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你可能喜欢galvanic是什么意思，词典释义与在线翻译：
Adjective:
pertaining to or producing electric curren
"a galvanic cell"
"a voltaic (or galvanic) couple"
affected by emotion
"gave an electric reading of the play"
"the new leader had a galvanic effect on morale"
galvanic的用法和样例：
A galvanic cell is represented by a diagram.
用简式表示自发电池。
The new leader had a galvanic effect on morale.
新领导大力鼓舞士气。
The new leader had a galvanic effect on our morale.
新领导极大地激励了我们的士气
Programmable isolating amplifier for the galvanic isolation, ampli.
可编程隔离放大器。
For example, in the work of Hamer, who studied the galvanic cell.
Severe galvanic corrosion will occur if potential difference in local area...
希望本文的讨论为油田开发的相关设计和决策提供一定的参考依据。
[医] 基强度
[医] 直流电池...
电防腐, 阴极保护...
电极极化作用...
电流,伽伐尼电流...
平流电试验,直羚刺激...
伽伐尼电池
电(化腐)蚀
电势序,电位序,电压...
She embraced the whole party with a last galvanic effort at cheerful enthusiasm.
出自：H. Sturgis
galvanic的海词问答与网友补充：
galvanic的相关资料：
galvanic&:&伽伐尼的， ...
在&&中查看更多...
galvanic&:&触电似的； ...
在&&中查看更多...
【近义词】
galvanic:galvanic adj. 流电的, 抽搐的, 以流电所产的…
相关词典网站：Galvanic Corrosion
Galvanic corrosion (also called ' dissimilar metal corrosion' or wrongly 'electrolysis') refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte. It occurs when two (or more) dissimilar metals are brought into electrical contact under water. When a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone.
Either (or both) metal in the couple may or may not corrode by itself (themselves). When contact with a dissimilar metal is made, however, the self corrosion rates will change:Corrosion of the anode will accelerate Corrosion of the cathode will decelerate or even stop.Galvanic coupling is the foundation of many corrosion monitoring techniques
The driving force for corrosion is a potential difference between the different materials. The bimetallic driving force was discovered in the late part of the eighteenth century by Luigi Galvani in a series of experiments with the exposed muscles and nerves of a frog that contracted when connected to a bimetallic conductor. The principle was later put into a practical application by Alessandro Volta who built, in 1800, the first electrical cell, or battery: a series of metal disks of two kinds, separated by cardboard disks soaked with acid or salt solutions. This is the basis of all modern wet-cell batteries, and it was a tremendously important scientific discovery, because it was the first method found for the generation of a sustained electrical current.
The principle was also engineered into the useful protection of metallic structures by Sir Humphry Davy and Michael Faraday in the early part of the nineteenth century. The sacrificial corrosion of one metal such as zinc, magnesium or aluminum is a widespread method of cathodically protecting metallic structures.In a bimetallic couple, the less noble material will become the anode of this corrosion cell and tend to corrode at an accelerated rate, compared with the uncoupled condition. The more noble material will act as the cathode in the corrosion cell. Galvanic corrosion can be one of the most common forms of corrosion as well as one of the most destructive.The following examples illustrated this type of attackGalvanic corrosion: stainless screw v cadmium plated steel washer Galvanic corrosion inside horizontal stabilizer Galvanic Corrosion of the Statue of Liberty Cadmium plated locknutThe relative nobility of a material can be predicted by measuring its corrosion potential. The well known galvanic series lists the relative nobility of certain materials in sea water. A small anode/cathode area ratio is highly undesirable. In this case, the galvanic current is concentrated onto a small anodic area. Rapid thickness loss of the dissolving anode tends to occur under these conditions. Galvanic corrosion problems should be solved by designing to avoid these problems in the first place. Galvanic corrosion cells can be set up on the macroscopic level or on the microscopic level. On the microstructural level, different phases or other microstructural features can be subject to galvanic currents
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Measurement System with Experiments for Galvanic Coupling Type Intra-Body Communication
2012 5th International Conference on BioMedical Engineering and Informatics (BMEI 2012)Measurement System with Experiments for GalvanicCoupling Type Intra-Body CommunicationYueming Gao, Renjun Ma
Siohang Pun, Pengun Mak, Mangi VaiDepartment of Electrical and Computer EngineeringUniversity of MacauMacau, ChinaIn the implementation stage of IBC, researchers do a lot of work on theoretical investigation. A four-terminal circuit model of the human body was proposed [11]. However, the internal resistances of the IBC devices were not considered in their research. And a waveguide IBC circuit model was developed and the transfer function of the waveguide IBC was derived based on the developed circuit model [12].Based on the Maxwell Equations, a quasi-static mathematical model of human limb of IBC was proposed [13]. Then a multilayer mathematical model that considers the inhomogeneous properties of human tissue to some content was proposed [14]. Maxwell’s equations are decoupled and capacitance effect is introduced to the governing equation for improvement. In order to achieve the integrity of research work, in vivo experiments need to be conducted to validate the previous modeling results.In this paper, we use these techniques to better understand the influences from the current amplitude, electrode size, positions, and distance between transceiver electrodes on signal attenuation. Safety requirements have to be fulfilledand optimal signal coupling is required [15]. The human body is characterized as communication channel for electrical current transmission. Therefore, we devise a quantitative measurement system to apply galvanically coupled currents to the human body. The versatile system offers up to 2 mA maximum current amplitude between 1 kHz and 100 kHz. The injected current is 10 times below the maximum allowed contact current [16]. Such a low-current approach has the potential for a data communication that is more energy-saving than other wireless technologies. Then in vivo experiments for IBC were carried out to investigate the physical characteristics of the human channel. Firstly the quantitative measurement system is designed in Section II. The system based in-vivo experiments and dedicated parameters are presented in Section III. Finally, the conclusions are given in Section IV.II. METHODOLOGIESThe objective of the study includes the analysis of the attenuation and distribution of the current in specific body regions. The most crucial factor for signal transmission through body parts at low frequency is the attenuation caused by geometrical dimensions and tissue properties. Inspired by the work of Hackisuka et al. in [8], Shinagawa et al. in [12], College of Physics and Information Engineering
Fuzhou University
Fuzhou, China Abstract―Intra-body communication (IBC) is a technique to transmit electric signal through the on-body and implanted sensors by means of the conducting properties of the human body. This technique could be an innovative networking method for sensors on the human body and sharing information among the devices scattered across the human body. To analyze the characteristics of human data channel, we devise a quantitative measurement system that can provide a quantitative current in the transmitter and a qualitative analysis in the receiver. The transmitter of the system includes a current driving circuit with an amplifying and filtering circuit in receiver. By testing performance of the system and conducting in-vivo experiments with the proposed measurement system, the physical characteristic of human data channel was studied. Experimental results show that the human body has a stable propagation characteristic in the frequency range from 1 kHz to 100 kHz, and the potential gain characteristics approximate to a high-pass filter. Keywords-Intra-body C in-vivo experiment I. INTRODUCTION Driven by the benefit of being able to share information between personal portable devices and sensors on the body, several attempts have been made to model the human body as electrical channel. With the personal area network (PAN) [1], a first data communication was realized. Different electrical coupling methods have shown the potential of data communication through the human body [2]-[4]. A further principle using electro-optic sensors opened the field for signals up to several megahertz [5], [6]. All these systems used a fixed carrier frequency and showed the feasibility of electrical signal propagation through the human body. Galvanic coupling intra-body communication was investigated by Oberle [7] and analyzed by Hachisuka et al. [8]. The galvanic coupling, which utilities the human body as the conducting medium, is achieved by coupling signal currents into the body and picking up the surface potential differentially by the pairs of transceiver electrodes [1][9][10]. According to the transmitting current propagation within the human tissue, the galvanic coupling type IBC has the better adaptability and reliability than other types. Thus, it can be appropriately applied to the field such as the medical care, motion monitoring, military training and personal entertainment.978-1-/12/$31.00 ?2012 IEEE
and Fujii et al. in [4], a quantitative measurement system was constructed to learn more about the influence of the human anatomy on the signal propagation.The measurement system is composed of transmitter and receiver as shown in Fig. 1. The current driving circuit can send a quantitative and more stable current to the transmitter electrodes. At the receiver, the signal was analyzed qualitatively by using the filtering and amplifying circuit. It deserves to pay special attention that the current drive, amplifier and filter circuit are battery powered to avoid transceiver in the same ground. Agilent MSO-7054A high-pass filter (HPF) and AD620 amplifier.
The high-pass filter utilizes a passive RC filter to remove the physiological signal within human body at low frequency. The AD620 amplifies the potential signal on body surface differentially. When the operating frequency is below 100 KHz and the gain is smaller than 40, the gain of AD620 can be written as:A??????49.4?RG??1??
??2??Where A?? represents the differential voltage magnification, assuming RG = 2k?, thus A?? ≈ 28.2dB.oscilloscope with the 1141A differential probe, 1142A probe controller and module power are used to observe and analyze the coupling potential signal manually.
Figure 1.Scheme of measurement system.The current driving circuit, which consists of voltage-buffer and direct current-feedback circuit shown in Fig. 2, uses the AD844 current-feedback amplifier as the key element. The voltage-buffer circuit decreases the deviation resulted from the first stage gain of AD844 amplifier. The current-feedback circuit determines the actual director currentpotential of Z point to correct the input, so as to approximatethe DC output voltage before the capacitance to zero. So it hasno additional circuit for Z point, which will lower the outputimpedance. The output constant current of current drive canbe written as:I????V???R??(1)Figure 2.Current driving circuit.The circuit of receiver shown in Fig. 3 has two parts: aFigure 3.Circuit of filtering and amplifying.The attenuation of electric signal is one of the important indexes of data channel in the quasi-static field [2, 3]. The resistance capacitance network shown in Fig. 4 is conducted to validate the correctness and effectiveness of the measurement system. The transfer function is written as:H??s????1?sC??1
??3??Figure 4.
Circuit for testing the measurement system. Assuming f?? represents the cut-off frequency, based on the preliminary experimental results [12], parameters of circuit are defined at R = 1.2 k?, C = 3.3 nF, thus f?? = 1/4πRC =20 kHz. The resistance capacitance network is adopted as the load resistor RL for current driver circuit shown in Fig.2. By importing a sinusoidal current I = 1 mA (effective value) signal to a-b side, the experiments measure the input voltageV????, output voltageVVdefined at 20log??V???? , and calculate the voltage gain ???????????.The measurement and simulation results are shown in Fig. 5.
The test line is close to the simulation line. Both of them cross the -3 dB line around 20 kHz. So the measurement system designed in this paper can be used to test body channel transmitting gain correctly, in the frequency range of quasi-static field.762
Figure 5.Comparison of measurement and simulation.III. EXPERIMENT AND DISCUSSIONThe experiments for galvanic coupling type IBC aim at observing the potential response in other human locations by injecting a safe current into human body [9]. The sinusoidal current of 1 mA, in the frequency range from 1 kHz to 100 kHz, was adopted as the excitation signal.The study has been conducted with 9 subjects. The average age was 28, and six of the group was male. Measurements on the human subject were done for three days, and before the experiment, the skin of the subject was prepared to ensure good contact with the electrodes. Additionally, the transfer characteristic of the measurement setup is taken as the baseline for later compensation.The attenuation factors are shown as follows: the amplitude of input current, the size of transmitter and receiver electrodes, different diameter of arm, different positions of in vivo experiment, and distance between transceiver. The transmitting potential gain can be written as:Gain??20?log??????V???V????
??4??Where V?? denotes the voltage of receiver, and V?? represents the voltage of transmitter.During the measurement, the physiotherapy electrodes (4 cm by 4 cm in area) were used for coupling the signal into human body, and the distance between transceiver at forearm has been chosen 10 cm. The current signal I=0.5 mA, 1mA and 2 mA (effective value) were coupled into human body separately. As shown in Table Ι, the gain of potential on body surfaces almost has no change.TABLE I.Measurement results with different input current.
Frequency Input current (mA)(kHz)0.5 1 21 -45.78 -45.87 -46.38 2 -41.15 -41.26 -41.38 10 -31.87 -32.18 -32.50 20 -30.38 -30.58 -30.84 100 -33.26 -33.44 -33.80 200-37.45-37.76-37.79
In Fig. 6, where (t) denotes the size of transmitter electrodes with the receiver electrodes (4 cm by 4 cm in area) fixed, and (r) represents the size of receiver electrodes with the transmitter electrodes (4 cm by 4 cm in area) fixed. From
Fig. 6, when the transmitter is fixed, different sizes of receiver electrodes have little influence on signal. However, when the receiver is fixed, the larger transmitter electrodes have the larger gain. Yet the ECG electrodes have the worst performance.
Figure 6.Attenuation in forearm measurement with different
electrode sizes: (ECG: electrocardiogram).From Fig. 7, forearm, upper arm and calf were chosen to measure the gain separately, as well as the arms of three volunteers with the diameter of arm d=10.2 cm, 8.1 cm and 6.4 cm. In the experiment, 1 mA current was injected into body through physiotherapy electrodes (4 cm by 4 cm in area). Distance between transmitter and receiver is 10 cm. The calf with maximum diameter has the largest potential gain, upper arm has a smaller gain than calf, and forearm has the smallest gain. Moreover, the arm with larger diameter has a larger gain.
Figure 7.Results of different diameter and different parts of body.The gain measurements for different distance between transmitter and receiver are shown in Fig. 8. Physiotherapy electrode of 4 cm by 4 cm is chosen to test the potential gain with the distance between transceiver electrodes 5 cm, 10 cm, 15 cm, 20 cm, and from left wrist to right wrist. The gain decreases as the distance increases. In addition, attenuation changes apparently when distance increases but not greater than 20 cm. When distance is greater than 20 cm, for example763from left forearm to right forearm, the gain changes slightly and potential tends to be a constant.
Attenuation in forearm measurements with transmitter and receiver separated in distance of 5, 10, 15, 20 cm and from left to right arm.IV. CONCLUSIONSGalvanic coupling is a promising approach for intra-body communication over a frequency range from 1 kHz to 100 kHz. Especially in the field of medical instrumentation, it can facilitate efficient data exchange for on-body and in-body devices without hindering daily movement.In this paper, the authors attempted to analyze the human data channel and devised a quantitative measurement system. By conducting in vivo experiments over the operating frequency range, the characteristics of data channel were summarized. The following conclusions can be obtained: (1) The first experimental results reveal that the gain of potential on body surfaces is independent of the amplitude of the input current in the safe current range.(2) The size of transmitter electrodes has greater influence on attenuation than receiver. The ECG electrodes have the worst performance.(3) The location of body with more muscles has a larger potential gain.(4) The gain changes apparently as distance increases but not greater than 20 cm. When distance is greater than 20 cm, for example from left forearm to right forearm, the gain changes slightly and potential tends to be a constant.The measurement results reveal that the human body has a stable propagation characteristic in the frequency range from 1 kHz to 100 kHz, and its potential gain characteristic approximates to a high-pass filter. Additionally, the research conclusions will provide important guidance suggestions for the future research on hardware implementation, and the revise for the quasi-static modeling theory of the galvanic coupling type of IBC.However, the proposed measurement system is preliminary. In the next step, the system will be miniaturized in terms of the electronic circuitry size with the goal of realizing a data transmission based on galvanic coupling. Moreover, extending the experiment to other parts of the human body is also worthstudying.ACKNOWLEDGEMENTThe authors would like to express their gratitude to The Science and Technology Development Fund of Macau and the Key Laboratory of Medical Instrumentation & Pharmaceutical Technology C Fujian Province, Institute of Precision Instrument C Fuzhou University,Reference[1] Zimmerman T. G, “Personal area networks: near-field intra-bodycommunication,” in Media Art and Science. Master Thesis: Massachusetts Institute of Technology, 1995.[2] K.Partridge, B, Dahlquist, A. Veiseh, A. Cain, A. Foreman, ”Empircalmeasurements of intra-body communication performance under varied physical conifigurations,” in proc. ACM Symp. User Interface Software Technol.,2001,pp.183-190.[3] M. Fukumoto and Y. Tonomura, “Body coupled fingering:wirelesswearable keyboard,” in Proc. Conf. Human Factors Comp. Syst.(CHI),1997,pp.147-154.[4] K. Fujii, M. Takahashi, K. Ito, K. Hachisuka, Y. Terauchi, Y. Kishi, andK. Sasaki, “A study on the transmission mechanism for wearable devices using the human body as a transmission channel,” IEICE Trans. Commun., vol. E88-B, no. 6, pp., 2005.[5] M. Shinagawa, M. Fukomoto, K. Ochiai, and H. Kyruagi, “Anear-field-sensing transceiver for intra-body communication based on the electro-optic effect,” in Proc. Instrum. Meas. Technol. Conf., 2003, pp. 296-301.[6] A. Sasaki, M. Shingawa, and K. Ochiai, “Sensitive and stableelectro-optic sensor for intra-body communication,” in Proc. Conf. Lasers Electro-Optics Soc. (LEOS), 2004, vol. 1, pp. 122-123.[7] M. Oberle, “Low power system-on-chip for biomedical application,”Ph.D. dissertation, Integrated Syst. Lab. (IIS), ETH Zurich, Zurich, Switzerland, 2002.[8] K. Hachisuka, A. Nakata, T. Takeda, Y. Terauchi, K. Shiba, K. Sasaki, H.Hosaka, and K. Itao, “Development and performance analysis of an intra-body communication device,” in Proc. 12th Int. Conf. Solid State Sensors, Actuators Microsyst., 2003, vol. 2, pp. .[9] M. S. Wegmueller, “Galvanic coupling for data transmission through thehuman body,” In Instrumentation and Measurement Technology Conference. Sorrento, Italy, pp. , April 2006.[10] M. S. Wegmueller, A. Kuhn, J. Froehlich, et al. “An attempt to modelthe human body as a communication channel,” IEEE Trans. Biomed. Eng. pp. , 2007.[11] M. S. Wegmueller, M. Oberle, N. Felber, N. Kuster, and W, Fichtner,“Galvanic coupling for data transmitting through the human body,” in IEEE IMTC. Sorrento, Italy, pp: , 2006.[12] Yong Song, Kai Zhang, Bangzhi Kang, Qun Hao, “The mathematicalsimulations based on the transfer function of the waveguide intra-body,” 3rd International Conference on Biomedical Engineering and Informatics. pp. , 2010.[13] P. S. H, Y. M. Gao, P. A. Mou, P. U. Mak, “Multilayer limb quasi-staticelectromagnetic modeling with experiments for galvanic coupling type intra-body communication,” 32nd Annual International Conference of the IEEE EMBS. Buenos Aires, Argentina, pp. 378-381, August 31 - September 4, 2010.[14] P. S. H, Y. M. Gao, “Quasi-static modeling of human limb for intra-bodycommunication with experiment,” IEEE Transaction on Information Technology in Biomedicine. pp. 870-876, November 2011.[15] International Electrotechnical Commission (IEC), “Medical electricalequipment―part 1: general requirements for basic safety and essential performance,” Geneva, Switzerland, 05.[16] Ziegelberger. G, “Guidelines for limiting exposure to time-varyingelectric, magnetic, and electromagnetic fields (up to 300GHz),” International Commission on Non-Ionizing Radiation Protection
(ICNIRP). Germany, 1997, pp. 511-513.764
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