1994, 9(3):134-141. DOI: 10.3871/j.1004-7220.1994.3.141.
Abstract:The in vitro study was to quantitively determine the movements of each of the cervical intervertebral joints(C2-C6) of normal structure and those following expansive open-door laminoplasty(EODL).Seven fresh young cadaveric specimens of whole cervical spine(Occipital bone to C7) were used in the determination of the movements in flexion,extension,left and right lateral bending.Pure moments with a maximum of 1.5 N.m were incrementally applied and the movements of bones were recorded by photography.Each moment was applied individually in three load/unload cycles.Parameters of neutral zone.elastic zone and range of motion were computed The difference in segmental motions were of no significant(P>0.05) when the motions of each segment from C2 to C6 in the intact cervical spine were compared with those of the same segment following EODL at C3-5 or C2-5.Worsened instability was unlikely to be seen in the middle/lower cervical spine following EODL.
1994, 9(3):142-147. DOI: 10.3871/j.1004-7220.1994.3.147.
Abstract:In this paper,the variation of blood flow velocity wave along the radial position of carotid artery is analyzed,and the influence of the radial position on velocity maximum(Vmax)and minimum(Vmin)are discussed in detail.These results are applicable for assessing the effect of the ultrasonic probe deviating from the axis of carotid artery on the measured Velocity measurement can be controlled to around 10 percent when the probe deviated its position from the blood vessel axis is y=r/R=0.2.This plays an important role in the operation and analysis of non-invasive blood flow velocity measurement.
1994, 9(3):148-155. DOI: 10.3871/j.1004-7220.1994.3.155.
Abstract:Thirty-two dogs were divided into 4 equal groups randomly following experimental traumatic brain injury.Group I,as control,without any treatment after injury,GroupⅡ,Ⅲ,Ⅳ were treated by mannitol,mannitol adding DX 40 and isovolumetric hemodilution(IHD)respectively after injury.Hemorheology,hemodynamic parameters and intracranial pressure(ICP)were monitored at different intervals during the study,Meanwhile the traumatic brains were examined pathologically.The results demonstrated that hematocrit(HCT),blood apparent viscosity at low and high shear rates(η0.512,η51.2).erythrocyte aggregation index(AI),viscous component(η'),elastic component(η''),elastic modules(G') and ICP increased Significantly after brain injury.In group Ⅱ,HCT,η0.512,η51.2,AI-η',η''decreased obviously at 1 hour after therapy,but increased to the level before in jury at 2 hours after therapy.Except for η51.2,the rest of hemorheol logical parameters decreased significantly in group Ⅲ and IV at 2 hours and 8 hours after therapy,While ICP in group IV was lower than that of the other groups at 8 hours after therapy The Study indicated that IHD is particularly effective in lowering blood viscosity,vlscoelasticity and erythrocyte aggregation,IHD does not result in an increase in cardiac output or ICP,IHD can lead to reduction in cerebra vascular resistance and increasing blood volume in microcirculation and can reduce cerebral edema and the extent of brain damage.We suggest that it is important to examine HCT during the routine treatment of traumatic brain injury and IHD is one of the safe,acceptable and effective therapies in the treatment of brain injury.
1994, 9(3):156-161. DOI: 10.3871/j.1004-7220.1994.3.161.
Abstract:According to the biphasic poroelastic theory,a layer of skin and suboutaneous tissue on a bony substratum was modeled as a homogenous layer of biphasic poroelastic material with uniform thickness.The dynamic biomechanical responses under a cyclic pressure load were obtained by using an analytical method followed by numerical solutions.
1994, 9(3):162-166. DOI: 10.3871/j.1004-7220.1994.3.166.
Abstract:The segmental motion of lower cervical vertebrae of 26 patients with cervical spondylitis were observed dynamically through digital video-fluoroscopic system.A significant decrease of the lower cervical motion was found in all patients as compared with normal control.Although the limitatoin of motion mainly occurred at the degenerative level,alteration in the range and mode of motion was shown over the whole cervieal spine,resulting disturbance of its physical stress distri bution and aggravation of the degenerative change of the segment.
1994, 9(3):167-171. DOI: 10.3871/j.1004-7220.1994.3.171.
Abstract:This work was aimed to observe,using the in vitro experimental model,the role of calcium in injury process of the cultured hepatic cells(HCs) wounded by the pressure waves derived from high vclocity projectiles(HVP).The results showed that the HCs can be injured and its injury:severity was partiallay related to the increment of the intracellular calceium,The higher the values of the pressure waves,the severer the damage of HCs.The cellular impairments can be alleviated to some extent by pretreaitng the HCs with calcium antagonist diltiazem.