Sleep disorders impair the quality of life for many individuals, but often go undiagnosed and untreated due to the cost and sleep-disturbing aggravation of polysomnography, the clinical sleep test. Simpler sleep monitoring systems that could be used at home may provide useful health information. A 2D grid of force sensors within a mat beneath the thorax of a sleeping subject has been reported to enable monitoring of respiration during sleep. A physical model of a thorax over such a 2D grid of force sensors may enable more tests and perturbations of parameters than could be done using only human subjects. The purpose of this project was to develop and test a physical model of a thorax undergoing volume changes, and measuring the changes in force by a grid of force sensors under the model. A prototype system was developed. Early testing shows promise for being able to monitor the changes in force as volume of the model changes. More development and testing are required toward development of improved algorithms and systems for sleep monitoring mats.