Search results

This study aims to examine the efficacy of 3D printing polymers to realistically mimic the fossa ovalis (FO) – a cardiac structure that is positioned in the interatrial septum – for simulating transseptal puncture (TP) procedures.

Specimen of different materials and thicknesses were prepared and tested simulating the puncturing of the FO using a 12F ID/14F OD TP catheter. Force and tenting length results were compared with literature references. Scanning electron microscope images of the specimen were acquired to observe the perforated region as well as the structure of the specimen in the unaffected area.

Significant changes in the properties of interest were registered for the same material on specimens tested at different moments after fabrication. Suturable vessel wall polyjet material offers the best characteristics to replicate FO anatomy and mimic its behavior to puncturing.

The originality of the work lies in the test of different commercial materials. Similar works are already present in literature but specifically designed materials are used. Demonstrating that off-the-shelf materials could be viable for FO specimens would simplify the design of realistic TP simulators in the future.

Left atrial appendage occlusion (LAAO) is a structural interventional cardiology procedure that offers several possibilities for the application of additive manufacturing technologies. The literature shows a growing interest in the use of 3D-printed models for LAAO procedure planning and occlusion device choice. This study aims to describe a full workflow to create a 3D-printed LAA model for LAAO procedure planning.

The workflow starts with the patient’s computed tomography diagnostic image selection. Segmentation in a commercial software provides initial geometrical models in standard tessellation language (STL) format that are then preprocessed for print in dedicated software. Models are printed using a commercial stereolithography machine and postprocessing is performed.

Models produced with the described workflow have been used at the Careggi Hospital of Florence as LAAO auxiliary planning tool in 10 cases of interest, demonstrating a good correlation with state-of-the-art software for device selection and improving the surgeon’s understanding of patient anatomy and device positioning.

3D-printed models for the LAAO planning are already described in the literature. The novelty of the article lies in the detailed description of a robust workflow for the creation of these models. The robustness of the method is demonstrated by the coherent results obtained for the 10 different cases studied.

This paper aims to present the design of a particular non-reactive test rig for combustion swirlers and first stage turbine nozzles. The test rig is required for important experimental activities aimed at the optimization of a specific class of gas turbines.

A multi-disciplinary team performed the design process by following a tailored design approach, which has been developed for the specific case. The design outcomes allowed to build a fully functional test rig to be introduced in a test cell and then to perform preliminary experiments about the fluid dynamic behaviour of the turbine elements.

The followed design approach allowed to efficiently perform the task, by supporting the information exchange among the different subjects involved in both the conceptual and the embodiment design of the test rig. Additionally, the performed experiments allowed to achieve a final configuration that makes the test rig a valuable test case for combustor-turbine interaction studies.

The study described in this paper is focused on the design of a specific test rig, used for first validation tests. However, the achieved results (both in terms of design and test) constitutes the underpinning of the in-depth investigations to be performed in the next steps of the experimental campaign.

To the best of the authors’ knowledge, the present paper is the first one that comprehensively describes the design activity of an experimental test rig for turbine application, also providing indications about the specific methodological procedure used to manage the process.

This paper aims to argue about the involvement of additive technologies (ATs) in the prototyping issues of designing. More precisely, it reviews the literature contributions focused on the different perspectives of prototyping activities for design purposes, searching for both available knowledge and research needs concerning the correct exploitation of ATs.

A two-step literature review has been performed. In the first step, general information has been retrieved about prototyping issues related to design. In the second step, the literature searches were focused on retrieving more detailed information about ATs, concerning each of the main issues identified in the previous step. Extracted information has been analyzed and discussed for understanding the actual coverage of the arguments and for identifying possible research needs.

Four generally valid prototyping issues have been identified in the first step of the literature review. For each of them, available information and current lacks have been identified and discussed about the involvement of AT, allowing to extract six different research hints for future works.

This is the first literature review concerning AT-focused contributions that cover the complex and inter-disciplinary issues characterizing prototyping activities in design contexts.