membrane with openings that communicate with space that communicates with a source of suction force the catheter is positioned within the body the sample is taken by exposing the membrane by placing it in proximity with a desired location so that the bodily sample is received by the membrane the catheter is removed from the patient and the sample is collected outside the body application_number US 17594993 A description referring to fig1 a sample collection apparatus 2 includes a catheter 4 that is constructed to be threaded through a lumen of a blood vessel the catheter 4 includes near its distal end an expandable portion which may be for example a balloon 8 the balloon is inflated and deflated by injecting or withdrawing fluid from a source 3 through a lumen 5 in the catheter and a port 10 located within the balloon the apparatus may include a protective sheath 30 that extends over the balloon while it is threaded into and out of the body the balloon can be exposed from the sheath once the site is reached the sheath may be an introducer catheter of the type used to direct angioplasty catheters to the coronary arteries referring as well to.