Wearable sensor technology and medical robotics for fatigue assessment using electromyography signal processing, 2024,

[Dolphin]

Wearable sensor technology and medical robotics for fatigue assessment using electromyography signal processing

Byeon, H., Seno, M.E., Yajid, M.S.A. et al. Wearable sensor technology and medical robotics for fatigue assessment using electromyography signal processing. SIViP (2024). https://doi.org/10.1007/s11760-024-03505-6

https://link.springer.com/article/10.1007/s11760-024-03505-6

Abstract

This study integrates Wearable sensor technology and medical robotics to propose a unilateral approach to assessing fatigue in passive lower limb exoskeleton users.

Addressing the one-sidedness in evaluating the fatigue status of wearers of passive lower limb exoskeletons, a comprehensive exoskeleton efficacy evaluation method combining muscle fatigue threshold value Electromyographic Fatigue Threshold (EMGFT), biomechanical analysis, and subjective Rating of Perceived Exertion (sRPE) scale is proposed.

Unlike traditional methods relying solely on surface electromyography (sEMG) or blood oxygen saturation measurement, the proposed method can effectively enhance the accuracy of passive lower limb exoskeletons efficacy evaluation.

By capturing movements for gait comparison analysis, spatial position information and muscle force data are obtained, along with calculation of ankle joint stability.

Subject’s sEMG is pre-processed to calculate muscle fatigue baseline values; combined with sRPE scores and ankle joint deviation variance, EMGFT is subjected to subjective and objective validation.

Results indicate that the proposed method effectively alleviates fatigue by 30.3%.

 

[Hutan]

By capturing movements for gait comparison analysis, spatial position information and muscle force data are obtained, along with calculation of ankle joint stability.

I don't understand the abstract. It was sounding like a useful system for assessing fatigue from various sensors. Something like that could be useful for a study in ME/CFS, e.g. to quantify what happens after an extended period of walking when it seems like it takes a lot more conscious effort to walk smoothly, and sometimes even conscious effort isn't enough.

But the last line suggests that the methodology was therapeutic? If anyone has free access to the paper and an interest in wearables, perhaps you can let us know some more details?

 

[SNT Gatchaman]

I've just glanced but it looks like they were trying different attachment styles and seeing what subjective fatigue scores were, on use.

Through feature extraction from the data of each group in the experiment, it was found that the passive lower limb exoskeletons effectively reduce the muscle load generated during walking under load conditions, especially when proficiently used. Participant healthcare feedback indicated that when the exoskeleton alleviated pressure through the backboard and connection parts, noticeable local pressure on the shoulders affected subjective fatigue ratings.

A bit more on methods —

For this medical study, we recruited 18 healthy males who did not engage in any risky behaviours. The average age, height, and weight of the participants were 25 ± 2 years, 168.0 ± 3.0 cm, and 62.0 ± 5.0 kg, respectively. There were no aches or pains, and no individuals had recently engaged in strenuous physical activity, so we can safely say that their overall health was excellent.

(Not sure that definitely follows but I'll allow!)

ls in both Group A and Group B in rapid succession so that we could compare the various wear and non-wear phases of tiredness. The subjects in Group A wore the exoskeleton during the trials, but those in Group B did not. [...] separated by 48 h.

To explore the effects of exoskeleton proficiency and user strength on the effectiveness of lower limb exoskeleton use, participants’ healthcare was classified according to their weekly physical training duration and total exoskeleton usage duration. The 18 participants were divided into three groups: normal, proficient, and strong, with six participants in each group. Participants who exercised for less than three hours per week and did not utilise the exoskeleton were assigned to the usual group. Participants who trained for fewer than three hours per week but utilised the exoskeleton for more than 20 h were considered proficient. The strong group included participants who exercised more than 7 h per week but did not utilise an exoskeleton. The load for the experiment was a 20 kilogramme standard weight sandbag placed in a backpack. In addition, all participants received subjective fatigue rating quantification training for more than four hours.

Group A participants Participants in this group wore the exoskeleton and carried a backpack containing a 20 kg standard weight sandbag placed on a backboard. To prevent sliding of the IMU sensors due to wearing the exoskeleton, sensors 03 and 04 on the outer side of the thigh and sensors 02 and 05 on the front side of the calf were reinforced with electrical tape, while the remaining IMU and sEMG sensors were fixed with double-sided tape.

Group B Participants Participants in this group did not wear the exoskeleton but carried a backpack containing a 20 kg standard weight sandbag. wearable sensor was fixed in designated positions using double-sided tape. Before the experiment began, to ensure that the participants were not fatigued, Groups A and B had a 48-hour interval between experiments, during which participants were not allowed to engage in vigorous exercise.

 

[bobbler]

I don't understand the abstract. It was sounding like a useful system for assessing fatigue from various sensors. Something like that could be useful for a study in ME/CFS, e.g. to quantify what happens after an extended period of walking when it seems like it takes a lot more conscious effort to walk smoothly, and sometimes even conscious effort isn't enough.

But the last line suggests that the methodology was therapeutic? If anyone has free access to the paper and an interest in wearables, perhaps you can let us know some more details?

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9229674/

I did a Google of these exoskeleton things and it’s a whole new world

I think you might be right and @Dolphin fir posting that this area could have a lot to offer re methods and understanding of gait and signals of fariguability and other pertinent issues

I didn’t know you could get wearables to help with energy or exhaustion

but makes sense they need to understand the mechanics of eg tge legs in those states well to not cause more problems than they solve

 

[bobbler]

When I think of the risk of OnlY using actimeters for measuring eg PEM

and of course the issue being we haven’t really got a good way of measuring what I think is at the core which is cumulative and like a residue from jog back/perfotm-agsin recovery rather than rest until fully recovered from exertion … yet

and the issue of the floor/ceiling effect even if you are done in but need the loo or have to care for a child , not being able to measure how much thinking or a conversation or spreadsheet takes out of someone yet. Or twelve hours of it.

Vs issues of bias, coercion, manipulation in subjective replies so people might ‘think’ they are feeling good because of adrenaline, geeing up and being told ‘that pains a good sign’ because no pain no gain and they’ve not be around the block trying to cheat the illness enough times yet.

but I bet the gait of me when I was pushing through would show the difference between ‘smiling and loading up with caffeine and riding the adrenaline to complete this work task me’ and ‘I’ve just had my week off in bed where I sleep of 6weeks worth of PEM me just in time for Monday morning me’ in a way humans mightnt spot without those tools.

importantly they might do the holy grail of being able to compare a year or more apart.

nevermind adding in that it’s about more than exercise but sitting up and doing work thinking of talking etc too

well these things probably do or might have the incentive to be looking at the longer harms and indicators instead of just the ‘can you get a bump in performance short term’ so might be interesting to dive into

if for example you are doing something for healthy military purposes to make eg soldiers better at energy intense things or able to do more for less short term then you need to know what you are really measuring

edit: including long term side effects/unintended consequences