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Recording characteristics of electrical impedance-electromyography needle electrodes.

ABSTRACT: OBJECTIVE:Needle EMG remains the standard clinical test for neuromuscular disease (NMD) assessment, but it only characterizes myofiber membrane depolarization. On the other hand, electrical impedance provides non-electrically active structural and compositional data of tissues. Here, we designed a prototype of needle electrode integrating electrical impedance and EMG measurement capabilities, the so-called I-EMG needle electrode. APPROACH:We use finite element method models to study the impedance recording characteristics of I-EMG needle electrodes. The simulated electrical and mechanical design specifications are then manufactured to create a prototype of an I-EMG needle electrode. We pilot these new needle electrodes by conducting in vivo impedance measurements with muscle at rest on healthy wild-type (wt, n??=??5) and muscular dystrophy (mdx, n??=??5) mice. Comparisons between wt and mdx mice are performed using Mann-Whitney test, two-tailed, p??

SUBMITTER: Kwon H

PROVIDER: S-EPMC5997185 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature

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Recording characteristics of electrical impedance-electromyography needle electrodes.

Kwon H H Di Cristina J F JF Rutkove S B SB Sanchez B B

Physiological measurement 20180522 5

<h4>Objective</h4>Needle EMG remains the standard clinical test for neuromuscular disease (NMD) assessment, but it only characterizes myofiber membrane depolarization. On the other hand, electrical impedance provides non-electrically active structural and compositional data of tissues. Here, we designed a prototype of needle electrode integrating electrical impedance and EMG measurement capabilities, the so-called I-EMG needle electrode.<h4>Approach</h4>We use finite element method models to stu ...[more]

PMID: 29616985

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Project description:Multi-electrode arrays, both active or passive, emerged as ideal technologies to unveil intricated electrophysiological dynamics of cells and tissues. Active MEAs, designed using complementary metal oxide semiconductor technology (CMOS), stand over passive devices thanks to the possibility of achieving single-cell resolution, the reduced electrode size, the reduced crosstalk and the higher functionality and portability. Nevertheless, most of the reported CMOS MEA systems mainly rely on a single operational modality, which strongly hampers the applicability range of a single device. This can be a limiting factor considering that most biological and electrophysiological dynamics are often based on the synergy of multiple and complex mechanisms acting from different angles on the same phenomena. Here, we designed a CMOS MEA chip with 16,384 titanium nitride electrodes, 6 independent operational modalities and 1,024 parallel recording channels for neuro-electrophysiological studies. Sixteen independent active areas are patterned on the chip surface forming a 4 × 4 matrix, each one including 1,024 electrodes. Electrodes of four different sizes are present on the chip surface, ranging from 2.5 × 3.5 ?m2 up to 11 × 11.0 ?m2, with 15 ?m pitch. In this paper, we exploited the impedance monitoring and voltage recording modalities not only to monitor the growth and development of primary rat hippocampal neurons, but also to assess their electrophysiological activity over time showing a mean spike amplitude of 144.8 ± 84.6 ?V. Fixed frequency (1 kHz) and high sampling rate (30 kHz) impedance measurements were used to evaluate the cellular adhesion and growth on the chip surface. Thanks to the high-density configuration of the electrodes, as well as their dimension and pitch, the chip can appreciate the evolutions of the cell culture morphology starting from the moment of the seeding up to mature culture conditions. The measurements were confirmed by fluorescent staining. The effect of the different electrode sizes on the spike amplitudes and noise were also discussed. The multi-modality of the presented CMOS MEA allows for the simultaneous assessment of different physiological properties of the cultured neurons. Therefore, it can pave the way both to answer complex fundamental neuroscience questions as well as to aid the current drug-development paradigm.

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Dataset Information

Recording characteristics of electrical impedance-electromyography needle electrodes.

Publications

Recording characteristics of electrical impedance-electromyography needle electrodes.

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