How 3D printing could tackle PPE shortages during a future pandemic

The PPE shortage in 2020 led to worldwide shortages and rocketing prices. Jean-Charles Bricongne (Aix-Marseille University and Business to Ideas consortium) and members of the CAR3D consortium explain how 3D printing could enable countries to scale up their production during health emergencies

3D printed surgical planning prototype manufactured by a hybrid multi-material 3D printer

Surgical planning is a preoperative method of pre-visualization that is carried out before or during a surgical intervention in order to achieve the best outcome. This can be done either image-based or hands-on. Regarding the first strategy, it is based on the use of medical images. However, it has a huge limitation, which is the difficulty of identifying anatomical structures (crucial for surgeons to make correct decisions) and distances between tissues without any physical support. This problem is overcome with the use of 3D models. Despite this important development, until nowadays most of the surgical planning prototypes were 3D printed either using the moulding technique, which might take several days, or high-cost technologies as is material jetting. That is why, the present manuscript seeks to solve the problems arose by the use of a hybrid-multi material 3D printer which can not only use several materials at the time, but also two 3D printing technologies. The prototype introduced in this study is a neuroblastoma, a common cancer among children.Peer ReviewedPostprint (published version

Patient-specific 3D printed soft models for liver surgical planning and hands-on training

Background: Pre-surgical simulation-based training with three-dimensional (3D) models has been intensively developed in complex surgeries in recent years. This is also the case in liver surgery, although with fewer reported examples. The simulation-based training with 3D models represents an alternative to current surgical simulation methods based on animal or ex vivo models or virtual reality (VR), showing reported advantages, which makes the development of realistic 3D-printed models an option. This work presents an innovative, low-cost approach for producing patient-specific 3D anatomical models for hands-on simulation and training. Methods: The article reports three paediatric cases presenting complex liver tumours that were transferred to a major paediatric referral centre for treatment: hepatoblastoma, hepatic hamartoma and biliary tract rhabdomyosarcoma. The complete process of the additively manufactured liver tumour simulators is described, and the different steps for the correct development of each case are explained: (1) medical image acquisition; (2) segmentation; (3) 3D printing; (4) quality control/validation; and (5) cost. A digital workflow for liver cancer surgical planning is proposed. Results: Three hepatic surgeries were planned, with 3D simulators built using 3D printing and silicone moulding techniques. The 3D physical models showed highly accurate replications of the actual condition. Additionally, they proved to be more cost-effective in comparison with other models. Conclusions: It is demonstrated that it is possible to manufacture accurate and cost-effective 3D-printed soft surgical planning simulators for treating liver cancer. The 3D models allowed for proper pre-surgical planning and simulation training in the three cases reported, making it a valuable aid for surgeons.The research undertaken in this paper has been partially funded by the QuirofAM project (Exp. COMRDI16-1-0011) co-financed by the European Union through the European Regional Development Fund FEDER with the support of ACCIÓ-Generalitat de Catalunya 2014–2020.Peer ReviewedPostprint (published version

A state-of-the-art guide about the effects of sterilization processes on 3D-printed materials for surgical planning and medical applications: a comparative study

Surgeons use different medical devices in the surgery, such as patient-specific anatomical models, cutting and positioning guides, or implants. These devices must be sterilized before being used in the operation room. There are many sterilization processes available, with autoclave, hydrogen peroxide, and ethylene oxide being the most common in hospital settings. Each method has both advantages and disadvantages in terms of mechanics, chemical interaction, and post-treatment accuracy. The aim of the present study is to evaluate the dimensional and mechanical effect of the most commonly used sterilization techniques available in clinical settings, i.e., Autoclave 121, Autoclave 134, and hydrogen peroxide (HPO), on 11 of the most used 3D-printed materials fabricated using additive manufacturing technologies. The results showed that the temperature (depending on the sterilization method) and the exposure time to that temperature influence not only the mechanical behavior but also the original dimensioning planned on the 3D model. Therefore, HPO is a better overall option for most of the materials evaluated. Finally, based on the results of the study, a recommendation guide on sterilization methods per material, technology, and clinical application is presented.The research described in this paper was partially funded by the project named QuirofAM (Exp. COMRDI16-1-0011) and funded by ACCIÓ from the Catalan government and ERDF from European Union.Postprint (published version

Patient comprehension of oncologic surgical procedures using 3D printed surgical planning prototypes

Patient understanding of complex surgical procedures and post-intervention consequences is often poor. Little is known about the effectiveness of 3D printed models to improve the comprehension of the medical information provided to patients. The purpose of this study was to determine if 3D printed patient-specific anatomical models could help improve patients’ satisfaction and understanding of complex oncological surgical procedures, their risks, benefits, and alternatives. Basic procedure A randomized, controlled crossover experiment was performed, where subjects were randomly assigned to different treatments of the study. This experiment involved teenage patients experts from Kids Barcelona, a Young Person's Advisory Group. The team (n = 14, age range 14–20, 9 females and 5 males) was divided into two groups involved in two simulated pre-surgical outpatient visits for complex oncologic surgical procedures: a high-risk stage 4 abdominal neuroblastoma, and a biliary tract rhabdomyosarcoma. Two senior oncologic surgeons participated in the study by performing the structured outpatient pre-surgical visit. Each participant received information before the study explaining the study methodology and was given a questionnaire. Main findings Data analysis of the group using the 3D printed model for the neuroblastoma case showed better results than without the 3D model. On the other hand, conversely, on the data analysis of the rhabdomyosarcoma case with the 3D printed model no better results were observed as compared to the case of not using a 3D model. However, the results of the participants’ knowledge were still better than before the intervention. Satisfaction was significantly better with a 3D model in both cases.Peer ReviewedObjectius de Desenvolupament Sostenible::3 - Salut i BenestarPostprint (published version

Exploration of a hearing protective device solution for premature babies

Exploration of a hearing protective device solution for premature babiesThe levels of noise in most hospital NICUs frequently exceed recommended World Health Organization (WHO) standards and recommended international limits. Additionally, premature babies and newborns can have stays of up to 3 months in these settings. In recent years, the combination of these two factors has raised concerns in the medical community about the effects of patients' exposure to noise, starting to be clearly recognized as a potentially significant health issue. Studies show that the exposure to these levels of unwanted sounds can lead to physiological and psychological problems for newborns and premature infants. Several strategies are being applied to tackle the noise problem; however, none of the existing solutions solves the problem well and some may have side effects. This thesis presents two new potential solutions for solving the noise problem in NICUs. The first strategy is a study of the geometrical properties of what would be a structural solution based on a combination of modified Helmholtz resonators created by Kim and Lee. The second and final strategy is a personal Hearing Protecting Device (HPD). This solutions aims to be an all in one solution working as a platform for different functionalities currently used in. This work has been focused in on finding the best materials to be used in the noise protective earmuff, trying to find a solution that improves the soundproofing effectiveness of currently used noise protecting devices. An experiment to proof the effectiveness of different sandwich materials and to study the intrinsic microstructure properties of these materials has also been carried out with promising results when compared to existing earmuffs.Los niveles de ruido en la mayoría de UCIs neonatales suelen sobrepasar los límites recomendados internacionalmente y los estándares definidos por la Organización Mundial de la Salud (OMS). En estas UCIs se tratan neonatos y prematuros con estancias de hasta 3 meses. En los últimos años la preocupación por los efectos que los altos niveles de ruido pueden provocar a estos pacientes en pleno desarrollo ha crecido considerablemente en el entorno médico, haciendo aparecer nuevas líneas de investigación y publicaciones. Los estudios publicados hasta el momento muestran que la exposición a niveles altos de ruido puede conllevar problemas psicológicos y fisiológicos a neonatos y prematuros a corto y largo plazo. De hecho, en los últimos años han empezado a aplicarse estrategias para intentar reducir los niveles de ruido en UCIs neonatales. No obstante, ninguna de las soluciones existentes ha conseguido resolver de forma eficaz el problema, y algunas tienen efectos secundarios. Este trabajo presenta dos nuevas posibles soluciones para el problema de exceso de ruido en UCIs neonatales. En la primera estrategia, se presenta la “Soundproof Window” creada por Kim y Lee, una modificación de los resonadores de Helmholtz, y se hace un estudio de la relación entre su geometría y sus propiedades acústicas. La segunda estrategia, presenta un sistema personal de protección sonora. Esta solución tendría varias funciones en un mismo producto: Los esfuerzos de este trabajo en la segunda estrategia se han centrado en buscar los mejores materiales para el protector acústico, intentando encontrar una solución más eficaz que la protección auditiva personal actualmente utilizada. En este sentido, se han seleccionado distintos materiales que se han combinado para crear soluciones acústicas tipo sándwich más efectivas. Estos materiales se han testeado para comprobar su capacidad de atenuar el sonido en función de la frecuencia, y comparar algunas de sus propiedades estructurales. Los materiales finales se han comparado con los sistemas de protección auditiva personal actualmente utilizados con resultados prometedores.Els nivells de soroll de la majoria d'UCIs neonatals acostumen a sobrepassar els estàndards internacionals i els límits recomanats per l'Organització Mundial de la Salut (OMS). En aquestes UCIs es tracten nounats i prematurs en períodes de fins a 3 mesos. En els últims anys la preocupació pels efectes que aquests alts nivells sonors poden provocar en aquests pacients en vies de desenvolupament ha aixecat interès en el món mèdic i ha portat a dur a terme varies investigacions al respecte. Els estudis fets mostren que l'exposició a nivells alts de soroll pot provocar problemes psicològics i fisiològics als nounats i prematurs. De fet, en els últims anys han començat a aplicar-se diferents estratègies per intentar resoldre el problema. No obstant, cap de les solucions existents han aconseguit acabar de forma eficaç amb el problema de soroll, i algunes tenen efectes secundaris. Aquest treball presenta dues noves possibles solucions pel problema d’excés de soroll a les UCIs neonatals. A la primera estratègia, es presenta la “Soundproof window” creada per Kim i Lee, una modificació dels ressonadors de Helmholtz, i es fa un estudi de la relació entre la seva geometria i les seves propietats acústiques. La segona estratègia, presenta un sistema personal de protecció sonora. Aquesta solució tindria vàries funcions en un mateix producte. Els esforços d’aquest treball en la segona estratègia s’han centrat a buscar els millors materials per al protector acústic, intentant trobar una solució més eficient que la protecció auditiva personal actualment utilitzada. En aquest sentit, s’han seleccionat diferents materials que s’han combinat per crear solucions acústiques tipus sandvitx més efectives. Aquests materials s’han testejat per comprovar la seva capacitat d’atenuar el so en funció de la freqüència, i comparar algunes de les seves propietats estructurals. Els materials finals s’han comparat amb els sistemes de protecció auditiva personal actuals amb resultats prometedors

Exploration of a hearing protective device solution for premature babies

Exploration of a hearing protective device solution for premature babiesThe levels of noise in most hospital NICUs frequently exceed recommended World Health Organization (WHO) standards and recommended international limits. Additionally, premature babies and newborns can have stays of up to 3 months in these settings. In recent years, the combination of these two factors has raised concerns in the medical community about the effects of patients' exposure to noise, starting to be clearly recognized as a potentially significant health issue. Studies show that the exposure to these levels of unwanted sounds can lead to physiological and psychological problems for newborns and premature infants. Several strategies are being applied to tackle the noise problem; however, none of the existing solutions solves the problem well and some may have side effects. This thesis presents two new potential solutions for solving the noise problem in NICUs. The first strategy is a study of the geometrical properties of what would be a structural solution based on a combination of modified Helmholtz resonators created by Kim and Lee. The second and final strategy is a personal Hearing Protecting Device (HPD). This solutions aims to be an all in one solution working as a platform for different functionalities currently used in. This work has been focused in on finding the best materials to be used in the noise protective earmuff, trying to find a solution that improves the soundproofing effectiveness of currently used noise protecting devices. An experiment to proof the effectiveness of different sandwich materials and to study the intrinsic microstructure properties of these materials has also been carried out with promising results when compared to existing earmuffs.Los niveles de ruido en la mayoría de UCIs neonatales suelen sobrepasar los límites recomendados internacionalmente y los estándares definidos por la Organización Mundial de la Salud (OMS). En estas UCIs se tratan neonatos y prematuros con estancias de hasta 3 meses. En los últimos años la preocupación por los efectos que los altos niveles de ruido pueden provocar a estos pacientes en pleno desarrollo ha crecido considerablemente en el entorno médico, haciendo aparecer nuevas líneas de investigación y publicaciones. Los estudios publicados hasta el momento muestran que la exposición a niveles altos de ruido puede conllevar problemas psicológicos y fisiológicos a neonatos y prematuros a corto y largo plazo. De hecho, en los últimos años han empezado a aplicarse estrategias para intentar reducir los niveles de ruido en UCIs neonatales. No obstante, ninguna de las soluciones existentes ha conseguido resolver de forma eficaz el problema, y algunas tienen efectos secundarios. Este trabajo presenta dos nuevas posibles soluciones para el problema de exceso de ruido en UCIs neonatales. En la primera estrategia, se presenta la “Soundproof Window” creada por Kim y Lee, una modificación de los resonadores de Helmholtz, y se hace un estudio de la relación entre su geometría y sus propiedades acústicas. La segunda estrategia, presenta un sistema personal de protección sonora. Esta solución tendría varias funciones en un mismo producto: Los esfuerzos de este trabajo en la segunda estrategia se han centrado en buscar los mejores materiales para el protector acústico, intentando encontrar una solución más eficaz que la protección auditiva personal actualmente utilizada. En este sentido, se han seleccionado distintos materiales que se han combinado para crear soluciones acústicas tipo sándwich más efectivas. Estos materiales se han testeado para comprobar su capacidad de atenuar el sonido en función de la frecuencia, y comparar algunas de sus propiedades estructurales. Los materiales finales se han comparado con los sistemas de protección auditiva personal actualmente utilizados con resultados prometedores.Els nivells de soroll de la majoria d'UCIs neonatals acostumen a sobrepassar els estàndards internacionals i els límits recomanats per l'Organització Mundial de la Salut (OMS). En aquestes UCIs es tracten nounats i prematurs en períodes de fins a 3 mesos. En els últims anys la preocupació pels efectes que aquests alts nivells sonors poden provocar en aquests pacients en vies de desenvolupament ha aixecat interès en el món mèdic i ha portat a dur a terme varies investigacions al respecte. Els estudis fets mostren que l'exposició a nivells alts de soroll pot provocar problemes psicològics i fisiològics als nounats i prematurs. De fet, en els últims anys han començat a aplicar-se diferents estratègies per intentar resoldre el problema. No obstant, cap de les solucions existents han aconseguit acabar de forma eficaç amb el problema de soroll, i algunes tenen efectes secundaris. Aquest treball presenta dues noves possibles solucions pel problema d’excés de soroll a les UCIs neonatals. A la primera estratègia, es presenta la “Soundproof window” creada per Kim i Lee, una modificació dels ressonadors de Helmholtz, i es fa un estudi de la relació entre la seva geometria i les seves propietats acústiques. La segona estratègia, presenta un sistema personal de protecció sonora. Aquesta solució tindria vàries funcions en un mateix producte. Els esforços d’aquest treball en la segona estratègia s’han centrat a buscar els millors materials per al protector acústic, intentant trobar una solució més eficient que la protecció auditiva personal actualment utilitzada. En aquest sentit, s’han seleccionat diferents materials que s’han combinat per crear solucions acústiques tipus sandvitx més efectives. Aquests materials s’han testejat per comprovar la seva capacitat d’atenuar el so en funció de la freqüència, i comparar algunes de les seves propietats estructurals. Els materials finals s’han comparat amb els sistemes de protecció auditiva personal actuals amb resultats prometedors

Perspectives on medical 3D printing at the point-of-care from the new European 3D Printing Special Interest Group

Abstract This editorial presents the vision for the newly formed (2022) European 3D Special Interest Group (EU3DSIG) in the landscape of medical 3D printing. There are four areas of work identified by the EU3DSIG in the current landscape, namely: 1) creating and fostering communication channels among researches, clinicians and industry, 2) generating awareness of hospitals point-of-care 3D technologies; 3) knowledge sharing and education; 4) regulation, registry and reimbursement models

Расслоения над точками проективного пространства

Рассматривается многообразие точек конечномерного пространства и его отображение в проективную область. Приводится оценка количества точек проек-тивного конечномерного пространства как количество расслоений

3D printed prototype of a complex neuroblastoma for preoperative surgical planning

Neuroblastoma is the most common abdominal solid tumour in childhood. Its removal implies a complex surgery that requires surgical experience due to the usual encassement of major abdominal blood vessels. Standard surgical planning is based on CT or MRI images. However, in complex cases, normal anatomy is altered and it is dificult to interpret. 3D virtual planning and 3D Printing (3DP) can overcome this difficulties of comprehension. The most common 3DP technology used for this cases is material jetting. Nevertheless, this technology is very expensive and cannot be widely used. Consequently, its use is limited. The present study seeks to introduce the possibility of reducing costs whilst mantaining the quality of the 3D printed protypes. A full-process of a neuroblastoma case using hybrid manufacturing combining some FFF and some SLS 3D printed parts is presented. The two processes are carried out separately and then joined in a final assembly. The cost of the prototype was 347 €, which is significantly lower than a prototype 3D printed by material jetting.Peer ReviewedPostprint (published version