public function _initDoctrine()
    {
        // include and register Doctrine's class loader
        require_once('Doctrine/Common/ClassLoader.php');
        $classLoader = new \Doctrine\Common\ClassLoader(
            'Doctrine'
        );
        $classLoader->register();

        // create the Doctrine configuration
        $config = new \Doctrine\ORM\Configuration();

        // setting the cache ( to ArrayCache. Take a look at
        // the Doctrine manual for different options ! )
        $cache = new \Doctrine\Common\Cache\ArrayCache;
        $config->setMetadataCacheImpl($cache);
        $config->setQueryCacheImpl($cache);

        // choosing the driver for our database schema
        // we'll use annotations
        $driver = $config->newDefaultAnnotationDriver(
            APPLICATION_PATH . '/modules/default/models'
        );
        $config->setMetadataDriverImpl($driver);

        // set the proxy dir and set some options
        $config->setProxyDir(APPLICATION_PATH . '/modules/default/models/Proxies');
        $config->setAutoGenerateProxyClasses(true);
        $config->setProxyNamespace('App\Proxies');

        // now create the entity manager and use the connection
        // settings we defined in our application.ini
        $connectionSettings = $this->getOption('doctrine');
        $conn = array(
            'driver'    => $connectionSettings['connection']['driver'],
            'user'      => $connectionSettings['connection']['user'],
            'password'  => $connectionSettings['connection']['password'],
            'dbname'    => $connectionSettings['connection']['dbname'],
            'host'      => $connectionSettings['connection']['host']
        );
        $entityManager = \Doctrine\ORM\EntityManager::create($conn, $config);

        // push the entity manager into our registry for later use
        $registry = Zend_Registry::getInstance();
        $registry->entityManager = $entityManager;

        return $entityManager;
    }