You need to use the JParameter class to read the params. Do the following
$component =& JComponentHelper::getComponent('com_courseman');
$menus = & JSite::getMenu();
$items = $menus->getItems('componentid', $component->id);:
foreach($items as $item){
$params = new JParameter($item->params); $myParam = $params->get('theParamIwant');
}
