Final Year Project

Patrick Moran4th Electronic Eng.

A study on the human body parameters influencing blood flow during Neuromuscular electrical stimulation on the lower limbs

Project ObjectivesTo examine if the effectiveness of Neuromuscular Electrical Stimulation is influenced by the following:

• Anthropometrics of the calf Muscle•Body mass Index•Body Fat•Muscle Volume•Isometric Ankle Torque

And to establish any relationships that may exist

Neuromuscular Electrical Stimulation

What is Neuromuscular Electrical Stimulation?Application of electrical stimuli to a group of muscles to trigger an artificial muscle contraction

Where is Neuromuscular Electrical Stimulation used?• Correction of drop foot• Muscle strengthening• Mobilisation of spinal cord injury• Maintaining range of motion in immobilised subjects

Neuromuscular Electrical stimulation in this studySurface Neuromuscular electrical stimulation shall be used in this study.

Source of stimulation would be The Dou – STIM

Stimulation parameters• Max Voltage (100%) = 78Volts• Ramp up time = 1 second• On Time = 1 second• Ramp Down Time = 500 milliseconds• Frequency = 36 Hertz• Pulse Interval = 100μseconds• Pulse Width = 100 μseconds

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About the Study• Electrodes Placed on calf muscle

• Blood flow examined from popliteal Vein using doppler ultrasound

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• Stimulation was started at 25% and incremented in steps of 5%, until the

subject stated that they no longer found it comfortable

• Ethics Application - NUI Galway Research Ethics Committee

ResultsThe subjects were examined individually first. The following relationships were established while looking at the subject’s results as individuals.

• Stimulation Intensity Vs Venous Volume Flow• Stimulation Intensity Vs Isometric Ankle Torque• Isometric Ankle Torque Vs Venous Volume Flow• Stimulation Intensity Vs Peak Venous Velocity

Then the results were looked at from a group perspective. It was hoped to establish any relationships that may exist between the correlations obtained from the individual results and the anthropometrics of the lower limbs or the subject’s body mass index.

A p value of < 0.05 was considered significant in all analyses.

Stimulation Intensity Vs Venous Volume Flow

The correlation values ranged from 0.911 0.997. ‐

The regression calculations ranged from 0.83 0.995.‐

No p - value was greater than 0.05

Stimulation Intensity Vs Ankle Torque

The correlation values ranged from 0.911 0.997. ‐

The regression calculations ranged from 0.774 0.971.‐

No p - value was greater than 0.05

Venous Volume Flow Vs Ankle Torque

The correlation values ranged from 0.894 0.996. ‐

The covariance's calculated were all positive indicating a relationship.

No p - value was greater than 0.05

Stimulation Intensity Vs Peak Venous Velocity

The correlation values ranged from 0.911 0.997. ‐

The regression calculations ranged from 0.774 0.971.‐

No p - value was greater than 0.05

Group results

Conclusion

The effects of NMES on blood flow were proven, very significant relationships were found between:

• Stimulation Intensity Vs Venous Volume Flow• Stimulation Intensity Vs Isometric Ankle Torque• Isometric Ankle Torque Vs Venous Volume Flow• Stimulation Intensity Vs Peak Venous Flow

The fact that no relationships were found between these and the human body parameters can be put down to a small sample size and possibly human error.

Questions