Internal pressure measuring device using catheter with multiple lumens

An internal pressure measuring device comprising:

• an internal pressure measuring catheter constituted by at least three lumens which are an internal pressure measuring lumen whose distal end is open, a position correcting liquid-charged lumen whose distal end is closed and in which a liquid is charged, and a position correcting atmosphere-opened lumen whose proximal end is open to the atmosphere, said three lumens having adjoining peripheral surfaces, the liquid being brought into contact with the atmosphere at the distal end of said liquid-charged lumen and of said atmosphere-opened lumen;
• an internal pressure measuring transducer connected to a proximal end of said internal pressure measuring lumen and a pressure measuring transducer connected to a proximal end of said position correcting liquid-charged lumen, both of said internal pressure measuring transducer and said pressure measuring transducer being mounted on a common base;
• and
• an internal pressure measuring circuit portion for performing position correction on the output signal of said internal pressure measuring transducer using the output signal of said pressure measuring transducer to detect an internal pressure signal and for outputting the obtained internal pressure value to a display device or to a recording device,
• wherein the adjoining surfaces of the distal end portions of said liquid-charged lumen and said atmosphere-opened lumen have a small hole through which the charged liquid can be brought into contact with the atmosphere through said atmosphere-opened lumen.