Method and apparatus for treating sleep apnea
An oral appliance is disclosed that provides electrical stimulation to a patient's tongue in a manner that prevents collapse of the tongue and/or soft palate during sleep. More specifically, the appliance may induce a reversible current or currents in a lateral direction across the tongue in a manner that shortens the patient's Palatoglossus muscle, which in turn pulls the patient's soft palate downward towards a base of the tongue and/or decreases a volume of the tongue.
1. A system including a device configured to provide electrical stimulation to an oral cavity of a patient, the device comprising:
an appliance including a body having first and second lateral arms each terminating in a posterior-most free end;
a number of electrodes, comprising at least:
a first electrode including a first portion directly attached to a lingual side of the posterior-most free end of the first lateral arm and including a second portion extending posteriorly beyond the posterior-most free end of the first lateral arm; and
a second electrode including a first portion directly attached to a lingual side of the posterior-most free end of the second lateral arm and including a second portion extending posteriorly beyond the posterior-most free end of the second lateral arm, wherein the first and second electrodes are adapted to face opposite lateral sides of the patient's tongue; and
a control circuit configured to induce a reversible current in a lateral direction across the tongue via the first and second electrodes to generate the electrical stimulation, wherein:
one or more of the number of electrodes are configured to generate sensing signals indicative of a respiratory behavior of the patient; and
the control circuit is further configured to adjust an amplitude of a stimulation waveform based at least in part on the sensing signals.
2. The system of claim 1 , wherein the control circuit is configured to induce the current by providing the stimulation waveform to the number of electrodes.
3. The system of claim 2 , wherein the control circuit is further configured to adjust the amplitude of the stimulation waveform based on a time period.
4. The system of claim 3 , wherein the time period is indicative of a resistive-capacitive (RC) time constant of the tongue.
5. The system of claim 2 , wherein at least one of the number of electrodes comprises a vibration sensor configured to measure vibrations detected within the patient's oral cavity.
6. The system of claim 2 , wherein the stimulation waveform comprises a plurality of pulses each having a duration indicative of a resistive-capacitive (RC) time constant of the tongue.
7. The system of claim 2 , wherein the control circuit is further configured to reverse a polarity of the stimulation waveform after a time period.
8. The system of claim 1 , wherein the first and second electrodes are configured to induce the current by providing a voltage differential across the tongue.
9. The system of claim 1 , wherein the current comprises a zero-sum waveform.
10. The system of claim 1 , wherein the current is configured to be induced across a sublingual portion or a superior portion of the tongue.
11. The system of claim 1 , further comprising:
a transceiver configured to transmit the sensing signals to an external device.
12. The system of claim 11 , wherein the external device comprises a display device configured to display the respiratory behavior of the patient.
13. The system of claim 11 , wherein the external device comprises a display device configured to generate an alarm based on the sensing signals indicating that the patient is not breathing.
14. The system of claim 11 , wherein the external device comprises a storage device configured to store data indicating a relationship between the stimulation waveform applied to the patient and the patient's respiratory response to electrical stimulation associated with the applied stimulation waveform.
15. The system of claim 1 , wherein the control circuit is further configured to provide the stimulation waveform continuously.
16. The system of claim 1 , wherein the sensing signals are indicative of a presence of disturbed breathing in the patient.
17. The system of claim 1 , wherein the sensing signals are indicative of an absence of disturbed breathing in the patient.
18. The system of claim 1 , wherein the first and second electrodes are adapted to be in contact with opposite sides of the patient's tongue proximate to lateral points at which a Palatoglossus muscle inserts into the tongue when the appliance is inserted within the oral cavity.
19. The system of claim 1 , wherein at least a portion of each of the first and second electrodes is adapted to be positioned posterior to a last molar location of the patient when the appliance is inserted within the oral cavity.
20. The system of claim 1 , further comprising:
a power supply, mounted on the appliance, to provide power to the control circuit, wherein the appliance, the number of electrodes, the control circuit, and the power supply comprise a unitary device adapted to fit entirely within the patient's oral cavity.
21. The system of claim 1 , wherein the electrical stimulation is configured to shorten the patient's Palatoglossus muscle while pulling the patient's Palatoglossal arch in a downward direction towards a base of the tongue.
22. The system of claim 1 , wherein the electrical stimulation is configured to tense the patient's Palatoglossus muscle while pulling the patient's Palatoglossal arch in a downward direction towards a base of the tongue.
23. The system of claim 1 , wherein the electrical stimulation is configured to decrease a volume of the tongue without moving the tongue in an anterior direction.
24. The system of claim 1 , wherein one or more of the number of electrodes comprises a sensor configured to detect electrical activity of muscles within or connected to the patient's tongue.
25. The system of claim 1 , wherein at least one of the number of electrodes is further configured to detect snoring in the patient.