Se requiere una suscripción a JoVE para ver este contenido. Inicie sesión o comience su prueba gratuita.
Our purpose was to provide an updated, easy-to-follow guide on the fabrication and testing of epimysial electromyography electrodes. To that end, we provide instructions for material sourcing and a detailed walkthrough of the fabrication and testing process.
Electromyography (EMG) is a valuable diagnostic tool for detecting neuromuscular abnormalities. Implantable epimysial electrodes are commonly used to measure EMG signals in preclinical models. Although classical resources exist describing the principles of epimysial electrode fabrication, there is a sparsity of illustrative information translating electrode theory to practice. To remedy this, we provide an updated, easy-to-follow guide on fabricating and testing a low-cost epimysial electrode.
Electrodes were made by folding and inserting two platinum-iridium foils into a precut silicone base to form the contact surfaces. Next, coated stainless steel wires were welded to each contact surface to form the electrode leads. Lastly, a silicone mixture was used to seal the electrode. Ex vivo testing was conducted to compare our custom-fabricated electrode to an industry standard electrode in a saline bath, where high levels of signal agreement (sine [intraclass correlation - ICC= 0.993], square [ICC = 0.995], triangle [ICC = 0.958]), and temporal-synchrony (sine [r = 0.987], square [r = 0.990], triangle [r= 0.931]) were found across all waveforms. Low levels of electrode impedance were also quantified via electrochemical impedance spectroscopy.
An in vivo performance assessment was also conducted where the vastus lateralis muscle of a rat was surgically instrumented with the custom-fabricated electrode and signaling was acquired during uphill and downhill walking. As expected, peak EMG activity was significantly lower during downhill walking (0.008 ± 0.005 mV) than uphill (0.031 ± 0.180 mV, p = 0.005), supporting the validity of the device. The reliability and biocompatibility of the device were also supported by consistent signaling during level walking at 14 days and 56 days post implantation (0.01 ± 0.007 mV, 0.012 ± 0.007 mV respectively; p > 0.05) and the absence of histological inflammation. Collectively, we provide an updated workflow for the fabrication and testing of low-cost epimysial electrodes.
Electromyography (EMG) is a powerful tool for studying the electrical activity of muscle. EMG recordings can be especially useful in preclinical animal models to assess the effectiveness of interventions to treat neuromuscular dysfunction. In these models, implantable biocompatible electrodes are commonly used to assess the neurophysiological interface between motor neurons and muscle fibers. These implantable electrodes can provide localized measurements of muscle excitation and can be diverse in terms of their configuration, shape, and material, with the optimal design ultimately dictated by the location and intended use.
Despite their su....
The in vivo procedure was conducted under the approval of the Institutional Animal Care & Use Committee at the University of Michigan (IACUC approval #PRO00010765) and in accordance with the National Institutes of Health guidelines on the care and use of laboratory animals.
1. Electrode sourcing and fabrication
NOTE: Figure 1 provides a high-level summary of all key fabrication steps with a QR link that provides addit.......
Ex vivo performance
ICCs revealed high levels of agreement between the custom-fabricated and industry standard electrodes across all waveforms (sine [ICC = 0.993], square [ICC = 0.995], triangle [ICC = 0.958]; p < .001). Bland-Altman plots also revealed a high degree of signal agreement between electrodes. Bland Altman plots and Pearson correlations are summarized in Figure 3 with strong positive correlations between the custom-fabricated and industry stan.......
Our objective was to streamline the EMG fabrication process, enabling broader adoption and implementation of epimysial electrode designs, thus promoting accessibility, and advancing neuromuscular research. To this end, we present a user-friendly guide for sourcing, fabricating, and testing low-cost epimysial electrodes in-house. In hopes of supporting other research groups, we also provide supplemental 3D printing templates to facilitate the production of in-house epimysial electrodes for their research endeavors.
This work was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases Grant R01AR081235 (to L. K. Lepley). The authors thank the following individuals for their contribution to the fabrication and testing of our biocompatible electrode: Joel Pingel, Grant Gueller, Akhil Ramesh, Joe Letner, Jacky Tian, and Ross Brancati.
....Name | Company | Catalog Number | Comments |
Electrode Materials | |||
Quantity & price per electrode | |||
Contact surface | Prince and Izant PT90/IR10 1.25 mm x 5 mm foil | Catalog #1040055 | 2 per electrode $7.50 per foil $15.00 per electrode |
PFA coated stainless-steel electrode lead wire | A-M Systems Multi-Stranded PFA-Coated Stainless Steel Wire 50.8 µm strand diameter | Catalog #793500 | Dependent on desired lead length (e.g., 9 inch lead wires x2) $128 per 25 ft spool $5.12 per foot $0.42 per inch (x18) $7.68 per electrode |
Folding jig | 3D printed (see .gcode file) | NA | NA |
Sealant for electrode body | Nusil Med-1137 liquid silicone | Catalog #MED-1137 | 1 gram $344.66 per 2 oz. (59.15 mL) $5.83 per electrode |
Silicone base | Implantech Alliedsil Silicone Sheeting-Reinforced, Long Term Implantable (8” x 6”) .007 thick | Catalog #701-07 | 10mm x 5mm sheet $225.00 per 8 x 6 inch $0.36 per electrode (10 mm x 5 mm) |
Thinner for sealant mixture | Toluene 99.5% ACS Reagent 500mL or Xylene ACS 99.5% | Catalog #179418-500 ML | 0.75 mL $25.53 per 500 mL $0.38 per electrode |
Template for perforating silicone base | Cutting jig – 3D printed (see CAD file) | NA | NA |
Custom-fabricated electrode: $29.25 | |||
Industry standard electrode (EP105 EMG Patch Electrode, 2 contacts, single-sided, 7mm x 4mm, MicroProbe for Life Science): $305.00 | |||
Additional Fabrication Materials | |||
Quantity & price per electrode | |||
3D printing software | Solidworks (Solidworks, 2022) | ||
Micro-Tig welder | Micro-Tig Welder (CD1000SPM, Single Pulse Research and Light Production Resistance Spot Welder, Sunstone) | SKU 301010 | $3,500 |
Ultrasonic bath | Ultrasonic bath (CPX Series Ultrasonic Bath, Fisherbrand). | 15-337-403 | NA |
Ex Vivo Testing Materials | |||
Quantity & price per electrode | |||
Data acquisition platform and software | DigitalLynx 4sX Base Cheetah version 6.0 (Neuralynx Inc.) | NA | EMG acquisition hardware and software |
Electrode interface board (EIB) | EIB, EIB16-QC, Neuralynx Inc. | 31-0603-0007 | NA |
Signal generator | 5 MHz Function Generator, B&K Precision | 4005DDS220V | $387.46 |
Potentiostat | PGSTAT1 potentiostat (EcoChemie, Utrecht, Netherlands) | NA | NA |
Stainless steel screw | Fine Science Tools | 19010-00 | $98 |
Ex Vivo Testing Materials | |||
Quantity & price per electrode | |||
Rodent treadmill | Exer 3/6 Open Treadmill, Columbus Instruments | NA | NA |
Dental cement | Excel Formula® Pourable Dental Material, St. George Technology Inc. | #24211 | $125.60 |
Light microscope | Keyence BZ-X800, Keyence Corporation, Osaka, Japan | NA | NA |
Motion capture system | Optitrack Color Camera, Optitrack, NaturalPoint Inc. | NA | NA |
Peak detection algorithm | “SciPy.signal.find_peaks - SciPy v1.8.1 Manual”, 2022 | NA | NA |
Python software | Python Software Foundation. Python Language Reference, version 3.9. Available at http://www.python.org | NA | NA |
Rat | HsdBlu: LE, Envigo | 140 | NA |
Statistical sotware | GraphPad Prism version 10.0.0 (GraphPad Software, Boston, Massachusetts USA) | NA | NA |
This article has been published
Video Coming Soon
ACERCA DE JoVE
Copyright © 2025 MyJoVE Corporation. Todos los derechos reservados