The present invention provides a method for monitoring the actual pressure exerted by the interior wall of a biological channel at different locations along the length of said biological channel. The method comprises: i) introducing into the lumen of the biological channel a device comprising an elongated tube and at least two expandable means located at a predetermined distance on said elongated tube ii) inflating each of the expandable means to its contact pressure (Pc) and iii) measuring the internal pressure in each expandable means, wherein when said internal pressure is greater than Pc, the actual pressure exerted by the interior wall of the biological channel is equal to the difference between said internal pressure and Pc.