Stereoscopic laryngoscope with 3D video headset: Technical feasibility


Background and Goal of Study: 
Direct or video laryngoscopy provides a two dimensional view with no depth perception cues. Some endoscopic surgery devices such as the Da Vinci robot provide a three dimensional (3D) view using specialised monitors and glasses to facilitate manipulation of instruments in 3D space.(ref 1). This might be advantageous in the context of video laryngoscopy for potentially difficult airways.

Materials and Methods:
Two 6mm diameter fibreoptic video cameras with integrated light sources were mounted side by side in a custom designed 3D printed housing located half-way along the blade of a standard MAC4 MacIntosh laryngoscope blade. The video output of each camera was connected via cables to a heavily modified virtual reality headset in which right and left screens were mounted with lenses over the corresponding eyes (Fig 1).(ref 2)

Results and Discussion:
The geometry of stereoscopic images requires two different horizontally separated viewpoints. Human eyes are ~100 mm apart; (ref 3) however constraints of size on the laryngoscope blade meant that the two cameras had to be 10 mm apart. Despite this, we were able to obtain good quality real time 3D images which provided depth perception to aid simulated intubation of a manikin (Fig 2)*.
Potential future improvements include: wireless links between laryngoscope and headset; smaller cameras; high definition cameras & video screens; flip screens to allow observation of whole patient when not focusing on laryngoscopy.

Conclusion(s):
3D video laryngoscopy is a feasible and potentially useful innovation which is worthy of further research and development.


References
1. Int J Surg Case Rep 2013;4(4):365-7   and/or Int J Med Robot 2013;9(3):e34-8
2. Instructables build instructions link
3. 3D image theory / geometry / vision reference

*A 3D anaglyph video will run in the e-poster: glasses will be distributed

Stereoscopic laryngoscope with 3D video headset: technical feasibility