Three-Dimensional Printed Laryngoscopes as Allies Against COVID-19

Abstract

The COVID-19 pandemic has caused an overload on the health care system on a global scale. Because the disease affects the respiratory system, patients may require ventilator equipment for breathing, and consequently, numerous tracheal intubations have been performed. The video laryngoscope is a medical device that aids this procedure. It is used by anesthesiologists to visualize the anatomical structures of the larynx during tube insertion. Unfortunately, many hospitals worldwide are unable to afford sufficient units of this medical device. To satisfy the high demand, low-cost alternatives employing three-dimensional (3D) printing techniques have been developed for health care professional's use. With the intention of ensuring the efficiency, reproducibility, and security of the 3D-printed laryngoscope, this article presents a novel model with versions for pediatric and adult use, which was developed under the supervision of a medical team. The mechanical performance of 3D-printed prototypes (of the proposed models) was evaluated using mechanical assays, and the results indicated a satisfactory safety factor.

Keywords: 3D printing; COVID-19; laryngoscope; mechanical essays; medical device.

FIG. 1.

Comparison between adult and pediatric laryngoscopes. (A) Perspective view of the archetypes; (B) prototypes overlap; (C) side to side; (D) smooth face; (E) groove facet for borescope accoplation. Observe that the sinuous crevice extends over a conspicuous part of the handle to the proximal region of the blade making possible the camera stabilization and avoiding rotation. B, blade; CH, camera holder; F, flange; G, groove; H, handle; He, height; L, length; and T, tip.

FIG. 2.

Inclusion of support blockers is related to smooth construction of the laryngoscope blades. (A) SB, represented in light gray, along the adult laryngoscope placed at the build plate (223 × 223 mm). (B) Considering the narrow diameter of the Camera Holder, this should be manufactured avoiding the deposition of plastic inside the ring, a fact that would make post-processing difficult and could reduce the quality of this medical product. It is important to mention that the diameter of this part prevents the sliding of the borescope toward the patient's glottis. (C) Opening for insertion of the USB camera. At this place, we strongly recommend the maintenance of supports only near the identification letters (A or P), guaranteeing the adequate 3D printing process. 3D, three dimensional; SB, Support blockers.

FIG. 3.

Tridimensional printed laryngoscopes (scale bar represents 10 mm). (A–D) Adult blades: (A) Inferior view (bottom layer). (B) Superior view (top layer). (C) Borescope holder. (D) Layer thickness (0.15 mm). (E–H) Pediatric blades. (E) Inferior view (bottom layer). (F) Superior view (top layer). (G) Borescope holder. (H) Layer thickness (0.15 mm). Observe the extreme quality of plastic deposition, a sine qua non condition for safe use of these medical devices.

FIG. 4.

Management of the video laryngoscope in a simulation setting. (A) Endotracheal intubation performed on a human mannequin. (B) Use of a borescope attached to the laryngoscope for indirect tracheal intubation, demonstrating the same facilitation for intubation as models already established in the market.

FIG. 5.

Mechanical essays. (A) Test machine MTS. (B) Disposal used to fix the blades. (C) Pre and post-test sample, showing failure detail. (D) Stress-strain curves for pediatric and adult blades. MTS, Materials Testing System.