Medical instruments for use in hemodialysis and other extracorporeal blood treatments, namely instruments that monitor extracorporeal blood parameters such as blood volume, oxygen saturation, percent blood recirculation, and hematocrit, used as stand-alone monitors or incorporated into existing hemodialysis or other extracorporeal blood treatment apparatus; surgical, medical, dental and veterinary apparatus and instruments, artificial limbs, eyes and teeth; orthopedic articles; suture materials