natural sorting by sku

Hi, I’m using the following script for sorting order items by sku:

add_filter( 'wpo_wcpdf_order_items_data', 'wpo_wcpdf_sort_items_by_sku', 10, 2 );
function wpo_wcpdf_sort_items_by_sku ( $items, $order ) {
	usort($items, function ($a, $b) {
		return strcasecmp($a['sku'], $b['sku']);
	});
	return $items;
}

It works fine most of the time, but doen’t use “natural sorting”. F.ex when I have product K8 and K10 then K8 comes after K10 because 8 is higher then 1. Would it be possible to achieve natural sorting?

Thanks in advance!