Airway diagnostics utilizing phrenic nerve stimulation device and method

1. A method for diagnosing upper airway patency in a patient by providing electrical stimulation to the patient, the method comprising:

applying an electrical stimulation pulse or a plurality of electrical stimulation pulses to a diaphragm or phrenic nerve tissue of the patient at a pulse energy and frequency effective to induce a plurality of twitch contractions in the diaphragm which induce flow oscillations that are superimposed upon the patient's intrinsic breath;

measuring at least one parameter of the patient's respiration while applying the electrical stimulation pulse or plurality of electrical stimulation pulses;

terminating the electrical stimulation pulse or plurality of electrical stimulation pulses once the at least one parameter of the patient's respiration is measured;

comparing the measured at least one parameter of the patient's respiration to a baseline airway patency index for the patient; and

determining a degree of the patient's upper airway patency or collapse based on the comparison.

2. The method of claim 1 , wherein the plurality of electrical stimulation pulses are applied at a frequency of 5 Hz.

3. The method of claim 1 , wherein the at least one parameter of the patient's respiration comprises changes in airflow, volume, inspiration or exhalation, or thoracic impedance.

4. The method of claim 1 , wherein the at least one parameter of the patient's respiration is measured when the patient's upper airway is fully open, partially open, or fully closed.

5. The method of claim 1 , wherein the at least one parameter of the patient's respiration is measured during an inhalation and/or an exhalation phase of breathing.

6. The method of claim 1 , further comprising determining a level and timing of the electrical stimulation pulse or plurality of electrical stimulation pulses based on the baseline airway patency index.

7. The method of claim 1 , further comprising adjusting and subsequently applying the electrical stimulation pulse or plurality of electrical stimulation pulses based on the patient's airway patency in a closed loop response.

8. The method of claim 1 , further comprising measuring the patient's airway patency multiple times.

9. The method of claim 1 , wherein the baseline airway patency index is generated by applying the electrical stimulation pulse or plurality of electrical stimulation pulses to the diaphragm or phrenic nerve tissue of the patient at the pulse energy and frequency effective to induce the plurality of twitch contractions in the diaphragm which induce flow oscillations that are superimposed upon the patient's intrinsic breath when the patient's upper airway is fully open.

10. The method of claim 9 , wherein the baseline airway patency index is generated multiple times.

11. The method of claim 9 , wherein the baseline airway patency index is generated periodically.

12. A method for diagnosing upper airway patency in a patient by providing electrical stimulation to the patient, the method comprising:

generating a baseline patency index comprising reference data indicative of at least one parameter of the patient's respiration when the patient's upper airway is fully open, the baseline patency index being generated by applying electrical stimulation pulses to a diaphragm or phrenic nerve tissue of the patient to induce twitch contractions in the diaphragm sufficient to induce flow oscillations superimposed upon the patient's intrinsic breath while the patient's upper airway is fully open;

subsequently applying additional electrical stimulation pulses to the patient's diaphragm or phrenic nerve tissue of the patient at the pulse energy and frequency effective to induce the plurality of twitch contractions in the patient's diaphragm which induce the flow oscillations that are superimposed upon the patient's intrinsic breath when the patient's upper airway is partially open or closed;

measuring at least one parameter of the patient's respiration while applying the subsequent at least one electrical stimulation pulse;

comparing the measured at least one parameter of the patient's respiration to the baseline airway patency index for the patient; and

determining a degree of the patient's upper airway patency or collapse based on the comparison.

13. The method of claim 12 , further comprising generating a new baseline airway patency index after determining the degree of the patient's upper airway patency or collapse.

14. The method of claim 12 , wherein the baseline airway patency index is generated multiple times.

15. The method of claim 12 , wherein the baseline airway patency index is generated periodically.

16. The method of claim 12 , wherein the at least one electrical stimulation pulse is applied at a frequency of 5 Hz.

17. The method of claim 12 , wherein the at least one parameter of the patient's respiration comprises changes in airflow, volume, inspiration or exhalation, or thoracic impedance.