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Biomedical subjects

Jessica R Crouch

Publications and source records attributed to Jessica R Crouch.

4 recordsLinked to original sources

A software framework for surgical simulation virtual environments.

Surgical simulators are an integration of many models, capabilities, and functions. Development of a working simulator requires the flexibility to integrate various software models, to support interoperability, and facilitate performance optimizations. An object oriented framework is devised to support multithreaded integration of simulation, deformation, and interaction. A demonstration application has been implemented in Java, leveraging the features that are built into the language including multithreading, synchronization, and serialization. Future work includes expanding the capabilities of the framework with a broader range of model and interactive capabilities.

Computer Simulation↗

A simulation-based training system for surgical wound debridement.

A simulation-based training system for surgical wound debridement was developed and comprises a multimedia introduction, a surgical simulator (tutorial component), and an assessment component. The simulator includes two PCs, a haptic device, and mirrored display. Debridement is performed on a virtual leg model with a shallow laceration wound superimposed. Trainees are instructed to remove debris with forceps, scrub with a brush, and rinse with saline solution to maintain sterility. Research and development issues currently under investigation include tissue deformation models using mass-spring system and finite element methods; tissue cutting using a high-resolution volumetric mesh and dynamic topology; and accurate collision detection, cutting, and soft-body haptic rendering for two devices within the same haptic space.

Computer Simulation↗

Finite element model of cornea deformation.

Cornea surgeons have observed that changes in cornea curvature can follow cataract surgery and cause astigmatism. The placement of surgical incisions has been shown to influence these curvature changes. Though empirical data has been collected about this phenomenon, a biomechanical model has not been employed in predicting post-surgical outcomes. This work implemented an incised finite element model of the eye to investigate factors influencing corneal shape after surgery. In particular, the effects of eye muscle forces and intra-ocular pressure were simulated. Cornea shape change was computed via finite element analysis, and the resulting change in cornea curvature was measured by fitting quadratic curves to the horizontal and vertical meridians of the cornea. Results suggest that these two sources of deforming force counteract each other and contribute to astigmatism in perpendicular directions.

Astigmatism↗

A velocity-dependent model for needle insertion in soft tissue.

Models that predict the soft tissue deformation caused by needle insertion could improve the accuracy of procedures such as brachytherapy and needle biopsy. Prior work on needle insertion modeling has focused on static deformation; the experiments presented here show that dynamic effects such as relaxation are important. An experimental setup is described for recording and measuring the deformation that occurs with needle insertion into a soft tissue phantom. Analysis of the collected data demonstrates the time- and velocity-dependent nature of the deformation. Deformation during insertion is shown to be well represented using a velocity-dependent force function with a linear elastic finite element model. The model's accuracy is limited to the period during needle motion, indicating that a viscoelastic tissue model may be required to capture tissue relaxation after the needle stops.

Brachytherapy↗