Sleep apnea is characterized by recurrent collapse of the upper airway, which occurs when the air pressure internally becomes less than the surrounding tissue pressure. During normal breathing, the internal airway pressure is negative during inspiration and positive during expiration. For an airway to remain open, it must be able to resist the negative pressure during inspiration. This means tissue pressure must be less than the inspiratory pressure to prevent collapse. Essentially, the lower the tissue pressure, the more stable the airway.
Tissue pressure is determined by multiple factors, including tongue stability, BMI, the stability of the soft palate, external pressure on the neck, and sleep position. Moreover, the last two factors listed are influenced by your mattress and pillow setup. The shape of the mattress and the type of pillow used can affect sleep position. Additionally, the shape and firmness of the pillow can influence the pressure applied to the neck. Specifically, the area just below the jawline around the hyoid bone, as this area is responsible for supporting the base of the tongue. An ideal mattress and pillow setup will prevent you from sleeping on your back while also minimizing the pressure it applies to your neck.
Researchers at the University of Gothenburg sought to create a bed setup that would address these criteria. Through many trials and revisions, they had determined that the ideal setup consists of a T shaped pillow and a mattress with curved cutouts for the arms. This design forces your arm or shoulder to be placed in the cavity between the pillow and the mattress while also keeping the neck suspended between. Moreover, while on your back it is very uncomfortable because there is no place for the arms and shoulders to be supported.
After conducting numerous sleep studies, it was determined that participants essentially slept completely on their side and stomach rather than on their backs. Additionally, this reduction in back sleeping was also accompanied by a significant reduction in the severity of sleep apnea (AHI). Unfortunately, however, this mattress is not for sale in most parts of the world. So the only way to use it is to build your own. This is what I have done.
Building the Ideal Mattress:
- Electric Carving Knife
- 8 Inch Firm Foam Mattress
- Safety Glasses
- Remove or cut the mattress cover to expose the underlying foam.
- On the foam sketch, the red cut lines are depicted in the photo below using the dimensions listed. Scale-up as needed for a larger sized mattress.
- Use the electric carving knife to slowly cut along the red lines which you have drawn. Make sure the knife remains perpendicular to the foam.
- Cover with a standard twin mattress cover. For the pillow, you can use two separate large pillowcases covering the pillow from each side. Ideally, you could also attempt to sew your own pillow case.
- Finally, place this mattress atop your existing one and have a good night's sleep. There is also the option of placing it on the floor or carpet if thats comfortable for you.
After cutting the mattress you should end up with two pieces of foam like the ones shown in the photo below:
Positional Therapy Combined with PAP Therapy:
Personally, I have combined PAP therapy along with this bed setup and my sleep has been significantly better as opposed to using either therapy alone. The reduction of tissue pressure (Pcrit) facilitated by the mattress likely allows PAP to stabilize and expand the airway to a greater degree. Overall, adding this mattress to my routine has improved my ability to manage my sleep apnea.