Biomedical subjects

Haiyun Li

Publications and source records attributed to Haiyun Li.

3 recordsLinked to original sources

PubMed2006

Intervertebral disc biomechanical analysis using the finite element modeling based on medical images.

In this paper, a 3D geometric model of the intervertebral and lumbar disks has been presented, which integrated the spine CT and MRI data-based anatomical structure. Based on the geometric model, a 3D finite element model of an L1-L2 segment was created. Loads, which simulate the pressure from above were applied to the FEM, while a boundary condition describing the relative L1-L2 displacement is imposed on the FEM to account for 3D physiological states. The simulation calculation illustrates the stress and strain distribution and deformation of the spine. The method has two characteristics compared to previous studies: first, the finite element model of the lumbar are based on the data directly derived from medical images such as CTs and MRIs. Second, the result of analysis will be more accurate than using the data of geometric parameters. The FEM provides a promising tool in clinical diagnosis and for optimizing individual therapy in the intervertebral disc herniation.

Biomechanical Phenomena↗

PubMed2006

[An algorithm based on deformable contour models for medical image segmentation].

This paper provides a new medical image segmentation algorithm using a deformable contour model, which integrates Fuzzy C-Means(FCM) Clustering technique and deformable contour model. An external fuzzy constrain is defined from the membership function value of FCM, which joins the external constrain of the deformable model and drives the deformable model towards the contour ideal edge of the object. Examples are presented to demonstrate the efficiency and feasibility of the approach on spinal MRI images and the results are encouraging.

Algorithms↗

PubMed2005

Leukemia inhibitory factor inhibits neuronal development and disrupts synaptic organization in the mouse retina.

Leukemia inhibitory factor (LIF) belongs to the interleukin-6 cytokine family, all members of which signal through the common gp130 receptor. Neurotrophic members of this cytokine family are known to arrest photoreceptor maturation and are likely to regulate maturation of other retinal neurons as well. We have used transgenic mice that constitutively express LIF beginning in embryonic development to determine its effects on synaptic organization and molecular maturation of all classes of retinal neurons. LIF reduced the numbers of cells showing markers characteristic of mature cells of all neuronal classes and caused synaptic ectopia. The net effect was disrupted morphological development and disturbed synaptic organization. Our study suggests that cytokines signaling through gp130 are capable of regulating many aspects of neuronal differentiation in the retina, including synaptic targeting.

Amacrine Cells↗