Apparatus and methods for assisting breathing
The present invention provides, among other things, apparatus and methods of use for treating a subject in need of assistance with breathing. In some embodiments the subject suffers from airflow obstruction. In some embodiments, the subject suffers from chronic obstructive pulmonary disease.
1. A method of assisting breathing of a subject who is intubated or has recently been extubated, the method comprising treating the subject with an apparatus comprising: (a) a sensor suitable for detecting when a subject is exhaling; and (b) a device adapted to deliver an electrical stimulus to at least some of the subject's muscles of expiration during at least part of the expiratory phase of the subject's breathing in response to a signal generated by said sensor, wherein the stimulus is effective to cause or increase contraction of said muscle(s) during at least part of the expiratory phase of the subject's breathing.
2. The method of claim 1 , wherein the subject has an abnormally high EELV in the absence of the stimulus.
3. The method of claim 1 , wherein the subject suffers from dynamic hyperinflation in the absence of the stimulus.
4. The method of claim 1 , wherein the method comprises analyzing a subject's breathing pattern or activity level and adjusting one or more stimulus parameters based at least in part on the analysis.
5. The apparatus of claim 1 , wherein the stimulus is effective to result in a decrease in the subject's EELV as compared with the subject's EELV without the stimulus.
6. The method of claim 1 , wherein the sensor comprises a respiratory inductive plethysmography sensor and the device is adapted to deliver a stimulus to at least some of the subject's abdominal muscles.
7. The method of claim 1 , wherein the sensor, device, or both, are integrated into a garment or belt.
8. The method of claim 1 , wherein the sensor comprises a piezoelectric sensor and the device is adapted to deliver a stimulus to at least some of the subject's abdominal muscles.
9. The method of claim 1 , wherein the sensor stimulates at least the rectus abdominis.
10. The method of claim 1 , wherein the apparatus comprises a controller that determines an appropriate stimulus, based at least in part on analyzing the subject's breathing over one or more preceding breathing cycles.
11. The method according to claim 1 effective to increase abdominal muscle strength in the a subject.
12. The method of claim 1 , wherein the apparatus is capable of operating in two or more modes, wherein at least one mode comprises delivering, in response to signals generated by said sensor, tactile stimuli that are sufficient to be felt by the subject but are not effective to affect expiratory muscle contraction.
13. The method of claim 12 , wherein timing of the tactile stimuli is selected so as to prompt the subject to exhale at least a specified volume or for at least a specified time.
14. The method of claim 11 , wherein the subject suffers from an obstructive respiratory disorder.
15. The method of claim 1 , wherein the subject suffers from COPD.