Breathing tube arrangement for a lung function diagnostics device comprising a distal filter element

Breathing tube arrangement for a lung function diagnostics device comprising a distal filter element Abstract The invention relates to a breathing tube arrangement (14) for a lung function diagnostics device, comprising a breathing tube (15) defining a guiding path for breathing air to be analyzed by a lung function diagnostics device, the breathing tube (15) having a proximal end (16), a distal end (17) and an analysis zone (18) located between the proximal (16) end and the distal end (17). 0 According to an aspect of the invention, the breathing tube arrangement (14) comprises a filter element (1) having a filter material (9), a breathing air releasing region (30) arranged distally of the filter material (9), and a diffusor zone (5) arranged proximally of the filter material (9), wherein the diffusor zone (5) comprises a proximal end (6) having a first proximal cross-sectional area (61) and a distal end (7) having a first distal cross-sectional area (71) that is bigger than the first 5 proximal cross-sectional area (61), and wherein the breathing air releasing region (30) has a second distal cross-sectional area (31), wherein the second distal cross-sectional area (31) is bigger than the first proximal cross-sectional area (61) and at least as big as the first distal cross sectional area (71), wherein a ratio between the first proximal cross-sectional area (61) and the second distal cross-sectional area (31) lies in a range of between 1:2 to 1:20. C-C 9 71 52 620