.mfile Find pulse width and cycle

Sorry my English is Pool.

1.- I using Matlab R2012a function: (1)pulseperiod (2)dutycycle

to determine my square pulse's width and between pulse (n) and pulse (n+1) 's time, respectively.

But, the level(thereshold) is calculate from pulse 1, so pulse 2 used pulse 1's level.

When the pulse high and low,how can I set every pulse's level make it's mark high and low?

And I found a question, using the two functions some pulse were not determine? Lost some mark.

2.- I read the data .m file from: http://www.physionet.org/cgi-bin/atm/ATM I use importdata and plot can draw picture. But, I want to know another function can read and draw the file's picture?

How can I solve these questions?

Hope you can see my question's picture(3-pictures: Goal, duty cycle, pulseperiod). picture url: http://www.flickr.com/photos/82814421@N08/sets/72157630615535728/

I really need help with these. Anybody know how could I do the function?