The Experts below are selected from a list of 52548 Experts worldwide ranked by ideXlab platform
Wolfgang Gstoettner - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of an improved cochlear implant Electrode Design for electric acoustic stimulation
Laryngoscope, 2004Co-Authors: Oliver F Adunka, Jan Kiefer, Marc H Unkelbach, Thomas Lehnert, Wolfgang GstoettnerAbstract:Objective: The objective of this study was to assess the intracochlear position and the extent of trauma to cochlear structures using a new prototype Electrode carrier (Flex EAS). Special emphasis was placed on the practicality for combined electric and acoustic stimulation of the auditory system. Study Design: Human temporal bones were evaluated histologically after insertion of the Electrodes, and insertion forces were measured in an acrylic model of the scala tympani. Methods: 1) Insertion forces with the regular C40+ array and the new Electrode prototype were measured in an acrylic model of the scala tympani. 2) Ten human temporal bones were implanted using the same surgical procedure as in vivo. All bones underwent fixation methylmethacrylate embedding to allow cutting of the undecalcified bone with the Electrode in situ. In addition, radiography of the implanted devices was performed and correlated to histologic results. Electrode positions and trauma to cochlear structures were then evaluated histologically. Results: All insertions of the new Electrode array were performed in the scala tympani of the cochlea. All insertions were atraumatic and covered one cochlear turn. The only effect on cochlear structures that could be observed was a slight lifting of the basilar membrane in the middle turn limited to the tip of the Electrode. In three bones, basal trauma, which resulted from the cochleostomy itself, could be observed as well. All neural structures remained intact. Conclusions: The new Electrode prototype provides very good mechanical properties for safe and atraumatic implantation. All criteria for the use in hearing-preservation cochlear implantation for electric and acoustic stimulation were fulfilled. Surgical measures to prevent basal trauma appear to be very important Cochlear implant, intracochlear trauma, electric acoustic stimulation.
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development and evaluation of an improved cochlear implant Electrode Design for electric acoustic stimulation
Laryngoscope, 2004Co-Authors: Oliver F Adunka, Jan Kiefer, Marc H Unkelbach, Thomas Lehnert, Wolfgang GstoettnerAbstract:Objective: The objective of this study was to assess the intracochlear position and the extent of trauma to cochlear structures using a new prototype Electrode carrier (Flex EAS). Special emphasis was placed on the practicality for combined electric and acoustic stimulation of the auditory system. Study Design: Human temporal bones were evaluated histologically after insertion of the Electrodes, and insertion forces were measured in an acrylic model of the scala tympani. Methods: 1) Insertion forces with the regular C40+ array and the new Electrode prototype were measured in an acrylic model of the scala tympani. 2) Ten human temporal bones were implanted using the same surgical procedure as in vivo. All bones underwent fixation methylmethacrylate embedding to allow cutting of the undecalcified bone with the Electrode in situ. In addition, radiography of the implanted devices was performed and correlated to histologic results. Electrode positions and trauma to cochlear structures were then evaluated histologically. Results: All insertions of the new Electrode array were performed in the scala tympani of the cochlea. All insertions were atraumatic and covered one cochlear turn. The only effect on cochlear structures that could be observed was a slight lifting of the basilar membrane in the middle turn limited to the tip of the Electrode. In three bones, basal trauma, which resulted from the cochleostomy itself, could be observed as well. All neural structures remained intact. Conclusions: The new Electrode prototype provides very good mechanical properties for safe and atraumatic implantation. All criteria for the use in hearing-preservation cochlear implantation for electric and acoustic stimulation were fulfilled. Surgical measures to prevent basal trauma appear to be very important Cochlear implant, intracochlear trauma, electric acoustic stimulation.
Cameron C Mcintyre - One of the best experts on this subject based on the ideXlab platform.
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role of Electrode Design on the volume of tissue activated during deep brain stimulation
Journal of Neural Engineering, 2006Co-Authors: Christopher R Butson, Cameron C McintyreAbstract:Deep brain stimulation (DBS) is an established clinical treatment for a range of neurological disorders. Depending on the disease state of the patient, different anatomical structures such as the ventral intermediate nucleus of the thalamus (VIM), the subthalamic nucleus or the globus pallidus are targeted for stimulation. However, the same Electrode Design is currently used in nearly all DBS applications, even though substantial morphological and anatomical differences exist between the various target nuclei. The fundamental goal of this study was to develop a theoretical understanding of the impact of changes in the DBS Electrode contact geometry on the volume of tissue activated (VTA) during stimulation. Finite element models of the Electrodes and surrounding medium were coupled to cable models of myelinated axons to predict the VTA as a function of stimulation parameter settings and Electrode Design. Clinical DBS Electrodes have cylindrical contacts 1.27 mm in diameter (d) and 1.5 mm in height (h). Our results show that changes in contact height and diameter can substantially modulate the size and shape of the VTA, even when contact surface area is preserved. Electrode Designs with a low aspect ratio (d/h) maximize the VTA by providing greater spread of the stimulation parallel to the Electrode shaft without sacrificing lateral spread. The results of this study provide the foundation necessary to customize Electrode Design and VTA shape for specific anatomical targets, and an example is presented for the VIM. A range of opportunities exist to engineer DBS systems to maximize stimulation of the target area while minimizing stimulation of non-target areas. Therefore, it may be possible to improve therapeutic benefit and minimize side effects from DBS with the Design of target-specific Electrodes.
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tissue and Electrode capacitance reduce neural activation volumes during deep brain stimulation
Clinical Neurophysiology, 2005Co-Authors: Christopher R Butson, Cameron C McintyreAbstract:Objective The growing clinical acceptance of neurostimulation technology has highlighted the need to accurately predict neural activation as a function of stimulation parameters and Electrode Design. In this study we evaluate the effects of the tissue and Electrode capacitance on the volume of tissue activated (VTA) during deep brain stimulation (DBS).
Oliver F Adunka - One of the best experts on this subject based on the ideXlab platform.
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development and evaluation of an improved cochlear implant Electrode Design for electric acoustic stimulation
Laryngoscope, 2004Co-Authors: Oliver F Adunka, Jan Kiefer, Marc H Unkelbach, Thomas Lehnert, Wolfgang GstoettnerAbstract:Objective: The objective of this study was to assess the intracochlear position and the extent of trauma to cochlear structures using a new prototype Electrode carrier (Flex EAS). Special emphasis was placed on the practicality for combined electric and acoustic stimulation of the auditory system. Study Design: Human temporal bones were evaluated histologically after insertion of the Electrodes, and insertion forces were measured in an acrylic model of the scala tympani. Methods: 1) Insertion forces with the regular C40+ array and the new Electrode prototype were measured in an acrylic model of the scala tympani. 2) Ten human temporal bones were implanted using the same surgical procedure as in vivo. All bones underwent fixation methylmethacrylate embedding to allow cutting of the undecalcified bone with the Electrode in situ. In addition, radiography of the implanted devices was performed and correlated to histologic results. Electrode positions and trauma to cochlear structures were then evaluated histologically. Results: All insertions of the new Electrode array were performed in the scala tympani of the cochlea. All insertions were atraumatic and covered one cochlear turn. The only effect on cochlear structures that could be observed was a slight lifting of the basilar membrane in the middle turn limited to the tip of the Electrode. In three bones, basal trauma, which resulted from the cochleostomy itself, could be observed as well. All neural structures remained intact. Conclusions: The new Electrode prototype provides very good mechanical properties for safe and atraumatic implantation. All criteria for the use in hearing-preservation cochlear implantation for electric and acoustic stimulation were fulfilled. Surgical measures to prevent basal trauma appear to be very important Cochlear implant, intracochlear trauma, electric acoustic stimulation.
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development and evaluation of an improved cochlear implant Electrode Design for electric acoustic stimulation
Laryngoscope, 2004Co-Authors: Oliver F Adunka, Jan Kiefer, Marc H Unkelbach, Thomas Lehnert, Wolfgang GstoettnerAbstract:Objective: The objective of this study was to assess the intracochlear position and the extent of trauma to cochlear structures using a new prototype Electrode carrier (Flex EAS). Special emphasis was placed on the practicality for combined electric and acoustic stimulation of the auditory system. Study Design: Human temporal bones were evaluated histologically after insertion of the Electrodes, and insertion forces were measured in an acrylic model of the scala tympani. Methods: 1) Insertion forces with the regular C40+ array and the new Electrode prototype were measured in an acrylic model of the scala tympani. 2) Ten human temporal bones were implanted using the same surgical procedure as in vivo. All bones underwent fixation methylmethacrylate embedding to allow cutting of the undecalcified bone with the Electrode in situ. In addition, radiography of the implanted devices was performed and correlated to histologic results. Electrode positions and trauma to cochlear structures were then evaluated histologically. Results: All insertions of the new Electrode array were performed in the scala tympani of the cochlea. All insertions were atraumatic and covered one cochlear turn. The only effect on cochlear structures that could be observed was a slight lifting of the basilar membrane in the middle turn limited to the tip of the Electrode. In three bones, basal trauma, which resulted from the cochleostomy itself, could be observed as well. All neural structures remained intact. Conclusions: The new Electrode prototype provides very good mechanical properties for safe and atraumatic implantation. All criteria for the use in hearing-preservation cochlear implantation for electric and acoustic stimulation were fulfilled. Surgical measures to prevent basal trauma appear to be very important Cochlear implant, intracochlear trauma, electric acoustic stimulation.
Yu-ming Chen - One of the best experts on this subject based on the ideXlab platform.
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jackfruit like Electrode Design for advanced na se batteries
Journal of Power Sources, 2019Co-Authors: Qiuju Xu, Yu-ming Chen, Tingting Yang, Renming Zhan, Xiaoyan Li, Youquan Zhang, Maowen XuAbstract:Abstract Sodium-selenium (Na–Se) batteries are attracting much attention because of their high energy density. However, their practical application is still restricted by rapid capacity fading resulting from the inferior Electrode kinetics, low utilization of Se and enormous volumetric expansion. Herein, a jackfruit-like Electrode is Designed for advanced Na–Se batteries to solve these problems. The carbon nanorods are well-aligned to form a jackfruit-like Design as the Se host. Thanks to the unique structure, many hollow nanochannels between nanorods are able to provide multifold pathways for Na-ions diffusion and electrolyte penetration. Moreover, the nanopores in carbon nanorods can provide adequate space to store Se and to buffer volumetric expansion during cycling. More importantly, the well-aligned carbon nanorods can enable a fast electron transfer to improve the utilization of Se. As a result, the jackfruit-like Se-carbon Electrodes exhibit a high capacity of 616 mAh g−1 at 0.2 C, outstanding rate capability and long cycling life up to 600 cycles at 2 C with a very low capacity decay of 0.066% per cycle.
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a railway like network Electrode Design for room temperature na s battery
Journal of Materials Chemistry, 2019Co-Authors: Tingting Yang, Yu-ming Chen, Renming Zhan, Qiuju Xu, Hong He, Xiaoyan Li, Maowen XuAbstract:Poor conductivity and severe volume expansion of sulfur (S) Electrode are the key issues for the practical application of room temperature Na–S battery. In this paper, we propose a 3D railway-like Electrode Design to tackle these problems for room temperature Na–S battery. Nitrogen-doped porous carbon polyhedrons (NPCs) as “station” for loading S are tightly concatenated by 1D carbon nanotubes (CNTs) as “railway” for transporting electrons to form a 3D railway-like network (CNT/NPC) as S host. The 3D cross-linked railway-like network not only facilitates the rapid transfer of electrons for high capacity but also connects the polyhedrons during the cycling maintaining the integrity of the Electrode. With this rational Design, 3D railway-like S@CNT/NPC Electrode shows a high discharge capacity of ∼601 mA h g−1 at 0.5C and outstanding rate capability. In addition, a high capacity of 410 mA h g−1 can still be achieved after 500 cycles with a very low capacity decay rate of 0.064% per cycle.
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Chinese knot-like Electrode Design for advanced Li-S batteries
Nano Energy, 2018Co-Authors: Chunlong Dai, Yu-ming Chen, Rui Wang, Heng Liu, Hao Chen, Shu-juan Bao, Graeme HenkelmanAbstract:Abstract Rational Design of Li-S batteries requires efficient prevention of sulfur mobility and fast redox kinetics while accommodating the volumetric expansion of the sulfur cathode. Herein, we propose a multifunctional Chinese knot-like Electrode Design for advanced Li-S batteries. NiCo2S4 nanotubes are closely interwoven to form Chinese knot-like Designs as a sulfur host. The unique interconnectivity of the 2D Chinese knot-like networks constructed by 1D nanostructured nanotubes enables fast electron transfer for high capacity. Furthermore, the hollow structure can simultaneously provide enough space for volumetric expansion of sulfur and confine lithium polysulfides (LiPSs) in the internal void space by structural encapsulation. Besides these, experimental and theoretical analysis demonstrates that NiCo2S4 can effectively capture the LiPSs and then catalyze the captured LiPSs into solid Li2S2/Li2S. More importantly, the transition between low-spin and high-spin of Co ions, induced by extra sulfur atoms from LiPSs, provides an electronic way to stabilize the adsorption system and reduce system energy, leading to the inhibition of the shuttle effect in Li-S batteries. As a result, the Chinese knot-like S@NiCo2S4 Electrodes show a high capacity of 1348 mA h g−1 at 0.1 C and long cycling life up to 1000 cycles with a slow capacity decay of 0.02% per cycle at 1 C. Even with a higher sulfur loading of 5 mg cm−2, the Electrodes still deliver good electrochemical performance.
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muscle like Electrode Design for li te batteries
Energy Storage Materials, 2018Co-Authors: Minqiang Wang, Yu-ming Chen, Ting Liu, Shu-juan BaoAbstract:Abstract Li-Te batteries have been attracted much attention as a potential research for energy storage systems due to the overwhelming features in superior electronic conductivity and ultrahigh theoretical volumetric capacity when compared to Li-S and Li-Se batteries. The main challenge to develop Li-Te battery systems is to explore an ideal substrate for Te accommodation. Here we have Designed and exploited a “muscle” structured Electrode, which enables an excellent electrochemical performance. Te is confined in the hollow carbon cell as “tissue cell” and carbon nanotubes (CNTs) are induced as “blood capillary”. Such an interesting Design possesses multifold advantages. Specifically, many hollow carbon cells not only offer large void space for loading Te, giving rise to high mass loading of active materials, but also manifest a good contact between Te and carbon. In addition, the introduction of CNTs provides abundant channels along CNTs in the composites for both electron and ion transport upon cycling, yielding high discharge capacity. With this desired Design, muscle-like Electrode shows a high specific capacity of ~ 240 mA h g -1 after 500 cycles. This work would offer new ideas for developing other exceptional Electrodes for energy storage applications.
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Pie-like Electrode Design for high-energy density lithium-sulfur batteries
Nature Communications, 2015Co-Authors: Zhen Li, Jin-tao Zhang, Yu-ming Chen, Ju Li, Xiong Wen LouAbstract:Owing to the overwhelming advantage in energy density, lithium-sulfur (Li-S) battery is a promising next-generation electrochemical energy storage system. Despite many efforts in pursuing long cycle life, relatively little emphasis has been placed on increasing the areal energy density. Herein, we have Designed and developed a 'pie' structured Electrode, which provides an excellent balance between gravimetric and areal energy densities. Combining lotus root-like multichannel carbon nanofibers 'filling' and amino-functionalized graphene 'crust', the free-standing paper Electrode (S mass loading: 3.6 mg cm(-2)) delivers high specific capacity of 1,314 mAh g(-1) (4.7 mAh cm(-2)) at 0.1 C (0.6 mA cm(-2)) accompanied with good cycling stability. Moreover, the areal capacity can be further boosted to more than 8 mAh cm(-2) by stacking three layers of paper Electrodes with S mass loading of 10.8 mg cm(-2).
Yu Jia - One of the best experts on this subject based on the ideXlab platform.
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a new Electrode Design method in piezoelectric vibration energy harvesters to maximize output power
Sensors and Actuators A-physical, 2017Co-Authors: Yu Jia, Shaotuan Chen, Chun Zhao, Boqian Sun, Emmanuelle Arroyo, Ashwin A SeshiaAbstract:A resonant vibration energy harvester typically comprises of a clamped anchor and a vibrating shuttle with a proof mass. Piezoelectric materials are embedded in locations of high strain in order to transduce mechanical deformation into electrical charge. Conventional Design for piezoelectric vibration energy harvesters (PVEH) usually utilizes piezoelectric materials and metal Electrode layers covering the entire surface area of the cantilever with no consideration provided to examine the trade-off involved with respect to maximize output power. This paper reports on the theory and experimental verification underpinning optimization of the active Electrode area in order to maximize output power. The calculations show that, in order to maximize the output power of a PVEH, the Electrode should cover the piezoelectric layer from the peak strain area to a position, where the strain is a half of the average strain in all the previously covered area. With the proposed Electrode Design, the output power can be improved by 145% and 126% for a cantilever and a clamped-clamped beam, respectively. MEMS piezoelectric harvesters are fabricated to experimentally validate the theory.
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maximizing output power in a cantilevered piezoelectric vibration energy harvester by Electrode Design
Journal of Physics: Conference Series, 2015Co-Authors: Yu Jia, Ashwin A SeshiaAbstract:A resonant vibration energy harvester typically comprises of a clamped anchor and a vibrating shuttle with a proof mass. Piezoelectric materials are embedded in locations of high strain in order to transduce mechanical deformation into electric charge. Conventional Design for piezoelectric vibration energy harvesters (PVEH) usually utilizes piezoelectric material and metal Electrode layers covering the entire surface area of the cantilever with no consideration provided to examining the trade-off involved with respect to maximizing output power. This paper reports on the theory and experimental verification underpinning optimization of the active Electrode area of a cantilevered PVEH in order to maximize output power. The analytical formulation utilizes Euler-Bernoulli beam theory to model the mechanical response of the cantilever. The expression for output power is reduced to a fifth order polynomial expression as a function of the Electrode area. The maximum output power corresponds to the case when 44% area of the cantilever is covered by Electrode metal. Experimental results are also provided to verify the theory.