Ventilator with dual gas supply

1. A ventilator comprising:

a positive relative pressure gas supply;

a negative relative pressure gas supply;

a gas delivery device for delivering gas to a patient;

a diverter valve including a positive pressure port connected to said positive relative pressure gas supply, a negative pressure port connected to said negative relative pressure gas supply, and a gas supply port for communicating with said gas delivery device, wherein a gas supply from at least one of said positive relative pressure gas supply and said negative relative pressure gas supply is delivered to said gas delivery device for delivery of said gas to said patient, via said diverter valve:

a feedback sensor that detects a gas supply difference between said gas supply and a predetermined gas supply and generates a feedback signal that is substantially related to said gas supply difference; and

a diverter valve actuator communicating with said diverter valve and operating said diverter valve to communicate said positive relative pressure gas supply and said negative relative pressure gas supply to said gas supply port of said diverter valve based upon said feedback signal.

2. The ventilator of claim 1 , wherein said diverter valve is configured to allow selection of a mixture ratio of said positive relative pressure gas supply and said negative relative pressure gas supply for communicating with said gas supply port.

3. The ventilator of claim 1 , further comprising a control system that receives said feedback signal and commands said diverter valve actuator.

4. The ventilator of claim 1 , further comprising a control system that receives said feedback signal and commands said diverter valve actuator and wherein said control system commands said diverter valve actuator to substantially achieve a predetermined breathing profile.

5. The ventilator of claim 1 , wherein said ventilator further comprises a vent port.

6. The ventilator of claim 1 , wherein said diverter valve actuator is a linear actuator capable of positioning said diverter valve.

7. The ventilator of claim 1 , wherein said feedback sensor comprises a pressure sensor that measures a pressure of gas being supplied to said gas delivery device.

8. The ventilator of claim 1 , wherein said feedback sensor comprises a flow volume sensor that measures a volume of gas being supplied to said gas delivery device.

9. The ventilator of claim 1 , wherein said positive relative pressure gas supply and said negative relative pressure gas supply comprise blowers and motors and wherein said motors run at a substantially constant speed.

10. The ventilator of claim 1 , wherein said positive relative pressure gas supply and said negative relative pressure gas supply comprise blowers and motors and wherein said feedback sensor is an electrical load sensor that measures an electrical load of said blowers and motors.

11. The ventilator of claim 1 , wherein said positive relative pressure gas supply and said negative relative pressure gas supply comprise blowers and motors and wherein said feedback sensor is an optical rotational speed sensor that measures a motor speed.

12. The ventilator of claim 1 , wherein said positive relative pressure gas supply and said negative relative pressure gas supply comprise blowers and motors and wherein said feedback sensor is a magnetic rotational speed sensor that measures a motor speed.

13. The ventilator of claim 1 , wherein said positive relative pressure gas supply and said negative relative pressure gas supply comprise blowers and motors and wherein said feedback sensor is mechanical rotational speed sensor that measures a motor speed.

14. The ventilator of claim 1 , wherein said diverter valve is configured to allow selection between said positive pressure port and said negative pressure port for communicating with said gas supply port.

15. A method of pressure regulation for a ventilator, comprising the steps of:

providing a positive relative pressure gas supply;

providing a negative relative pressure gas supply;

providing a gas delivery device for delivering gas to a patient;

detecting a gas supply difference between a gas supply provided to said gas delivery device of said ventilator and a predetermined gas supply;

generating a feedback signal that is substantially related to said gas supply difference;

actuating a diverter valve to communicate said positive relative pressure gas supply and said negative relative pressure gas supply to said gas delivery device in order to substantially minimize said gas supply difference; and

delivering gas through said diverter valve to said gas delivery device for delivering said gas to said patient.

16. The method of claim 15 , wherein said detecting step comprises measuring a flow volume of said gas supply.

17. The method of claim 15 , wherein said detecting step comprises measuring motor speeds of motors and impellers used to generate said positive relative pressure gas supply and said negative relative pressure gas supply.

18. The method of claim 15 , wherein said detecting step comprises measuring electrical loads on motors and impellers used to generate said positive relative pressure gas supply and said negative relative pressure gas supply.

19. The method of claim 15 , wherein said actuating step further comprises actuating a valve to select a mixture ratio of said positive relative pressure gas supply to said negative relative pressure gas supply.

20. The method of claim 15 , wherein said method cycles said diverter valve to achieve a substantially predetermined flow volume.

21. The method of claim 15 , wherein said method cycles said diverter valve to achieve a substantially predetermined pressure.

22. The method of claim 15 , wherein said detecting step comprises measuring a pressure of said gas supply.

23. The method of claim 15 , wherein said actuating step further comprises actuating a valve to select only said negative relative pressure gas supply.

24. The method of claim 15 , wherein said actuating step further comprises actuating a valve to select only said positive relative pressure gas supply.

25. A ventilator, comprising:

a positive relative pressure gas supply operable to supply positive relative pressure; a negative relative pressure gas supply operable to supply negative relative pressure; a gas delivery device for delivering gas to a patient; and

a diverter valve including a positive pressure port connected to said positive relative pressure gas supply, a negative pressure port connected to said negative relative pressure gas supply, and a gas supply port for communicating with said gas delivery device;

wherein a gas supply from at least one of said positive relative pressure gas supply and said negative relative pressure gas supply is delivered to said gas delivery device for delivery of said gas to said patient via said diverter valve;

wherein said diverter valve is configured to allow selection of a mixture ratio of said positive relative pressure gas supply and said negative relative pressure gas supply for communicating with said gas supply port;

wherein a feedback sensor that detects a gas supply difference between said gas supply and a predetermined gas supply generates a feedback signal that is substantially related to said gas supply difference; and

wherein a diverter valve actuator communicating with said diverter valve and operating said diverter valve communicates said positive relative pressure gas supply and said negative relative pressure gas supply to said gas supply port of said diverter valve based upon said feedback signal.