Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Upcoming SlideShare
PRESENTATION LAB DSP.Analysis & classification of EMG signal - DSP LAB
Next

80

Share

EMG

Related Books

Free with a 30 day trial from Scribd

See all

EMG

  1. 1. Electromyography A practical guide to understanding muscle activity 1
  2. 2. Muscle function • Muscles are the physiological motors of the human body • Kinematics and kinetics give us a good indication of the muscle groups • For increased specificity we measure a muscles activity during gait 2
  3. 3. Electromyography • Definition of Electromyography (EMG) – Electromyography (EMG) is the detection and recording of the electrical signal produced by muscle tissue as it contracts. 3
  4. 4. Muscle activation (sEMG) • Measurement of electrical signals within the muscle with two electrodes • A summation of the action potentials generated during contractions due to a change in the cell’s membrane potential • The size of the signal is dependent on the number and frequency of firing of motor units 4
  5. 5. Why measure sEMG? • Measuring the muscle activity during gait allows: – an indication to whether the muscle is active – to see relative changes in timing of the muscles – to assess motor control and coordination – to determine any evidence of spasticity – to evaluate muscle function post-surgical transfer 5
  6. 6. EMG does not tell us: • The strength of the muscle • What type of movement the signal represents • Whether the activity is compensatory or the primary abnormality. 6
  7. 7. Electromyography • EMG includes the – Detection – Amplification – Recording – Processing and analysis – Interpretation • Three ways of recording the signals • Surface electromyography (sEMG) most popular 7
  8. 8. How to measure sEMG • Positioning the patient 8 Recommendations: www.seniam.org
  9. 9. How to measure sEMG • Determine the electrode location Recommendations: www.seniam.org 9
  10. 10. How to measure sEMG • Skin preparation 10 Recommendations: www.seniam.org
  11. 11. How to measure sEMG • Place and fix the electrodes securely 11 Recommendations: www.seniam.org
  12. 12. Fine Wire EMG • Determine Position 12
  13. 13. How to measure sEMG • Test the connection and accuracy of the placement 13 Recommendations: www.seniam.org
  14. 14. Processing the signal • Raw signal 14 Not active active
  15. 15. Processing the signal • Rectified signal 15 Not active active
  16. 16. Processing the signal • Muscle timings 16 smoothed & rectified signal threshold Onset Off
  17. 17. Processing the signal • Filtered 17 Not active active
  18. 18. Processing the signal • Fatigue 18
  19. 19. Factors that affect sEMG signal • Impedance of the tissue • Cross-talk between muscles • Changes in geometry between muscle and electrodes • External noise • All of these can be reduced using the 3P’s – Position, Preparation and Placement of the electrodes 19
  20. 20. Repeatability and Interpretation of EMG data 20 • Very few studies in the general literature • Displayed the same way as general gait data • Normalisation methods need to be appropriate • sEMG alongside kinematics and kinetics can offer further details about muscle function • However, many labs choose specific individuals
  21. 21. Demonstration Demonstration of sEMG and fwEMG 21
  • MDRahimi

    Jun. 23, 2021
  • PriyankaRangudu2

    May. 28, 2021
  • YashuSam

    Dec. 15, 2020
  • MohammadSaquib37

    Oct. 21, 2020
  • KalleshkumarHiremath

    Oct. 18, 2020
  • KvsKala

    Oct. 12, 2020
  • JstnJgadsh

    Sep. 29, 2020
  • sruthi4300

    Sep. 12, 2020
  • SalihAtroshey

    Sep. 5, 2020
  • DrjagadeesanV1

    Aug. 19, 2020
  • manish499

    Jul. 14, 2020
  • mohamedsaadsidawy

    Jul. 3, 2020
  • 100000785476698

    Jul. 3, 2020
  • HarithaMenon

    Jun. 30, 2020
  • saunakbhattacharya2

    May. 14, 2020
  • pavithrasrinivasalu1

    Apr. 20, 2020
  • muthavarapupriyanka

    Apr. 18, 2020
  • MunaishKumar

    Apr. 2, 2020
  • sidhusid5

    Mar. 9, 2020
  • RiyajuddinKhan2

    Feb. 27, 2020

Views

Total views

27,771

On Slideshare

0

From embeds

0

Number of embeds

94

Actions

Downloads

0

Shares

0

Comments

0

Likes

80

×