Patent ID: 7811301

Claim:
A device for positioning a guiding tube ( 1 ) for a nephroscope, comprising: an aspiration needle ( 2 ) having a first distal end and a second distal end; and an inflatable enlargement device ( 4 , 36 ) slidably positioned around the aspiration needle between the first and second distal ends such that the aspiration needle serves as a guide means for the inflatable enlargement device ( 4 , 36 ), the inflatable enlargement device serving as the guide tube for the nephroscope at the time of its positioning on a patient; the inflatable enlargement device comprising: a sliding tube ( 13 , 39 ) positioned around the aspiration needle such that it slides along the aspiration needle and having a first sliding tube end ( 18 ) comprising at least two cutting blades ( 19 , 46 ) making up a trocar and a second sliding tube end ( 33 ) comprising a handling sleeve ( 34 , 53 ); a support tube ( 15 , 40 ) shorter in length than the sliding tube, positioned around the sliding tube and attached at its ends to the sliding tube, a first support tube end positioned adjacent to the cutting blades, and a cuff ( 25 , 41 ) surrounding the support tube ( 15 , 40 ) and secured to the support tube at a first cuff end and a second cuff end, the first cuff end positioned immediately adjacent the first support tube end; the support tube having an inner diameter that is larger than an outer diameter of the sliding tube to form an inflation fluid circulation space where a pressurized inflation fluid can flow between the sliding tube and the support tube, the inflation fluid circulation space communicating with an inside area of the cuff through a first orifice ( 29 , 42 ) opened in the support tube inside the cuff ( 25 , 41 ) and with a filling tube ( 31 , 57 ) through a second orifice opened in the support tube outside the cuff, such that an interior area of the cuff is in fluid communication with a supply of pressurized inflation fluid connected to the filling tube.