3D printing in medicine最新文献

Background: The global pandemic of novel coronavirus (SARS-CoV-2) has led to global shortages of ventilators and accessories. One solution to this problem is to split ventilators between multiple patients, which poses the difficulty of treating two patients with dissimilar ventilation needs. A proposed solution to this problem is the use of 3D-printed flow splitters and restrictors. There is little data available on the reliability of such devices and how the use of different 3D printing methods might affect their performance.

Methods: We performed flow resistance measurements on 30 different 3D-printed restrictor designs produced using a range of fused deposition modelling and stereolithography printers and materials, from consumer grade printers using polylactic acid filament to professional printers using surgical resin. We compared their performance to novel computational fluid dynamics models driven by empirical ventilator flow rate data. This indicates the ideal performance of a part that matches the computer model.

Results: The 3D-printed restrictors varied considerably between printers and materials to a sufficient degree that would make them unsafe for clinical use without individual testing. This occurs because the interior surface of the restrictor is rough and has a reduced nominal average diameter when compared to the computer model. However, we have also shown that with careful calibration it is possible to tune the end-inspiratory (tidal) volume by titrating the inspiratory time on the ventilator.

Conclusions: Computer simulations of differential multi patient ventilation indicate that the use of 3D-printed flow splitters is viable. However, in situ testing indicates that using 3D printers to produce flow restricting orifices is not recommended, as the flow resistance can deviate significantly from expected values depending on the type of printer used.

Trial registration: Not applicable.

Background: The ability of the patient specific 3D printed neurovascular phantoms to accurately replicate the anatomy and hemodynamics of the chronic neurovascular diseases has been demonstrated by many studies. Acute occurrences, however, may still require further development and investigation and therefore we studied acute ischemic stroke (AIS). The efficacy of endovascular procedures such as mechanical thrombectomy (MT) for the treatment of large vessel occlusion (LVO), can be improved by testing the performance of thrombectomy devices and techniques using patient specific 3D printed neurovascular models.

Methods: 3D printed phantoms were connected to a flow loop with physiologically relevant flow conditions, including input flow rate and fluid temperature. A simulated blood clot was introduced into the model and placed in the proximal Middle Cerebral Artery (MCA) region. Clot location, composition, length, and arterial angulation were varied and MTs were simulated using stent retrievers. Device placement relative to the clot and the outcome of the thrombectomy were recorded for each situation. Digital subtraction angiograms (DSA) were captured before and after LVO simulation. Recanalization outcome was evaluated using DSA as either 'no recanalization' or 'recanalization'. Forty-two 3DP neurovascular phantom benchtop experiments were performed.

Results: Clot angulation within the MCA region had the most significant impact on the MT outcome, with a p-value of 0.016. Other factors such as clot location, clot composition, and clot length correlated weakly with the MT outcome.

Conclusions: This project allowed us to gain knowledge of how such characteristics influence thrombectomy success and can be used in making clinical decisions when planning the procedure and selecting specific thrombectomy tools and approaches.

Background: The COVID-19 pandemic has led to large-scale shutdowns in society. This resulted in global supply bottlenecks for medical protective equipment. The so-called Maker Movement recognized this emerging problem early on and, with the help of additive manufacturing (AM), began developing and manufacturing half masks or face shields as personal protective equipment (PPE). This knowledge has been made available in many places in form of open source product data, so that products could be adapted and improved, saving development time.

Methods: This production and innovation potential has been taken up and professionalized by the authors of this article. By means of a proof-of-principle we provide an overview of the possibility and successful unique introduction of a so-called professional "hybrid production" in a micro factory using 3D-printing at the place of greatest demand in a hospital by medical personnel to produce their own PPE. Furthermore the learning process and future benefits of on site 3D-printing are described.

Results: Our proof-of-principle successfully showed that the allocation of 3D-printing capabilities in the hospital infrastructure is possible. With assistance of the engineers, responsible for product design and development, the medical staff was able to produce PPE by means of AM. However, due to legal uncertainties and high material and production costs the usability is severely limited.

Conclusions: The practical research showed that a complete implementation of the concept and the short-term establishment of a 3D-printing factory for the autonomous supply of a hospital with PPE was not feasible without further efforts. Nevertheless, it has enabled the medical staff to use AM technologies for future research approaches.