How to submit multiple arrays based on selected checkboxes?

I have a list of items and I am selecting some of them but when I submit the form I need to have 3 arrays with different values submitted to PHP, so the following three arrays: Device id, Client comment and Manufacturer comment.

<input type="checkbox" name="devices[<?php echo $cases["dev_comment"]; ?>][<?php echo $cases["manuf_comment"]; ?>]" value="<?php echo $cases["Dev_Id"] ?>">

and in php I am doing:

$devices_selected = $_POST['devices'];    

print :

Array (
    [comment 1 for IMEI no. 277745.5] => Array (
        [manuf comment for dev 1] => 1298
    )
    [comment 2 for IMEI no.576] => Array (
        [0] => 1318
    )
)

It doesnt look correct, I dont even know how to access each value of 3 arrays this way.