3D printing for medical training: what it can and cannot teach.

3D printing is used for anatomy a team can name and travel, for procedural task trainers and for a solid model of a device a company sells. A narrative review of the method in anatomy education and surgical training describes these uses beside dissection and atlases (Li, Kui et al., MedEdPublish, 2017). The same review states two limits. Very small structures still cannot be replicated, and a printed model does not give the tissue feel of a cadaveric specimen.

This guide is for simulation and training leads, clinical educators and training teams at device companies.

Solid models matched to the device you sell, from your geometry, and our own training models for bronchoscopy and ureteroscopy. You send the geometry. We make a solid model so your team can show how the device works. Each piece is checked before it leaves. They are listed under medical training and demonstration models. These are demonstration models. They are not for clinical use. They are not medical devices.

A printed anatomy model is only as accurate as its source data and the design record behind it. Ask the supplier where each value comes from.

The bronchoscopy training airway is a life-size adult airway a scope can travel, built to the average adult male airway in a published CT study. Every design value is written down with its source. This compares the design with published averages. It is not a clinical validation. The model shows one normal anatomy, without variants such as a tracheal bronchus. Women's central airways are on average 13–21% narrower.

The ureteroscopy training kidney is a life-size adult right kidney. The outer form is fitted to CT scans of 33 adult right kidneys. This compares the design with published averages. It is not a clinical validation. Each cartridge shows one normal anatomy, and real kidneys vary widely. The renal vessels are not modelled.

On the airway, an airway counts when it is at least as wide as the scope, so a 4.0 mm scope has no clearance in the narrowest ones. This compares published scope diameters with the design. Bends and friction reduce reach, and no scope has been through a finished model yet, so check tight fits with your own scope.

On the kidney, reach is modelled for an 8.6 Fr flexible ureteroscope at its measured bend, in one plane, through rigid walls: a best case. A real collecting system distends under irrigation and gives way to the scope, so the print is harder than a patient. No scope has been through a printed model yet, so check tight fits with your own scope.

Dimensions, wall thickness and the size of each branch are shared on enquiry. Ask where each value comes from, and whether a scope has been through a finished model.

The bronchoscopy training airway is PLA, a plant-derived polymer, and the ureteroscopy training kidney is PETG, matte light pink. Both of these models are rigid. Stones in amber. PLA starts to soften at about 55°C. PETG takes a little more, but not a dishwasher. Once a piece slumps, it does not go back.

For a model of your device, the material is part of the brief. We work to that brief.

Tell us the device, the geometry, how many you need and when. Add the scopes or instruments the model must take. We work from your geometry or model it with you. We reply by email.

• The device or the anatomy the model has to show.
• The source geometry, in the form you already have. The format is agreed in the brief.
• The instruments, scopes and sizes the model must accept.
• What the model has to show, and what it should not be asked to show.
• How many you need. The same five steps cover one prototype and a production run.
• The date you need them. The lead time is agreed in the brief.
• The documents you need. All material lab test documentation comes with the models.
• Confidentiality. Clean Layers signs NDAs.

Where a point above is still open, say so. We work to the brief you send. Clean Layers signs NDAs, and all material lab test documentation comes with the models.