.edf images couldn't import to matlab

Hello, everyone. I am doing with data processing and I have to import all the data to matlab but all are in .edf format. I use the command edfread, but every time it will remind me like this:

dpc=edfread('phantom_dicn_AA.edf'); Undefined function 'readedfheader' for input arguments of type 'double'.

Error in edfread (line 32) hd=readedfheader(fid);

Can anyone who solve this problem? Thank you so much! Joanna