Implantable marker for a surgical navigation system, the marker having a stem with a separation zone to facilitate the removal of the marker

Abstract

A marker for use with a surgical navigation system for tracking the tissue with which the marker is associated. The overall dimensions of the mark is such that it is shaped to be disposed below the skin of the patient in which the marker is implanted. The marker has a stem that allows the marker to be implanted in hard tissue such as bone. A head, containing navigation system components is located above the stem or spike. The stem is formed with a section of reduced tensile strength. Once the procedure is completed, a force is applied to the marker. The force breaks the stem at the separation zone. This allows the portion of the marker above the separation zone to be removed.

1 - 18 . (canceled) 
     
     
         19 . A marker for use with a surgical navigation system, said marker including:
 a head;   transducer components disposed in said head for receiving EM or RF signals from a complementary navigation system component or transmitting EM or RF signals to a complementary navigation system component; and   a stem formed from biocompatible material that extends outwardly from said head, said stem having features for engaging bone so that the stem is held to the bone and a separation section that, in comparison to an adjacent portion of said stem, is of lower mechanical strength so that, when an extraction force is applied to said head, said stem separates at the separation section so that head can be withdrawn away from said stem features that hold said stem to the bone.   
     
     
         20 . The marker of  claim 19 , wherein the stem separation section is formed so that in comparison to the rest of said stem, the separation section is of low tensile strength. 
     
     
         21 . The marker of  claim 19 , wherein said head is formed with features to which a removal tool can engage. 
     
     
         22 . The marker of  claim 19 , wherein said stem has a proximal end adjacent said head and a distal end spaced from said head and the stem separation section is adjacent the proximal end of said stem. 
     
     
         23 . The marker of  claim 19 , wherein said stem is formed with barbs that hold said stem to the bone. 
     
     
         24 . The marker of  claim 19 , wherein said stem is formed with indentions, the indentations defining the stem separation section.