DIY videolaryngoscope for approx. 15€
I was very fascinated of the idea of www.airangelblade.org . From a cheap USB endoscope camera (under 10€ from China) and a 3D print part, a fully functional video laryngoscope for tutoring and training use or even life-saving respiratory protection in regions where you can not afford a commercial videolaryngoscope. I contacted the address from the website and Bryan Archpru immediately sent me the STL file of the laryngoscope.

Difficult to print.
But then I encountered difficulties. To my astonishment, the finished print part costs about 70 € at Shapeways. Which puts the low-cost idea into perspective. The print model proved to be suitable for DIY-3D printing to a limited extent. Due to the design, the laryngoscope can only be printed with large overhangs. Which means that it cannot be laid flat on the printing surface. This requires huge support structures, which significantly increase the printing time and material requirements and deteriorate the surfaces of the raw finished part on standard household 3D printers significantly.

Hyperangulated laryngoscope?
Bryan Archpru and Steven Bazan, the makers of Airangel, have opted for a hyperangulated video laryngoscope. I prefer a videolaryngoscope with Macintosh (-like) blades as recommended in the S1 guidelines for prehospital airway management of the German Society of Anaesthesiology & Intensive Care Medicine: "When using videolaryngoscopes with Macintosh or Macintosh-like blades, a direct visualization of the vocal cord level is possible at any time parallel to the indirect videolaryngoscopic view. If the videolaryngoscopy is compromised by contamination of the lens, it is possible to switch from (indirect) videolaryngoscopy to direct laryngoscopy at any time without changing the laryngoscope and the tube can be placed under sight".

Own design
So I modelled a draft of a low-cost DIY video laryngoscope in Autodesk Fusion 360 (free for hobbyists). The blade shape is a Mcintosh blade slightly larger than size 3. The length of the handle is oriented to conventional laryngoscope handles because the handle of the Airangelblade seemed too short in my opinion. The design allows to print the video laryngoscope lying on the left side without any support structure on any household 3D printer with one extruder. There are no overhangs that make printing difficult and even the raw part has well rounded edges. The fixation of the 5,5 mm endoscope camera was taken over by the Airangelblade. Additionally a light notch for a 20 mm velcro cable tie was added to the handle.

Disclaimer:
A DIY-Videolaryngoscope is not a medical product! It has not been tested according to any specifications (BfArM/MPG, FDA, etc.) and must therefore not be used on humans. The application is limited to training and education (as well as perhaps a life-saving application in underdeveloped regions or crisis areas). Use on the patient could result in injury and life-threatening complications.

3D Printing
The prototypes were printed on an Ultimaker 2 plus. Layer height: 0,2 mm, nozzle: 0,4 mm, infill: 100%
PA (nylon) is recommended as the material as the printed part becomes dishwasher-safe and high-strength. But even PLA delivers excellent results, except for the temperature sensitivity. The mechanical strength of 3D printing parts is strongly dependent on the printer settings and temperatures. Even my prototypes made of PLA could easily be loaded with 150 N tension (equivalent to 15.3 kg of load) at the tip of the blade. This should exceed the loads of a (difficult) intubation by far.

If you try it out, I would be very happy about feedback.

https://youtu.be/KcYtOkkSHvY

Addendum
I have also published a slightly modified draft. It turned out that some 5.5 mm endoscope cameras sit very loosely in their fixation. They have the tendency to rotate unintentionally. Therefore, the camera bore was reduced by 0.1 mm. (With the smaller hole it might be possible that the hole has to be drilled with a 5.5 mm drill to fit the camera) Additionally the handle was shortened by 2 cm to make the laryngoscope more compact and to save material and printing time and the groove for the cable was reduced to hold thinner cables well.