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.

Lung function monitoring is a critical technique for clinical medicine. Currently, the lung function testing devices used in our domestic hospitals are both expensive and bulky. A portable and accurate lung function parameters testing system is highly desired and is proposed in this paper. The hardware of the system is based on DSP technology. The breathing passage is designed with an aim suitable for the breathe and signal detection. We use the direct detection method to detect the gas flow, the breathing passage pressure and the breathing time. Thanks to the powerful data processing ability and the high operation speed of the DSP, breathing signals can be easily analyzed. Thus, several lung function parameters of clinical significance can be obtained. Experiments show that the accuracy of the system is better than 3%, and could meet the demand of the lung function testing.
Humans ; Respiratory Function Tests ; instrumentation ; methods ; Software ; Software Design

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

The vascular mechanical parameters are important indicators for human vascular and they play important roles in clinical research. This paper developed a new vascular mechanical properties testing system. This system not only realizes the tensile rupture test in one dimensional, but also the reciprocating tensile test for vascular, which provides more comprehensive experimental data and theoretical basis for the study of human vascular. The system consists of three parts: the mechanical platform, hardware circuit and upper computer system. The mechanical platform transforms the rotation movement of motor into linear movement via the structure of bal screw. And the bal screw and tension sensor are connected, which is used for mechanical data reading. The displacement data is col ected by displacement sensor. Experiments show that the accuracy is better than 0.292%, and could meet the demand of the testing of vascular biomechanical characteristics.

Complex and huge wound closure is a key step in pre hospital emergency care. Wound closure can effectively reduce the loss of blood and fluid inpatients before arriving hospital. Also, it has important significance to save the lives of patients. In this paper, a new type of wound closure device is developed, which is used for the rapid closure of complex and huge wound. Firstly, based on the detailed introduction of the structure working principle, the finite element simulation technology is adopted to analyze the stress of the structure. The results show that the stress of the structure has not beyond the allowable stress of the material. On the basis of this, the experiment was carried out in vitro. Test results show that the closure device operating time is 18.24 s and the minimum penetration of the skin force is 4.08 kg. The closure device can resist the horizontal tension of 1.53 kg and vertical tension of 2.25 kg. It also has good sealing performance and meets the design requirements. The results show that the device designed is reasonable, which can be quickly and effectively to achieve closure of the wound.

In the background of the high incidence of vascular injury in wartime,this paper introduces the characteristics of vascular injury in war environment and the development of early treatment technique of vascular injury applied in wars since World War Ⅱ. Then,the advantages and limitations of various treatment techniques are also analyzed. Finally,The development of technology and research direction are summarized and prospected.

A novel testing system is designed to simulate the mechanical performance and evaluate the biomechanical properties of the bone and the corresponding bone fixator. It is mainly composed of movement platform and servo motor system, sensors and hardware circuit system and software system. In order to prove the feasibility of the design, on the basis of the calibration for the force sensor, the fatigue experiment is carried out using the tibia of the sheep. It is concluded from the result that under the condition of 1 Hz in frequency, 50 kg in loading force and 18 000 cycles, the bone fixator can be still in good condition, which proves the feasibility of the design.
Animals ; Biomechanical Phenomena ; Bone Screws ; Mechanical Phenomena ; Sheep ; Stress, Mechanical ; Tibia ; physiology