OBJECTIVEA new kind of external fixator for orthopaedics is designed in order to overcome the shortcomings of high weight, hard to operate and high degree of hurt for the conventional external fixator.

METHODSThe quick casting method is used to realize fast shaping, and FEM (Finite Element Method) is used to verify the practicability of the design.

RESULTSIn order to verify the correctness of the design, FEM is used to simulate it. It is concluded from the simulated result that the biggest relative displacement between the borders of the separated bones is just 0.37 mm, which is much less than the requested value 1 mm. This fits the request to cure the patients whose bones are broken and shows the correctness of the design. Finally, ten sheep are used as specimen to verify the feasibility of the design. It is concluded from the X ray sketches of 2 weeks, 4 weeks and 8 weeks that there is no relative displacement happened between the border of the broken bone and the bone is well cured.

CONCLUSIONSThis kind of device is feasible to cure the broken bones and the design scheme can be used as the final treatment means.

Animals ; Equipment Design ; External Fixators ; Fracture Fixation ; instrumentation ; Sheep

This paper introduces the development on the research of measuring theory for orthopaedic biomechanics in detail. Then, the measuring method and corresponding measuring device are also mentioned. Advantages, disadvantages and development for the device are also introduced. Finally, the research prospect for it is introduced.
Biomechanical Phenomena ; Bone and Bones ; physiology ; physiopathology ; Physics ; instrumentation ; methods