Elastography

Now I am working on tracing the movement of M mode in sonography.

This is the raw movie recorded by sonography. Now I need to trace the change of different layers.

Here is the result of my tracing program. 

The Correlation Between fascicle Curvature and Muscle Hardness

Here is a short introduction of the topic I presented in ISB 2007.

In this study, we try to find the relationship between muscle hardness and  fasicles' curvature which become more 

curved during muscle contraction. We used a tool called myotonometer which claims it can measure the muscle

hardness. The concept is simple. It just measure the force which is resisted by muscle and the displacement.

We also measure the fasicle curvature by sonography. Then we find the force which we applied the myotonomer on the muscle and find the same force in the sonography trial that we can know the change of fasicle curvature.




We calculated the stiffness we tested from myotonometer.

Also, we measured the fasicle curvature in sonography.

Tendon Viscoelastic Properties

One of big parts in my Thesis.

This part is called tendon mechanical properties which means we need to calculate tendon stiffness and hysteresis. 

In order to measure the displacement and applied force of tendon, we use sonography and load cell. However, in my lab, sonography and load cell are two different system. We need to synchronize those two system, so I use a switch which can generate 5 volt to be a mark. Here is the animations.

EMG Median Frequency

Now we try to calculate the median frequency of this raw EMG data:

1. We need to use fast fourier transform.

2. Integrate the half of the data, because the other half is image of the real data.

3. Find the median value of this Integrated data.

    Here is my matlab function:

EMG RMS

Now we want to calculate the root mean square of this raw EMG data:

Here is my code:

window means how many points do we want to calculate one RMS.

over means how many points do we need to overlap.

You can also find the example in my matlab blog: (Chinese Version)

http://labmatpt.blogspot.com/2006/12/moving-averagerms.html

EMG Filter

Here is a Matlab code for high pass, low pass and band pass filter:

Take low pass filter for example:

I wrote the code by modifying the "butterworth" filter function.

We can switch to high pass, band pass or band stop by changing the string 'low'

Research

EMG
    
    Time Domain
           EMG Onset
           EMG Filter
           EMG RMS
      
    Frequency Domain
        EMG Median Frequency


Sonography
    My thesis
        Tendon Viscoelastic Properties
    ISB Conference
        The Correlation Between fascicle Curvature and Muscle Hardness
    Recent Study
        Elastography
        
Publications
Wu YK, Lien YH, Lin KH, Shih TF, Wang TG, Wang HK.  Relationships between three potentiation effects of plyometric training and performance. Scandinavian Journal of Medicine & Science in Sports: in press  (SCI) PDF

Wang HK, Wu YK, Lin KH, Shih TF.  Noninvasive analysis of fascicle curvature and mechanical hardness in calf muscle during contraction and relaxation. Manual Therapy 2009; 14(3): 264-269  (SCI) PDF

Chiu CM, Wu YK, Lin KH; Shih TF; Lien YH; Wang HK. Effects of Plyometric Training on Eletromechanical Delay Human Plantarflexor Muscles. FJPT2008; 33(1): 34-40