Stimulation For Treating Sleep Disordered Breathing

What is this patent about?

’424 is related to the field of medical devices, specifically devices and methods for treating obstructive sleep apnea (OSA) . The background of the invention acknowledges that electrical stimulation of nerves, such as the hypoglossal nerve, can help maintain upper airway patency and alleviate OSA. However, prior approaches may have relied on complex, sensor-based systems to synchronize stimulation with the patient's breathing, potentially increasing cost and complexity.

The underlying idea behind ’424 is to provide effective nerve stimulation for treating OSA without requiring real-time synchronization with a sensed respiratory waveform. This is achieved by using a pre-programmed stimulation protocol that alternates between stimulation and non-stimulation periods, where the timing of these periods is independent of any sensors that would otherwise be used to detect and time the stimulation. The key insight is that by carefully selecting the durations of the stimulation and non-stimulation periods, the stimulation can effectively overlap with the inspiratory phase of breathing, even without precise synchronization.

The claims of ’424 focus on a device for treating OSA that includes a means for stimulating the hypoglossal nerve according to a first stimulation therapy protocol. This protocol involves alternating periods of stimulation and non-stimulation, where the timing of the stimulation periods is implemented without a sensing element for timing stimulation . The duration of each stimulation period is greater than the duration of each non-stimulation period. The means for stimulating includes an implantable electrode and/or an implantable pulse generator electrically connectable to the implantable electrode.

In practice, the device delivers electrical pulses to the hypoglossal nerve, which controls tongue movement, to prevent the tongue from collapsing and obstructing the airway during sleep. The stimulation protocol is designed such that the stimulation periods overlap with the inspiratory phase of breathing, even though the timing is not directly synchronized with the patient's actual breathing. This is achieved by basing the duration of the stimulation period on a reference respiration-related parameter , such as the average duration of a breath, and by ensuring that the stimulation cycle (stimulation period plus non-stimulation period) has a duration that is either shorter or longer than the reference breath duration.

This approach differs from prior solutions that rely on real-time sensing of the respiratory waveform to trigger and synchronize the stimulation. By eliminating the need for sensors, ’424 simplifies the device, reduces its cost, and potentially makes it easier to implant. The asynchronous stimulation protocol also helps to overcome situations where sensor-based systems are unable to achieve synchronization or when the sensing signal becomes unstable. The use of alternating stimulation and non-stimulation periods also helps to minimize potential muscle fatigue.