Stimulatory device and methods to electrically stimulate the phrenic nerve

• US 20020188332A1
• Filed: 05/29/2002
• Published: 12/12/2002
• Est. Priority Date: 06/11/1998
• Status: Active Grant

• Current Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Original Assignee: Advanced Circulatory Systems, Inc. (Asahi Kasei Corporation)
• Inventors: Voelckel, Wolfgang, Lindner, Karl, Lurie, Keith G., Zielinski, Todd M., Patterson, Robert, McKnite, Scott, Samniah, Nemer
• Granted Patent: US 6,587,726 B2
• Time in Patent Office: Days
• US Class Current: 607/48
• CPC Class Codes: A61H 2031/002 fixed on the chest by adhesives
• CPC Class Codes: A61H 2201/165 Wearable interfaces
• CPC Class Codes: A61H 2201/5007 computer controlled
• CPC Class Codes: A61H 2201/5043 Displays
• CPC Class Codes: A61H 2201/5048 Audio interfaces, e.g. voice or music controlled
• CPC Class Codes: A61H 2201/5061 Force sensors
• CPC Class Codes: A61H 31/00 Artificial respiration or heart stimulation, e.g. heart massage artificial respiration by treatment with gas or air, e.g. mouth-to-mouth respiration A61M16/00; applying electric currents by contact electrodes for stimulation, e.g. heart pace-makers A61N1/36 ; teaching or training models, demonstration models for medical purposes G09B23/288
• CPC Class Codes: A61H 31/005 with feedback for the user
• CPC Class Codes: A61H 31/006 Power driven
• CPC Class Codes: A61H 31/007 Manual driven
• CPC Class Codes: A61M 16/0084 self-reinflatable by elasticity, e.g. resuscitation squeeze bags
• CPC Class Codes: A61M 16/04 Tracheal tubes catheters in general A61M25/00
• CPC Class Codes: A61M 16/0434 Cuffs
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0683 Holding devices therefor
• CPC Class Codes: A61M 16/205 used for exhalation control
• CPC Class Codes: A61M 16/209 Relief valves
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2230/08 Other bio-electrical signals
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/50 : Temperature
• CPC Class Codes: A61N 1/0456 : Specially adapted for transcutaneous electrical nerve stimulation [TENS]
• CPC Class Codes: A61N 1/046 : Specially adapted for shock therapy, e.g. defibrillation
• CPC Class Codes: A61N 1/3601 : of respiratory organs
• CPC Class Codes: A61N 1/36031 : using physiological parameters for adjustment
• CPC Class Codes: A61N 1/36034 : specified by the stimulation parameters
• CPC Class Codes: A61N 1/39044 : in combination with cardiopulmonary resuscitation [CPR] therapy
• CPC Class Codes: A61N 1/39046 : User protection from shock
• CPC Class Codes: A61N 2/002 : in combination with another treatment

Abstract

The invention provides exemplary devices and methods electrically stimulating the phrenic nerve. In one embodiment, electrodes are placed posterior and anterior in the region of the cervical vertebrae. Electrical current having a multi-phasic waveform is periodically applied to the electrodes to stimulate the phrenic nerve, thereby causing the diaphragm to contract.

Claims

1. A method for increasing blood flow to the thorax of a patient, the method comprising:

periodically stimulating the phrenic nerve to cause the diaphragm to contract and thereby cause an increase in the magnitude and duration of negative intrathoracic pressure; and

periodically occluding airflow to the lungs during contraction of the diaphragm with a valve that is positioned to control airflow into the patient'"'"'s airway to further increase the magnitude and duration of negative intrathoracic pressure, thereby forcing more blood into the thorax.

2. A method as in claim 1, wherein the stimulating step comprises applying electrical current to the phrenic nerve with electrode that are positioned over the cervical vertebrae between C3 and C7.

3. A method as in claim 2, wherein the stimulating step further comprises placing the electrodes both posterior and anterior between C3 and C5.

4. A method as in claim 2, wherein the electrical current is provided in monophasic or multiphasic form.

5. A method as in claim 4, wherein the multi-phasic form comprises an asymmetrical biphasic waveform.

6. A method as in claim 5, wherein the biphasic electrical current is in the range from about 100 milliamps to about 2,000 milliamps at a frequency in the range from about 10 Hz to about 100 Hz, and wherein the electrical current is supplied in pulse widths in the range from about 1 μ

s to about 5 ms.

7. A method as in claim 1, wherein the patient is suffering from hemorrhagic shock, and wherein the stimulating step further comprises stimulating the phrenic nerve about 5 to about 30 times per minute.

8. A method as in claim 7, wherein the phrenic nerve is stimulated after each breath for time intervals of about 0.25 seconds to about 5 seconds.

9. A method as in claim 7, wherein the phrenic nerve is stimulated to contract in the range from about twice per every one breath to about once about every five breaths.

10. A method as in claim 1, wherein the patient is suffering from hypovolemic shock, and wherein the stimulating step further comprises stimulating the phrenic nerve about 3 to about 30 times per minute.

11. A method as in claim 1, wherein the patient is suffering from cardiogenic shock, and wherein the stimulating step further comprises stimulating the phrenic nerve about 5 to about 80 times per minute.

12. A method as in claim 1, wherein the patient is suffering from cardiac arrest, wherein the stimulating step further comprises stimulating the phrenic nerve about 10 to about 80 times per minute, and further comprising repeatedly compressing the chest at a rate in the range from about 60 compressions to about 100 compressions per minute.

13. A method as in claim 12, further comprising sensing the chest compressions and stimulating the phrenic nerve based on the sensed compressions.

14. A method as in claim 12, further comprising indicating to a rescuer when to perform the chest compressions based on the timing of phrenic nerve stimulation.

15. A method as in claim 12, further comprising counting the number of chest compressions relative to the number of phrenic nerve stimulations.

16. A method as in claim 1, wherein the patient is suffering from post resuscitation pulseless electrical activity, and wherein the stimulating step further comprises stimulating the phrenic nerve about 10 to about 80 times per minute.

17. A method as in claim 1, wherein the patient is suffering from right ventricular failure, wherein the stimulating step further comprises stimulating the phrenic nerve about 5 to about 80 times per minute.

18. A method as in claim 2, further comprising sensing the magnitude of negative intrathoracic pressure and adjusting the current supplied to the electrodes based on the measurement so that the magnitude of negative intrathoracic pressure remains within the range from about −

5 mmHg to about −

30 mmHg after diaphragmatic stimulation.

20. A method as in claim 19, wherein the multi-phasic wave form comprises an asymmetrical biphasic waveform.

21. A method as in claim 20, wherein the biphasic electrical current is in the range from about 100 milliamps to about 2,000 milliamps at a frequency in the range from about 10 Hz to about 100 Hz, and wherein the electrical current is supplied in pulse widths in the range from about 1 μ

s to about 5 ms.

22. A method as in claim 19, wherein the patient is suffering from respiratory distress or apnea, and wherein the stimulating step comprises stimulating the phrenic nerve about 10 to about 30 times per minute.

24. A method as in claim 23, wherein the stimulating step comprises stimulating the phrenic nerve about 10 to about 30 times per minute.

26. A method as in claim 25, further comprising controlling the amount of current so that the magnitude of negative intrathoracic pressure is within the range from about −

5 mmHg to about −

30 mmHg after diaphragmatic stimulation.

27. A method as in claim 25, further comprising stimulating the phrenic nerve in the region of the cervical vertebrae to stimulate diaphragmatic contraction.

28. A method as in claim 27, wherein the electrodes are placed posterior and anterior in the C3 to C5 region of the cervical vertebrae, and further comprising applying electrical current having an asymmetric biphasic waveform to the electrodes to stimulate the phrenic nerve.

30. A medical kit as in claim 29, further comprising a pair of electrodes that are adapted to be placed posterior and anterior in the C3 to C6 region of the cervical vertebrae.

31. A medical kit as in claim 30, wherein the controller is configured to produce biphasic electrical current that is in the range from about 100 milliamps to about 2,000 milliamps at a frequency in the range from about 10 Hz to about 100 Hz, and wherein the controller is configured to supply the electrical current in pulse widths in the range from about 1 μ

s to about 5 ms.

19. A method for stimulating the phrenic nerve of a patient, the method comprising:

placing electrodes posterior and anterior in the region of the cervical vertebrae; and

periodically applying electrical current having a multi-phasic waveform to the electrodes to stimulate the phrenic nerve, thereby causing the diaphragm to contract.

23. A method for ventilating a patient, the method comprising:

placing electrodes posterior and anterior in the C3 to C5 region of the cervical vertebrae; and

periodically applying electrical current having a monophasic or biphasic waveform to the electrodes to stimulate the phrenic nerve, thereby causing the diaphragm to contract and draw respiratory gases into the patient'"'"'s lungs.

25. A method for increasing blood flow to the thorax of a patient, the method comprising:

repeatedly electrically stimulating the diaphragm to contract with at least two electrodes;

sensing the magnitude of negative intrathoracic pressure after diaphragmatic stimulation; and

controlling the amount of current supplied to the electrodes based on the measured pressure.

29. A medical kit for increasing blood flow to the thorax, the method comprising:

at least one electrode that is adapted to be placed over the cervical vertebrae to stimulate the phrenic nerve when actuated;

a controller to which the electrode is electrically coupled, wherein the controller is configured to supply electrical current to the electrode to electrically stimulate the phrenic nerve, thereby causing the diaphragm to contract;

a valve that is configured to prevent the flow of respiratory gases into the lungs until a certain negative intrathoracic pressure is exceeded, at which time the valve opens to permit the flow of respiratory gases into the lungs.

32. A system for increasing blood flow to the thorax, the system comprising:

a collar that is configured to be placed around the neck in a secured arrangement; and

at least two electrodes coupled to the collar such that the electrodes are positioned posterior and anterior to cervical vertebrae C3 to C6 when the collar is secured about the neck.

33. A system as in claim 32, further comprising a controller that is configured to supply electrical current to the electrodes to stimulate the phrenic nerve.

35. A method as in claim 34, further comprising periodically occluding airflow to the lungs during contraction of the diaphragm with a valve that is positioned to control airflow into the patient'"'"'s airway to further increase the magnitude and duration of negative intrathoracic pressure, thereby forcing more blood into the thorax.

37. A device as in claim 36, wherein the electrodes comprise phrenic nerve stimulation electrodes.

38. A device as in claim 37, further comprising a pair of defibrillation electrodes coupled to the stimulation device.

40. A method as in claim 39, further comprising lifting the chest about 20 to about 60 times per minute, and occluding airflow until the negative intrathoracic pressure exceeds a pressure in the range from about −

5 to about −

30 cmH₂O.

41. A method as in claim 39, further comprising lifting the chest with a suction cup device and occluding airflow with an impedance threshold valve.

34. A method for increasing blood flow to the thorax, the method comprising:

placing a collar having at least two electrodes around a patient'"'"'s neck in a secured arrangement such that the two electrodes are positioned posterior and anterior to the cervical vertebrae C3 to C6; and

periodically supplying electrical current to the electrodes to stimulate the phrenic nerve to cause the diaphragm to contract and thereby cause an increase in the magnitude and duration of negative intrathoracic pressure to force more blood into the thorax.

36. A stimulation device, comprising:

a generally flat back plate that is configured to be placed below a patient'"'"'s back when the patient is lying down;

a neck support that is coupled to the back plate, wherein the neck support is raised relative to the back plate and is adapted to tilt the patient'"'"'s head backward; and

at least two electrodes coupled to the stimulation device that are adapted to electrically stimulate the patient.

39. A method for increasing blood flow to the thorax of a patient suffering from hemorrhagic shock, the method comprising:

periodically lifting the patient'"'"'s chest to cause an increase in the magnitude and duration of negative intrathoracic pressure; and

periodically occluding airflow to the lungs during contraction of the diaphragm with a valve that is positioned to control airflow into the patient'"'"'s airway to further increase the magnitude and duration of negative intrathoracic pressure, thereby forcing more blood into the thorax.