I’ve visited www.copyright.gov, but I couldn’t find it.
Try this resource
I don’t think you can patent a “technique”. There are numerous techniques used in surgery and I can tell you that there are not royalities paid out.
I am not sure that you can’t patent a medical technique, but I am sure you can’t get information of how or what to do by going the way of the copyright office or the copyright laws.
For information, you need to go to www.uspto.gov