Jayme Rubenstein, a spokesperson for ResMed, said the company is prioritizing the manufacture of devices for patients with immediate ventilation needs, including Covid patients, followed by machines for those with central and obstructive sleep apnea.

In a survey of home medical device providers conducted in April 2020, more than half reported interruptions in the supply chain for CPAP devices and 62 percent reported delays of up to 60 days. The Philips recall “certainly exacerbated the situation,” said Thomas Ryan, chairman of the American Association for Homecare, which commissioned the study and represents the suppliers. (Philips is on his board.)

“Given the shortage of materials to make these devices, such as resins and computer chip modules, and transportation bottlenecks, I expect supply will continue to lag behind demand through 2022,” he said. “It will be a crisis”

Amy Sloane, who learned she had sleep apnea in 2017, began using a DreamStation BiPAP Auto SV device the following year. Overall, she said, her sleep improved. However, after reading about the recall, she became concerned to learn that the sonic cleaning device she was using could break the foam barrier.

“Even more annoying,” she said, “when I manually wiped my DreamStation water tank, there were black particles on the wipe.”

Ms. Sloane, 57, a Baltimore-based attorney, early registered her device with Philips for recall. But she said the company’s only response was to tell her to consult her doctor, who advised her to stop using it immediately. Within a few days, her doctor was able to prescribe a self-adjusting CPAP device from another manufacturer.

As of June, around 40 lawsuits have been filed against Philips on behalf of patients in more than 20 states. Steven Bloch, an attorney for Silver Golub & Teitell in Stamford, Connecticut, said his law firm has filed four lawsuits in Massachusetts, where Philips’ US headquarters are located.