The present invention relates a pulmonary plethysmographic system (10), the system with a garment (11) wearable on the body of a mammal, e.g. a human, the garment comprising a shape sensing fiber (12) with a plurality of optical fibers (30) to facilitate optical measurements of strain along the length of the shape sensing fiber. An optical interrogation unit (13) is optically connected with the optical fibers in the shape sensing fiber for measuring the strain along the plurality of optical fibers. A processing unit (14) is processing the strain data into three-dimensional position data over time, the processing unit further being arranged for processing the position data over time into volume data indicative of pulmonary data about the mammal wearing the garment. The invention is advantageous for obtaining an improved system for pulmonary measurement providing a more realistic measurement of the pulmonary function of the mammal.
