Transvascular nerve stimulation apparatus and methods
Electrode structures for transvascular nerve stimulation combine electrodes with an electrically-insulating backing layer. The backing layer increases the electrical impedance of electrical paths through blood in a lumen of a blood vessel and consequently increases the flow of electrical current through surrounding tissues. The electrode structures may be applied to stimulate nerves such as the phrenic, vagus, trigeminal, obturator or other nerves.
1. A method for treating a subject, the method comprising:
sensing an onset of the subject's breathing; and
in response to the sensing, delivering a stimulus to the subject's thorax or abdomen during the subject's breathing;
wherein the stimulus causes a contraction of a breathing muscle of the subject, assisting the subject with ventilation; and
wherein at least one of the sensing and delivering is carried out by one or more electrodes supported on a flexible insulating sheet, positioned within a blood vessel, and configured to deliver a stimulus.
2. The method of claim 1 , wherein sensing an onset of the subject's breathing includes sensing an onset of an inspiration phase.
3. The method of claim 1 , wherein delivering the stimulus to the subject's thorax or abdomen includes stimulating a diaphragm.
4. The method of claim 3 , wherein stimulating the diaphragm includes delivering electrical stimulus to the diaphragm or a nerve.
5. The method of claim 1 , wherein the contraction of the breathing muscle includes a contraction of a diaphragm.
6. The method of claim 1 , wherein assisting the subject with ventilation includes promoting regular ventilation and/or maintaining a normal ventilation drive.
7. The method of claim 1 , wherein the one or more electrodes includes an electrode pair, and delivering the stimulus includes delivering an electrical signal via the electrode pair.
8. The method of claim 1 , wherein sensing an onset of the subject's breathing includes using an accelerometer to determine a movement of the subject.
9. An apparatus comprising:
one or more sensors suitable for detecting when a subject is breathing;
a device configured to deliver a stimulus to the subject's thorax or abdomen during at least part of a phase of the subject's breathing in response to a signal generated by the one or more sensors; and
a flexible insulating sheet including one or more electrodes;
wherein the stimulus is delivered via the one or more electrodes positioned within a blood vessel, and is effective to cause a contraction in a muscle of the subject.
10. The apparatus of claim 9 , wherein the one or more sensors include an accelerometer configured to determine a movement of the subject.
11. The apparatus of claim 9 , wherein the one or more sensors are suitable for detecting when a subject is inhaling or exhaling.
12. The apparatus of claim 9 , wherein the phase of breathing is an inspiration phase.
13. The apparatus of claim 9 , wherein delivering stimulus to the subject's thorax or abdomen includes delivering stimulus to a diaphragm.
14. The apparatus of claim 13 , wherein delivering stimulus to the diaphragm includes delivering electrical stimulus to the diaphragm or a nerve.
15. The apparatus of claim 9 , wherein the contraction of the breathing muscle includes a contraction of a diaphragm.
16. The apparatus of claim 9 , wherein the device is configured to deliver stimulus during an inspiration phase of the subject's breathing.
17. The apparatus of claim 9 , wherein delivering the stimulus includes delivering an electrical signal via an electrode pair of the one or more electrodes.
18. The apparatus of claim 9 , wherein the apparatus is at least in part implantable in the subject's thorax or abdomen.
19. The apparatus of claim 9 , wherein the one or more electrodes are first electrodes, the stimulus is a first stimulus, and the apparatus further includes one or more second electrodes;
wherein the first electrodes are configured to deliver the first stimulus to a first region of the subject's thorax or abdomen;
the second electrodes are configured to deliver a second stimulus to a second region of the subject's thorax or abdomen; and
the first stimulus causes contraction of a first portion of a respiratory muscle, and the second stimulus causes contraction of a second portion of the respiratory muscle.
20. The apparatus of claim 9 , wherein the flexible insulating sheet includes a lead connecting the one or more electrodes to the device; and
wherein the stimulus delivered via the one or more electrodes includes an electrical field emitted from one surface of the flexible insulating sheet.
21. The apparatus of claim 9 , wherein the flexible insulating sheet is configured to conform to a portion of the subject's anatomy.
22. The method of claim 1 , wherein the one or more electrodes are components of one or more implanted sensors or implanted devices.
23. The method of claim 1 , wherein the flexible insulating sheet includes a lead connecting the one or more electrodes to a stimulation source.
24. The method of claim 1 , wherein the one or more electrodes are configured to emit an electrical field that extends from only a portion of the circumference of the flexible insulating sheet.
25. The method of claim 1 , wherein while the stimulus is being delivered, the one or more electrodes do not contact the breathing muscle.
26. The method of claim 1 , wherein sensing an onset of the subject's breathing including sensing an onset of the subject's breathing with one or more implanted sensors or electrodes.
27. A method for treating a subject, the method comprising:
sensing a subject's breathing; and
in response to the sensing, delivering a stimulus to the subject's thorax or abdomen during the subject's breathing, wherein:
the stimulus causes a contraction of a breathing muscle of the subject, assisting the subject with ventilation;
the delivering is carried out by at least one pair of electrodes supported on at least one flexible insulating sheet, wherein the at least one pair of electrodes is positioned within a blood vessel and configured to emit an electrical field that extends from only a portion of the circumference of the at least one flexible insulating sheet;
the at least one flexible insulating sheet includes a lead connecting the at least one pair of electrodes to a stimulation source; and
while the stimulus is being delivered, the one or more electrodes do not contact the breathing muscle.
28. The method of claim 27 , wherein the flexible insulating sheet is configured to conform to a portion of the subject's anatomy.