A pair of Yale and Harvard professors have co-designed a circuit device to make machines used by sleep apnea patients safer for use by those infected with the COVID-19 virus, according to the Yale News.
Many people being treated for sleep apnea use small devices known as positive airway pressure (PAP) machines to prevent interruption of breathing during the night. But the devices were not designed for patients with a highly contagious virus like COVID-19, said Dr. Meir Kryger, professor of medicine (pulmonary) and clinical professor of nursing at Yale. In fact, he said, they could be dangerous.
“These machines have a great potential to increase shedding of the virus,” Kryger said. “The machine generates a huge airflow, and the circuits are not designed to filter the air the patient exhales.”
When used on a patient with the virus, the existing models could potentially contaminate the room air and increase risk of transmission. However, with the right modification, Kryger said, PAP machines could be used more safely.
He and Harvard colleague Dr. Robert Thomas designed a circuit using off-the-shelf parts that can be attached to PAP devices to filter the air both breathed in by and exhaled by patients. They published their circuit design as a letter in the Journal of Clinical Sleep Medicine.
The circuit consists of a non-venting full-face mask, a safety valve, a heat-moisture exchanger or viral filter, and tubing. If needed, a standard adaptor can be attached to allow oxygen or metered inhalers to be added to the circuit. Kryger said that he hopes manufacturers will produce such a circuit, and cautioned that it should only be fitted by an equipment provider or respiratory technician.