The Sensitivity of Bipolar Electromyograms to Muscle Excitation Scales With the Inter-Electrode Distance
The value of surface electromyograms (EMGs) lies in their potential to non-invasively probe the neuromuscular system. Whether muscle excitation may be accurately inferred from bipolar EMGs depends on how much the detected signal is both sensitive and specific to the excitation of the target muscle....
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IEEE
2023-01-01
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| Series: | IEEE Transactions on Neural Systems and Rehabilitation Engineering |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/10286504/ |
| _version_ | 1797643640738152448 |
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| author | Taian M. Vieira Giacinto Luigi Cerone Alberto Botter Kohei Watanabe Andrew D. Vigotsky |
| author_facet | Taian M. Vieira Giacinto Luigi Cerone Alberto Botter Kohei Watanabe Andrew D. Vigotsky |
| author_sort | Taian M. Vieira |
| collection | DOAJ |
| description | The value of surface electromyograms (EMGs) lies in their potential to non-invasively probe the neuromuscular system. Whether muscle excitation may be accurately inferred from bipolar EMGs depends on how much the detected signal is both sensitive and specific to the excitation of the target muscle. While both are known to be a function of the inter-electrode distance (IED), specificity has been of long concern in the physiological literature. In contrast, sensitivity, at best, has been implicitly assumed. Here we provide evidence that the IED imposes a biophysical constraint on the sensitivity of surface EMG. From 20 healthy subjects, we tested the hypothesis that excessively reducing the IED limits EMGs’ physiological content. We detected bipolar EMGs with IEDs varying from 5 mm to 50 mm from two skeletal muscles with distinct architectures, gastrocnemius and biceps brachii. Non-parametric statistics and Bayesian hierarchical modelling were used to evaluate the dependence of the onset of muscle excitation and signal-to-noise ratio (SNR) on the IED. Experimental results revealed that IED critically affects the sensitivity of bipolar EMGs for both muscles—indeliberately reducing the IED yields EMGs that are not representative of the whole muscle, hampering validity. Simulation results substantiate the generalization of experimental results to small and large electrodes. Based on current and previous findings, we discuss a potentially valid procedure for defining the most appropriate IED for a single bipolar, surface recording—i.e., the distance from the electrode to the target muscle boundary may heuristically serve as a lower bound when choosing an IED. |
| first_indexed | 2024-03-11T14:17:50Z |
| format | Article |
| id | doaj.art-01d739a1e31844caa81ea21b75af0538 |
| institution | Directory Open Access Journal |
| issn | 1558-0210 |
| language | English |
| last_indexed | 2024-03-11T14:17:50Z |
| publishDate | 2023-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Transactions on Neural Systems and Rehabilitation Engineering |
| spelling | doaj.art-01d739a1e31844caa81ea21b75af05382023-10-31T23:00:09ZengIEEEIEEE Transactions on Neural Systems and Rehabilitation Engineering1558-02102023-01-01314245425510.1109/TNSRE.2023.332513210286504The Sensitivity of Bipolar Electromyograms to Muscle Excitation Scales With the Inter-Electrode DistanceTaian M. Vieira0https://orcid.org/0000-0002-6239-7301Giacinto Luigi Cerone1https://orcid.org/0000-0002-5295-5314Alberto Botter2https://orcid.org/0000-0002-4797-0667Kohei Watanabe3Andrew D. Vigotsky4Department of Electronics and Telecommunications, LISiN, the PolitoBIOMedLab, Politecnico di Torino, Turin, ItalyDepartment of Electronics and Telecommunications, LISiN, the PolitoBIOMedLab, Politecnico di Torino, Turin, ItalyDepartment of Electronics and Telecommunications, LISiN, the PolitoBIOMedLab, Politecnico di Torino, Turin, ItalyLaboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Toyota, JapanDepartment of Biomedical Engineering and the Department of Statistics, Northwestern University, Evanston, IL, USAThe value of surface electromyograms (EMGs) lies in their potential to non-invasively probe the neuromuscular system. Whether muscle excitation may be accurately inferred from bipolar EMGs depends on how much the detected signal is both sensitive and specific to the excitation of the target muscle. While both are known to be a function of the inter-electrode distance (IED), specificity has been of long concern in the physiological literature. In contrast, sensitivity, at best, has been implicitly assumed. Here we provide evidence that the IED imposes a biophysical constraint on the sensitivity of surface EMG. From 20 healthy subjects, we tested the hypothesis that excessively reducing the IED limits EMGs’ physiological content. We detected bipolar EMGs with IEDs varying from 5 mm to 50 mm from two skeletal muscles with distinct architectures, gastrocnemius and biceps brachii. Non-parametric statistics and Bayesian hierarchical modelling were used to evaluate the dependence of the onset of muscle excitation and signal-to-noise ratio (SNR) on the IED. Experimental results revealed that IED critically affects the sensitivity of bipolar EMGs for both muscles—indeliberately reducing the IED yields EMGs that are not representative of the whole muscle, hampering validity. Simulation results substantiate the generalization of experimental results to small and large electrodes. Based on current and previous findings, we discuss a potentially valid procedure for defining the most appropriate IED for a single bipolar, surface recording—i.e., the distance from the electrode to the target muscle boundary may heuristically serve as a lower bound when choosing an IED.https://ieeexplore.ieee.org/document/10286504/Excitation onsetmuscle excitationsurface electrodestransfer function |
| spellingShingle | Taian M. Vieira Giacinto Luigi Cerone Alberto Botter Kohei Watanabe Andrew D. Vigotsky The Sensitivity of Bipolar Electromyograms to Muscle Excitation Scales With the Inter-Electrode Distance IEEE Transactions on Neural Systems and Rehabilitation Engineering Excitation onset muscle excitation surface electrodes transfer function |
| title | The Sensitivity of Bipolar Electromyograms to Muscle Excitation Scales With the Inter-Electrode Distance |
| title_full | The Sensitivity of Bipolar Electromyograms to Muscle Excitation Scales With the Inter-Electrode Distance |
| title_fullStr | The Sensitivity of Bipolar Electromyograms to Muscle Excitation Scales With the Inter-Electrode Distance |
| title_full_unstemmed | The Sensitivity of Bipolar Electromyograms to Muscle Excitation Scales With the Inter-Electrode Distance |
| title_short | The Sensitivity of Bipolar Electromyograms to Muscle Excitation Scales With the Inter-Electrode Distance |
| title_sort | sensitivity of bipolar electromyograms to muscle excitation scales with the inter electrode distance |
| topic | Excitation onset muscle excitation surface electrodes transfer function |
| url | https://ieeexplore.ieee.org/document/10286504/ |
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