reactive oxygen species[ROSs],Na+,K+,Ca2+,and pH)in the subcutaneous space.Each type of analyte was detected by a discrete MN electrode assembled in an integrated array with single-MN resolution.Moreover,this device utilized an MN-delivery-mediated self-calibration technique to address the inherent problem of decreased accuracy of implantable electrodes caused by long-term tissue variation and enzyme degradation,and this technique might increase the reliability of the MN sensors.Our results indicated that SC-MMNEA could provide real-time monitoring of multiplexed analyte concentrations in a rat model with good accuracy,especially after self-calibration.SC-MMNEA has the advantages of in situ and minimally invasive monitoring of physiological states and the potential to promote wearable devices for long-term monitoring of chemical species in vivo.
基金supported by the National Natural Science Foundation of China,No.60672001Special Fund of Education Department of Shaanxi Province,China,No.05JC03
文摘The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice sig- nals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequen- cy analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to dis- tinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes＇ hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized.
基金supported by the National Natural Science Foundation of China(T2425003,52272277 and T2241026).
文摘The pursuit of precisely recording and localizing neural activities in brain cortical regions drives the development of advanced electrocorticography(ECoG)devices.Remarkable progress has led to the emergence of micro-ECoG(μECoG)devices with sub-millimeter resolutions.This review presents the current research status,development directions,potential innovations and applications of high-density,high-throughputμECoG devices.First,we summarize the challenges associated with accurately recording single or multiple neurons using existingμECoG devices,including passive multielectrode and active transistor arrays.Second,we focus on cutting-edge advancements in passiveμECoG devices by discussing the design principles and fabrication strategies to optimize three key parameters:impedance,mechanical flexibility,and biocompatibility.Furthermore,recent findings highlight the need for further research and development in active transistor arrays,including silicon,metal oxide,and solution-gated transistors.These active transistor arrays have the potential to unlock the capabilities of high-density,high-throughputμECoG devices and overcome the limitations of passive multielectrode arrays.The review explores the potential innovations and applications ofμECoG devices,showcasing their effectiveness for both brain science research and clinical applications.
基金support from the National Natural Science Foundation of China(Grant No.42176209)the Natural Science Foundation of Shandong Province(Grant No.ZR2021MD064)the Fundamental Research Funds for the Central Universities(Grant No.19CX05001A).
文摘The corrosion behavior of B10 copper-nickel alloy welded joints in seawater pipeline system was analyzed under local turbulence induced by weld residual height.The corrosion behavior was evaluated by array electrode technology,mor-phology and elemental characterization,and COMSOL Multiphysics simulation.The results provide a theoretical basis for the corrosion and leakage of B10 alloy in seawater pipeline under the action of turbulence.The results show that residual height-induced turbulence exhibits a significant effect on the corrosion behavior in different areas of welded joints in B10 alloy.Turbulence can damage some surfaces,causing polarity deflection followed by acceleration of corrosion,or it is easier to form a protective film to slow down corrosion.COMSOL Multiphysics results show that the shear rate and turbulent kinetic energy increase linearly with the increase in residual height and velocity.The corrosion behavior of alloy surface is influenced by controlling the mass transfer rate and surface state.
基金financially supported by the 111 Project (No.D18016)the Application and Fundamental Research of Sichuan Province, China (No.2017JY0171)the Scientific and Technological Innovation Team for the Safety of Petroleum Tubular Goods in Southwest Petroleum University (No.2018CXTD01)。
文摘We investigated erosion-corrosion(E-C) and its mitigation on the internal surface of the expansion segment of N80 steel tube in a loop system using array electrode technique, weight-loss measurement, computational-fluid-dynamics simulation, and surface characterization techniques.The results show that high E-C rates can occur at locations where there is a high flow velocity and/or a strong impact from sand particles, which results in different E-C rates at various locations.Consequently, it can be expected that localized corrosion often occurs in such segments.The E-C rate at each location in the expansion segment can be significantly mitigated with an imidazoline derivative inhibitor, as the resulting inhibitor layer significantly impedes the electrochemical reaction rate.However, we found that this inhibitor layer could not effectively reduce the difference in the erosion rates at different locations on the internal surface of the expansion segment.This means that localized corrosion can still occur at the expansion segment despite the presence of the inhibitor.
基金supported by the National Basic Research Program of China(2012CB932600)the National Natural Science Foundation of China(21327902,21475058,21121091)
文摘A novel disposable paper-based bipolar electrode （BPE） array is fabricated for multiplexed electrochemiluminescence （ECL） detection of pathogenic DNAs. This proposed BPE array device consists of 15 units, each consisting of six sensing cells and two reporting cells patterned using hydrophobic wax. A hairpin structure DNA assembled on the cathodes of BPEs hybridizes with Pt nanoparticles （NPs） labeled probe DNA in the presence of complementary target DNA. The introduction of Pt NPs catalyzes the reduction of dissolved 02 at cathodes and induces an enhanced ECL signal from Ru（bpy）32＋/tripropylamine （TPrA） at the anodes of BPEs. The dissolved 02 lost in reduction reaction could be promptly replenished due to the relatively large contact area of the paper-based cells with air, which ensures the stability of ECL signal. This obtained paper-based BPE array sensor showed excellent performances for the multiplexed analysis of the syphilis （Treponema pallidum） gene, the immunodeficiency virus gene （HIV） and hepatitis B virus gene （HBV）.
文摘The electronic excitation temperature in a direct current positive streamer discharge based on ultra-thin sheet electrodes was measured by optical emission spectrometry in order to deposit materials for potential future applications. It was remarkable that the electronic excitation temperature （Text） did not vary monotonically with the discharge current, but demonstrated a peak at a certain position. In a mixture of oxygen and argon （80% oxygen）, the maximum Texc reached about 6300 K at an average current of 600 pA. Both the positive ions accumulation in the discharge region and the increase of the local temperature around the streamer channel caused by Joule heating are considered to be the main reasons for the variations of Texc.
文摘AIM To test of the implantable-cardioverter-defibrillator is done at the time of implantation. We investigate if any testing should be performed.METHODS All consecutive patients between January 2006 and December 2008 undergoing implantable cardioverterdefibrillator(ICD) implantation/replacement(a total of 634 patients) were included in the retrospective study.RESULTS Sixteen patients(2.5%) were not tested(9 with LA/LVthrombus, 7 due to operator's decision). Analyzed were 618 patients [76% men, 66.4 + 11 years, 24% secondary prevention(SP), 46% with left ventricular ejection fraction(LVEF) < 20%, 56% had coronary artery disease(CAD)] undergoing defibrillation safety testing(SMT) with an energy of 21 + 2.3 J. In 22/618 patients(3.6%) induced ventricular fibrillation(VF) could not be terminated with maximum energy of the ICD. Six of those(27%) had successful SMT after system modification or shock lead repositioning, 14 patients(64%) received a subcutaneous electrode array. Younger age(P = 0.0003), non-CAD(P = 0.007) and VF as index event for SP(P = 0.05) were associated with a higher incidence of ineffective SMT. LVEF < 20% and incomplete revascularisation in patients with CAD had no impact on SMT.CONCLUSION Defibrillation testing is well-tolerated. An ineffective SMT occurred in 4% and two third of those needed implantation of a subcutaneous electrode array to passa SMT > 10 J.
文摘Background and objective:The size of the cochlea varies a lot among the human population bringing the necessity for electrode arrays to be available in various lengths irrespective of the cochlear implant(CI)brand.This research software helps in the estimation of the patient’s cochlear duct length(CDL)which is then used for the simulation of the correct length electrode array matching the patient’s cochlear size and as well in getting the patient specific cochlear frequency map.Methods:Visual Studio Express 2012 for Windows Desktop is used in the architecture of this research software.The basal turn diameter of the cochlea("A"value)needs to be measured from the pre-operative computed tomography(CT)image of the patient’s temporal bone.This"A"will be taken as the input for the CDL equations proposed by Alexiades et al for estimating the CDL along the basilar membrane for various insertion depths.Greenwood’s equation is then used in combination with the CDL for the full length of the cochlea in getting the patient specific frequency map.Results:The research software with the help of the"A"value as input,with few button clicks,gives the patient specific CDL for various insertion depths and the Greenwood’s frequency map.The users have the choice to select any electrode array of their choice and place it under the frequency map to see how good it fits to that particular patient’s cochlea.Also,given the possibility to drag and move the electrode array picture to mimic the post-operative actual electrode insertion depth.Conclusions:This research software simplifies the overall process of CDL estimation and in getting the patient specific cochlear frequency map.The clinicians get the chance to simulate placing the various electrode array lengths in patient cochlea in identifying the best fit electrode.This could help in pushing the CI field into the concept of individualized CI electrode array solution that ultimately benefits the patients.
基金he Natural Science Foundation of Shandong Province of China(Grant No.ZR2020MB024)and the Open Project Program of Guangdong Provincial Key Laboratory for Electronic Functional Materials and Devices,Huizhou University(Grant No.EFMD2021001Z)for financially supporting this work.
文摘NiCoP_(4)O_(12)/NiCoP nanorod-like arrays with tunable grain boundary density and pores were synthesized by the processes composed of hydrothermal and pyrolysis,in which,the electron structure of Ni and Co atoms characterized by X-ray photoelectron spectroscopy was contemporaneous inverse manipulated.The optimized NiCoP_(4)O_(12)/NiCoP arrays have a high specific capacitance of 507.8μAh∙cm^(–2)at 1 mA∙cm^(–2),and good rate ability of 64.7%retention at 30-folds increased current density.Importantly,an ultra-stable ability,88.5%of retention after 10000 cycles,was achieved in an asymmetric cell assembled of the NiCoP_(4)O_(12)/NiCoP arrays with activated carbon.In addition,the energy and power densities of an asymmetric cell were higher than those of other work,demonstrating as-prepared NiCoP_(4)O_(12)/NiCoP arrays are promising electrodes for supercapacitors.
基金This work was supported by the National Key R&D Program of China(No.2017YFE0112000)the National Natural Science Foundation of China(NSFC)(No.51603227).
文摘Electrodes based on composites of silver nanowires(AgNWs)and elastic polymers have been widely studied and applied in various stretchable electronic devices.However,due to the high aspect ratio of nanowires,the patterning of AgNW-based composite electrodes remains a huge challenge,especially for high-resolution complex circuit wiring on large-size elastic substrates.In this paper,we propose a method for preparing large-size stretchable circuit boards with high-resolution electrodes by the combination of screen printing and vacuum filtration of AgNWs/polydimethylsiloxane(PDMS)composite.The as-prepared stretchable electrodes have smooth edges with patterning resolution up to-50 μm.The conductivity of the composite electrode can be precisely controlled by varying deposition densities of AgNWs and have reached to 1.07 x 10^(4) S/cm when the deposition density was 2.0 mg/cm^(2).In addition,the uniformity of conductivity and the resistance-strain characteristics of composite electrodes were systematically evaluated with different AgNWs deposition densities.The composite electrodes have been successfully employed to construct a large-size programmable display system and an 18-channel surface electromyography(EMG)recording,showing great potentials for some strain-insensitive stretchable circuits in wearable and health-related electronic applications.
基金Swiss National Science Foundation,Grant numbers:W81XWH-17-NFRP-IIRASinergia Neuroprosthetic Platform for Personalized and Impantable Systems,US Department of Defense Grant numbers:W81XWH-17-NFRP-IIRA.
文摘The auditory brainstem implant(ABI)was originally developed to provide rehabilitation of retrocochlear deafness caused by neurofibromatosis type 2(NF2).Recent studies of the ABI have investigated outcomes in non-NF2 cohorts,such as patients with cochlear nerve aplasia or cochlear ossification and more recently,intractable tinnitus.New technologies that improve the ABI-neural tissue interface are being explored as means to improve performance and decrease side effects.Innovative discoveries in optogenetics and bioengineering present opportunities to continually evolve this technology into the future,enhancing spatial selectivity of neuronal activation in the cochlear nucleus and preventing side effects through reduction in activation of non-target neuronal circuitry.These advances will improve surgical planning and ultimately improve patients1 audiological capabilities.ABI research has rapidly increased in the 21st century and applications of this technology are likely to continually evolve.Herein,we aim to characterize ongoing clinical,basic science,and bioengineering advances in ABIs and discuss future directions of this technology.
基金This study was supported by the Natural Science Foundation of Shandong Province under Grant ZR2020KF012.The authors would like to thank Faezeh Jahanmiri-Nezhad,PhD and Xiaoyan Li,PhD for their help in data collection.
文摘This pilot study presents a novel application of high density surface electromyography(EMG)decomposition in pediatric patients,with a view toward promoting its potential clinical application for examination of pediatricneuromuscular diseases.Automatic progressive FastICA peel-off(APFP)framework was used to decompose high density surface EMG signals recorded from the first dorsal interosseous and abductor pollicis brevis muscles ofchildren with spinal muscular atrophy.The performance of the decomposition with reduced EMG recordingchannels was also investigated.In total 131 motor units were extracted from 15 trials of 64-channel(8×8)surface EMG.The decomposition yield reduced to 102 motor units when 36-channel(6×6)was used,amongwhich 84 motor units were common ones with an average matching rate of(95.68±5.26)%.The decompositionyield further reduced to 65 motor units when only 16-channel(4×4)was used,among which 57 were common ones with an average matching rate of(95.99±4.56)%.These results indicate that using the APFP frameworksingle motor unit activity can be reliably and automatically extracted from pediatric surface EMG signals recordedby an electrode array,which can facilitate potential clinical application of surface EMG as an alternative or supplement to invasive needle EMG for examination of neuromuscular diseases in children.
