A respiration waveform drawing system (100) for drawing the respiration waveform of a test subject on a bed is equipped with: a plurality of load detectors (11, 12, 13, 14) that detect the load from the test subject and are provided in the bed (BD) or in the legs of the bed； a gravity-center location calculation unit (31) for obtaining the location of the center of gravity (G) of the test subject on the basis of the load from the test subject； an oscillation coordinates setting unit (34) which, with the location of the center of gravity at a given time as an initial starting point (TO1), obtains a first extreme point (EP1), which is the location at which the distance between the initial starting point and the location of the center of gravity which has shifted from the initial starting point is greatest, obtains a second extreme point (EP2), which appears on the opposite side of the initial starting point from the first extreme point and is the location at which the distance between the initial starting point and the location of the center of gravity which has shifted from the first extreme point is greatest, sets the direction connecting the first extreme point and the second extreme point as a provisional oscillation axis (TA2), and sets the center point between the first extreme point and the second extreme point as a provisional oscillation starting point (TO2)； and a waveform drawing unit (35) for drawing the respiration waveform as an expression of the shift (D) over time from the provisional oscillation starting point of the location of the center of gravity as projected along the provisional oscillation axis.La présente invention concerne un système d'étirage de forme d'onde de respiration (100) permettant d'étirer la forme d'onde de respiration d'un sujet test sur un lit, ledit système étant équipé : d'une pluralité de détecteurs de charge (11, 12, 13, 14) qui détectent la charge du sujet test et qui sont prévus dans le lit (BD) ou dans les pieds du lit ； u
