Cut string at space with a regex but watch for umlauts?

Question

This is my code:

if (preg_match('/^.{1,22}\b/s', $myString, $match)) {
    $name = $match[0];
}

It cuts a string after 22 chars and at a whitespace. Problem is, it does not work if there are unmlauts like ü in the string.

• That works: Lorem ipsum dolor sit amet
• That does not work: 12345678 - Schlüsselband

Any ideas how to fix that?