The pocket mask is a convenient, reusable, small device that can be easily carried and used quickly by an emergency responder for mouth-to-mask resuscitation in between chest compressions. They are widely used to deliver rescue breaths to the patient’s lungs during cardiac or respiratory arrest by exhaling air through a one-way valve attached to the mask. This provides immediate respiratory support to the patient. The one-way valve acts an effective physical barrier between the patient and rescuer, which prevents the exhaled air of the patient being inhaled by the rescuer. Therefore, the mask and valve minimises the risk of any cross contamination of mouth-to-mouth resuscitation. Commercially available pocket masks can cost approximately $10-20 USD.
The 3D printed mask comes in 2 sizes, a larger one for adults and a smaller one for children. They are circular in shape to fit around the patient’s mouth, and require an additional rubber tubing to be glued onto the perimeter for a better seal to prevent air leakage during resuscitation. As the mask does not cover the patient’s nose, the rescuer must pinch the patient’s nose closed while giving each breath. The size of the mask permits the rescuer to have both hands on the head of the patient to perform a head-tilt/chin-lift manoeuvre. The masks have a standard 15mm diameter male connection which makes it compatible with other commercially available one-way filtered valves and bags of bag-valve masks for more effective oxygen delivery.
The 3D printed one-way valve is made of 3 components and has a standard 15mm diameter female connection, making it compatible with other commercially available pocket masks. It uses a moving disc mechanism which directs the airflow towards the patient when the rescuer exhales and upon patient exhalation, the air is directed through an alternative output.
The 3D CAD model was designed on Solidworks® and 3D printed using polylactic acid (PLA) and an Ultimaker 2 3D-printer. On the software Cura, the mask was orientated flat onto the baseplate. The valve was orientated with the larger circular output laying flat on the build plate. The mask and valve were printed separately under normal print speed, with support material, and normal PLA settings: 20% fill density, 50 mm/s print speed, 0.1mm layer height, and 210°C temperature.
We successfully tested the use of the 3D printed masks and valves in combination with other commercially available masks, one-way filter valves and bag-valve masks on CPR models. We believe 3D-printing of pocket masks and valves using PLA may provide a simple, cheap and life-saving option for medical staff in emergency situations who are based in less-resourceful regions.
The following tables contain all the information related to the cost of the manufacturing of each device.
*, ** As per Radionics Ltd. 2016
***As per Electric Ireland charges 2016
The energy E in kilowatt-hours (kWh) is obtained from the power P in watts (W), times the time period t in hours (hr) divided by 1000:
E(kWh) = (P(W) x t(hr))/1000