Thread by @ricardoNOmesqui, [1/27]I would like to talk (a bit) about high-density surface EMG-based motor [...]

[1/27]

I would like to talk (a bit) about high-density surface EMG-based motor unit identification

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="💻" title="Computer" aria-label="Emoji: Computer"> #ISEK2020 starting soon!

2 years ago I felt excited & overwhelmed at #ISEK2018 in Dublin

https://abs.twimg.com/emoji/v2/... draggable="false" alt="🍀" title="Vierblättriges Kleeblatt" aria-label="Emoji: Vierblättriges Kleeblatt"> with all the cool stuff people were doing with HD-EMG. And I was about to start!

[1/27]I would like to talk (a bit) about high-density surface EMG-based motor unit identificationhttps://abs.twimg.com/emoji/v2/... draggable=

https://abs.twimg.com/emoji/v2/... draggable="false" alt="💻" title="Computer" aria-label="Emoji: Computer"> #ISEK2020 starting soon!2 years ago I felt excited & overwhelmed at #ISEK2018 in Dublinhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="🍀" title="Vierblättriges Kleeblatt" aria-label="Emoji: Vierblättriges Kleeblatt"> with all the cool stuff people were doing with HD-EMG. And I was about to start!" title="[1/27]I would like to talk (a bit) about high-density surface EMG-based motor unit identificationhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">https://abs.twimg.com/emoji/v2/... draggable="false" alt="💻" title="Computer" aria-label="Emoji: Computer"> #ISEK2020 starting soon!2 years ago I felt excited & overwhelmed at #ISEK2018 in Dublinhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="🍀" title="Vierblättriges Kleeblatt" aria-label="Emoji: Vierblättriges Kleeblatt"> with all the cool stuff people were doing with HD-EMG. And I was about to start!" class="img-responsive" style="max-width:100%;"/>

[2/27]
Full disclosure: I am not an expert. I have just been learning a few things during my PhD which I would like to share and maybe generate some discussion. This thread might be more interesting/useful for those of you who are not very familiarised with this technique (yet)

[3/27]
Shall we start with a throwback?

https://abs.twimg.com/emoji/v2/... draggable="false" alt="📸" title="Kamera mit Blitz" aria-label="Emoji: Kamera mit Blitz">Full room for an interesting workshop by Dario Farina and Ales Holobar at #ISEK2018

"Extraction of information from high-density EMG: recent developments and perspectives."

Excited to hear more about recent progresses at #ISEK2020

[3/27]Shall we start with a throwback?https://abs.twimg.com/emoji/v2/... draggable=

Full room for an interesting workshop by Dario Farina and Ales Holobar at #ISEK2018"Extraction of information from high-density EMG: recent developments and perspectives."Excited to hear more about recent progresses at #ISEK2020" title="[3/27]Shall we start with a throwback?https://abs.twimg.com/emoji/v2/... draggable="false" alt="📸" title="Kamera mit Blitz" aria-label="Emoji: Kamera mit Blitz">Full room for an interesting workshop by Dario Farina and Ales Holobar at #ISEK2018"Extraction of information from high-density EMG: recent developments and perspectives."Excited to hear more about recent progresses at #ISEK2020" class="img-responsive" style="max-width:100%;"/>

[4/27]
#MotorUnits are the key functional units of human muscle contractions.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">Motor Unit

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">

Spinal motor neurone
+
Muscle fibres it innervates

[5/27]

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">Electromyographic (EMG) signals are the electrical activity of the motor units of a muscle.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="🔎" title="Nach rechts zeigende Lupe" aria-label="Emoji: Nach rechts zeigende Lupe">Can we take a close look at these signals and identify the firing of individual motor units?

[6/27]
Yes! EMG signals are the summation of the action potentials of active motor units (MUs), and different MUs have different waveforms which can be identified.

Via invasive intramuscular EMG

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">

[6/27]Yes! EMG signals are the summation of the action potentials of active motor units (MUs), and different MUs have different waveforms which can be identified.Via invasive intramuscular EMG https://abs.twimg.com/emoji/v2/... draggable=

" title="[6/27]Yes! EMG signals are the summation of the action potentials of active motor units (MUs), and different MUs have different waveforms which can be identified.Via invasive intramuscular EMG https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">" class="img-responsive" style="max-width:100%;"/>

[7/27]
Via high-density surface EMG: matrices/arrays with many small electrodes

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Non-invasive

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">High(er) number of MUs identified

https://abs.twimg.com/emoji/v2/... draggable="false" alt="📸" title="Kamera mit Blitz" aria-label="Emoji: Kamera mit Blitz"> @AlecsDelVecchio et al

https://abs.twimg.com/emoji/v2/... draggable="false" alt="📖" title="Offenes Buch" aria-label="Emoji: Offenes Buch">Tutorial: Analysis of motor unit discharge characteristics from high-density surface EMG signals
https://www.sciencedirect.com/science/article/pii/S1050641120300419">https://www.sciencedirect.com/science/a...

[7/27]Via high-density surface EMG: matrices/arrays with many small electrodeshttps://abs.twimg.com/emoji/v2/... draggable=

Non-invasivehttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">High(er) number of MUs identifiedhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="📸" title="Kamera mit Blitz" aria-label="Emoji: Kamera mit Blitz"> @AlecsDelVecchio et alhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="📖" title="Offenes Buch" aria-label="Emoji: Offenes Buch">Tutorial: Analysis of motor unit discharge characteristics from high-density surface EMG signals https://www.sciencedirect.com/science/a..." title="[7/27]Via high-density surface EMG: matrices/arrays with many small electrodeshttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Non-invasivehttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">High(er) number of MUs identifiedhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="📸" title="Kamera mit Blitz" aria-label="Emoji: Kamera mit Blitz"> @AlecsDelVecchio et alhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="📖" title="Offenes Buch" aria-label="Emoji: Offenes Buch">Tutorial: Analysis of motor unit discharge characteristics from high-density surface EMG signals https://www.sciencedirect.com/science/a..." class="img-responsive" style="max-width:100%;"/>

[8/27]
Which matrix (or matrices) to use?
No simple answer (?) Depends on the size and shape of your muscle(s) of interest. Also consider number of electrodes, inter-electrode distance, max number of channels of your system

Pilot testing w/ different ones? Probably a good idea

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👍" title="Thumbs up" aria-label="Emoji: Thumbs up">

[9/27]

https://abs.twimg.com/emoji/v2/... draggable="false" alt="📌" title="Reißzwecke" aria-label="Emoji: Reißzwecke">Location of the matrix
In my case, for gastrocnemius medialis, I use palpation to find the orientation and shape of the muscle and place the matrix in the location suggested by this paper
(which was actually the best one in my pilot testing)

https://www.researchgate.net/publication/221762414_Preferred_Sensor_Sites_for_Surface_EMG_Signal_Decomposition">https://www.researchgate.net/publicati...

[9/27]https://abs.twimg.com/emoji/v2/... draggable=

Location of the matrixIn my case, for gastrocnemius medialis, I use palpation to find the orientation and shape of the muscle and place the matrix in the location suggested by this paper (which was actually the best one in my pilot testing) https://www.researchgate.net/publicati..." title="[9/27]https://abs.twimg.com/emoji/v2/... draggable="false" alt="📌" title="Reißzwecke" aria-label="Emoji: Reißzwecke">Location of the matrixIn my case, for gastrocnemius medialis, I use palpation to find the orientation and shape of the muscle and place the matrix in the location suggested by this paper (which was actually the best one in my pilot testing) https://www.researchgate.net/publicati..." class="img-responsive" style="max-width:100%;"/>

[10/27]

https://abs.twimg.com/emoji/v2/... draggable="false" alt="📌" title="Reißzwecke" aria-label="Emoji: Reißzwecke">Location of the matrix

Some researchers have identified the motor point and aligned it between columns of the grid.

This might improve the decomposition but honestly, I am not sure.

[11/27]

https://abs.twimg.com/emoji/v2/... draggable="false" alt="📐" title="Geodreieck" aria-label="Emoji: Geodreieck">Matrix orientation

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">It shouldn& #39;t matter much in theory (?)

Maybe better results if it is oriented in relation to the propagation of action potentials? If we do this, we can also estimate conduction velocity
Figure below: @AlecsDelVecchio et al

https://www.sciencedirect.com/science/article/pii/S1050641120300419">https://www.sciencedirect.com/science/a...

[11/27]https://abs.twimg.com/emoji/v2/... draggable=

Matrix orientationhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">It shouldn& #39;t matter much in theory (?)Maybe better results if it is oriented in relation to the propagation of action potentials? If we do this, we can also estimate conduction velocityFigure below: @AlecsDelVecchio et al https://www.sciencedirect.com/science/a..." title="[11/27]https://abs.twimg.com/emoji/v2/... draggable="false" alt="📐" title="Geodreieck" aria-label="Emoji: Geodreieck">Matrix orientationhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">It shouldn& #39;t matter much in theory (?)Maybe better results if it is oriented in relation to the propagation of action potentials? If we do this, we can also estimate conduction velocityFigure below: @AlecsDelVecchio et al https://www.sciencedirect.com/science/a..." class="img-responsive" style="max-width:100%;"/>

[12/27]
Conductive paste? Cream? Or gel?

I did some pilot testing and...

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Paste (ac cream) and cream (EC2) gave me a similar number of MUs

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">It was harder to remove the cream (EC2) from the matrices

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Gel was not so good to identify MUs

[12/27]Conductive paste? Cream? Or gel?I did some pilot testing and...https://abs.twimg.com/emoji/v2/... draggable=

[13/27]
During automatic decomposition, the shapes of the motor units are identified from the background noise.

To increase the ratio of the "energy" in the EMG signals to the "energy" in the noise signal, the noise signal should be minimised.

A few things I have noticed

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">

[13/27]During automatic decomposition, the shapes of the motor units are identified from the background noise. To increase the ratio of the "energy" in the EMG signals to the "energy" in the noise signal, the noise signal should be minimised.A few things I have noticedhttps://abs.twimg.com/emoji/v2/... draggable=

" title="[13/27]During automatic decomposition, the shapes of the motor units are identified from the background noise. To increase the ratio of the "energy" in the EMG signals to the "energy" in the noise signal, the noise signal should be minimised.A few things I have noticedhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">" class="img-responsive" style="max-width:100%;"/>

[14/27]
Tracking MUs between trials is possible due to the high spatial resolution of motor unit action potential shapes in HD-EMG signals.

Note: During a fatiguing task, the MUAP shapes will likely change and it will be harder to track MUs.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="📸" title="Kamera mit Blitz" aria-label="Emoji: Kamera mit Blitz">Some data from my PhD

[14/27]Tracking MUs between trials is possible due to the high spatial resolution of motor unit action potential shapes in HD-EMG signals.Note: During a fatiguing task, the MUAP shapes will likely change and it will be harder to track MUs.https://abs.twimg.com/emoji/v2/... draggable=

Some data from my PhD" title="[14/27]Tracking MUs between trials is possible due to the high spatial resolution of motor unit action potential shapes in HD-EMG signals.Note: During a fatiguing task, the MUAP shapes will likely change and it will be harder to track MUs.https://abs.twimg.com/emoji/v2/... draggable="false" alt="📸" title="Kamera mit Blitz" aria-label="Emoji: Kamera mit Blitz">Some data from my PhD" class="img-responsive" style="max-width:100%;"/>

[15/27]
And MUs have been successfully tracked across days... Even weeks!

Methodological papers:

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts"> http://tiny.cc/8pyasz
https://tiny.cc/8pyasz&qu... class="Emoji" style="height:16px;" src=" https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts"> http://tiny.cc/jqyasz ">https://tiny.cc/jqyasz&qu...

[15/27]And MUs have been successfully tracked across days... Even weeks!Methodological papers:https://abs.twimg.com/emoji/v2/... draggable=

https://tiny.cc/8pyasz&qu... class="Emoji" style="height:16px;" src=" " title="[15/27]And MUs have been successfully tracked across days... Even weeks!Methodological papers:https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts"> https://tiny.cc/8pyasz&qu... class="Emoji" style="height:16px;" src=" ">

[16/27]
#ManualEditingNeeded
Manual editing of spike trains is required. Automatic decomposition procedures are not perfect: they will include firings of similar MUs & not include firings of the MU of interest.

[17/27]
#ManualEditingNeeded
Pulse to noise ratio of the firings might be lower at MU recruitment as the MUAP shape slightly changes during recruitment.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Rückhand Zeigefinger nach unten" aria-label="Emoji: Rückhand Zeigefinger nach unten">
Higher likelihood of automatic decomposition procedures missing firings at recruitment?

[18/27]
#ManualEditingNeeded
Nicely demonstrated by @AlecsDelVecchio et al. (2020)

https://www.sciencedirect.com/science/article/pii/S1050641120300419">https://www.sciencedirect.com/science/a...

[19/27]
#LessCanBeMore
Excluding 5% of the channels may improve the decomposition procedures. This will exclude a couple of channels with a lower pulse to noise ratio. Below is a layout of the DEMUSE tool and the exclusion of 2 channels is highlighted

[20/27]

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">Factors influencing number of identified MUs

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Contraction intensity
It becomes harder to discriminate different MUs at high intensities.

Below some of my pilot data at different %MVC from 2 (good) participants (gastroc medialis). Each dot is a different trial

[20/27]https://abs.twimg.com/emoji/v2/... draggable=

Factors influencing number of identified MUshttps://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Contraction intensityIt becomes harder to discriminate different MUs at high intensities. Below some of my pilot data at different %MVC from 2 (good) participants (gastroc medialis). Each dot is a different trial" title="[20/27]https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">Factors influencing number of identified MUshttps://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Contraction intensityIt becomes harder to discriminate different MUs at high intensities. Below some of my pilot data at different %MVC from 2 (good) participants (gastroc medialis). Each dot is a different trial" class="img-responsive" style="max-width:100%;"/>

[21/27]
(...)

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Contraction intensity
"For example, in the tibialis anterior muscle, which is a reliable muscle for decomposition, we observed a 30% reduction in the number of motor units that can be identified when the target force increases from 35% to 70% of maximum force."

[21/27](...)https://abs.twimg.com/emoji/v2/... draggable=

Contraction intensity"For example, in the tibialis anterior muscle, which is a reliable muscle for decomposition, we observed a 30% reduction in the number of motor units that can be identified when the target force increases from 35% to 70% of maximum force."" title="[21/27](...)https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Contraction intensity"For example, in the tibialis anterior muscle, which is a reliable muscle for decomposition, we observed a 30% reduction in the number of motor units that can be identified when the target force increases from 35% to 70% of maximum force."" class="img-responsive" style="max-width:100%;"/>

[22/27]

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">Factors influencing number of identified MUs

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Subcutaneous layer
Thicker subcutaneous layer

https://abs.twimg.com/emoji/v2/... draggable="false" alt="➡️" title="Pfeil nach rechts" aria-label="Emoji: Pfeil nach rechts">greater distance between the electrodes and the muscle

It can act as a biological “filter”: shapes from different MUs will look + similar

https://abs.twimg.com/emoji/v2/... draggable="false" alt="📸" title="Kamera mit Blitz" aria-label="Emoji: Kamera mit Blitz">Example of possible MU merging

[22/27]https://abs.twimg.com/emoji/v2/... draggable=

[23/27]

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">Factors influencing number of identified MUs

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Effect of sex?

https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤷" title="Person shrugging" aria-label="Emoji: Person shrugging">
When investigating this effect we need to be careful & take into consideration confounding factors (e.g. subcutaneous fat)

https://abs.twimg.com/emoji/v2/... draggable="false" alt="💪" title="Angespannter Bizeps" aria-label="Emoji: Angespannter Bizeps">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👩" title="Frau" aria-label="Emoji: Frau">In fact, my participant with the highest number of MUs is a lean female

[24/27]

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">Factors influencing number of identified MUs

https://abs.twimg.com/emoji/v2/... draggable="false" alt="⚡️" title="Hochspannungszeichen" aria-label="Emoji: Hochspannungszeichen">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Orientation of muscle fibres
Possibly less MUs identified in muscles with parallel fibres, due to superimposition of muscle fibre action potentials (?)

[25/27]
MUs during dynamic contractions? Challenging. Change of

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Distance between electrodes & muscle

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Latency at which APs arrive at muscle-tendon junction

Glaser & Holobar used overlapping short epochs to consider the change in MUAP shapes
https://ieeexplore.ieee.org/document/8579211">https://ieeexplore.ieee.org/document/...

[25/27]MUs during dynamic contractions? Challenging. Change ofhttps://abs.twimg.com/emoji/v2/... draggable=

Distance between electrodes & musclehttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Latency at which APs arrive at muscle-tendon junctionGlaser & Holobar used overlapping short epochs to consider the change in MUAP shapes https://ieeexplore.ieee.org/document/..." title="[25/27]MUs during dynamic contractions? Challenging. Change ofhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Distance between electrodes & musclehttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Latency at which APs arrive at muscle-tendon junctionGlaser & Holobar used overlapping short epochs to consider the change in MUAP shapes https://ieeexplore.ieee.org/document/..." class="img-responsive" style="max-width:100%;"/>

[26/27]
#RealTimeNeuralInterfacing
In fact, a real-time decomposition method for the identification of MU discharges from HD-EMG signals in dynamic contractions has recently been proposed

https://ieeexplore.ieee.org/document/9075399?denied=">https://ieeexplore.ieee.org/document/...

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Final thought

We can& #39;t identify a high number of reliable MUs from everyone

Shall we check during data collection the signals are decomposable? If not, adjust the matrix and/or exclude the participant? Of course the latter needs transparency and could bias our sample.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤔" title="Denkendes Gesicht" aria-label="Emoji: Denkendes Gesicht">Post-conference thought 1/3

Another interesting #ISEK2020 came to an end. Nice to see so many developments in EMG decomposition. I must say that we should not forget that it is exciting to have more people using this technique, but there is also a higher risk for misuse...

https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤔" title="Denkendes Gesicht" aria-label="Emoji: Denkendes Gesicht">Post-conference thought 2/3

E.g. making strong claims when the data is not accurate

Some of the things that should NOT happen IMO

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Not carefully editing the spike trains after decomp

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Including inaccurate MUs

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Including spike trains with merged MUs

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👉" title="Rückhand Zeigefinger nach rechts" aria-label="Emoji: Rückhand Zeigefinger nach rechts">Including repeated MUs

https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤔" title="Denkendes Gesicht" aria-label="Emoji: Denkendes Gesicht">Post-conference thought 3/3

We now have the tools to avoid these

https://abs.twimg.com/emoji/v2/... draggable="false" alt="👆" title="Rückhand Zeigefinger nach oben" aria-label="Emoji: Rückhand Zeigefinger nach oben"> And we must use them.

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