Arrangement in connection with an anaesthesia/ventilation system for a patient and a gas separation unit for an anaesthesia/ventilation system

1. An anaesthesia/ventilation system for a patient comprising means for flowing expiratory gas from the patient to a gas separation means and further through the gas separation means back to an inspiratory flow, the gas separation means comprising:

a chamber unit having a high pressure side and a low pressure side, the high pressure side and the low pressure side being separated by a membrane where carriers are fixed on the membrane, and the membrane is configured as a polymer backbone, and the expiratory gas from the patient containing retentates and permeates flowing to the high pressure side of the chamber unit to have contact with the membrane surface whereby the membrane reacts with the permeates so that the permeates flow through the membrane to the low pressure side of the chamber unit and the retentates flow through the high pressure side of the chamber unit without permeating the membrane.

2. The system of claim 1 , wherein the membrane in the chamber unit is a flat design.

3. The system of claim 1 , wherein the membrane is a folded envelope design.

4. The system of claim 1 , wherein the membrane is a tubular design being formed of several membrane tubes and the expiratory gases from the patient being arranged to flow through the tubes.

5. The system of claim 1 , wherein the membrane is a fixed-site-carrier (FSC) membrane.

6. The system of claim 1 , wherein a sweep gas flow is arranged in the low pressure side of the chamber unit.

7. The system of claim 1 , wherein water separation means is connected to the low pressure side of the chamber unit to separate the permeate and water.

8. The system of claim 1 , wherein the gas separation means is provided with a pump and a power supply unit for maintaining at least a partial vacuum on the low pressure side.

9. A gas separation unit for an anaesthesia/ventilation system of a patient, the gas separation unit comprising:

a shell forming an enclosed space, the enclosed space having an input conduit and an output conduit, and the enclosed space being divided into a high pressure side and a low pressure side by using a membrane where carriers are fixed on the membrane, and the membrane is configured as a polymer backbone, the input and outlet conduits for expiratory gas flow from the patient containing retentates and permeates through the high pressure side of the unit so that the expiratory gas flow contacts with the membrane whereby the membrane reacts with the permeates so that the permeates flow through the membrane to the low pressure side of the unit and the retentates flow through the high pressure side of the unit and through the outlet conduit without permeating the membrane.

10. The gas separation unit of claim 9 , wherein the membrane in the unit is a flat design.

11. The gas separation unit of claim 9 , wherein the membrane is a folded envelope design.

12. The gas separation unit of claim 9 , wherein the membrane is a tubular design being formed of several membrane tubes and the expiratory gas from the patient being arranged to flow through the tubes.

13. The gas separation unit of claim 9 , wherein the membrane is a fixed-site-carrier (FSC) membrane.

14. The gas separation unit of claim 9 , wherein the shell comprises an input and an outlet conduit for a sweep gas flow, the outlet conduit for the sweep gas flow being in flow connection with the low pressure side of the shell.

15. The gas separation unit of claim 9 , wherein the shell is provided with a water separation unit, the water separation unit being in flow connection with the low pressure side of the shell.

16. The gas separation unit of claim 9 , wherein the shell and the conduits are dimensioned to minute volumes from 500 ml-30 l.

17. The gas separation unit of claim 9 , wherein the shell is provided with a pump and a power supply unit for maintaining at least a partial vacuum on the low pressure side.