Miniaturizing the GlideScope® Video Laryngoscope System: A New Design for Enhanced Portability

Doyle DJ.  Miniaturizing the GlideScope video laryngoscope system: a new design for enhanced portability. Can J Anaesth. 2004 51:642-3.

The GlideScope® Video Laryngoscope (GVL) (Saturn Biomedical Systems, Burnaby, BC, Canada) is a novel system for tracheal intubation that utilizes a video camera embedded into a plastic laryngoscope blade. The blade is 18 mm at its maximum width, and bends 60 degrees at the mid-line. This configuration provides a view that is far superior to that from a conventional laryngoscope (Figure 2). The video image is displayed on a Liquid Crystal Display (LCD) monitor, and can also be recorded electronically.   Experience using the GVL has been excellent [1, 2].

One problem with the GVL, however, is that its size and its requirement for AC power makes it impractical for use in a number of important clinical settings such as in air ambulances or to carry to "code blue" events. The purpose of this note is to report on a modification of the GVL system to achieve miniaturization for use in such settings. In essence, this modification involves constructing a simple interface circuit that allows the GVL to be connected to any NTSC compatible display, eliminating entirely the need for the base unit. Figure 1 shows how the Panasonic "e-ware SD Multi AV Device" can be used as a miniature video display / recording system for the GVL when the interface is used. The display device, which costs about $400 US and is under 3 inches in size in its largest dimension, features a 2 inch LCD display and has the ability to record both static images and extended video clips to a SD type flash memory card. The arrangement has been used successfully in over a dozen cases without any difficulties.

Figure 2 shows a schematic diagram of the electronic interface. A 12-volt power source supplies the 130 ma of electrical current required for the GVL. Two 6-volt lithium photo batteries (e.g., Radio Shack 23-366 2CR-1/3N) serves this purpose well. These batteries fit together (in series) in a single AA-size battery holder mounted in a small electronic box equipped with an RCA-type video jack. Finally, the required cable is most easily obtained by sacrificing an existing GVL cable, available from the manufacturer (model GS1001-600 connector cable).

Figure 1

Photograph showing the electronic interface with a Panasonic e-ware SD Multi AV Device used as a miniature video display for the Glidescope. 

Figure 2

Electrical schematic of the electronic interface to allow the GlideScope handle to be connected to ordinary video displays.

References

[1] Cooper R. Use of a new videolaryngoscope (GlideScope®) in the management of a difficult airway. Can J Anesth 2003; 50: 611-613

[2] Agro F. Barzoi G. Montecchia F. Tracheal intubation using a Macintosh laryngoscope or a GlideScope in 15 patients with cervical spine immobilization. British Journal of Anaesthesia. 2003;  90:705-6.