ABSTRACT
Objective To construct a three-dimensional (3D) dynamic head-neck finite element model which ac cords with the anatomical structure,and study its dynamic responses under the extemal force.Methods By using the neck CT images of a Chinese adult male volunteer and obtaining the 3D cervical point cloud data,the finite element model of cervical spine was established using ICEM-CFD and HyperMesh software.This model,including vertebrae,intervertebral discs,facet joints,ligaments and cartilage tissues,and combining with the es tablished and verified head finite element model,was assembled as human head-neck finite element model with detailed anatomical structures.Results The model was validated by data of head-neck axial impact experiments reported in previously published literature.The simulation results showed that the neck deformation,head acceleration,head force and injury positions were preferably consistent with the experimental data.Conclusions The established 3D dynamic finite element model can be used to study head-neck dynamic responses and damage mechanism in the fields of traffic safety and impact injuries.
ABSTRACT
Objective To construct a three-dimensional finite element model of human skull with anatomic structure and to study biomechanical responses of the head under various loading conditions. Methods The finite element model of high-precision human head with anatomic structure was reconstructed with the constitutive skull made from elastic-plastic material to simulate the fracture. This model was used to simulate frontal impact intracranial pressure testing, dynamic skull fracture testing and head drop testing reported by the literature, and the simulation reproduced the experimental process of head subjected to impact loads, skull fractures, and biomechanical responses of head fall at different speed. Results Under frontal impact loading, the model showed hedge-side positive-negative intracranial pressure distributions, and the occipital deformation was more serious than that in prefrontal, parietal under similar loading. The faster falling speed would cause more serious injuries. Conclusions To establish the accurate anatomic finite element model of human head can preferably simulate biomechanical responses of the head under the loading of impact and fall. Through quantifying parameters such as contact force and intracranial pressure, injury risks can be assessed to provide scientific references for design of protective devices.
ABSTRACT
<p><b>OBJECTIVE</b>The sex therapy is not yet popularized at present. This study aimed to evaluate the effect of the combination of the improved sex therapy and oral sildenafil on erectile dysfunction (ED).</p><p><b>METHODS</b>A total of 3130 Uigur cases of ED received in Xinjiang Bogda Hospital were divided into a control group (n=625) and a trial group (n=2505), the former treated with oral sildenafil alone, and the latter by the combination of the improved genital therapy and sildenafil, both for 3 months and followed up at 6 and 12 months after the treatment. The therapeutic effects were evaluated and compared using IIEF-5.</p><p><b>RESULTS</b>The IIEF-5 scores of the control group were 12.80 +/- 3.76 and 18.10 +/- 2.61 before and after the treatment, and 17.35 +/- 2.73 and 16.64 +/- 2.63 at 6 and 12 months, respectively, while those of the trial group were 12.73 +/- 3.52 and 19.06 +/- 4.07 before and af- ter the treatment, and 19.86 +/- 2.42 and 20.47 +/- 2.38 at 6 and 12 months, respectively, with statistically significant differences either between pre- and post-treatment (P < 0.05) or between the control and trial groups at 6 and 12 months (P < 0.05).</p><p><b>CONCLUSION</b>The combination of the improved sex therapy and oral sildenafil is superior to sildenafil alone in the treatment of ED, and its efficacy is relatively stable at 12 months.</p>