Abstract:Seating pressure sore is always one of main problem for rehabilitation engineering and biomedicalengineering. Many people need to stay much time in the chair owing to work and sick, resulting inuncomfortable and pressure sore. For relieving pressure sore and providing the information used inclinical diagnosis, in this research, a clinical instrument is designed to assess pressure distributionand at last suggest the proper posture and cushion. The evaluation system include the adjustedposition system-adjusting character of variable body, interface pressure system and buttock contoursystem.From the result of experiment, one can see that the max. pressure in the spinal cord injury isgreater than that in the normal people and as the seat angle and seat to back angle increase,themax. pressure decrease. one can understand spinal cord injury easily get the pressure sore thannormal people do. We use the appropriate seat and seat to back angle to reduce the interfacepressure to prevent the pressure sore.

Abstract:Combining spiral CT scanning technology with three-dimensional finite element method, togetherwith Auto-CAD software, a three-dimensional nonlinear finite element model with nonlinearcharacteristic such as nonlinear material and contact relationship in the joint was developed fromin vivo for calculating and analyzing the stress distribution wit.hin the human temporomandibularoint (TMJ) during centric occlusion in order to simulate and analyze the stress distribution anddisplacement of the human TMJ.

Abstract:To compare the cutting and reversing property of there different diameter conicalpulling-screws. Methods: In the material experimental machine, the conical pulling-screws withtheir respective diameter of 4mm, 5mm, 6mm which had been deeply frozen from fresh cadavericfemur shaft of young adult, examine the cutting intensity and rigidity property of the smooth partsof screw and the saw tooth parts seperately, then the reversing and destorying. Rusultf The cuttingintensity of the smooth part of screws were respectively 526N, 1034N, 1459N, and of the saw-toothpart of screws were respectively 290N, 505N, 931N. There marked differences in the cutting intensityand rigidity between the smooth of screw were marked and the saw-tooth part, which are of thesame diameter. The differences were also significant with different diameters. The maximummoments of force among the 4mm-diameter, 5mm-diameter, 6mm-diameter pulling-screw were0.64Nm, 1.59Nm, 2.10Nm respectively.While the moments of force of pulling-screws with differentdiameters were siguificant diferent. Conclusiont The biomechanical property of the pulling-screwswith same diameters is different, and the property of those with different diameter was slgnificantdifferent.

Abstract:Both thighs of the dogs with or without ligated fern oral artery and vein were wounded. Thehemorheologic changes during 72 hours after trauma and the effect of the hemodynamics in atwinkle of the trauma on hemorheology were studied.The results suggested that the hemodynamicsin a twinkle of the trauma was one of the important reasons f'or blood viscosity and RBCaggregation increasing after trauma.

Abstract:image topology method and the curvature vatiation calculation was used in method for autorecognizing the positon of turn and isthmus. This method could get the position of two parametersImpersonality and reduce the time and error.

Abstract:To investigate the longitudinal residue strain and stress-strain relation of extremitiesarteries and veins in human, evaluated the particular reference to the option of vascular repair.Methods: A mechanical analysis including stretch experiment and longitudinal stretch ratiomeasurement was undertaken to evaluated.the longitudinal residue strain and stress-strain relationof extremities arteries and veins in human. Results: The longitudinal stretch ratio of extremitiesartery decreased along vessel branch but that of vein increased. There was significant differenceamong the longitudinal stretch ratio of extremities artery and those of branchiocephalicae vein orsaphena megna vein but subclavia and femoral artery (p<0.05). The longitudinal stretch ratio ofvein was higher than those of artery at same level. The stress-strain relation curve of artery turnedright along vessel branch but that of vein turned left .Conclusion: The longitudinal residue strainand the stiffness of extremities artery decreased along vessel branch but that of vein increased. Itsuggested to orepair the injuried vessel according to the biomechanlcal effect.

Abstract:According to the biomechanical principle, 18 specimens of human pelvie were selected from freshcadavers and made into samples for biomechanical laboratory test. Using cadaveric pelvicinstrumented with strain gauges displacement instrument compare five different interfixationresults. Blomechanical studies demonstrated utilizing π- shaped rod and T - shaped plates,sufaficient stability of pelvic ring could be Provided. Its the Strength, rigidity and stability appear tooffer distinct biomechanical advantage over the three interfixation method (P<0.01). BiomechamIcal Parameters were provided the theoretical basis in clinical application of different interfixationfor Vertically unstable pelvic fracture.

Abstract:Aim: To revel the relationship between porosity, collagen fiber orientation and strengh of theplated bone after rigid plate fixation and removal. Methods: Seventy-two new zealand white rabbitswere used in this experiment. Eight anmals served as control and the other sixty-four were platedon their intact left tibiae with stailess steel (316L) 4-hole plates to induce early osteoporosis. Theplates were removed 2 months after internal fixation in 40 plated animals, 8 of which were sacrificedimmediately following plate removal and the other 32 were killed in successive groups of & each at1,2,3 and 4 months after plate removal. The remaining 24 plated animals were killed at 3,4 and 6months after plate fixation. After sacrifice, the samples of plated bone were prepared for lightmicroscopy, quantitative histological analysis, polarized light microscopy and biomechanical test.Results: The internal fixation with a rigid plate could induce the regional osteoporosis whichmanifested both bone loss and disorganized bone structure (loss of the orientation of the collagenfibers) leading to decreased strength of the plated bone. Although the regional osteoporois couldrecover gradually after plate removal, the bone structure remained disorderly when the bone masshad returned to normal. Delayed restoration of bone structure was related to delayed restoration ofbone strength. Conclusion f Besides the bone loss, the disorganized bone structure is the main causeof decrease of bone strength after rigid plate fixation and removal.

Abstract:Finite element method was used in the present study, of stress distribution of supporting tissuesunderlying extension edentulism which were restored with RPD using telescopic crown. mesial anddistal occlusal rest respectively as retainers were tested by means of finite element. Results showedthat the stress of both abutment and underlying supporting tissues of telescopic crown retaineddemure were more evenly distributed than that of the other two types, and it produces no trauma tooral hard and soft tissues, thus proved to be a sound way of restoring extension edentulism.

Abstract:Objective: in order to improve the effect of the spinal reduction and fixation, let fixation devicesare good enough to conform the biomechanical requirement. Mathods: The experiment was carriedout with 7 human cadaver thoracolumbar spinal specimens. Models of unable thoraco lumberfracfures were caused by artificial stress on these specimens and new spinal fixation devices wereused in these specimens. The stress(stain), displacement, strength, rigidity and stabilization on thelumbar spinal specimens were measured with four different physiological conditions. Rusultf Theresult of the biomechanical tests on this device showed that MF was better than Dick and Steffee inall of strength, anti-axial compression, anti-rotation, rigidity and stability(p<0.01). Conclusion f Theresults of this spinal fixation instrument in treatment of 21 cases of unstable thoracolumbarfractures were statisfactory. This study indicated that this device is worth for application andpopularizing.

Abstract:In this paper, we considered the cement line between the osteon and the interstitial bone to be theviscoelastic interface, and established the micromechanics model of conical bone. The stressresponse of this model under the strain loading along with the axial direction of bone and somemacroscopic effective modulus of conical bone were provided. We also found that the difference ofPoisson's ratios of the osteon and the interstitial bone was very important for the effective modulusand the transverse stress distribution of conical bone.

Abstract:In this paper the mechanism of intervertebral disc active was analysed. The intervertebral discwas modeled by a rollingball. The differential equations of rolling ball motion were presented, andthe influence of external force on the intervertebral disc motion was discussed.

Abstract:Aims: To chosing the locating patterns that have better biomechanical properties and more simpleand convenient for clinic. Methods f o fresh calf specimens were used in the study the stability of 4kinds of the FC(Fusing Cage)'s locating patterns was compared at these motion segments. Results;The sit f'fness and laxitt under all kinds of the conditions among the former 3 kinds of the FC'slocating patterns was similar. They have more stability than the forth one. The former 2 kinds ofthe patterns were used to treat the 14 patients with Low Back Pain and made satisfied effectpreliminary. Conclutlons: The most direct stability effect is neither from FC's orientation nor it'snumber. It is FC's diameter that will effect directly on the stability. If the FC's diameter and lengthare chosen properly. AFC patterns located either in the middle of interbody space at L5S1 orleft-lateral obliquely at L4.5 by anterior approachh would be effective and convenient.