The Enhancement of a Chronically Implanted Microwire Electrode Performance

2014 ◽  
Vol 960-961 ◽  
pp. 689-694
Author(s):  
Li Shi ◽  
Jian Wei Chen ◽  
Song Wei Wang
Keyword(s):  
Surface Modification ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Signal Acquisition ◽  
Key Factors ◽  
Signal To Noise ◽  
Factors Affecting ◽  
Fabrication Cost ◽  
Electrode Fabrication

Electrodes are expensive consumables of electrophysiological experiments. Cheap and homemade microwire electrodes have been widely applied, but their implantation performance is not good. To fabricate low cost and acceptable performance of microwire electrode, first, we analyzed the key factors affecting the long-term recording performance and determined the direction of the enhancement of electrode. We improved the existing fabrication process through electrode fabrication and the electrode tip surface modification, and systematically evaluated its properties, signal acquisition ability and biocompatibility. The result shows that the improved electrode tip surface is smooth and tidy, and its impedance decreased by 56.1% on average; record signal-to-noise ratio is higher; recording longevity reached 45 days; biocompatibility is better. It can meet the use of the general electrophysiological experimental, and electrode fabrication cost is less than 58 yuan.

A compact guided-wave EMAT with pulsed electromagnet for ferromagnetic tube inspection

2020 ◽  
Vol 64 (1-4) ◽  
pp. 951-958
Author(s):  
Tianhao Liu ◽  
Yu Jin ◽  
Cuixiang Pei ◽  
Jie Han ◽  
Zhenmao Chen
Keyword(s):  
Power Plants ◽  
Signal To Noise Ratio ◽  
Small Diameter ◽  
Performance Testing ◽  
Guided Wave ◽  
High Signal ◽  
Receiver Coil ◽  
Signal To Noise ◽  
Corrosion Defects

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.

scholarly journals Assessing Stability of Crutch Users by Non-Contact Methods

2021 ◽  
Vol 18 (6) ◽  
pp. 3001
Author(s):  
Achilles Vairis ◽  
Suzana Brown ◽  
Maurice Bess ◽  
Kyu Hyun Bae ◽  
Jonathan Boyack
Keyword(s):  
Signal To Noise Ratio ◽  
Time Derivative ◽  
Assistive Devices ◽  
Signal To Noise ◽  
Physically Disabled ◽  
Significant Difference ◽  
Novice Users ◽  
Noise Ratio ◽  
Physically Disabled People

Enhancing gait stability in people who use crutches is paramount for their health. With the significant difference in gait compared to users who do not require an assistive device, the use of standard gait analysis tools to measure movement for temporary crush users and physically disabled people proves to be more challenging. In this paper, a novel approach based on video analysis is proposed as non-contact low-cost solution to the more expensive alternative with the data collected from processed videos, two values are calculated: the Signal to Noise Ratio (SNR) of acceleration, and the Signal to Noise Ratio of the jerk (time derivative of acceleration), to assess the user’s stability while they walk with crutches. The adopted methodology has been tested on a total of 10 participants. Five are temporary users of assistive devices with one being a long-term user and the other four novice users, and five are disabled participants who use those assistive devices permanently. Preliminary results show differences between novice users, long-term users, and physically disabled users. The approach is promising and could improve the assessment of crutch user stability, allowing for the correction of gait for individuals while using an inexpensive non-contact setup and preventing unnecessary falls.

All polarization-maintaining Er:fiber-based optical frequency comb for frequency comparison of optical clocks

2021 ◽  
Author(s):  
Zhang Pan ◽  
Zhang Yan-Yan ◽  
Li Ming-Kun ◽  
Rao Bing-Jie ◽  
Yan Lu-Lu ◽  
...  
Keyword(s):  
Frequency Comb ◽  
Signal To Noise Ratio ◽  
Frequency Instability ◽  
Optical Frequency Comb ◽  
Optical Frequency ◽  
Thermal Drift ◽  
Signal To Noise ◽  
Frequency Comparison ◽  
Polarization Maintaining

Abstract In this research, we demonstrate an optical frequency comb (OFC) based on a turnkey mode-locked laser with a figure-9 structure and polarization-maintaining fibers for frequency comparison between optical clocks with wavelengths of 698 nm, 729 nm, 1068 nm and 1156 nm. We adopt a multi-branch approach in order to produce high power OFC signals at these specific wavelengths, enabling the signal-to-noise ratio of the beatnotes between the OFC and the clock lasers beyond 30 dB at a resolution bandwidth of 300 kHz. This approach makes the supercontinuum spectra generating process much easier in comparison to a single branch OFC; however, more out-of-loop fibers degrade the long term frequency instability due to thermal drift. To minimize the thermal drift effect, we set the fiber lengths of different branches to be similar, and we stabilize the temperature as well. The out-of-loop frequency instability of the OFC due to the incoherence of the multi-branch is about 5.5×10-19 @ 4000 s, while the in-loop frequency instability of f ceo and that of f beat are 7.5×10-18 @1 s and 8.5×10-18 @1 s, respectively. The turnkey OFC meets the requirement of frequency comparison between the best optical clocks.

Internally Modulated Chirped Pulse Based Direct Detection Type φ-OTDR System with High Signal-to-Noise Ratio and Low Cost

2019 ◽  
Vol 46 (8) ◽  
pp. 0806003
Author(s):  
李鲁川 Luchuan Li ◽  
卢斌 Bin Lu ◽  
王校 Xiao Wang ◽  
梁嘉靖 Jiajing Liang ◽  
郑汉荣 Hanrong Zheng ◽  
...  
Keyword(s):  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
High Signal ◽  
Signal To Noise ◽  
Chirped Pulse ◽  
Noise Ratio

Key factors affecting long-term penetration of global onshore wind energy integrating top-down and bottom-up approaches

2016 ◽  
Vol 85 ◽  
pp. 19-30 ◽  
Author(s):  
Hancheng Dai ◽  
Diego Silva Herran ◽  
Shinichiro Fujimori ◽  
Toshihiko Masui
Keyword(s):  
Wind Energy ◽  
Key Factors ◽  
Top Down ◽  
Bottom Up ◽  
Onshore Wind ◽  
Factors Affecting

scholarly journals Signal-to-noise optimization and evaluation of a home-made visible diode-array spectrophotometer

1993 ◽  
Vol 15 (6) ◽  
pp. 227-232 ◽  
Author(s):  
Ivo M. Raimundo, Jr. ◽  
Celio Pasquini
Keyword(s):  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Low Cost ◽  
Optical Design ◽  
Signal To Noise ◽  
Noise Optimization ◽  
Instrument Control ◽  
Automatic Methods ◽  
Photodiode Array ◽  
Variable Integration

This paper describes a simple low-cost multichannel visible spectrophotometer built with an RL512G EGG-Reticon photodiode array. A symmetric Czerny-Turner optical design was employed; instrument control was via a single-board microcomputer based on the 8085 Intel microprocessor. Spectral intensity data are stored in the single-board's RAM and then transferred to an IBM-AT 3865X compatible microcomputer through a RS-232C interface. This external microcomputer processes the data to recover transmittance, absorbance or relative intensity of the spectra. The signal-to-noise ratio and dynamic range were improved by using variable integration times, which increase during the same scan; and by the use of either weighted or unweighted sliding average of consecutive diodes. The instrument is suitable for automatic methods requiring quasi-simultaneous multiwavelength detections, such as multivariative calibration and flow-injection gradient scan techniques.

A Motorized Microdrive for Recording of Neural Ensembles in Awake Behaving Rats

2005 ◽  
Vol 127 (6) ◽  
pp. 1035-1040 ◽  
Author(s):  
R. Venkateswaran ◽  
Chris Boldt ◽  
J. Parthasarathy ◽  
B. Ziaie ◽  
A. G. Erdman ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Low Cost ◽  
Dynamic Control ◽  
Experimental Paradigm ◽  
Signal To Noise ◽  
Implanted Electrodes ◽  
Neural Ensembles ◽  
Dc Motors ◽  
Cell Electrode ◽  
Scientific Advances

The recording of neural ensembles in awake, behaving rats has been an extremely successful experimental paradigm, providing demonstrable scientific advances. Dynamic control of the position of the implanted electrodes is of key importance as mobile electrodes provide a better signal-to-noise ratio and a better cell/electrode yield than nonmobile electrodes. Here we describe the use of low cost, soon to be commercially available dc motors to successfully control the depth of electrodes. The prototype designed is approximately 30mm in diameter and 50mm in length and weighed about 30gms. This paper presents the results of linear displacements of electrodes achievable with this motorized microdrive.

Key factors affecting the spring emergence of pea moth (Cydia nigricana)

2010 ◽  
Vol 101 (2) ◽  
pp. 127-133 ◽  
Author(s):  
G. Thöming ◽  
H. Saucke
Keyword(s):  
Day Length ◽  
Strong Correlations ◽  
Key Factors ◽  
Factors Affecting ◽  
Pea Moth ◽  
Temperature Regimes ◽  
Cydia Nigricana ◽  
Flight Phenology ◽  
Spring Emergence

AbstractThe hypothesis that spring emergence of the pea moth Cydia nigricana is regulated by environmental factors, particularly photoperiod and temperature, was examined in this study. A long-term field study was conducted in two distinct pea-growing areas in Hesse and Saxony, Germany. Strong correlations between the flight phenology of pea moth in spring and air temperature, soil temperature, solar radiation and day length were demonstrated for three consecutive years. In laboratory experiments, we elucidated the interaction of different photoperiod-temperature regimes, verifying cumulative day-degree data in relation to pea moth emergence rates in the field. C. nigricana temperature sensitivity is apparently initiated by long day conditions with a critical day length of about 14 h L:D. The overall results contribute to the theory that photoperiod and temperature interact as regulatory cues for spring emergence of C. nigricana. The findings are discussed in terms of the development of predictive models and decision support systems for pea moth control.

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