Catálogo de publicaciones - libros

This paper presents a novel method for defining an osteotomy that can be used to represent all types of osteotomy procedures. In essence, we model an osteotomy as a lower-pair mechanical joint to derive the kinematic geometry of the osteotomy. This method was implemented using a commercially available animation software suite in order to simulate a variety of osteotomy procedures. Two osteotomy procedures are presented for a femoral malunion in order to demonstrate the advantages of our kinematic model in developing optimal osteotomy plans. The benefits of this kinematic model include the ability to evaluate the effects of various kinds of osteotomy and the elimination of potentially error-prone radiographic assessment of deformities.

This paper exploits the use of temporal information to minimize the ambiguity of camera motion tracking in bronchoscope simulation. The condensation algorithm (Sequential Monte Carlo) has been used to propagate the probability distribution of the state space. For motion prediction, a second-order auto-regressive model has been used to characterize camera motion in a bounded lumen as encountered in bronchoscope examination. The method caters for multi-modal probability distributions, and experimental results from both phantom and patient data demonstrate a significant improvement in tracking accuracy especially in cases where there is airway deformation and image artefacts.

A 3D forward-dynamics model of a total knee replacement was developed using an explicit finite-element package. The model incorporated both a tibiofemoral and a patellofemoral joint and allowed full 6-DOF kinematics for both joints. Simulated quadriceps contraction was used to drive the model. For validation, a unique experimental apparatus was constructed to simulate an open-chain extension motion under quadriceps control. The ligamentous constraints of the MCL and LCL were simulated using tension springs. The kinematics of the tibia and patella were recorded along with the net forces and moments applied to the femur. Several ligament and inertial configurations were simulated. The RMS differences between the experimental data and model predictions across all simulations were excellent for both the kinematics (angles: 0.3 – 1.6°, displacements: 0.1 – 0.8 mm) and kinetics (forces: 5 – 11 N, moments: 0.2 – 0.6 Nm). The validated model will be extended with physiologically realistic ligaments and utilized in surgical planning simulations.

An in vitro patient-tailored reproduction model of cerebral artery, a hardware platform for simulating endovascular intervention for making diagnoses and surgical trainings is presented. 3-D configuration of vessel lumen is reproduced as vessel model with 13 m modeling resolution, using CT and MRI information. Physical characteristics of cerebral artery, such as elastic modulus and friction coefficient, are also reproduced. We also propose a novel method to visualize stress condition on vessel wall using photoelastic effect. Consequently, it should be helpful for clinical applications, academic researches and other various purposes.