Most patients with large focal skull bone loss after craniectomy are referred for cranioplasty. Reverse engineering is a technology which creates a computer-aided design (CAD) model of a real structure. Rapid prototyping is a technology which produces physical objects from virtual CAD models. The aim of this study was to assess the clinical usefulness of these technologies in cranioplasty prosthesis manufacturing. CT was performed on 19 patients with focal skull bone loss after craniectomy, using a dedicated protocol. A material model of skull deficit was produced using computer numerical control (CNC) milling, and individually pre-operatively adjusted polypropylene-polyester prosthesis was prepared. In a control group of 20 patients a prosthesis was manually adjusted to each patient by a neurosurgeon during surgery, without using CT-based reverse engineering/rapid prototyping. In each case, the prosthesis was implanted into the patient. The mean operating times in both groups were compared. In the group of patients with reverse engineering/rapid prototyping-based cranioplasty, the mean operating time was shorter (120.3 min) compared to that in the control group (136.5 min). The neurosurgeons found the new technology particularly useful in more complicated bone deficits with different curvatures in various planes. Reverse engineering and rapid prototyping may reduce the time needed for cranioplasty neurosurgery and improve the prosthesis fitting. Such technologies may utilize data obtained by commonly used spiral CT scanners. The manufacturing of individually adjusted prostheses should be commonly used in patients planned for cranioplasty with synthetic material.
31 December 2017 in Fibres & Textiles in Eastern Europe
On the basis of models developed and experimental studies, the impact of a compression garment on average and local changes in unit pressure was analysed. The study was based on the analysis of the results of 3D scans of selected parts of female and male bodies. It was found out that surface pressure exerted by the compression garment leads to some changes in the geometry of body circumferences and in their lengths and, consequently, to a change in the average pressure value, as well as local changes along the circumference. The main purpose of this work was to estimate the size of these changes in the example of selected parts of female and male bodies.
1 March 2023 in Polish Journal of Medical Physics And Engineering
Introduction: This paper describes the results of research aimed at developing a method of otolaryngological diagnosis based on computational fluid dynamics, which has been called Virtual Rhinomanometry. Material and methods: Laboratory studies of airflows through a 3D printed model of nasal cavities based on computed tomography image analysis have been performed. The CFD results have been compared with those of an examination of airflow through nasal cavities (rhinomanometry) of a group of 25 patients. Results: The possibilities of simplifying model geometry for CFD calculations have been described, the impact of CT image segmentation on geometric model accuracy and CFD simulation errors have been analysed, and recommendations for future research have been described. Conclusions: The measurement uncertainty of the nasal cavities’ walls has a significant impact on CFD simulations. The CFD simulations better approximate RMM results of patients after anemization, as the influence of the nasal mucosa on airflow is then reduced. A minor change in the geometry of the nasal cavities (within the range of reconstruction errors by CT image segmentation) has a major impact on the results of CFD simulations.
1 December 2015 in Management and Production Engineering Review
This paper describes some manufacturing aspects and an example of application of the Incremental Sheet Forming (ISF) technology which was used for production of the craniofacial prosthesis. The brief description of prosthesis designing was presented as well. The main topic of the paper is comparison of milling and ISF technologies for preparing the tools for prosthesis thermoforming.
31 August 2018 in Fibres & Textiles in Eastern Europe