| 摘要 |
A three-pin skull clamp [ 10 ] includes a C-shaped frame [ 12 ] which partially encircles the head [ 18 ] of the patient, with a spring-loaded single skull pin assembly [ 22 ] located at one end of the frame [ 12 ] and adapted to engage the head [ 18 ] of the patient with a desired engagement force, and two spaced skull pins [ 30 ] mounted to a rocker arm [ 44 ] located at an opposite end of the frame [ 12 ]. Each of the rocker arm skull pins [ 30 ] resides in operative contact with an indicator cap [ 66 ] held by a spring-loaded pin carrier assembly [ 50 ], the indicator cap [ 66 ] being movable relative to the rest of the pin carrier assembly [ 50 ] in response to the engagement force applied to the corresponding skull pin [ 30 ] by the head [ 18 ] of the patient. By visibly comparing the positions of the indicator caps [ 66 ] relative to their respective pin carrier assemblies [ 50 ], one can readily determine whether the engagement forces are equally distributed between the two rocker arm skull pins [ 30 ]. If the indicator caps [ 66 ] show significantly unequal load distribution, the rocker arm [ 44 ] can be pivotally adjusted to produce a rocker arm orientation which results in a more equal load distribution on the two spaced rocker arm skull pins [ 30]. |
