In MRI, changes in lung volume can affect the static encoding field during brain imaging, inducing phase modulations in the acquired signal. In segmented EPI, these phase modulations manifest as ghost artifacts. To enable rapid development of new segmented EPI image formation methods, this work presents a respiratory phantom that can be monitored using an ultrasound transducer. Using inexpensive materials, the transducer tracks the thickness of a flexible water bottle as the respiratory phantom inflates/deflates. Results verify that phase changes induced by the changing air volume can be observed in both MR and ultrasound data, and are well correlated.