Biomedical subjects

Xianlian Zhou

Publications and source records attributed to Xianlian Zhou.

3 recordsLinked to original sources

PubMed2006

Inverse elastostatic stress analysis in pre-deformed biological structures: Demonstration using abdominal aortic aneurysms.

In stress analysis of membrane-like biological structures, the geometry constructed from in vivo image, which often corresponds to a deformed state, is routinely taken as the initial stress-free geometry. In this paper, we show that this limitation can be completely removed using an inverse elastostatic approach, namely, a method for finding the initial geometry of an elastic body from a given deformed state. We demonstrate the utility of the inverse approach using a patient-specific abdominal aortic aneurysm model, and identify the scope of error in stress estimation in the conventional approach within a realistic range of material parameter variations.

Aortic Aneurysm, Abdominal↗

PubMed2004

[Study on the 3D mathematical mode of the muscle groups applied to human mandible by a linear programming method].

Four types of 3D mathematical mode of the muscle groups applied to the human mandible have been developed. One is based on electromyography (EMG) and the others are based on linear programming with different objective function. Each model contains 26 muscle forces and two joint forces, allowing simulation of static bite forces and concomitant joint reaction forces for various bite point locations and mandibular positions. In this paper, the method of image processing to measure the position and direction of muscle forces according to 3D CAD model was built with CT data. Matlab optimization toolbox is applied to solve the three modes based on linear programming. Results show that the model with an objective function requiring a minimum sum of the tensions in the muscles is reasonable and agrees very well with the normal physiology activity.

Bite Force↗

PubMed2004

[Three-dimensional finite element study on middle face advancement with distraction osteogenesis].

Based on the anatomic structure of a girl with class III skelet al malocclusion, a three-dimensional finite element biomechanical model of facial soft tissue was established. With the use of this model, three surgery plans of distraction osteogenesis, LeFort I, II, III maxillary complex advancement in the direction of functional occlusal plane, were simulated. As a result, the facial soft tissue deformation was predicted and the ratio of the facial location deformation to the free bone advancement was calculated. The facial shape after surgery could be viewed in 3D. In addition, the location of center of resistance was investigated when the free bone was protracted forward in the process of LeFort I maxillary complex advancement; it was located at a site about 30 mm posterior to the soft tissue A point. The research result indicates that three-dimensional finite element research on distraction osteogenesis can provide instruction for setting the suitable protraction point and direction of the protraction force in surgery, and by predicting the facial soft tissue deformation, it also can provide the surgeon and patient with information on the options and reference to the surgery plans.

Adolescent↗