Smoke evacuation system for continuously removing gas from a body cavity

1. An evacuation system for continuously removing gas from a body cavity of a patient during an endoscopic surgical procedure, comprising:

a) an inlet flow path leading to a first trocar communicating with the body cavity through which a continuous flow of clean gas is delivered to the body cavity, wherein the inlet flow path includes a flow sensor for measuring a gas flow rate in the inlet path and a pressure sensor for measuring a driving pressure in the inlet flow path;

b) an outlet flow path leading from a second trocar communicating with the body cavity though which a continuous flow of smoky gas is removed from the body cavity, wherein the outlet flow path includes a flow sensor for measuring a gas flow rate in the outlet path and a pressure sensor for measuring a driving pressure in the outlet path;

c) a pump communicating at least with the outlet flow path for removing the continuous flow of smoky gas from the body cavity; and

d) a processor operatively associated with the pump for controlling the continuous flow of smoky gas from the body cavity through the outlet flow path, and for controlling the delivery of clean gas to the body cavity through the inlet flow path at a gas flow rate that relates to a gas flow rate at which smoky gas is removed from the body cavity.

2. The evacuation system of claim 1 , wherein the pump communicates with the inlet flow path and the outlet flow path for delivering a continuous flow of clean gas to the body cavity while removing a continuous flow of smoky gas from the body cavity.

3. The evacuation system of claim 2 , wherein the processor controls the pump in such a manner so that clean gas is delivered to the body cavity by the pump at a gas flow rate that relates to a gas flow rate at which smoky gas is removed from the body cavity by the pump.

4. The evacuation system of claim 3 , wherein the processor controls the pump in such a manner so that clean gas is delivered to the body cavity by the pump at a gas flow rate that is equal to the gas flow rate at which smoky gas is removed from the body cavity by the pump.

5. The evacuation system of claim 3 , wherein the processor controls the pump and one or more valves in such a manner so that clean gas is delivered to the body cavity by the pump at a gas flow rate that is greater than or less than the gas flow rate at which smoky gas is removed from the body cavity by the pump, in the event of an under-pressure condition or an over-pressure condition in the body cavity.

6. The evacuation system of claim 3 , wherein the system is configured so that the gas flow rate, supplied at a programmed driving pressure, varies depending upon a body cavity pressure and the processor is configured to determine the body cavity pressure corresponding to a gas flow rate measurement continuously measured by the flow sensor included in at least one of the inlet flow path and the outlet flow path.

7. The evacuation system of claim 3 , wherein the system is configured so that a driving pressure required to maintain a specified gas flow rate varies depending upon a body cavity pressure and the processor is configured to determine the body cavity pressure corresponding to a measured driving pressure continuously measured by the pressure sensor included in at least one of the inlet flow path and the outlet flow path.

8. The evacuation system of claim 1 , wherein an insufflation unit communicates with the inlet flow path for delivering a continuous flow of clean gas to the body cavity and the pump communicates with the outlet flow path for removing a continuous flow of smoky gas from the body cavity.

9. The evacuation system of claim 8 , wherein the processor controls both the insufflation unit and the pump in such a manner so that clean gas is delivered to the body cavity by the insufflation unit at a gas flow rate that relates to the gas flow rate at which smoky gas is removed from the body cavity by the pump.

10. The evacuation system of claim 9 , wherein the processor controls both the insufflation unit and the pump in such a manner so that clean gas is delivered to the body cavity by the insufflation unit at a gas flow rate that is equal to the gas flow rate at which smoky gas is removed from the body cavity by the pump.

11. The evacuation system of claim 9 , wherein the processor controls both the insufflation unit and the pump in such a manner so that clean gas is delivered to the body cavity by the insufflation unit at a gas flow rate that is greater than or less than the gas flow rate at which smoky gas is removed from the body cavity by the pump, in the event of an under-pressure condition or an over-pressure condition in the body cavity.

12. The evacuation system of claim 9 , wherein the system is configured so that the gas flow rate, supplied at a programmed driving pressure, varies depending upon a body cavity pressure and the processor is configured to determine the body cavity pressure corresponding to a gas flow rate measurement continuously measured by the flow sensor included in at least one of the inlet flow path and the outlet flow path.

13. The evacuation system of claim 9 , wherein the system is configured so that a driving pressure required to maintain a specified gas flow rate varies depending upon a body cavity pressure and the processor is configured to determine the body cavity pressure corresponding to a measured driving pressure continuously measured by the pressure sensor included in at least one of the inlet flow path and the outlet flow path.

14. The evacuation system of claim 8 , wherein the pump is operatively connected to an exhaust valve.

15. The evacuation system of claim 8 , wherein the insufflation unit is operatively connected to a gas source.

16. The evacuation system of claim 1 , further comprising a filter operatively associated with at least one of the inlet flow path and the outlet flow path.

17. The evacuation system of claim 1 , wherein the processor relies upon data stored in memory in a look up table based upon a known resistance characteristic of at least one of the inlet flow path and the outlet flow path, and wherein the processor utilizes a calibration algorithm to determine the resistance characteristic of at least one of the inlet flow path and the outlet flow path when it is initially unknown.

18. An evacuation system for continuously removing gas from a body cavity of a patient during an endoscopic surgical procedure, comprising:

a) an inlet flow path leading to a first trocar communicating with the body cavity through which a continuous flow of clean gas is delivered to the body cavity, wherein the inlet flow path includes a flow sensor for measuring a gas flow rate in the inlet path and a pressure sensor for measuring a driving pressure in the inlet flow path;

b) an outlet flow path leading from a second trocar communicating with the body cavity though which a continuous flow of smoky gas is removed from the body cavity, wherein the outlet flow path includes a flow sensor for measuring a gas flow rate in the outlet path and a pressure sensor for measuring a driving pressure in the outlet path;

c) a pump communicating with the inlet flow path for delivering the continuous flow of clean gas to the body cavity and with the outlet flow path for removing the continuous flow of smoky gas from the body cavity; and

d) a processor for controlling the pump and one or more valves in such a manner so that clean gas is delivered to the body cavity through the inlet flow path by the pump at a gas flow rate that relates to the gas flow rate at which smoky gas is removed from the body cavity through the outlet flow path by the pump.

19. The evacuation system of claim 18 , wherein the processor is configured to control the pump in such a manner so that clean gas is delivered to the body cavity by the pump at a gas flow rate that is equal to a gas flow rate at which smoky gas is removed from the body cavity by the pump.

20. The evacuation system of claim 18 , wherein the processor is configured to control the pump and the one or more valves in such a manner so that clean gas is delivered to the body cavity by the pump at a gas flow rate that is greater than or less than a gas flow rate at which smoky gas is removed from the body cavity by the pump, in the event of an under-pressure condition or an over-pressure condition in the body cavity.

21. The evacuation system of claim 18 , wherein the system is configured so that the gas flow rate at which clean gas is delivered to the body cavity by the pump, supplied at a programmed driving pressure, varies depending upon a body cavity pressure and the processor is configured to determine the body cavity pressure corresponding to a gas flow rate measurement continuously measured by the flow sensor included in at least one of the inlet flow path and the outlet flow path.

22. The evacuation system of claim 18 , wherein the system is configured so that a driving pressure required to maintain a specified gas flow rate varies depending upon a body cavity pressure and the processor is configured to determine the body cavity pressure corresponding to a measured driving pressure continuously measured by the pressure sensor included in at least one of the inlet flow path and the outlet flow path.

23. The evacuation system of claim 18 , wherein the processor relies upon data stored in memory in a look up table based upon a known resistance characteristic of at least one of the inlet flow path and the outlet flow path, and wherein the processor utilizes a calibration algorithm to determine the resistance characteristic of at least one of the inlet flow path and the outlet flow path when it is initially unknown.

24. The evacuation system of claim 18 , further comprising a filter operatively associated with at least one of the inlet flow path and the outlet flow path.