Pieter Slagmolen June 19, 2017

In addition to its many other benefits, Medical 3D Printing has revolutionized how the pathology of a disease can be visualized. In a growing number of hospitals worldwide, it has earned its rightful place as standard procedure, for instance, in the placement of standard knee implants or in using cardiovascular 3D-printed heart model for preparing congenital heart defects surgery.

In-hospital 3D Printing labs however, have not reached such a status yet. As 3D technology is a strategic investment, the needs of the hospital should be properly mapped before a decision is made to implement it. The perfect way to get started is by using a stepwise approach.

For new initiatives, one approach is to start small by outsourcing some of the hard work. As such, you can experience the added value that anatomical models bring to medical visualization, without any significant investments. Today, it can be as easy as sending your STL file to a 3D printing facility like Materialise, and receiving a high-quality 3D-printed anatomical model in return.

Efficient and smart, isn’t it? Check out these five powerful tips to take into account when to make a printable 3D anatomical model and what to select as the right material. They'll help you secure a high-quality outcome.

Heart model

Tip #1 Keep the spatial relationship between parts

To get a holistic view of a pathology, printing parts surrounding the one you need is sometimes necessary. This is when keeping a spatial relationship between the parts you design is essential. Make sure to connect different parts of the anatomy, for example by using the connector tools in software such as Materialise inPrint. Alternatively, you can create another form of connection to maintain the relative distance.

Tip #2 Think of a suitable material before you start

Outsourcing your 3D print service gives you a wide range of options in 3D printing technologies and materials. Make sure you select the best material for your application.

Orthopedic cases such as scoliosis, calcaneus fracture, hip fracture, bone tumor, and cranio-maxillofacial cases, typically use rigid models. Polyamide (SLS), transparent resin (SLA technology), and ABS plastic (orthopedic only) are the most suitable materials.

Medical_3D_printing_service
Medical_3D_printing_service
Medical_3D_printing_service

Although soft tissue anatomies can be printed using different materials, HeartPrint Flex is the most flexible material, and bears the closest resemblance to the characteristics of the heart's muscle tissue or other soft tissue structures. This material is extremely useful for cardiovascular, kidney, liver and other soft-tissue anatomy.

CHD
Kidney

Tip #3 Adapt wall thickness to the 3D Printing technology

Each printing material has its own characteristics and minimal layer wall thickness. This means that a minimum number of layers need to build up during the 3D Printing process, before achieving strong walls that will support a solid model. If the minimal wall thickness is not respected your model will break or tear. Therefore, make sure you determine the corresponding wall thickness for your model, once you've decided which material to use.

For example, the recommended wall thickness for polyamide, transparent resin and ABS plastic is minimum 1mm. In the case of a multicolor print, wall thickness should be at least 2mm.

If you'd like more information on the technical details of the materials and recommendations on how to use them, you can find them on our design guidelines.

Tip #4 Avoid hollow chambers

When creating your model with hollow parts, such as a hollow bone or a tumor, make sure you include drainage holes in the design. If residue material remains inside a hollow chamber, pressure can build up and cause your model to crack or break when you least expect it, leaving a substantial mess. The drainage holes should have a minimum diameter of 5 mm.

Tip # 5 Include colors in your design if printing in multicolor

Multicolor prints provide a better visualization of different structures. Think of e. g. a renal or liver tumor. You want to view and understand its anatomical relationship, orientation and position, as well as the surrounding vasculature. Models made with Multicolor material are constructed with a ColorJet binding technique, using a fine granular powder. When designing your multicolored anatomical model, include all colors in your file, and upload it in a .wrl or .zpr format.

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